Invariance for Single Curved Manifold
Castro, Pedro Machado Manhaes de
2012-08-01
Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.
Single curved fiber sedimentation under gravity
Xiaoying Rong; Dewei Qi; Junyong Zhu
2005-01-01
Dynamics of single curved fiber sedimentation under the gravity are simulated by using lattice Boltzmann method. The results of migration and rotation of the curved fiber at different Reynolds numbers are reported. The results show that the rotation and migration processes are sensitive to the curvature of the fiber.
Use of universal functional optimisation for TL glow curve analysis
International Nuclear Information System (INIS)
Pernicka, F.; Linh, H.Q.
1996-01-01
The effective use of any TL instrument requires an efficient software package to be able to fulfil different tasks required by research and practical applications. One of the standard features of the package used at the NPI Prague is the application of the interactive modular system Universal Functional Optimisation (UFO) for glow curve deconvolution. The whole system has been tested on standard glow curves using different models of the TL process (a single peak described by the Podgorsak approximation, first order kinetics and/or general order kinetics). Calculated values of basic TL parameters (E and s) show a good agreement with the results obtained by other authors. The main advantage of the system is in its modularity that enables flexible changes in the TL model and mathematical procedures of the glow curve analysis. (author)
International Nuclear Information System (INIS)
Kim, Y; Waldron, T; Pennington, E
2016-01-01
Purpose: To test the radiobiological impact of hypofractionated choroidal melanoma brachytherapy, we calculated single fraction equivalent doses (SFED) of the tumor that equivalent to 85 Gy of I125-BT for 20 patients. Corresponding organs-at-risks (OARs) doses were estimated. Methods: Twenty patients treated with I125-BT were retrospectively examined. The tumor SFED values were calculated from tumor BED using a conventional linear-quadratic (L-Q) model and an universal survival curve (USC). The opposite retina (α/β = 2.58), macula (2.58), optic disc (1.75), and lens (1.2) were examined. The % doses of OARs over tumor doses were assumed to be the same as for a single fraction delivery. The OAR SFED values were converted into BED and equivalent dose in 2 Gy fraction (EQD2) by using both L-Q and USC models, then compared to I125-BT. Results: The USC-based BED and EQD2 doses of the macula, optic disc, and the lens were on average 118 ± 46% (p < 0.0527), 126 ± 43% (p < 0.0354), and 112 ± 32% (p < 0.0265) higher than those of I125-BT, respectively. The BED and EQD2 doses of the opposite retina were 52 ± 9% lower than I125-BT. The tumor SFED values were 25.2 ± 3.3 Gy and 29.1 ± 2.5 Gy when using USC and LQ models which can be delivered within 1 hour. All BED and EQD2 values using L-Q model were significantly larger when compared to the USC model (p < 0.0274) due to its large single fraction size (> 14 Gy). Conclusion: The estimated single fraction doses were feasible to be delivered within 1 hour using a high dose rate source such as electronic brachytherapy (eBT). However, the estimated OAR doses using eBT were 112 ∼ 118% higher than when using the I125-BT technique. Continued exploration of alternative dose rate or fractionation schedules should be followed.
Energy Technology Data Exchange (ETDEWEB)
Kim, Y; Waldron, T; Pennington, E [University Of Iowa, College of Medicine, Iowa City, IA (United States)
2016-06-15
Purpose: To test the radiobiological impact of hypofractionated choroidal melanoma brachytherapy, we calculated single fraction equivalent doses (SFED) of the tumor that equivalent to 85 Gy of I125-BT for 20 patients. Corresponding organs-at-risks (OARs) doses were estimated. Methods: Twenty patients treated with I125-BT were retrospectively examined. The tumor SFED values were calculated from tumor BED using a conventional linear-quadratic (L-Q) model and an universal survival curve (USC). The opposite retina (α/β = 2.58), macula (2.58), optic disc (1.75), and lens (1.2) were examined. The % doses of OARs over tumor doses were assumed to be the same as for a single fraction delivery. The OAR SFED values were converted into BED and equivalent dose in 2 Gy fraction (EQD2) by using both L-Q and USC models, then compared to I125-BT. Results: The USC-based BED and EQD2 doses of the macula, optic disc, and the lens were on average 118 ± 46% (p < 0.0527), 126 ± 43% (p < 0.0354), and 112 ± 32% (p < 0.0265) higher than those of I125-BT, respectively. The BED and EQD2 doses of the opposite retina were 52 ± 9% lower than I125-BT. The tumor SFED values were 25.2 ± 3.3 Gy and 29.1 ± 2.5 Gy when using USC and LQ models which can be delivered within 1 hour. All BED and EQD2 values using L-Q model were significantly larger when compared to the USC model (p < 0.0274) due to its large single fraction size (> 14 Gy). Conclusion: The estimated single fraction doses were feasible to be delivered within 1 hour using a high dose rate source such as electronic brachytherapy (eBT). However, the estimated OAR doses using eBT were 112 ∼ 118% higher than when using the I125-BT technique. Continued exploration of alternative dose rate or fractionation schedules should be followed.
A Universal Genus-Two Curve from Siegel Modular Forms
Malmendier, Andreas; Shaska, Tony
2017-11-01
Let p be any point in the moduli space of genus-two curves M_2 and K its field of moduli. We provide a universal equation of a genus-two curve C_{&alpha,; β} defined over K(α, β), corresponding to p, where α and β satisfy a quadratic α^2+ b β^2= c such that b and c are given in terms of ratios of Siegel modular forms. The curve C_{α, β} is defined over the field of moduli K if and only if the quadratic has a K-rational point (α, β). We discover some interesting symmetries of the Weierstrass equation of C_{α, β}. This extends previous work of Mestre and others.
Learning curve, diagnostic yield and safety of single balloon enteroscopy.
Dutta, Amit Kumar; Sajith, Kattiparambil Gangadharan; Joseph, Anjilivelil J; Simon, Ebby George; Chacko, Ashok
2012-01-01
Single balloon enteroscopy (SBE) is a recently developed diagnostic modality to assess small bowel mucosa. The data on learning curve of SBE is scanty. We aimed to assess the learning curve, diagnostic yield and safety of SBE. All patients who underwent SBE at our centre from December 2007 to December 2010 were included retrospectively. The clinical details, enteroscopy findings and procedure related details were obtained for each patient from a prospectively maintained database. The extent of small bowel visualised with increasing number of procedures by a single endoscopist (Endoscopist A) who performed most of the procedures was used to estimate the learning curve using locally weighted regression curve. The diagnostic yield and complications rates of SBE were also estimated. The study was approved by the institute review board and ethics committee. Ninety SBEs were performed in 84 patients (age: 42+15 years, 27.4% females). 57 procedures were performed (32 antegrade and 25 retrograde) by endoscopist A. There was gradual improvement in the extent of small bowel visualised during the first 15 procedures via antegrade route followed by flattening of curve. The retrograde route showed no definite trend towards improvement during the procedures performed. The overall diagnostic yield of SBE was 32.1%. There was no complication except for mild self-limiting abdominal pain in one patient. SBE via antegrade route has a higher success rate and better learning curve than the retrograde route. SBE is a safe procedure and helps in establishing a diagnosis in one-third of the patients examined.
Closed timelike curves in asymmetrically warped brane universes
Päs, Heinrich; Pakvasa, Sandip; Dent, James; Weiler, Thomas J.
2009-08-01
In asymmetrically-warped spacetimes different warp factors are assigned to space and to time. We discuss causality properties of these warped brane universes and argue that scenarios with two extra dimensions may allow for timelike curves which can be closed via paths in the extra-dimensional bulk. In particular, necessary and sufficient conditions on the metric for the existence of closed timelike curves are presented. We find a six-dimensional warped metric which satisfies the CTC conditions, and where the null, weak and dominant energy conditions are satisfied on the brane (although only the former remains satisfied in the bulk). Such scenarios are interesting, since they open the possibility of experimentally testing the chronology protection conjecture by manipulating on our brane initial conditions of gravitons or hypothetical gauge-singlet fermions (“sterile neutrinos”) which then propagate in the extra dimensions.
SILC for SILC: Single Institution Learning Curve for Single-Incision Laparoscopic Cholecystectomy
Directory of Open Access Journals (Sweden)
Chee Wei Tay
2013-01-01
Full Text Available Objectives. We report the single-incision laparoscopic cholecystectomy (SILC learning experience of 2 hepatobiliary surgeons and the factors that could influence the learning curve of SILC. Methods. Patients who underwent SILC by Surgeons A and B were studied retrospectively. Operating time, conversion rate, reason for conversion, identity of first assistants, and their experience with previous laparoscopic cholecystectomy (LC were analysed. CUSUM analysis is used to identify learning curve. Results. Hundred and nineteen SILC cases were performed by Surgeons A and B, respectively. Eight cases required additional port. In CUSUM analysis, most conversion occurred during the first 19 cases. Operating time was significantly lower (62.5 versus 90.6 min, P = 0.04 after the learning curve has been overcome. Operating time decreases as the experience increases, especially Surgeon B. Most conversions are due to adhesion at Calot’s triangle. Acute cholecystitis, patients’ BMI, and previous surgery do not seem to influence conversion rate. Mean operating times of cases assisted by first assistant with and without LC experience were 48 and 74 minutes, respectively (P = 0.004. Conclusion. Nineteen cases are needed to overcome the learning curve of SILC. Team work, assistant with CLC experience, and appropriate equipment and technique are the important factors in performing SILC.
Jones, Gareth; Schmidt, Harry
2018-01-01
We study the intersection of an algebraic variety with the maximal compact subgroup of a universal vectorial extension of a product of elliptic curves. For this intersection we show a Manin-Mumford type statement. This answers some questions posed by Corvaja-Masser-Zannier which arose in connection with their investigation of the intersection of a curve with real analytic subgroups of various algebraic groups. They prove finiteness in the situation of a single elliptic curve. Using Khovanskii...
Hung, Nguyen T.; Nugraha, Ahmad R. T.; Saito, Riichiro
2018-02-01
This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. Analytical formulas for thermoelectric figures of merit and power factors are derived based on the one-band model. We find that there is a direct relationship between the optimum figures of merit and the optimum power factors of semiconductors despite of the fact that the two quantities are generally given by different values of chemical potentials. By introducing a dimensionless parameter consisting of the optimum power factor and lattice thermal conductivity (without electronic thermal conductivity), it is possible to unify optimum figures of merit of both bulk and low-dimensional semiconductors into a single universal curve that covers many materials with different dimensionalities.
Vibrational Analysis of Curved Single-Walled Carbon Nanotube on a Pasternak Elastic Foundation
DEFF Research Database (Denmark)
Mehdipour, I.; Barari, Amin; Kimiaeifar, Amin
2012-01-01
Continuum mechanics and an elastic beam model were employed in the nonlinear force vibrational analysis of an embedded, curved, single-walled carbon nanotube. The analysis considered the effects of the curvature or waviness and midplane stretching of the nanotube on the nonlinear frequency....... By utilizing He’s Energy Balance Method (HEBM), the relationships of the nonlinear amplitude and frequency were expressed for a curved, single-walled carbon nanotube. The amplitude frequency response curves of the nonlinear free vibration were obtained for a curved, single-walled carbon nanotube embedded...... in a Pasternak elastic foundation. Finally, the influence of the amplitude of the waviness, midplane stretching nonlinearity, shear foundation modulus, surrounding elastic medium, radius, and length of the curved carbon nanotube on the amplitude frequency response characteristics are discussed. As a result...
Lukovich, Peter; Sionov, Valery Ben; Kakucs, Timea
2016-01-01
Lately single-port surgery is becoming a widespread procedure, but it is more difficult than conventional laparoscopy owing to the lack of triangulation. Although, these operations are also possible with standard laparoscopic instruments, curved instruments are being developed. The aims of the study were to identify the effect of training on a box trainer in single-port setting on the quality of acquired skills, and transferred with the straight and curved instruments for the basic laparoscopic tasks, and highlight the importance of a special laparoscopic training curriculum. A prospective study on a box trainer in single-port setting was conducted using 2 groups. Each group performed 2 tasks on the box trainer in single-port setting. Group-S used conventional straight laparoscopic instruments, and Group-C used curved laparoscopic instruments. Learning curves were obtained by daily measurements recorded in 7-day sessions. On the last day, the 2 groups changed instruments between each other. 1st Department of Surgery, Semmelweis University of Medicine from Budapest, Hungary, a university teaching hospital. In all, 20 fifth-year medical students were randomized into 2 groups. None of them had any laparoscopic or endoscopic experience. Participation was voluntary. Although Group-S performed all tasks significantly faster than Group-C on the first day, the difference proved to be nonsignificant on the last day. All participants achieved significantly shorter task completion time on the last day than on the first day, regardless of the instrument they used. Group-S showed improvement of 63.5%, and Group-C 69.0% improvement by the end of the session. After swapping the instruments, Group-S reached significantly higher task completion time with curved instruments, whereas Group-C showed further progression of 8.9% with straight instruments. Training with curved instruments in a single-port setting allows for a better acquisition of skills in a shorter period. For this
Troppmann, Christoph; Santhanakrishnan, Chandrasekar; Fananapazir, Ghaneh; Troppmann, Kathrin M; Perez, Richard V
2017-05-01
The learning curve for laparoendoscopic single-incision live donor nephrectomy, which is technically more complex than the multiport, conventional laparoendoscopic approach, is unknown. In a retrospective cohort study, we analyzed the learning curve of the initial 114 consecutive single-incision laparoendoscopic nephrectomies performed in nonselected live kidney donors. Median donor body mass index was 26 kg/m 2 (range 20-34). In all, 92% of the nephrectomies were performed on the left side; 18% of the recovered kidneys had multiple renal arteries. Cumulative sum (CUSUM) analysis of operating time (OT) demonstrated that the learning curve was achieved after case 61. For the learning curve phase (Group 1 [cases 1-61]) vs the postlearning phase (Group 2 [cases 62-114]), the difference of the mean OT was 20 minutes (p = 0.05). Mean warm ischemic time in the donors was significantly longer during the learning phase (Group 1, 6 minutes; Group 2, 5 minutes; p = 0.04). Rates of conversions to multiport procedures and of donor complications were not significantly different between Groups 1 and 2. For the recipients, we observed delayed graft function in 2 (2%) cases, no technical graft losses; and 1-year death-censored graft survival was 100% (p = n.s. for all comparisons of Group 1 vs 2). Single-incision laparoendoscopic donor nephrectomy had a long learning curve (>60 cases), but resulted in excellent donor and recipient outcomes. The long learning curve has significant implications for the programs and surgeons who contemplate transitioning from multiport to single-incision nephrectomy. Furthermore, our observations are highly relevant for informing the development of training requirements for fellows to be trained in single-incision laparoendoscopic nephrectomy.
Nambiar, Mithun; Yang, Yi; Liew, Susan; Turner, Peter L; Torode, Ian P
2016-10-01
Single or dual-rod instrumentation can be used for the anterior fixation of the spine in adolescent idiopathic scoliosis (AIS). We aim to compare the complications, radiographic and functional outcomes of patients with AIS who have undergone single and dual-rod instrumentation. This is a multi-centre study involving the Royal Children's, Royal Melbourne and Epworth hospitals. Three primary surgeons were involved to ensure homogeneity of surgical technique and implants. Patients with AIS and thoracolumbar curves (Lenke 5 and 6) undergoing anterior instrumentation from 1st January 2000 to 30th June 2013 were included. Radiographic data were collected from X-rays. The functional outcome was measured through the Scoliosis Research Society questionnaire (SRS-30). The study included 58 patients (38 single-rod and 20 dual-rod patients). Thirty-nine patients were classified with Lenke 5 curves, while 19 patients had Lenke 6 curves. Structural interbody supports were used in 95 % of cases. In the preoperative to postoperative period, patients with single rods had an improvement of 75 and 51 % for primary and secondary curves, respectively, while patients with dual rods had an improvement of 70 and 38 % for primary and secondary curves, respectively. There were no cases of pseudoarthrosis or metalware failure in either group. Two patients (one single-rod and one dual-rod patient) required further unplanned posterior fusion. 91 % of patients were satisfied with the results of their back management. Pseudoarthrosis and metalware failure are rare complications of anterior instrumentation. Our study found no significant difference in functional or radiographic outcome between single and dual-rod instrumentation. Level III.
Universal rescaling of flow curves for yield-stress fluids close to jamming.
Dinkgreve, M; Paredes, J; Michels, M A J; Bonn, D
2015-07-01
The experimental flow curves of four different yield-stress fluids with different interparticle interactions are studied near the jamming concentration. By appropriate scaling with the distance to jamming all rheology data can be collapsed onto master curves below and above jamming that meet in the shear-thinning regime and satisfy the Herschel-Bulkley and Cross equations, respectively. In spite of differing interactions in the different systems, master curves characterized by universal scaling exponents are found for the four systems. A two-state microscopic theory of heterogeneous dynamics is presented to rationalize the observed transition from Herschel-Bulkley to Cross behavior and to connect the rheological exponents to microscopic exponents for the divergence of the length and time scales of the heterogeneous dynamics. The experimental data and the microscopic theory are compared with much of the available literature data for yield-stress systems.
LEARNING CURVE IN SINGLE-LEVEL MINIMALLY INVASIVE TLIF: EXPERIENCE OF A NEUROSURGEON
Directory of Open Access Journals (Sweden)
Samuel Romano-Feinholz
Full Text Available ABSTRACT Objective: To describe the learning curve that shows the progress of a single neurosurgeon when performing single-level MI-TLIF. Methods: We included 99 consecutive patients who underwent single-level MI-TLIF by the same neurosurgeon (JASS. Patient’s demographic characteristics were analyzed. In addition, surgical time, intraoperative blood loss and hospital stay were evaluated. The learning curves were calculated with a piecewise regression model. Results: The mean age was 54.6 years. The learning curves showed an inverse relationship between the surgical experience and the variable analyzed, reaching an inflection point for surgical time in case 43 and for blood loss in case 48. The mean surgical time was 203.3 minutes (interquartile range [IQR] 150-240 minutes, intraoperative bleeding was 97.4ml (IQR 40-100ml and hospital stay of four days (IQR 3-5 days. Conclusions: MI-TLIF is a very frequent surgical procedure due to its effectiveness and safety, which has shown similar results to open procedure. According to this study, the required learning curve is slightly higher than for open procedures, and is reached after about 45 cases.
An experimental assessment of proposed universal yield curves for secondary electron emission
International Nuclear Information System (INIS)
Salehi, M.; Flinn, E.A.
1980-01-01
A variety of 'Universal Yield Curves' for the secondary emission process have been proposed. A series of precise measurements of the secondary emission properties of a range of related amorphous semiconducting materials, made under UHV on freshly vacuum-cleaved surfaces, and covering a wide range of primary energies, have recently made possible an accurate assessment of the validity of the various UYC's suggested. It is found that no truly universal curve exists; the atomic number of the target material plays an important part in determining the secondary emission properties. Agarwal's (Proc. Phys. Soc.; 71: 851 (1958)) semi-empirical expression, which takes account of the atomic number and weight, is found to give good agreement for all the materials studied. Further theoretical investigation is required. (author)
The "curved lead pathway" method to enable a single lead to reach any two intracranial targets.
Ding, Chen-Yu; Yu, Liang-Hong; Lin, Yuan-Xiang; Chen, Fan; Lin, Zhang-Ya; Kang, De-Zhi
2017-01-11
Deep brain stimulation is an effective way to treat movement disorders, and a powerful research tool for exploring brain functions. This report proposes a "curved lead pathway" method for lead implantation, such that a single lead can reach in sequence to any two intracranial targets. A new type of stereotaxic system for implanting a curved lead to the brain of human/primates was designed, the auxiliary device needed for this method to be used in rat/mouse was fabricated and verified in rat, and the Excel algorithm used for automatically calculating the necessary parameters was implemented. This "curved lead pathway" method of lead implantation may complement the current method, make lead implantation for multiple targets more convenient, and expand the experimental techniques of brain function research.
Oliva-Pascual-Vaca, Ángel; Heredia-Rizo, Alberto Marcos; Barbosa-Romero, Alejandro; Oliva-Pascual-Vaca, Jesús; Rodríguez-Blanco, Cleofás; Tejero-García, Sergio
2014-06-01
The purpose of this study was to evaluate the hardness of the paraspinal muscles in the convexity and concavity of patients with scoliosis curvatures and in the upper trapezius (UT) muscle in subjects with mild idiopathic scoliosis (IS) and to observe the correlation between the myotonometer (MYO) measurements and the value of body mass index (BMI) and the Cobb angle. The sample included 13 patients with a single-curve mild IS (Risser sign ≤ 4) at thoracic, lumbar, or thoracolumbar level (mean Cobb angle of 11.53º). Seven females and 6 males were recruited, with a mean age of 12.84 ± 3.06 (9-18) years. A MYO was used to examine the differences in muscle hardness on both sides of the scoliosis curvature at several points: (a) apex of the curve, (b) upper and lower limits of the curve, and (c) the midpoint between the apex and the upper limit and between the apex and the lower limit. The UT was also explored. Although the MYO recorded lower values in all points on the concave side of the scoliosis, there were no significant differences in the comparison between sides (P > .05). No association was observed between BMI and MYO values, whereas the Cobb angle negatively correlated with muscle hardness only at 2 points on the convex side. The preliminary findings show that, in subjects with a single-curve mild IS, muscular hardness in the UT and paraspinal muscles, as assessed using a MYO, was not found to differ between the concave and the convex sides at different reference levels. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.
Universal scaling of the stress-strain curve in amorphous solids.
Lin, Jie; Zheng, Wen
2017-09-01
The yielding transition of amorphous solids is a phase transition with a special type of universality. Critical exponents and scaling relations have been defined and proposed near the yield stress. We show here that, even in the initial stage of shear far below the yield stress, the stress-strain curve of amorphous solids also shows critical scaling with universal exponents. The key point is to remove the elastic part of the strain, and the shear stress exhibits a sublinear scaling with the plastic strain. We show how this critical scaling is related to the finite size effect of the minimum strain to trigger the first plastic avalanche after a quench. We point out that this sublinear scaling between the stress and the plastic strain implies the divergence of a high-order shear modulus. A scaling relation is derived between two exponents characterizing the stress-strain curve and the density distribution of the local stabilities, respectively. We test the critical scaling of the stress-strain curve using both mesoscopic and atomistic simulations and get satisfying agreement in two and three dimensions.
Salucci, P.; Lapi, A.; Tonini, C.; Gentile, G.; Yegorova, I.; Klein, U.
2007-01-01
In the current LambdaCDM cosmological scenario, N-body simulations provide us with a Universal mass profile, and consequently a Universal equilibrium circular velocity of the virialized objects, as galaxies. In this paper we obtain, by combining kinematical data of their inner regions with global observational properties, the Universal Rotation Curve (URC) of disk galaxies and the corresponding mass distribution out to their virial radius. This curve extends the results of Paper I, concerning...
International Nuclear Information System (INIS)
Bourgeois, L.N.; Bursill, L.A.
1997-01-01
A high resolution transmission electron microscopic study of a nanoporous carbon rich in curved graphite monolayers is presented. Observations of very thin regions. including the effect of tilting the specimen with respect to the electron beam, are reported. The initiation of single sheet material on an oriented graphite substrate is also observed. When combined with image simulations and independent measurements of the density (1.37g cm -3 ) and sp 3 /sp 2 +sp 2 bonding fraction (0.16), these observations suggest that this material is a two phase mixture containing a relatively low density aggregation of essentially capped single shells like squat nanotubes and polyhedra, plus a relatively dense 'amorphous' carbon structure which may be described using a random-Schwarzite model. Some negatively-curved sheets were also identified in the low density phase. Finally, some discussion is offered regarding the growth mechanisms responsible for this nanoporous carbon and its relationship with the structures of amorphous carbons across a broad range of densities, porosities and sp 3 /sp 2 +sp 3 bonding fractions
Tomassini, Federico; Scuderi, Vincenzo; Colman, Roos; Vivarelli, Marco; Montalti, Roberto; Troisi, Roberto Ivan
2016-10-01
The aim of the study was to evaluate the single-surgeon learning curve (SSLC) in laparoscopic liver surgery over an 11-year period with risk-adjusted (RA) cumulative sum control chart analysis.Laparoscopic liver resection (LLR) is a challenging and highly demanding procedure. No specific data are available for defining the feasibility and reproducibility of the SSLC regarding a consistent and consecutive caseload volume over a specified time period.A total of 319 LLR performed by a single surgeon between June 2003 and May 2014 were retrospectively analyzed. A difficulty scale (DS) ranging from 1 to 10 was created to rate the technical difficulty of each LLR. The risk-adjusted cumulative sum control chart (RA-CUSUM) analysis evaluated conversion rate (CR), operative time (OT) and blood loss (BL). Perioperative morbidity and mortality were also analyzed.The RA-CUSUM analysis of the DS identified 3 different periods: P1 (n = 91 cases), with a mean DS of 3.8; P2 (cases 92-159), with a mean DS of 5.3; and P3 (cases 160-319), with a mean DS of 4.7. P2 presented the highest conversion and morbidity rates with a longer OT, whereas P3 showed the best results (P learning curve should be anticipated to broaden the indications for LLR.
Energy Technology Data Exchange (ETDEWEB)
Bourgeois, L.N.; Bursill, L.A.
1997-12-31
A high resolution transmission electron microscopic study of a nanoporous carbon rich in curved graphite monolayers is presented. Observations of very thin regions. including the effect of tilting the specimen with respect to the electron beam, are reported. The initiation of single sheet material on an oriented graphite substrate is also observed. When combined with image simulations and independent measurements of the density (1.37g cm {sup -3}) and sp{sup 3}/sp{sup 2}+sp{sup 2} bonding fraction (0.16), these observations suggest that this material is a two phase mixture containing a relatively low density aggregation of essentially capped single shells like squat nanotubes and polyhedra, plus a relatively dense `amorphous` carbon structure which may be described using a random-Schwarzite model. Some negatively-curved sheets were also identified in the low density phase. Finally, some discussion is offered regarding the growth mechanisms responsible for this nanoporous carbon and its relationship with the structures of amorphous carbons across a broad range of densities, porosities and sp{sup 3}/sp{sup 2}+sp{sup 3} bonding fractions. 29 refs., 8 figs., 2 tabs.
Spin-curvature interaction from curved Dirac equation: Application to single-wall carbon nanotubes
Zhang, Kai; Zhang, Erhu; Chen, Huawei; Zhang, Shengli
2017-06-01
The spin-curvature interaction (SCI) and its effects are investigated based on curved Dirac equation. Through the low-energy approximation of curved Dirac equation, the Hamiltonian of SCI is obtained and depends on the geometry and spinor structure of manifold. We find that the curvature can be considered as field strength and couples with spin through Zeeman-like term. Then, we use dimension reduction to derive the local Hamiltonian of SCI for cylinder surface, which implies that the effective Hamiltonian of single-wall carbon nanotubes results from the geometry and spinor structure of lattice and includes two types of interactions: one does not break any symmetries of the lattice and only shifts the Dirac points for all nanotubes, while the other one does and opens the gaps except for armchair nanotubes. At last, analytical expressions of the band gaps and the shifts of their positions induced by curvature are given for metallic nanotubes. These results agree well with experiments and can be verified experimentally.
Defining the learning curve of laparoendoscopic single-site Heller myotomy.
Ross, Sharona B; Luberice, Kenneth; Kurian, Tony J; Paul, Harold; Rosemurgy, Alexander S
2013-08-01
Initial outcomes suggest laparoendoscopic single-site (LESS) Heller myotomy with anterior fundoplication provides safe, efficacious, and cosmetically superior outcomes relative to conventional laparoscopy. This study was undertaken to define the learning curve of LESS Heller myotomy with anterior fundoplication. One hundred patients underwent LESS Heller myotomy with anterior fundoplication. Symptom frequency and severity were scored using a Likert scale (0 = never/not bothersome to 10 = always/very bothersome). Symptom resolution, additional trocars, and complications were compared among patient quartiles. Median data are presented. Preoperative frequency/severity scores were: dysphagia = 10/8 and regurgitation = 8/7. Additional trocars were placed in 12 patients (10%), of whom all were in the first two quartiles. Esophagotomy/gastrotomy occurred in three patients. Postoperative complications occurred in 9 per cent. No conversions to "open" operations occurred. Length of stay was 1 day. Postoperative frequency/severity scores were: dysphagia = 2/0 and regurgitation = 0/0; scores were less than before myotomy (P learning curve of LESS Heller myotomy with anterior fundoplication is short and safe, because proficiency is quickly attained.
Martin-Ucar, Antonio E; Aragon, Javier; Bolufer Nadal, Sergio; Galvez Munoz, Carlos; Luo, Qigang; Perez Mendez, Itzel; Sihoe, Alan D L; Socci, Laura
2017-06-01
Competency in video-assisted thoracoscopic (VATS) lobectomy is estimated to be reached after the surgeon completes 50 cases. We wanted to explore the impact of competency in performing multiport VATS lobectomies on completing the needed number of single-port VATS. In a retrospective multicentre study, 6 individual surgeons (3 with previous competency in multiport VATS lobectomy and 3 without) submitted their first 50 cases of single-port VATS lobectomies. Extended and sublobar resections were excluded. Pre-, peri- and postoperative data were compared between the groups of surgeons. Chi-square and Wilcoxon's rank tests were used. The less experienced surgeons had previously attended dedicated training courses and visited with experts. A total of 300 cases were included [150 in Group A (surgeons with previous experience performing multiport VATS) and 150 in Group B (surgeons without extensive experience performing multiport VATS)]. Surgeons in Group B performed significantly more elective open lobectomies during their learning curve period than surgeons of Group A (58 vs 1). Patients in Group B were older and had more risk factors. There were 3 in-hospital deaths (respiratory failure, sepsis and fatal stroke). There were no differences between the groups in operative time, intensive care unit admissions, hospital stay, total complications, tumour size or number of N2 stations explored. Only the duration of intercostal drainage (2 vs 3 days, 0.012), incidence of respiratory tract infections (1% vs 7%, P = 0.002) and conversion rates (4% vs 12%, P = 0.018) were better in Group A. Patients characteristics played a role in the development of respiratory infections and longer drainage times but not in the need for conversion. Overall, postoperative outcomes during the learning curve period for single-port VATS lobectomies are not noticeably affected by previous multiport VATS experience. Less experienced surgeons were more selective in order to achieve
A single-operator learning curve analysis for the endoscopic sleeve gastroplasty.
Saumoy, Monica; Schneider, Yecheskel; Zhou, Xi Kathy; Shukla, Alpana; Kahaleh, Michel; Aronne, Louis; Sharaiha, Reem Z
2018-02-01
Endoscopic sleeve gastroplasty (ESG) is a novel, incisionless technique for gastric volume reduction to promote weight loss. Our aim was to describe the learning curve for performing ESG using a prospective case series. Using a prospective case series design, we analyzed the first 128 consecutive patients at a tertiary care academic medical center who underwent ESG performed by a single operator from August 2013 to December 2016. Efficiency (refining performance to decrease procedure time) and mastery (absence of outliers) for performing ESG was evaluated by using a penalized basis-spline regression and cumulative sum analysis. Efficiency for ESG was attained after 38 ESGs, with mastery after 55 procedures. At 12 months, the mean percent total body weight loss was 15.8% (standard deviation, 9.47%). A total of 71.7% of patients achieved successful weight loss. When using multiple linear regression analysis, both number of sutures and baseline weight were significantly associated with procedure time. Other patient characteristics, such as age, sex, and race, did not significantly affect procedure time. In addition, number of sutures, baseline weight, and endoscopist achieving efficiency were not correlated with successful weight loss at 12 months. Mastery of ESG by a single operator is suggested after sufficient endoscopic experience and may help guide widespread clinical adaptability. Copyright © 2018. Published by Elsevier Inc.
The “curved lead pathway” method to enable a single lead to reach any two intracranial targets
Ding, Chen-Yu; Yu, Liang-Hong; Lin, Yuan-Xiang; Chen, Fan; Lin, Zhang-Ya; Kang, De-Zhi
2017-01-01
Deep brain stimulation is an effective way to treat movement disorders, and a powerful research tool for exploring brain functions. This report proposes a “curved lead pathway” method for lead implantation, such that a single lead can reach in sequence to any two intracranial targets. A new type of stereotaxic system for implanting a curved lead to the brain of human/primates was designed, the auxiliary device needed for this method to be used in rat/mouse was fabricated and verified in rat, and the Excel algorithm used for automatically calculating the necessary parameters was implemented. This “curved lead pathway” method of lead implantation may complement the current method, make lead implantation for multiple targets more convenient, and expand the experimental techniques of brain function research.
Directory of Open Access Journals (Sweden)
Iman Eshraghi
2016-09-01
Full Text Available Imperfection sensitivity of large amplitude vibration of curved single-walled carbon nanotubes (SWCNTs is considered in this study. The SWCNT is modeled as a Timoshenko nano-beam and its curved shape is included as an initial geometric imperfection term in the displacement field. Geometric nonlinearities of von Kármán type and nonlocal elasticity theory of Eringen are employed to derive governing equations of motion. Spatial discretization of governing equations and associated boundary conditions is performed using differential quadrature (DQ method and the corresponding nonlinear eigenvalue problem is iteratively solved. Effects of amplitude and location of the geometric imperfection, and the nonlocal small-scale parameter on the nonlinear frequency for various boundary conditions are investigated. The results show that the geometric imperfection and non-locality play a significant role in the nonlinear vibration characteristics of curved SWCNTs.
The motive of the moduli stack of G-bundles over the universal curve
Indian Academy of Sciences (India)
E-mail: dvb@math.purdue.edu. MS received 11 April 2007; revised 27 January 2008. Abstract. We define relative motives in the sense of André. After associating a complex in the derived category of motives to an algebraic stack we study this complex in the case of the moduli of G-bundles varying over the moduli of curves.
Current-Mode Universal Filters Employing Single FDCCII
Directory of Open Access Journals (Sweden)
F. Kacar
2012-12-01
Full Text Available In this study, to realize current-mode multifunction filters, three new circuit configurations are presented. The circuits include fully differential current conveyor (FDCCII and four passive components. First proposed circuit is a universal filter with single-input and three-outputs, which can simultaneously realize current mode low-pass, band-pass and high-pass filter responses employing all grounded passive components. The last two proposed are universal filters with three-inputs single-output, which can realize current mode low-pass, band-pass, high-pass, band-stop and all-pass filter responses employing single FDCCII. Furthermore, each of the proposed circuits still enjoys realization using a minimum number of active and passive components. First and last of the proposed circuits have no requirement with the component choice conditions to realize specific filtering functions. No parameter matching condition is required. Active and passive sensitivities of filters are investigated and calculated 5 percentage hangings. Simulation results are found in close agreement with the theoretical results.
Useinov, Arthur
2011-10-01
Spin-polarization asymmetry is the key parameter in asymmetric voltage behavior (AVB) of the tunnel magnetoresistance (TMR) in magnetic tunnel junctions. In this paper, we study the value of the TMR as a function of the applied voltage Va in the single as well as double barrier magnetic tunnel junctions (SMTJ & DMTJ, which are constructed from CoFeB/MgO interfaces) and numerically estimate the possible difference of the TMR-V a curves for negative and positive voltages in the homojunctions. As a result, we found that AVB may help to determine the exact values of Fermi wave vectors for minority and majority conducting spin sub-bands. Moreover, significant asymmetry of the experimental TMR-Va curves, which arises due to different annealing regimes, is explained by different heights of the tunnel barriers and values of the spin asymmetry. The numerical TMR-V a data are in good agreement with experimental ones. © 2011 IEEE.
Spinoglio, Giuseppe; Lenti, Luca Matteo; Maglione, Valeria; Lucido, Francesco Saverio; Priora, Fabio; Bianchi, Paolo Pietro; Grosso, Federica; Quarati, Raul
2012-06-01
Single-incision laparoscopic surgery is an emerging procedure developed to decrease parietal trauma and improve cosmetic results. However, many technical constraints, such as lack of triangulation, instrument collisions, and cross-handing, hamper this approach. Using a robotic platform may overcome these problems and enable more precise surgical actions by increasing freedom of movement and by restoring intuitive instrument control. We retrospectively collected, under institutional review board approval, data on the first 25 patients who underwent single-site robotic cholecystectomies (SSRC) at our center. Patients enrolled in this study underwent SSRC for symptomatic biliary gallstones or polyposis. Exclusion criteria were: BMI > 33; acute cholecystitis; previous upper abdominal surgery; ASA > II; and age >80 and <18 years. All procedures were performed with the da Vinci Si Surgical System and a dedicated SSRC kit (Intuitive). After discharge, patients were followed for 2 months. These SSRC cases were compared to our first 25 single-incision laparoscopic cholecystectomies (SILC) and with the literature. There were no differences in patient characteristics between groups (gender, P = 0.4404; age, P = 0.7423; BMI, P = 0.5699), and there were no conversions or major complications in either cohort. Operative time was significantly longer for the SILC group compared with SSRC (83.2 vs. 62.7 min, P = 0.0006), and SSRC operative times did not change significantly along the series. The majority of patients in each group were discharged within 24 h, with an average length of hospital stay of 1.2 days for the SILC group and 1.1 days for the SSRC group (P = 0.2854). No wound complications (infection, incisional hernia) were observed in the SSRC group and in the SILC. Our preliminary experience shows that SSRC is safe, can easily be learned, and performed in a reproducible manner and is faster than SILC.
International Nuclear Information System (INIS)
Freund, A K; Rehm, C
2014-01-01
The present study has been conducted in the framework of the channel-cut crystal design for the Kookaburra ultra-small-angle neutron scattering (USANS) instrument to be installed at the OPAL reactor of ANSTO. This facility is based on the classical Bonse-Hart method that uses two multiple-reflection crystal systems. The dynamical theory of diffraction by perfect crystals distinguishes two cases: the Darwin case applying to infinitely thick crystals and the Ewald solution for very small absorption taking into account the reflection from the rear face of a plane-parallel crystal reflecting in Bragg geometry. The former is preferable because it yields narrower rocking curves. To prevent the neutrons to 'see' the rear face, grooves were machined into the backside of perfect Si test crystals for single reflection and filled with neutron absorbing material. These samples were examined at the S18 instrument of the Institut Laue-Langevin. Unexpectedly the crystals with empty slots showed an increase of the rocking curve width. When filling the slots with an absorber the widths decreased, but without reaching that of the Darwin curve. Understanding the results and achieving a successful crystal design call for the development of a theory that permits to describe neutron diffraction from crystals with a structured back face.
Freund, A. K.; Rehm, C.
2014-07-01
The present study has been conducted in the framework of the channel-cut crystal design for the Kookaburra ultra-small-angle neutron scattering (USANS) instrument to be installed at the OPAL reactor of ANSTO. This facility is based on the classical Bonse-Hart method that uses two multiple-reflection crystal systems. The dynamical theory of diffraction by perfect crystals distinguishes two cases: the Darwin case applying to infinitely thick crystals and the Ewald solution for very small absorption taking into account the reflection from the rear face of a plane-parallel crystal reflecting in Bragg geometry. The former is preferable because it yields narrower rocking curves. To prevent the neutrons to "see" the rear face, grooves were machined into the backside of perfect Si test crystals for single reflection and filled with neutron absorbing material. These samples were examined at the S18 instrument of the Institut Laue-Langevin. Unexpectedly the crystals with empty slots showed an increase of the rocking curve width. When filling the slots with an absorber the widths decreased, but without reaching that of the Darwin curve. Understanding the results and achieving a successful crystal design call for the development of a theory that permits to describe neutron diffraction from crystals with a structured back face.
Measurement of Photomultipier Plateau Curves and Single MIP response in the AD detector at ALICE
Sanchez Falero, Sebastian De Jesus
2015-01-01
The Alice Diffractive (AD) detector is a forward detector in the ALICE experiment at CERN. It is aimed to the triggering on diffractive events and extends the pseudorapidity coverage to about 4.9 < /n/ < 6.3. In this work, a PMT's efficiency plateau and single MIP response are measured using a replica of the detector's scintillator modules, electronic and data acquisition system and cosmic rays as particle source.
A single nano cantilever as a reprogrammable universal logic gate
International Nuclear Information System (INIS)
Chappanda, K N; Ilyas, S; Kazmi, S N R; Younis, M I; Holguin-Lerma, J; Batra, N M; Costa, P M F J
2017-01-01
The current transistor-based computing circuits use multiple interconnected transistors to realize a single Boolean logic gate. This leads to higher power requirements and delayed computing. Transistors are not suitable for applications in harsh environments and require complicated thermal management systems due to excessive heat dissipation. Also, transistor circuits lack the ability to dynamically reconfigure their functionality in real time, which is desirable for enhanced computing capability. Further, the miniaturization of transistors to improve computational power is reaching its ultimate physical limits. As a step towards overcoming the limitations of transistor-based computing, here we demonstrate a reprogrammable universal Boolean logic gate based on a nanoelectromechanical cantilever (NC) oscillator. The fundamental XOR, AND, NOR, OR and NOT logic gates are condensed in a single NC, thereby reducing electrical interconnects between devices. The device is dynamically switchable between any logic gates at the same drive frequency without the need for any change in the circuit. It is demonstrated to operate at elevated temperatures minimizing the need for thermal management systems. It has a tunable bandwidth of 5 MHz enabling parallel and dynamically reconfigurable logic device for enhanced computing. (paper)
Single CFTA Based Current-Mode Universal Biquad Filter
Directory of Open Access Journals (Sweden)
S.V. Singh
2016-12-01
Full Text Available This paper introduces a new current-mode (CM universal biquad filter structure with optimum number of active and passive elements. In the design, the proposed circuit uses a single active element namely, current follower trans-conductance amplifier (CFTA and two grounded capacitors as passive elements. The main feature of the proposed circuit is that it can realize all five standard filtering functions such as low pass (LP, band pass (BP, high pass (HP, band stop (BS and all pass (AP responses across an explicit high impedance output terminal through the appropriate selection of three inputs. In addition, the same circuit is also capable to simultaneously realize three filtering functions (LP, BP and HP by the use of single current input signal. Moreover, the proposed structure is suited for low voltage, low power operations and offers the feature of electronic tunability of pole-frequency and quality factor. Further to extend the utility of the proposed circuit block higher order current-mode filters are also realized through direct cascading. A detailed non-ideal and parasitic study is also included. The performance of the circuits has been examined using standard 0.25 μ m CMOS parameters from TSMC.
A single nano cantilever as a reprogrammable universal logic gate
Chappanda, K. N.
2017-02-24
The current transistor-based computing circuits use multiple interconnected transistors to realize a single Boolean logic gate. This leads to higher power requirements and delayed computing. Transistors are not suitable for applications in harsh environments and require complicated thermal management systems due to excessive heat dissipation. Also, transistor circuits lack the ability to dynamically reconfigure their functionality in real time, which is desirable for enhanced computing capability. Further, the miniaturization of transistors to improve computational power is reaching its ultimate physical limits. As a step towards overcoming the limitations of transistor-based computing, here we demonstrate a reprogrammable universal Boolean logic gate based on a nanoelectromechanical cantilever (NC) oscillator. The fundamental XOR, AND, NOR, OR and NOT logic gates are condensed in a single NC, thereby reducing electrical interconnects between devices. The device is dynamically switchable between any logic gates at the same drive frequency without the need for any change in the circuit. It is demonstrated to operate at elevated temperatures minimizing the need for thermal management systems. It has a tunable bandwidth of 5 MHz enabling parallel and dynamically reconfigurable logic device for enhanced computing.
Yucelen, G Ipek; Choudhury, Rudra Prosad; Vyalikh, Anastasia; Scheler, Ulrich; Beckham, Haskell W; Nair, Sankar
2011-04-13
We report the identification and elucidation of the mechanistic role of molecular precursors and nanoscale (1-3 nm) intermediates with intrinsic curvature in the formation of single-walled aluminosilicate nanotubes. We characterize the structural and compositional evolution of molecular and nanoscale species over a length scale of 0.1-100 nm by electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy ((27)Al liquid-state, (27)Al and (29)Si solid-state MAS), and dynamic light scattering. Together with structural optimization of key experimentally identified species by solvated density functional theory calculations, this study reveals the existence of intermediates with bonding environments, as well as intrinsic curvature, similar to the structure of the final nanotube product. We show that "proto-nanotube-like" intermediates with inherent curvature form in aqueous synthesis solutions immediately after initial hydrolysis of reactants, disappear from the solution upon heating to 95 °C due to condensation accompanied by an abrupt pH decrease, and finally form ordered single-walled aluminosilicate nanotubes. Detailed quantitative analysis of NMR and ESI-MS spectra from the relevant aluminosilicate, aluminate, and silicate solutions reveals the presence of a variety of monomeric and polymeric aluminate and aluminosilicate species (Al(1)Si(x)-Al(13)Si(x)), such as Keggin ions [AlO(4)Al(12)(OH)(24)(H(2)O)(12)](7+) and polynuclear species with a six-membered Al oxide ring unit. Our study also directly reveals the complexation of aluminate and aluminosilicate species with perchlorate species that most likely inhibit the formation of larger condensates or nontubular structures. Integration of all of our results leads to the construction of the first molecular-level mechanism of single-walled metal oxide nanotube formation, incorporating the role of monomeric and polymeric aluminosilicate species as well as larger nanoparticles. © 2011 American
de Martín, Lilian; Ottevanger, Coen; van Ommen, J. Ruud; Coppens, Marc-Olivier
2018-03-01
A granular layer can form regular patterns, such as squares, stripes, and hexagons, when it is fluidized with a pulsating gas flow. These structures are reminiscent of the well-known patterns found in granular layers excited through vibration, but, contrarily to them, they have been hardly explored since they were first discovered. In this work, we investigate experimentally the conditions leading to pattern formation in pulsed fluidized beds and the dimensionless numbers governing the phenomenon. We show that the onset to the instability is universal for Geldart B (sandlike) particles and governed by the hydrodynamical parameters Γ =ua/(utϕ ¯) and f /fn , where ua and f are the amplitude and frequency of the gas velocity, respectively, ut is the terminal velocity of the particles, ϕ ¯ is the average solids fraction, and fn is the natural frequency of the bed. These findings suggest that patterns emerge as a result of a parametric resonance between the kinematic waves originating from the oscillating gas flow and the bulk dynamics. Particle friction plays virtually no role in the onset to pattern formation, but it is fundamental for pattern selection and stabilization.
Near room temperature magnetocaloric properties and the universal curve of MnCoGe1-xCux
Si, Xiaodong; Liu, Yongsheng; Lu, Xiaofei; Shen, Yulong; Wang, Wenli; Yu, Wenying; Zhou, Tao; Gao, Tian
2017-05-01
Intermetallic compounds based on MnCoGe have drawn attention due to the coupled magnetic and structural transformations and the large magnetocaloric entropy. Here, we provide a systematic comparison of experimental data under different magnetic fields with magnetic and the magnetocaloric properties. The ferromagnetic transition temperature (TC) increases from 353.4(6) K for x = 0.01 to 363.4(4) K for x = 0.04 with increasing nominal copper content. The maximum magnetic entropy change |ΔSM| in a magnetic field change of 5 T is found to be 18.3(2) J/(kg K) with a large relative cooling power (RCP) value of 292.5(4) J/kg for x = 0.01, revealing that the present system can provide an acceptable magnetocaloric effect at a cheaper price for magnetic refrigeration materials. Making attempt to contrast a master curve for the present system, we find the experimental values of magnetic field dependence of the magnetic entropy change are consistent with a phenomenological universal curve.
Directory of Open Access Journals (Sweden)
Aneesh Srivastava
2016-01-01
Full Text Available Context: The retroperitoneoscopic or retroperitoneal (RP surgical approach has not become as popular as the transperitoneal (TP one due to the steeper learning curve. Aims: Our single-institution experience focuses on the feasibility, advantages and complications of retroperitoneoscopic surgeries (RS performed over the past 10 years. Tips and tricks have been discussed to overcome the steep learning curve and these are emphasised. Settings and Design: This study made a retrospective analysis of computerised hospital data of patients who underwent RP urological procedures from 2003 to 2013 at a tertiary care centre. Patients and Methods: Between 2003 and 2013, 314 cases of RS were performed for various urological procedures. We analysed the operative time, peri-operative complications, time to return of bowel sound, length of hospital stay, and advantages and difficulties involved. Post-operative complications were stratified into five grades using modified Clavien classification (MCC. Results: RS were successfully completed in 95.5% of patients, with 4% of the procedures electively performed by the combined approach (both RP and TP; 3.2% required open conversion and 1.3% were converted to the TP approach. The most common cause for conversion was bleeding. Mean hospital stay was 3.2 ± 1.2 days and the mean time for returning of bowel sounds was 16.5 ± 5.4 h. Of the patients, 1.4% required peri-operative blood transfusion. A total of 16 patients (5% had post-operative complications and the majority were grades I and II as per MCC. The rates of intra-operative and post-operative complications depended on the difficulty of the procedure, but the complications diminished over the years with the increasing experience of surgeons. Conclusion: Retroperitoneoscopy has proven an excellent approach, with certain advantages. The tips and tricks that have been provided and emphasised should definitely help to minimise the steep learning curve.
Lv, Houning; Zhao, Ningning; Zheng, Zhongqing; Wang, Tao; Yang, Fang; Jiang, Xihui; Lin, Lin; Sun, Chao; Wang, Bangmao
2017-05-01
Peroral endoscopic myotomy (POEM) has emerged as an advanced technique for the treatment of achalasia, and defining the learning curve is mandatory. From August 2011 to June 2014, two operators in our institution (A&B) carried out POEM on 35 and 33 consecutive patients, respectively. Moving average and cumulative sum (CUSUM) methods were used to analyze the POEM learning curve for corrected operative time (cOT), referring to duration of per centimeter myotomy. Additionally, perioperative outcomes were compared among distinct learning curve phases. Using the moving average method, cOT reached a plateau at the 29th case and at the 24th case for operators A and B, respectively. CUSUM analysis identified three phases: initial learning period (Phase 1), efficiency period (Phase 2) and mastery period (Phase 3). The relatively smooth state in the CUSUM graph occurred at the 26th case and at the 24th case for operators A and B, respectively. Mean cOT of distinct phases for operator A were 8.32, 5.20 and 3.97 min, whereas they were 5.99, 3.06 and 3.75 min for operator B, respectively. Eckardt score and lower esophageal sphincter pressure significantly decreased during the 1-year follow-up period. Data were comparable regarding patient characteristics and perioperative outcomes. This single-center study demonstrated that expert endoscopists with experience in esophageal endoscopic submucosal dissection reached a plateau in learning of POEM after approximately 25 cases. © 2016 Japan Gastroenterological Endoscopy Society.
Zeilfelder, Sarah; Hebig, Klaus; Ito, Narimitsu; Machida, Isao; Scheytt, Traugott; Marui, Atsunao
2013-04-01
What method is appropriate to investigate an aquifer when there is only one well available? A single well "push-pull" tracer test (PP Test) may be a suitable method in order to characterize an aquifer and to obtain information about the hydraulic and chemical properties when only one well is available for the investigations. In a PP test, a test solution that contains a known amount of solutes and a conservative tracer is injected into the aquifer ("push") and extracted afterwards ("pull"). Optionally, the test solution is flushed out of the well and the casing with untreated test solution with a so called "chaser" before being extracted. Also between the injection and the extraction phase a drifting time may be included. The breakthrough of the tracer during the extraction phase is measured and used for analyses and interpretation. In the last three years, several PP Test campaigns were conducted at two different test sites in Japan (Hebig et al. 2011, Zeilfelder et al. 2012). The aim was to investigate the applicability of the PP Test method in different geological settings and in different types of aquifers. The latest field campaign thus focussed on the question how variations of the setup are influencing the breakthrough curve of the PP Test in order to develop and enhance this method. Also the standardization of the PP Test was an aim of this study. During the campaign, a total of seven PP Tests were performed, while only single aspects of the setup were varied from test to test. The tests differed in injection and extraction rate, in the salinity of the injected test solution and in the use of a chaser solution. The general shapes of the breakthrough curves were similar and conclusions about the repeatability of the PP Test could be drawn. However, a sharp anomaly was observed in the breakthrough curve of one specific setup type. By repeating this PP test under the same boundary conditions, we were able to recreate the anomaly and could exclude any technical
Patel, Kumkum Sarkar; Calixte, Rose; Modayil, Rani J; Friedel, David; Brathwaite, Collin E; Stavropoulos, Stavros N
2015-05-01
Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States. To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons. Prospective cohort study. Tertiary-care academic medical center. We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013. (1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model. Clinical outcomes, procedure time, technical errors. Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P myotomy, or type of knife used (all P > .05). Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience. These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Smith, A. M. S.; Anderson, D. R.; Hellier, C.; Maxted, P. F. L.; Smalley, B.; Southworth, J. [Astrophysics Group, Keele University, Staffordshire, ST5 5BG (United Kingdom); Collier Cameron, A. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, Fife, KY16 9SS (United Kingdom); Gillon, M.; Jehin, E. [Institut d' Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout, 17 Bat. B5C, Liege 1 (Belgium); Lendl, M.; Queloz, D.; Triaud, A. H. M. J.; Pepe, F.; Segransan, D.; Udry, S. [Observatoire de Geneve, Universite de Geneve, 51 Chemin des Maillettes, 1290 Sauverny (Switzerland); West, R. G. [Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Barros, S. C. C.; Pollacco, D. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University, University Road, Belfast, BT7 1NN (United Kingdom); Street, R. A., E-mail: amss@astro.keele.ac.uk [Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA 93117 (United States)
2012-04-15
We report the discovery, from WASP and CORALIE, of a transiting exoplanet in a 1.54 day orbit. The host star, WASP-36, is a magnitude V = 12.7, metal-poor G2 dwarf (T{sub eff} = 5959 {+-} 134 K), with [Fe/H] =-0.26 {+-} 0.10. We determine the planet to have mass and radius, respectively, 2.30 {+-} 0.07 and 1.28 {+-} 0.03 times that of Jupiter. We have eight partial or complete transit light curves, from four different observatories, which allow us to investigate the potential effects on the fitted system parameters of using only a single light curve. We find that the solutions obtained by analyzing each of these light curves independently are consistent with our global fit to all the data, despite the apparent presence of correlated noise in at least two of the light curves.
Koh, Eunjung; Song, Ha Jeong; Kwon, Na Young; Kim, Gi Won; Lee, Kwang Ho; Jo, Soyeon; Park, Sujin; Park, Jihyun; Park, Eun Kyeong; Hwang, Seung Yong
2017-06-01
Real time PCR is a standard method for identification of species. One of limitations of the qPCR is that there would be false-positive result due to mismatched hybridization between target sequence and probe depending on the annealing temperature in the PCR condition. As an alternative, fluorescence melting curve analysis (FMCA) could be applied for species identification. FMCA is based on a dual-labeled probe. Even with subtle difference of target sequence, there are visible melting temperature (Tm) shift. One of FMCA applications is distinguishing organisms distributed and consumed globally as popular food ingredients. Their prices are set by species or country of origin. However, counterfeiting or distributing them without any verification procedure are becoming social problems and threatening food safety. Besides distinguishing them in naked eye is very difficult and almost impossible in any processed form. Therefore, it is necessary to identify species in molecular level. In this research three species of squids which have 1-2 base pair differences each are selected as samples since they have the same issue. We designed a probe which perfectly matches with one species and the others mismatches 2 and 1 base pair respectively and labeled with fluorophore and quencher. In an experiment with a single probe, we successfully distinguished them by Tm shift depending on the difference of base pair. By combining FMCA and qPCR chip, smaller-scale assay with higher sensitivity and resolution could be possible, andc furthermore, enabling results analysis with smart phone would realize point-of-care testing (POCT).
Abdel-Karim, Aly M; Elhenawy, Ibrahim M; Eid, Ahmed A; Yahia, Elsayed; Elsalmy, Salah A
2017-09-01
To define the learning curve of laparoendoscopic single-site surgery (LESS) of an experienced laparoscopist. Patients who had LESS, since its implementation in December 2009 until December 2014, were retrospectively analysed. Procedures were divided into groups of 10 and scored according to the European Scoring System for Laparoscopic Operations in Urology. Different LESS indications were done by one experienced laparoscopist. Technical feasibility, surgical safety, outcome, as well as the number of patients required to achieve professional competence were assessed. In all, 179 patients were included, with mean (SD) age of 36.3 (17.5) years and 25.4% of the patients had had previous surgeries. Upper urinary tract procedures were done in 65.9% of patients and 54.7% of the procedures were extirpative. Both transperitoneal and retroperitoneal LESS were performed in 92.8% and 7.2% of the patients, respectively. The intraoperative and postoperative complication rates were 2.2% and 5.6% (Clavien-Dindo Grade II 3.9% and IIIa 1.7%), respectively. In all, 75% of intraoperative complications and all conversions were reported during the first 30 LESS procedures; despite the significantly higher difficulty score in the subsequent LESS procedures. One 5-mm extra port, conversion to conventional laparoscopy and open surgery was reported in 14%, 1.7%, and 1.1% of the cases, respectively. At mean (SD) follow-up of 39.7 (11.4) months, all the patients that underwent reconstructive LESS procedures but one were successful. In experienced hands, at least 30 LESS procedures are required to achieve professional competence. Although difficult, both conversion and complication rates of LESS are low in experienced hands.
International Nuclear Information System (INIS)
Wennberg, Berit M.; Baumann, Pia; Gagliardi, Giovanna
2011-01-01
Background. In SBRT of lung tumours no established relationship between dose-volume parameters and the incidence of lung toxicity is found. The aim of this study is to compare the LQ model and the universal survival curve (USC) to calculate biologically equivalent doses in SBRT to see if this will improve knowledge on this relationship. Material and methods. Toxicity data on radiation pneumonitis grade 2 or more (RP2+) from 57 patients were used, 10.5% were diagnosed with RP2+. The lung DVHs were corrected for fractionation (LQ and USC) and analysed with the Lyman- Kutcher-Burman (LKB) model. In the LQ-correction α/β = 3 Gy was used and the USC parameters used were: α/β = 3 Gy, D 0 = 1.0 Gy, n = 10, α 0.206 Gy-1 and d T = 5.8 Gy. In order to understand the relative contribution of different dose levels to the calculated NTCP the concept of fractional NTCP was used. This might give an insight to the questions of whether 'high doses to small volumes' or 'low doses to large volumes' are most important for lung toxicity. Results and Discussion. NTCP analysis with the LKB-model using parameters m = 0.4, D50 = 30 Gy resulted for the volume dependence parameter (n) with LQ correction n = 0.87 and with USC correction n = 0.71. Using parameters m = 0.3, D 50 = 20 Gy n = 0.93 with LQ correction and n 0.83 with USC correction. In SBRT of lung tumours, NTCP modelling of lung toxicity comparing models (LQ,USC) for fractionation correction, shows that low dose contribute less and high dose more to the NTCP when using the USC-model. Comparing NTCP modelling of SBRT data and data from breast cancer, lung cancer and whole lung irradiation implies that the response of the lung is treatment specific. More data are however needed in order to have a more reliable modelling
Universal quantum gates for Single Cooper Pair Box based quantum computing
Echternach, P.; Williams, C. P.; Dultz, S. C.; Braunstein, S.; Dowling, J. P.
2000-01-01
We describe a method for achieving arbitrary 1-qubit gates and controlled-NOT gates within the context of the Single Cooper Pair Box (SCB) approach to quantum computing. Such gates are sufficient to support universal quantum computation.
Wellman, Samuel S; Klement, Mitchell R; Queen, Robin M
2017-11-01
Midflexion stability after total knee arthroplasty (TKA) is dependent, in part, on implant design. Midflexion performance of a single-radius (SR) design and a multi-radius, or J-curve (JC), design were compared using the Lower Quarter Y-Balance Test (YBT-LQ). Patient-reported outcomes and measures of physical performance were also compared. The authors hypothesized that the SR design would provide superior midflexion stability and, therefore, a greater reach distance in the YBT-LQ when compared with the JC design. Patients undergoing primary, unilateral TKA were prospectively enrolled and block randomized to receive either the SR (n=30) or the JC (n=30) implant. Patients reported outcome measures (Knee Injury and Osteoarthritis Outcome Score, Knee Society Score, and University of California at Los Angeles Activity Score), performed the YBT-LQ, and completed physical performance measures (walking speed, timed up-and-go test, and sit-to-stand test) before surgery and 1 year postoperatively. One year postoperatively, 40 patients (20 SR, 20 JC) were available for analysis. There were no significant differences between the groups regarding age, sex, body mass index, American Society of Anesthesiologists score, YBT-LQ results, or any other variable of interest. In both groups, significant improvements were observed for all variables of interest when compared from preoperatively to 1 year postoperatively. Implant type did not affect patient-reported or physical performance outcomes following TKA; however, patients showed significant improvement in most outcome measures by 1 year postoperatively. The significant limitations in strength and balance in this cohort of patients likely outweigh any subtle differences in implant design. [Orthopedics. 2017; 40(6):e1074-e1080.]. Copyright 2017, SLACK Incorporated.
Energy Technology Data Exchange (ETDEWEB)
Koper, Marc T.M.; Schmidt, Thomas J.; Markovic, Nenad M.; Ross, Philip N.
2001-03-01
The occurrence of an S-shaped polarization curve in a simple model for the continuous electrochemical oxidation of CO on a platinum electrode is discussed. In the model, the S-shaped polarization curve is caused by the competitive Langmuir-Hinshelwood mechanism between surface-bonded CO and OH. The reaction is studied experimentally on single-crystal platinum rotating disk electrodes in perchloric and sulfuric acid solution, and it is shown that the voltammetry is in good agreement with the model predictions. When studied under current-controlled conditions, a fast galvanodynamic scan indeed suggests the existence of the S-shaped polarization curve. At lower scan rates, however, irregularities and small-amplitude irregular fluctuations or oscillations in potential are observed. Very regular potential oscillations under current-controlled conditions are observed only on Pt(111) in sulfuric acid. The possible origin of these irregularities and oscillations is discussed in relation to the existing theories of electrochemical instabilities.
DEFF Research Database (Denmark)
Srinivas, Nuggehally R; Syed, Muzeeb
2016-01-01
concentration–time curve (AUC) and minimum plasma drug concentration (Cmin) versus AUC relationship was established by linear regression models. The predictions of the AUC values were performed using published mean/median Cmax or Cmin data and appropriate regression lines. The quotient of observed and predicted...
Do Single-Sex Classes Affect Achievement? A Study in a Coeducational University
Alison L. Booth; Lina Cardona-Sosa; Patrick Nolen
2013-01-01
We examine the effect of single-sex classes on the pass rates, grades, and course choices of students in a coeducational university. We randomly assign students to all-female, all-male, and coed classes and, therefore, get around the selection issues present in other studies on single-sex education. We find that one hour a week of single-sex education benefits females: females are 7.5% more likely to pass their first year courses and score 10% higher in their required second year classes than...
International Nuclear Information System (INIS)
Peter, I. J.
1995-06-01
The work deals with space-times with fixed background metric. The topics were arranged in a straight course, the first chapter collects basic facts on Lorentzian manifolds as time-orientability, causal structure, ... Further free neutral scalar fields and spinor fields described by the Klein-Gordon equation resp. the Dirac equation are dealt with. Having in mind the construction of the Weyl algebra and the Fermi algebra in the second chapter, it was put emphasis on the structure of the spaces of solutions of these equations: In the first case the space of solutions is a symplectic vector space in a canonical manner, in the second case a Hilbert space. It was made some effort to stay as general as possible. Most of the material in the second chapter already exists for several years, but it is largely scattered over various journal articles. In the third chapter the construction of a vacuum on the special example of deSitter universe is described. A close investigation of a recent work by J. Bros and U. Moschella made it possible to refine a result concerning temperature felt by an accelerated observer in deSitter space. The last part of this thesis is concerned with vacua for spinor fields on the two-dimensional deSitter universe. A procedure introduced by R. Haag, H. Narnhofer and U. Stein for four dimensional space-times does not seem to work in two dimensions. (author)
Energy Technology Data Exchange (ETDEWEB)
Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr
2016-12-15
Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.
Labbaf, Hossein; Nazari Moghadam, Kiumars; Shahab, Shahriar; Mohammadi Bassir, Mahshid; Fahimi, Mohammad Amin
2017-01-01
As a consequence of root canal preparation, dentinal chips, irrigants and pulp remnants are extruded into preradicular space. This phenomenon may lead to post endodontic flare-ups. The purpose of this study was to compare the amount of extruded debris with four endodontic NiTi engine-driven systems. Sixty mesiobuccal roots of maxillary molars with 15-30˚ curvature were divided randomly into four groups ( n =15). Each group was instrumented up to apical size of 25 using Reciproc, ProTaper Universal, Neolix and Hyflex. Bidistilled water was used as irrigant and extruded debris was collected in pre-weighted Eppendorf tubes. Tubes were stored in incubator for drying the debris. Extruded debris were weighted in electronic microbalance with accuracy of 0.0001 g. The raw data was analyzed with one way analysis of variance (ANOVA) and Tukey's HSD post hoc test. Level of significance was set at 0.05. The debris extrusion with Reciproc files was significantly higher than the other groups ( P extruded less debris than other files ( P extruded debris ( P =0.98). All systems extruded debris during the instrumentation. Reciproc system significantly extruded more debris. Caution should be taken when interpreting the results of this study and applying it to the real clinical situation.
DEFF Research Database (Denmark)
Alrabadi, Osama; Papadias, C.B.; Kalis, A.
2009-01-01
A universal scheme for encoding multiple symbol streams using a single driven element (and consequently a single radio frequency (RF) frontend) surrounded by parasitic elements (PE) loaded with variable reactive loads, is proposed in this paper. The proposed scheme is based on creating a MIMO...... systems. The array can spatially multiplex the input streams by creating all the desired linear combinations (for a given modulation scheme) of the basis functions. The desired combinations are obtained by projecting the ratio of the symbols to be spatially multiplexed on the ratio of the basis functions...
Shang, Ying; Zhu, Pengyu; Xu, Wentao; Guo, Tianxiao; Tian, Wenying; Luo, Yunbo; Huang, Kunlun
2013-12-15
In this study, a novel single universal primer multiplex ligation-dependent probe amplification (SUP-MLPA) technique that uses only one universal primer to perform multiplex polymerase chain reaction (PCR) was developed. Two reversely complementary common sequences were designed on the 5' or 3' end of the ligation probes (LPs), which allowed the ligation products to be amplified through only a single universal primer (SUP). SUP-MLPA products were analyzed on sequencing gel electrophoresis with extraordinary resolution. This method avoided the high expenses associated with capillary electrophoresis, which was the commonly used detection instrument. In comparison with conventional multiplex PCR, which suffers from low sensitivity, nonspecificity, and amplification disparity, SUP-MLPA had higher specificity and sensitivity and a low detection limit of 0.1 ng for detecting single crop species when screening the presence of genetically modified crops. We also studied the effect of different lengths of stuffer sequences on the probes for the first time. Through comparing the results of quantitative PCR, the LPs with different stuffer sequences did not affect the ligation efficiency, which further increased the multiplicity of this assay. The improved SUP-MLPA and sequencing gel electrophoresis method will be useful for food and animal feed identification, bacterial detection, and verification of genetic modification status of crops. Copyright © 2013 Elsevier Inc. All rights reserved.
2010-10-25
... Single-Source Expansion Supplements to The University of Colorado Health Sciences Center in Aurora, CO...), Administration on Developmental Disabilities (ADD) has awarded three single-source expansion supplements for data... people with intellectual and developmental disabilities in all facets of community life. The University...
Directory of Open Access Journals (Sweden)
Taha ÖZYÜREK
2017-04-01
Full Text Available Purpose: The aim of this study was to compare the cleanliness of root canal walls after retreatment using ProTaper Next (PTN, ProTaper Universal Retreatment (PTR nickel-titanium (NiTi systems and Hedström hand files in curved mesial canals of mandibular molar teeth and the time required for gutta-percha and sealer removal. Materials and Methods: Ninety mandibular molar teeth with curved mesial roots were instrumented up to #35.04 with Mtwo NiTi rotary instruments and obturated using the continuous wave of condensation technique. Removal of gutta-percha and sealer was performed using one of the following: PTN and PTR NiTi systems and Hedström hand files. Samples were placed on the VistaScan phosphor plates in the mesio-distal direction and the radiographs were taken. The digital radiographs were analyzed using AutoCAD software. Also, the total time required for gutta-percha removal was calculated by a chronometer. Results: The total retreatment time was significantly shorter in the PTN and PTR groups compared with the manual group (p<0.05. There was a significant difference between the groups according to the total residual gutta-percha and sealer (p<0.05. The PTN and PTR groups left significantly less gutta-percha and sealer remnant than the manual group (p<0.001. Conclusion: Within the limitations of this study, the PTN and PTR groups showed less residual gutta-percha and sealer than the manual group. The NiTi rotary systems were significantly faster than the manual group in the time required for gutta-percha and sealer removal.
Gawart, Matthew; Dupitron, Sabine; Lutfi, Rami
2012-03-01
We aimed to evaluate our learning curve comparing surgical time of laparoendoscopic single-site (LESS) banding with multiport laparoscopy. We performed a retrospective analysis of prospectively collected data comparing our first 48 LESS bands with our first 50 multiport laparoscopic bands at our institution. We then compared the first 24 LESS bands with the last 24 bands. The average body mass index for the LESS group was significantly lower than for the laparoscopic group (43.19 vs 48.3; P < .0001). The surgical time was much faster toward the second half of our experience performing the LESS procedure (85.34 vs 68.8; P = .0055). LESS banding took significantly longer than our early traditional laparoscopic adjustable gastric banding (76.85 vs 64.4; P = .0015). We conclude that in experienced hands, single-incision banding is feasible and safe to perform. Long-term data are needed to prove that LESS banding is as good a surgery as traditional laparoscopic surgery. Copyright © 2012 Elsevier Inc. All rights reserved.
Study of FCNC-mediated rare Bs decays in a single universal extra dimension scenario
International Nuclear Information System (INIS)
Mohanta, R.; Giri, A. K.
2007-01-01
We study the rare semileptonic and radiative leptonic B s decays in the universal extra dimension model. In this scenario, with a single extra dimension, there exists only one new parameter beyond those of the standard model, which is the inverse of the compactification radius R. We find that with the additional contributions due to the Kaluza-Klein (KK) modes the branching ratios of the rare B s decays are enhanced from their corresponding standard model values and the zero point of the forward-backward asymmetries are shifted towards the left
Universal large deviations for the tagged particle in single-file motion.
Hegde, Chaitra; Sabhapandit, Sanjib; Dhar, Abhishek
2014-09-19
We consider a gas of point particles moving in a one-dimensional channel with a hard-core interparticle interaction that prevents particle crossings--this is called single-file motion. Starting from equilibrium initial conditions we observe the motion of a tagged particle. It is well known that if the individual particle dynamics is diffusive, then the tagged particle motion is subdiffusive, while for ballistic particle dynamics, the tagged particle motion is diffusive. Here we compute the exact large deviation function for the tagged particle displacement and show that this is universal, independent of the individual dynamics.
Directory of Open Access Journals (Sweden)
Yen-Chuan Ou
2014-10-01
Full Text Available To analyze the learning curve for cancer control from an initial 250 cases (Group I and subsequent 250 cases (Group II of robotic-assisted laparoscopic radical prostatectomy (RALP performed by a single surgeon. Five hundred consecutive patients with clinically localized prostate cancer received RALP and were evaluated. Surgical parameters and perioperative complications were compared between the groups. Positive surgical margin (PSM and biochemical recurrence (BCR were assessed as cancer control outcomes. Patients in Group II had significantly more advanced prostate cancer than those in Group I (22.2% vs 14.2%, respectively, with Gleason score 8-10, P= 0.033; 12.8% vs 5.6%, respectively, with clinical stage T3, P= 0.017. The incidence of PSM in pT3 was decreased significantly from 49% in Group I to 32.6% in Group II. A meaningful trend was noted for a decreasing PSM rate with each consecutive group of 50 cases, including pT3 and high-risk patients. Neurovascular bundle (NVB preservation was significantly influenced by the PSM in high-risk patients (84.1% in the preservation group vs 43.9% in the nonpreservation group. The 3-year, 5-year, and 7-year BCR-free survival rates were 79.2%, 75.3%, and 70.2%, respectively. In conclusion, the incidence of PSM in pT3 was decreased significantly after 250 cases. There was a trend in the surgical learning curve for decreasing PSM with each group of 50 cases. NVB preservation during RALP for the high-risk group is not suggested due to increasing PSM.
International Nuclear Information System (INIS)
Moon, B. S.; Han, S. H.; Kim, Y. K.; Chung, C. E.
2001-01-01
The conversion efficiency of a cesium iodine coated micro-channel plate is studied. We use the EGS4 code to transport photons and generated electrons until their energies become less than 1keV and 10keV respectively. Among the generated electrons, the emission from the secondary electrons located within the escape depth of 56mm from the photo-converter boundary is estimated by integrating the product of the secondary electrons with a probability depending only on their geometric locations. The secondary electron emission from the generated electrons of energy higher than 100eV is estimated by the 'universal yield curve'. The sum of these provides an estimate for the secondary electron yield and we show that results of applying this algorithm agree with known experimental results. Using this algorithm, we computed secondary electron emissions from a micro-channel plate used in a gas electron multiplier detector that is currently being developed at Korea Atomic Energy Research Institute
FCNC Bs and Λb transitions: Standard model versus a single universal extra dimension scenario
International Nuclear Information System (INIS)
Colangelo, P.; De Fazio, F.; Ferrandes, R.; Pham, T. N.
2008-01-01
We study the flavor changing neutral current B s →φγ, φνν and Λ b →Λγ, Λνν transitions in the standard model and in a scenario with a single universal extra dimension. In particular, we focus on the present knowledge of the hadronic uncertainties and on possible improvements. We discuss how the measurements of these modes can be used to constrain the new parameter involved in the extra-dimensional scenario, the radius R of the extra dimension, completing the information available from B-factories. The rates of these b→s induced decays are within the reach of new experiments, such as LHCb.
Universal flow-density relation of single-file bicycle, pedestrian and car motion
Energy Technology Data Exchange (ETDEWEB)
Zhang, J., E-mail: ju.zhang@fz-juelich.de [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Mehner, W., E-mail: w.mehner@fz-juelich.de [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Holl, S., E-mail: st.holl@fz-juelich.de [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Boltes, M., E-mail: m.boltes@fz-juelich.de [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Andresen, E., E-mail: e.andresen@uni-wuppertal.de [Department of Computer Simulation for Fire Safety and Pedestrian Traffic, Bergische Universität Wuppertal, 42285 Wuppertal (Germany); Schadschneider, A., E-mail: as@thp.uni-koeln.de [Institut für Theoretische Physik, Universität zu Köln, 50937 Köln (Germany); Seyfried, A., E-mail: a.seyfried@fz-juelich.de [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Department of Computer Simulation for Fire Safety and Pedestrian Traffic, Bergische Universität Wuppertal, 42285 Wuppertal (Germany)
2014-09-12
The relation between flow and density is an essential quantitative characteristic to describe the efficiency of traffic systems. We have performed experiments with single-file motion of bicycles and compared the results with previous studies for car and pedestrian motion in similar setups. In the space–time diagrams we observe three different states of motion (free flow state, jammed state and stop-and-go waves) in all these systems. Despite their obvious differences they are described by a universal fundamental diagram after proper rescaling of space and time which takes into account the size and free velocity of the three kinds of agents. This indicates that the similarities between the systems go deeper than expected.
African Journals Online (AJOL)
Adele
Introduction. Both the Unique™ LMA, and lately the Cobra™ PLA, is available in most of the larger state hospitals in South Africa. This study's objective is to evaluate and compare the learning curves for insertion of these two single-use airway devices. This is to ascertain which of these two devices is easier and safer to ...
Single-input Multiple-output Tunable Log-domain Current-mode Universal Filter
Directory of Open Access Journals (Sweden)
P. Prommee
2013-06-01
Full Text Available This paper describes the design of a current-mode single-input multiple-output (SIMO universal filter based on the log-domain filtering concept. The circuit is a direct realization of a first-order differential equation for obtaining the lossy integrator circuit. Lossless integrators are realized by log-domain lossy integrators. The proposed filter comprises only two grounded capacitors and twenty-four transistors. This filter suits to operate in very high frequency (VHF applications. The pole-frequency of the proposed filter can be controlled over five decade frequency range through bias currents. The pole-Q can be independently controlled with the pole-frequency. Non-ideal effects on the filter are studied in detail. A validated BJT model is used in the simulations operated by a single power supply, as low as 2.5 V. The simulation results using PSpice are included to confirm the good performances and are in agreement with the theory.
Single Crystal and Large Grain Niobium Research at Michigan State University
Energy Technology Data Exchange (ETDEWEB)
Compton, Chris; Aizaz, Ahmad; Baars, Derek; Bieler, Tom; Bierwagen, John; Bricker, Steve; Grimm, Terry; Hartung, Walter; Jiang, Hairong; Johnson, Matt; Popielarski, John; Saxton, Laura; Antoine, Claire; Wagner, Bob; Kneisel, Peter
2007-09-01
As Superconducting Radio Frequency (SRF) technology is used in more accelerator designs, research has focused on increasing the efficiency of these accelerators by pushing gradients and investigating cast reduction options. Today, most SRF structures are fabricated from high purity niobium. Over years of research, a material specification has been derived that defines a uniaxial, fine gain structure for SRF cavity fabrication. Most recently a push has been made to investigate the merits of using single or large grain niobium as a possible alternative to fine grain niobium. Michigan State University (MSU), in collaboration with Fermi National Accelerator Laboratory (FNAL) and Thomas Jefferson National Accelerator Facility (JLAB), is researching large grain niobium via cavity fabrication processes end testing, as well as exploring materials science issues associated with recrystallization and heat transfer. Single-cell 1.3 GHz (Beta=0.081) cavities made from both fine end large grain niobium were compared both in terms of fabrication procedures and performance. Two 7-cell cavities are currently being fabricated.
Bemelmans, KJ; Wolters, G; Zwinderman, K; ten Berge, JMF; Goekoop, JG
The U-shaped serial position curve (SPC) of single-trial free recall is a well-established empirical fact, and there is ample evidence that it is the result of two different memory functions. However, it is insufficiently clear whether the same holds true for the SPC of multi-trial free recall. Free
A learning rule for very simple universal approximators consisting of a single layer of perceptrons.
Auer, Peter; Burgsteiner, Harald; Maass, Wolfgang
2008-06-01
One may argue that the simplest type of neural networks beyond a single perceptron is an array of several perceptrons in parallel. In spite of their simplicity, such circuits can compute any Boolean function if one views the majority of the binary perceptron outputs as the binary output of the parallel perceptron, and they are universal approximators for arbitrary continuous functions with values in [0,1] if one views the fraction of perceptrons that output 1 as the analog output of the parallel perceptron. Note that in contrast to the familiar model of a "multi-layer perceptron" the parallel perceptron that we consider here has just binary values as outputs of gates on the hidden layer. For a long time one has thought that there exists no competitive learning algorithm for these extremely simple neural networks, which also came to be known as committee machines. It is commonly assumed that one has to replace the hard threshold gates on the hidden layer by sigmoidal gates (or RBF-gates) and that one has to tune the weights on at least two successive layers in order to achieve satisfactory learning results for any class of neural networks that yield universal approximators. We show that this assumption is not true, by exhibiting a simple learning algorithm for parallel perceptrons - the parallel delta rule (p-delta rule). In contrast to backprop for multi-layer perceptrons, the p-delta rule only has to tune a single layer of weights, and it does not require the computation and communication of analog values with high precision. Reduced communication also distinguishes our new learning rule from other learning rules for parallel perceptrons such as MADALINE. Obviously these features make the p-delta rule attractive as a biologically more realistic alternative to backprop in biological neural circuits, but also for implementations in special purpose hardware. We show that the p-delta rule also implements gradient descent-with regard to a suitable error measure
Energy Technology Data Exchange (ETDEWEB)
Messaris, Gerasimos A. T., E-mail: messaris@upatras.gr [Department of Physics, Division of Theoretical Physics, University of Patras, GR 265 04 Rion (Greece); School of Science and Technology, Hellenic Open University, 11 Sahtouri Street, GR 262 22 Patras (Greece); Hadjinicolaou, Maria [School of Science and Technology, Hellenic Open University, 11 Sahtouri Street, GR 262 22 Patras (Greece); Karahalios, George T. [Department of Physics, Division of Theoretical Physics, University of Patras, GR 265 04 Rion (Greece)
2016-08-15
The present work is motivated by the fact that blood flow in the aorta and the main arteries is governed by large finite values of the Womersley number α and for such values of α there is not any analytical solution in the literature. The existing numerical solutions, although accurate, give limited information about the factors that affect the flow, whereas an analytical approach has an advantage in that it can provide physical insight to the flow mechanism. Having this in mind, we seek analytical solution to the equations of the fluid flow driven by a sinusoidal pressure gradient in a slightly curved pipe of circular cross section when the Womersley number varies from small finite to infinite values. Initially the equations of motion are expanded in terms of the curvature ratio δ and the resulting linearized equations are solved analytically in two ways. In the first, we match the solution for the main core to that for the Stokes boundary layer. This solution is valid for very large values of α. In the second, we derive a straightforward single solution valid to the entire flow region and for 8 ≤ α < ∞, a range which includes the values of α that refer to the physiological flows. Each solution contains expressions for the axial velocity, the stream function, and the wall stresses and is compared to the analogous forms presented in other studies. The two solutions give identical results to each other regarding the axial flow but differ in the secondary flow and the circumferential wall stress, due to the approximations employed in the matched asymptotic expansion process. The results on the stream function from the second solution are in agreement with analogous results from other numerical solutions. The second solution predicts that the atherosclerotic plaques may develop in any location around the cross section of the aortic wall unlike to the prescribed locations predicted by the first solution. In addition, it gives circumferential wall stresses
The purpose and appropriateness of carbapenem use in a single university hospital, 2009-2013.
Yoon, Doran; Koo, Hei Lim; Choe, Pyeong Gyun; Song, Kyoung-Ho; Park, Wan Beom; Bang, Ji Hwan; Kim, Eu Suk; Park, Sang Won; Kim, Hong Bin; Oh, Myoung-Don; Kim, Nam Joong
2016-06-01
This is a retrospective review study to investigate changes in carbapenem consumption and to evaluate the proportion of inappropriate empirical use of carbapenem in the months of September and October of 2009, 2011, and 2013 in a single university-affiliated hospital. Total carbapenem use was classified into 3 categories: prophylactic, directed, and empirical. If an empirical prescription was continued without documentation of any eligible etiologic microorganism, we defined this as 'inappropriate' use. We also considered it 'inappropriate' when a patient's culture revealed no pathogen and the patient was initially not in severe sepsis or septic shock and did not have a history of admission to a health-care facility or of colonization with a pathogen eligible for carbapenem within 3 months. The total amount was 48.1, 51.1, and 91.0 defined daily doses/1000 patient-days in 2009, 2011, and 2013, respectively. Empirical use accounted for 78.4% of all prescriptions. The proportion of inappropriate empirical use ranged from 15.0 to 38.9% of the empirical carbapenem prescriptions.
2015-12-17
No. DODIG-2016-034 D E C E M B E R 1 7 , 2 0 1 5 Quality Control Review of the PricewaterhouseCoopers LLP FY 2014 Single Audit of Carnegie...Projects Accounting Carnegie Mellon University SUBJECT: Quality Control Review of the PricewaterhouseCoopers LLP FY 2014 Single Audit of Carnegie... Audits of States, Local Governments, and Non-Profit Organizations.” We conducted this quality control review in accordance with the “ Quality
Reflection of curved shock waves
Mölder, S.
2017-09-01
Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.
Doudna, Kelly
2015-01-01
The Universe explores the science of what we see in the night sky. Kids will learn about the life cycle of a star, find out how our universe was created, explore nebulae, galaxies, black holes, giant stars and more. Engaging photos, exciting graphics, and a fun quiz at the end of each book will keep them learning. Aligned to Common Core Standards and correlated to state standards. Super Sandcastle is an imprint of Abdo Publishing, a division of ABDO.
Alternative Gravity Rotation Curves for the LITTLE THINGS Survey
O’Brien, James G.; Chiarelli, Thomas L.; Dentico, Jeremy; Stulge, Modestas; Stefanski, Brian; Moss, Robert; Chaykov, Spasen
2018-01-01
Galactic rotation curves have proven to be the testing ground for dark matter bounds in spiral galaxies of all morphologies. Dwarf galaxies serve as an increasingly interesting case of rotation curve dynamics due to their typically rising rotation curve as opposed to the flattening curve of large spirals. Dwarf galaxies usually vary in galactic structure and mostly terminate at small radial distances. This, coupled with the fact that Cold Dark Matter theories struggle with the universality of galactic rotation curves, allow for exclusive features of alternative gravitational models to be analyzed. Recently, The H I Nearby Galactic Survey (THINGS) has been extended to include a sample of 25 dwarf galaxies now known as the LITTLE THINGS Survey. Here, we show an application of alternative gravitational models to the LITTLE THINGS survey, specifically focusing on conformal gravity (CG) and Modified Newtonian Dynamics (MOND). In this work, we provide an analysis and discussion of the rotation curve predictions of each theory to the sample. Furthermore, we show how these two alternative gravitational models account for the recently observed universal trends in centripetal accelerations in spiral galaxies. This work highlights the similarities and differences of the predictions of the two theories in dwarf galaxies. The sample is not large or diverse enough to strongly favor a single theory, but we posit that both CG and MOND can provide an accurate description of the galactic dynamics in the LITTLE THINGS sample without the need for dark matter.
Energy Technology Data Exchange (ETDEWEB)
Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)
2008-11-15
The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.
Serati, Maurizio; Bogani, Giorgio; Braga, Andrea; Sorice, Paola; Salvatore, Stefano; Uccella, Stefano; Ghezzi, Fabio
2015-03-01
To evaluate for the first time in the literature the learning curve of Inside-out transobturator tape (TVT-O™). A prospective observational study was conducted in a tertiary reference center. Consecutive women treated by TVT-O™ performed by one surgeon were included. Data regarding subjective, objective cure rates, and adverse events were collected. Trends, over the number of procedures, were estimated using assay analyses. Number of procedures and variables were interpolating in standard curves using linear lines. Three hundred and seventy two procedures were included. Postoperative pain levels decreased with the increase in the level of expertise (pain levels: 1-day: from 6.6 (±3.3) to 4.3 (±3.1); 95%CI: -0.01603 to 0.001235, p=0.04; 2-day: from 5.6 (±4.1) to 3.6 (±3.7); 95%CI: -0.02092 to -0.002497, p=0.01; 12-month: from 0.1 (±0.7) to 0 (±0); 95%CI: -0.001814 to 0.05019, p=0.07). Overall, objective cure rate was achieved in 93.5% of patients. Additionally, 88.2% and 88.7% patients reported "much better" feeling at PGI-I scale and 80% reduction in UDI score, respectively. We observed, that delta ICIQ-sf (from 12 (±8.7) to 14 (±6.0); p=0.04) and delta-UDI (from 91% to 97%; p=0.04) improved over the time. TVT-O procedure offers excellent outcomes with high objective and subjective cure rates and low complications rate, even at the beginning of the surgeon's learning curve. However, a high experience of the surgeon could significantly improve the subjective cure rate and could reduce postoperative the groin pain. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Lee, Byung-Ki
2016-12-01
The purpose of this study was to determine the influence of the proprioceptive neuromuscular facilitation (PNF) exercise programs for idiopathic scoliosis with a female patient in the early 20s in terms of her spinal curve and balancing abilities. The study subject was selected among 21-year-old female college students. There were no particular activities that the subject could not perform, but patient complained of difficulty in maintaining the standing position for a prolonged time. Patient chest X-ray results showed S-shaped curves tilted towards the left or right in the lumbar spine, thoracic spine, and cervical spine areas. The PNF exercise programs consists of seven therapeutic exercise programs, including home exercises considering the patients' balancing abilities, the lateral symmetry of the spinal sway, the distortion, and the height of the pelvis and scapula bones. The programs last for 6 weeks and includes three sessions per week, with each session lasting for 30 min. Before and after the execution of the PNF exercise programs, the subject was monitored for the changes in her spinal sways through chest X-ray tests. Also, using a balance measurement instrument, the subject's static and dynamic balancing abilities were tested. After executing the PNF exercise programs for 6 weeks, the spinal sways of the subject were corrected, and her static and dynamic balancing abilities were improved compared to the baseline values.
Uezu, Tatsuya
1997-11-01
In learning under external disturbance, it is expected that some tolerance in the system will optimize the learning process. In this paper, we give one example of this in learning from stochastic rules by the Gibbs algorithm. Using the replica method, we show that for the case of output noise, there exists an optimal temperature at which the generalization error is a minimum. This temperature exists even in the limit of large training sets and is determined by the stable replica symmetric solution. On the other hand, for other types of noise no such temperature exists and the asymptotic behaviour is determined by the one-step replica symmetric breaking solution. Further, the asymptotic expressions for learning curves are derived. They are precisely the same as those for the minimum-error algorithm.
Arslan, Hakan; Yildiz, Ezgi Doganay; Gunduz, Hicran Ates; Sumbullu, Meltem; Bayrakdar, Ibrahim Sevki; Karatas, Ertugrul; Sumbullu, Muhammed Akif
2017-01-01
Aim: The aim of this study is to evaluate the root canal transportation, centering ability, and instrumentation times with the ProTaper Gold (Dentsply Tulsa Dental, Tulsa, OK, USA), Reciproc (VDW, Munich, Germany), and ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) using cone-beam computed tomography (CBCT). Materials and Methods: Thirty mesial root canals of mandibular first molars with curvature angles of 35°–70° and radii of 2–6 mm were included in the study. Root canal instrumentation was performed up to F2 or R25. The instrumentation times were recorded. CBCT scanning was performed both pre- and post-instrumentation. Root canal transportation and the centering ratio were calculated for groups, and the data were analyzed using a one-way ANOVA and least significant difference post hoc tests for the instrumentation time, root canal transportation, and centering ratio at the 95% confidence level (P = 0.05). Results: At 3, 5, and 7 mm levels, there was no significant difference in the root canal transportation and centering ratio among the groups (P > 0.05). There were significant differences between the Reciproc and ProTaper Universal groups in the instrumentation times (P < 0.05). Conclusion: Root canal transportation and the centering ratio with the ProTaper Gold were similar to those obtained with the ProTaper Universal and Reciproc. PMID:29259355
Lagrangian Curves on Spectral Curves of Monopoles
International Nuclear Information System (INIS)
Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.
2010-01-01
We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.
Curves from Motion, Motion from Curves
2000-01-01
tautochrone and brachistochrone properties. To Descartes, however, the rectification of curves such as the spiral (3) and the cycloid (4) was suspect - they...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012017 TITLE: Curves from Motion, Motion from Curves DISTRIBUTION...Approved for public release, distribution unlimited This paper is part of the following report: TITLE: International Conference on Curves and Surfaces [4th
A universal setup for active control of a single-photon detector
International Nuclear Information System (INIS)
Liu, Qin; Skaar, Johannes; Lamas-Linares, Antía; Kurtsiefer, Christian; Makarov, Vadim; Gerhardt, Ilja
2014-01-01
The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors
Pregnancy outcomes in a university hospital after legal requirement for single-embryo transfer.
Ercan, Cihangir Mutlu; Kerimoglu, Ozlem Secilmis; Sakinci, Mehmet; Korkmaz, Cem; Duru, Namik Kemal; Ergun, Ali
2014-04-01
To present our in vitro fertilization outcomes after implementation of the Turkish government policy limiting the number of transferred embryos to one, in women under the age of 35, and two, in women over age 35; and to demonstrate the feasibility of this policy. We retrospectively reviewed the records of 423 patients who underwent ovarian stimulation, oocyte pick-up, intracytoplasmic sperm injection and embryo transfer due to primary or secondary infertility over a 22-month time interval. Clinical pregnancy was defined as a fetal heartbeat in the seventh gestational week. Embryo transfers were carried out on day 3 or 5. Descriptive statistics are given as the number of subjects and percentages. A total of 353 embryo transfers were performed: 261 (73.9%) were single-embryo transfer (244 (69.1%) elective and 17 (4.8%) non-elective) and 92 (26.1%) were double-embryo transfer. Of the 244 elective single-embryo transfers, 6.6% (n=16) were performed using frozen-thawed embryos. The average patient age was 29.6±4.5 years in the single-embryo group and 36.5±2.4 years in the double-embryo group. The cumulative pregnancy rates per oocyte pick-up were similar in both groups: 41% (n=107) in the single-embryo group and 43.4% (n=40) in the double-embryo group (p=0.678). The cumulative live birth rate of the single-embryo group (32.1%) was not statistically different from the double-embryo group (35.8%) (p=0.518). The twin pregnancy rate after single-embro transfer was significantly lower than with double-embryo transfer (2.8% (n=3) vs. 32.5% (n=13); ppregnancies occurred in women 35 years or older who underwent double-embryo transfer. No significant difference in the spontaneous abortion rates was recorded between the single- and double-embryo transfer groups (16 (6.1%) vs. 6 (6.5%); p=0.894). Single-embryo transfer results in a pregnancy rate comparable to double-embryo transfer, with a significantly reduced multiple pregnancy rate. Double-embryo transfer in patients over
A note on families of fragility curves
International Nuclear Information System (INIS)
Kaplan, S.; Bier, V.M.; Bley, D.C.
1989-01-01
In the quantitative assessment of seismic risk, uncertainty in the fragility of a structural component is usually expressed by putting forth a family of fragility curves, with probability serving as the parameter of the family. Commonly, a lognormal shape is used both for the individual curves and for the expression of uncertainty over the family. A so-called composite single curve can also be drawn and used for purposes of approximation. This composite curve is often regarded as equivalent to the mean curve of the family. The equality seems intuitively reasonable, but according to the authors has never been proven. The paper presented proves this equivalence hypothesis mathematically. Moreover, the authors show that this equivalence hypothesis between fragility curves is itself equivalent to an identity property of the standard normal probability curve. Thus, in the course of proving the fragility curve hypothesis, the authors have also proved a rather obscure, but interesting and perhaps previously unrecognized, property of the standard normal curve
2009-01-01
The Universe, is one book in the Britannica Illustrated Science Library Series that is correlated to the science curriculum in grades 5-8. The Britannica Illustrated Science Library is a visually compelling set that covers earth science, life science, and physical science in 16 volumes. Created for ages 10 and up, each volume provides an overview on a subject and thoroughly explains it through detailed and powerful graphics-more than 1,000 per volume-that turn complex subjects into information that students can grasp. Each volume contains a glossary with full definitions for vocabulary help and an index.
2011-01-01
Updated for 2011, the Universe, is one book in the Britannica Illustrated Science Library Series that covers today's most popular science topics, from digital TV to microchips to touchscreens and beyond. Perennial subjects in earth science, life science, and physical science are all explored in detail. Amazing graphics-more than 1,000 per title-combined with concise summaries help students understand complex subjects. Correlated to the science curriculum in grades 5-9, each title also contains a glossary with full definitions for vocabulary.
Chen, Xueping; Zhou, Dandan; Shen, Huawei; Chen, Hui; Feng, Wenli; Xie, Guoming
2016-02-02
Single-nucleotide variation (SNV) is a crucial biomarker for drug resistance-related detection in cancer and bacterial infection. However, the unintended binding of DNA probes limits the specificity of SNV detection, and the need for redesigned sequences compromise the universality of SNV assay. Herein, we demonstrated a universal and low-cost assay for the colorimetric discrimination of drug-resistance related point mutation. By the use of a universal DNA probe and a split G-quadruplex, the signal could be recognized by naked eye at room temperature. The DNA probe was used as a signal reporter which not only improved the universality, but also enabled high specificity of probe hybridization. This assay was successfully applied in the detection of cancer-related SNV in the epidermal growth factor receptor (EGFR) gene, kirsten rat sarcoma viral oncogene homologue (KRAS), and tuberculosis drug-resistance related point mutation in RNA polymerase beta subunit gene (rpoB) with high specificity and visible readout. This method was simple, rapid, high-throughput and effective, which was suitable for point-of-care applications.
Single-Input Six-Output Voltage-Mode Filter Using Universal Voltage Conveyors
Minarcik, Martin; Vrba, Kamil
In this letter a new structure of multifunctional frequency filter using a universal voltage conveyor (UVC) is presented. The multifunctional circuit can realize a low-pass, high-pass and band-pass filter. All types of frequency filter can be realized as inverting or non-inverting. Advantages of the proposed structure are the independent control of the quality factor at the cut-off frequency and the low output impedance of output terminals. The computer simulations and measuring of particular frequency filters are depicted.
Shawl, S.
1996-12-01
The concept of single-sex education for science and mathematics has recently received renewed discussion in both the popular and professional literature. So important is the topic within higher education that the Duke Journal of Gender Law and Policy sponsored a symposium called "Gender & The Higher Education Classroom: Maximizing the Learning Environment" in February 1996 (http://www.duke.edu/ jrd4/djgcnf96.htm). The concept is especially controversial in publicly supported educational institutions. The idea of offering an optional discussion session limited to a single sex in a university-level introductory astronomy course at a State-supported school was considered through discussions with a number of faculty and administrators, and through a questionnaire aimed at determining student attitudes toward the concept. The results of the student questionnaire will be presented. (While the questionnaire results will be seen to be in favor of such an optional discussion session, such sessions have not been offered.)
Study of single- and two-phase fluid transfer between subchannels at Kumamoto University
International Nuclear Information System (INIS)
Sadatomi, Michio
2004-01-01
Firstly, the definitions of turbulent mixing, void drift and diversion cross-flow, which are three components of fluid transfer between subchannels, are given together with the relations of each component with equilibrium or non-equilibrium two-phase subchannel flows. Secondly, measuring techniques of the three components are briefly presented in turn together with typical measurement results. In turbulent mixing measurement, a tracer injection method has been adopted at Kumamoto University, while an isokinetic discharge method for both void drift an diversion cross-flow measurements. In the experiment of hydraulically non-equilibrium flow with both void drift and/or diversion cross-flow, experimental data on flow redistribution process have been obtained. The data include the axial variations of gas and liquid flow rates and void fraction in each subchannel and pressure difference between the subchannels. After analyzing these variations, some correlations on the void drift and the diversion cross-flow are obtained. Finally, a subchannel analysis code used at Kumamoto University is presented together with the results of its validation test against the experimental data on flow redistribution process mentioned above. The code is based on a two-phase two-fluid model, and is applicable to adiabatic two-phase flows under steady state condition. Basic equations in the code are the conservation equations of mass, axial momentum and lateral momentum, while the constitutive equations include the correlations of void diffusion coefficient, both interfacial and wall friction coefficients for the cross-flow, etc. (author)
Zemánek, Ivan; Havlíček, Václav
2006-09-01
A new universal control and measuring system for classic and amorphous soft magnetic materials single/on-line strip testing has been developed at the Czech Technical University in Prague. The measuring system allows to measure magnetization characteristic and specific power losses of different tested materials (strips) at AC magnetization of arbitrary magnetic flux density waveform at wide range of frequencies 20 Hz-20 kHz. The measuring system can be used for both single strip testing in laboratories and on-line strip testing during the production process. The measuring system is controlled by two-stage master-slave control system consisting of the external PC (master) completed by three special A/D measuring plug-in boards, and local executing control unit (slave) with one-chip microprocessor 8051, connected with PC by the RS232 serial line. The "user friendly" powerful control software implemented on the PC and the effective program code for the microprocessor give possibility for full automatic measurement with high measuring power and high measuring accuracy.
Mills, Dawn M; Martin, Christopher P; Armas, Stephanie M; Calvo-Marzal, Percy; Kolpashchikov, Dmitry M; Chumbimuni-Torres, Karin Y
2018-06-30
We report a label-free universal biosensing platform for highly selective detection of long nucleic acid strands. The sensor consists of an electrode-immobilized universal stem-loop (USL) probe and two adaptor strands that form a 4J structure in the presence of a specific DNA/RNA analyte. The sensor was characterized by electrochemical impedance spectroscopy (EIS) using K 3 [Fe(CN) 6 ]/K 4 [Fe(CN) 6 ] redox couple in solution. An increase in charge transfer resistance (R CT ) was observed upon 4J structure formation, the value of which depends on the analyte length. Cyclic voltammetry (CV) was used to further characterize the sensor and monitor the electrochemical reaction in conjunction with thickness measurements of the mixed DNA monolayer obtained using spectroscopic ellipsometry. In addition, the electron transfer was calculated at the electrode/electrolyte interface using a rotating disk electrode. Limits of detection in the femtomolar range were achieved for nucleic acid targets of different lengths (22 nt, 60 nt, 200 nt). The sensor produced only a background signal in the presence of single base mismatched analytes, even in hundred times excess in concentration. This label-free and highly selective biosensing platform is versatile and can be used for universal detection of nucleic acids of varied lengths which could revolutionize point of care diagnostics for applications such as bacterial or cancer screening. Copyright © 2018 Elsevier B.V. All rights reserved.
Multiphasic growth curve analysis.
Koops, W.J.
1986-01-01
Application of a multiphasic growth curve is demonstrated with 4 data sets, adopted from literature. The growth curve used is a summation of n logistic growth functions. Human height growth curves of this type are known as "double logistic" (n = 2) and "triple logistic" (n = 3) growth curves (Bock
Universal route to optimal few- to single-cycle pulse generation in hollow-core fiber compressors.
Conejero Jarque, E; San Roman, J; Silva, F; Romero, R; Holgado, W; Gonzalez-Galicia, M A; Alonso, B; Sola, I J; Crespo, H
2018-02-02
Gas-filled hollow-core fiber (HCF) pulse post-compressors generating few- to single-cycle pulses are a key enabling tool for attosecond science and ultrafast spectroscopy. Achieving optimum performance in this regime can be extremely challenging due to the ultra-broad bandwidth of the pulses and the need of an adequate temporal diagnostic. These difficulties have hindered the full exploitation of HCF post-compressors, namely the generation of stable and high-quality near-Fourier-transform-limited pulses. Here we show that, independently of conditions such as the type of gas or the laser system used, there is a universal route to obtain the shortest stable output pulse down to the single-cycle regime. Numerical simulations and experimental measurements performed with the dispersion-scan technique reveal that, in quite general conditions, post-compressed pulses exhibit a residual third-order dispersion intrinsic to optimum nonlinear propagation within the fiber, in agreement with measurements independently performed in several laboratories around the world. The understanding of this effect and its adequate correction, e.g. using simple transparent optical media, enables achieving high-quality post-compressed pulses with only minor changes in existing setups. These optimized sources have impact in many fields of science and technology and should enable new and exciting applications in the few- to single-cycle pulse regime.
Energy Technology Data Exchange (ETDEWEB)
Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.
1992-09-01
The coolant in the Savannah River Site (SRS) production nuclear reactor assemblies is circulated as a subcooled liquid under normal operating conditions. This coolant is evenly distributed throughout multiple annular flow channels with a uniform pressure profile across each coolant flow channel. During the postulated Loss of Coolant Accident (LOCA), which is initiated by a hypothetical guillotine pipe break, the coolant flow through the reactor assemblies is significantly reduced. The flow reduction and accompanying power reduction (after shutdown is initiated) occur in the first 1 to 2 seconds of the LOCA. This portion of the LOCA is referred to as the Flow Instability phase. This report presents the experimental results for the transient portion of the single annulus test program. The test program was designed to investigate the onset of flow instability in an annular geometry similar to the MARK 22 reactor. The test program involved testing of both a ribless heater and a ribbed heater under steady state as well as transient conditions. The ribbed heater testing is currently underway and will be reported separately. The steady state portion of this test program with ribless heater was completed and reported in report No. CU-HTRF-T3A. The present report presents transient test results obtained from a ribless, uniform annulus test section. A total of thirty five transients were conducted with six cases in which flow excursion occurred. No unstable conditions resulted for tests in which the steady state Q{sub ratio} OFI limit was not exceeded.
Energy Technology Data Exchange (ETDEWEB)
Nakayasu, Ernesto S.; Nicora, Carrie D.; Sims, Amy C.; Burnum-Johnson, Kristin E.; Kim, Young-Mo; Kyle, Jennifer E.; Matzke, Melissa M.; Shukla, Anil K.; Chu, Rosalie K.; Schepmoes, Athena A.; Jacobs, Jon M.; Baric, Ralph S.; Webb-Robertson, Bobbie-Jo; Smith, Richard D.; Metz, Thomas O.; Chia, Nicholas
2016-05-03
Integrative multi-omics analyses can empower more effective investigation and complete understanding of complex biological systems. Despite recent advances in a range of omics analyses, multi-omic measurements of the same sample are still challenging and current methods have not been well evaluated in terms of reproducibility and broad applicability. Here we adapted a solvent-based method, widely applied for extracting lipids and metabolites, to add proteomics to mass spectrometry-based multi-omics measurements. The
Directory of Open Access Journals (Sweden)
Miriam Raquel Diniz Zanetti
Full Text Available CONTEXT AND OBJECTIVE: Several risk factors are involved in perineal lacerations during vaginal delivery. However, little is known about the influence of perineal distensibility as a protective factor. The aim here was to determine a cutoff value for pelvic floor distensibility measured using the Epi-no balloon, which could be used as a predictive factor for perineal integrity in vaginal delivery. DESIGN AND SETTING: Prospective observational single cohort study conducted in a maternity hospital. METHODS: A convenience sample of 227 consecutive at-term parturients was used. All women had a single fetus in the vertex presentation, with up to 9.0 cm of dilation. The maximum dilation of the Epi-no balloon was measured using a tape measure after it had been inflated inside the vagina up to the parturients' maximum tolerance. The receiver operating characteristic (ROC curve was used to obtain the Epi-no circumference measurement with best sensitivity and specificity. RESULTS: Among the 161 patients who were included in the study, 50.9% underwent episiotomy, 21.8% presented lacerations and 27.3% retained an intact perineum. Age > 25.9 years; number of pregnancies > 3.4; number of deliveries > 2.2 and circumference measured by Epi-no > 21.4 cm were all directly correlated with an intact perineum. Circumference measurements using the Epi-no balloon that were greater than 20.8 cm showed sensitivity and specificity of 70.5% and 66.7% (area under curve = 0.713, respectively, as a predictive factor for an intact perineum in vaginal delivery. CONCLUSION: Circumferences greater than 20.8 cm achieved using the Epi-no balloon are a predictive factor for perineal integrity in parturients.
LENUS (Irish Health Repository)
Forde, Dónall
2009-01-01
BACKGROUND: Warfarin is an oral anticoagulant (OAT) that needs active management to ensure therapeutic range. Initial management is often carried out as an inpatient, though not requiring inpatient facilities. This mismatch results in financial costs which could be directed more efficaciously. The extent of this has previously been unknown. Here we aim to calculate the potential number of bed nights which may be saved among those being dose optimized as inpatients and examine associated factors. METHODS: A 6 week prospective audit of inpatients receiving OAT, at Cork University Hospital, was carried out. The study period was from 11th June 2007 to 20th July 2007. Data was collected from patient\\'s medications prescription charts, medical record files, and computerised haematology laboratory records. The indications for OAT, the patient laboratory coagulation results and therapeutic intervals along with patient demographics were analysed. The level of potentially avoidable inpatient nights in those receiving OAT in hospital was calculated and the potential cost savings quantified. Potential avoidable bed nights were defined as patients remaining in hospital for the purpose of optimizing OAT dosage, while receiving subtherapeutic or therapeutic OAT (being titred up to therapeutic levels) and co-administered covering low molecular weight heparin, and requiring no other active care. The average cost of euro638 was taken as the per night hospital stay cost for a non-Intensive Care bed. Ethical approval was granted from the Ethical Committee of the Cork Teaching Hospitals, Cork, Ireland. RESULTS: A total of 158 patients were included in the audit. There was 94 men (59.4%) and 64 women (40.6%). The mean age was 67.8 years, with a median age of 70 years.Atrial Fibrillation (43%, n = 70), followed by aortic valve replacement (15%, n = 23) and pulmonary emboli (11%, n = 18) were the commonest reasons for prescribing OAT. 54% had previously been prescribed OAT prior to
Thompson, James E; Egger, Sam; Böhm, Maret; Haynes, Anne-Maree; Matthews, Jayne; Rasiah, Krishan; Stricker, Phillip D
2014-03-01
Comparative studies suggest functional and perioperative superiority of robot-assisted radical prostatectomy (RARP) over open radical prostatectomy (ORP). To determine whether high-volume experienced open surgeons can improve their functional and oncologic outcomes with RARP and, if so, how many cases are required to surpass ORP outcomes and reach the learning curve plateau. A prospective observational study compared two surgical techniques: 1552 consecutive men underwent RARP (866) or ORP (686) at a single Australian hospital from 2006 to 2012, by one surgeon with 3000 prior ORPs. Demographic and clinicopathologic data were collected prospectively. The Expanded Prostate Cancer Index Composite quality of life (QoL) questionnaire was administered at baseline, 1.5, 3, 6, 12, and 24 mo. Multivariate linear and logistic regression modelled the difference in QoL domains and positive surgical margin (PSM) odds ratio (OR), respectively, against case number. A total of 1511 men were included in the PSM and 609 in the QoL analysis. RARP sexual function scores surpassed ORP scores after 99 RARPs and increased to a mean difference at 861st case of 11.0 points (95% confidence interval [CI], 5.9-16.1), plateauing around 600-700 RARPs. Early urinary incontinence scores for RARP surpassed ORP after 182 RARPs and increased to a mean difference of 8.4 points (95% CI, 2.1-14.7), plateauing around 700-800 RARPs. The odds of a pT2 PSM were initially higher for RARP but became lower after 108 RARPs and were 55% lower (OR: 0.45; 95% CI, 0.22-0.92) by the 866th RARP. The odds of a pT3/4 PSM were initially higher for RARP but decreased, plateauing around 200-300 RARPs with an OR of 1.15 (0.68-1.95) at the 866th RARP. Limitations include single-surgeon data and residual confounding. RARP had a long learning curve with inferior outcomes initially, and then showed progressively superior sexual, early urinary, and pT2 PSM outcomes and similar pT3 PSM and late urinary outcomes. Learning RARP
Thacher, Pamela V
2008-01-01
This study evaluated the self-reported patterns, motivations, and correlates of engagement in a single night of total sleep deprivation (SN-TSD) in a sample of 120 university students at a 4-year liberal arts college. Participants' mean age . was 20.1 years; the sample was 63% female. Measures included the Owl-Lark Scale of circadian preference; the Beck Depression Inventory; and the Pittsburgh Sleep Quality Index (PSQI); as well as self-reported usual bedtime, rise time, and total sleep time. Students' cumulative grade point averages (GPAs) were also obtained; these were reported from the university registrar. Sixty percent of students surveyed reported engaging in SN-TSD once or more since coming to college. No differences between genders or among class standing with respect to use of SN-TSD were detected. Engagement in SN-TSD was associated with later self-reported bedtimes, evening preference, and poorer academic achievement as measured by GPA. A trend for increased symptoms of depression was detected; sleep quality as measured by the PSQI was not related to engagement in SN-TSD.
Lozano-Quijada, Carlos; Poveda-Pagán, Emilio J; Segura-Heras, José V; Hernández-Sánchez, Sergio; Prieto-Castelló, María J
2017-09-01
The purpose of this study was to assess the effectiveness of a single session of global postural reeducation (GPR) in postural sway in young adult university students who use data visualization screens. A randomized controlled trial with 2 parallel groups was performed. Sixty-four subjects were randomized in the experimental group (12 men and 20 women) who underwent the GPR session, and a control group (13 men and 19 women) that did not receive any intervention was included. Center of pressure (COP) was assessed using a stabilometric platform, with eyes open and eyes closed before, immediately after, 48 hours after, and 7 days after intervention in both groups. In the interaction of time and gender, statistically significant differences were found for the area covered by COP (P = .020) and for the standard deviation (SD) in the mediolateral axis (P = .035). Considering the complete interaction time, gender, and group, statistically significant differences were found (P = .015) for the anteroposterior rate covered by COP and the SD in the anteroposterior axis (P = .033). In eyes closed condition, the intersubject analysis showed statistically significant differences for the interaction between group and gender for the variable mediolateral SD (P = .043). Considering the interaction of time with group, statistically significant differences were found for full length covered by COP (P = .017). Changes in postural sway were observed after a single GPR session, mainly at 48 hours, with different behaviors between men and women. Copyright © 2017. Published by Elsevier Inc.
Directory of Open Access Journals (Sweden)
Janusz Charatonik
1991-11-01
Full Text Available Results concerning contractibility of curves (equivalently: of dendroids are collected and discussed in the paper. Interrelations tetween various conditions which are either sufficient or necessary for a curve to be contractible are studied.
Thompson, James E; Egger, Sam; Böhm, Maret; Siriwardana, Amila R; Haynes, Anne-Maree; Matthews, Jayne; Scheltema, Matthijs J; Stricker, Phillip D
2017-12-19
Our earlier analysis suggested that robot-assisted radical prostatectomy (RARP) achieved superiority over open radical prostatectomy (ORP) in terms of positive surgical margin (PSM) rates and functional outcomes. With larger sample size and longer follow-up, the objective of this study update is to assess whether our previous findings are upheld and whether the improved PSM rates for RARP after an initial learning curve compared with ORP-as observed in our earlier analysis-ultimately resulted in improved biochemical control. Prospective observational study comparing two surgical techniques; 2271 consecutive men underwent RARP (1520) or ORP (751) at a single centre from 2006 to 2016. Demographic and clinicopathological data were prospectively collected. The EPIC-QOL questionnaire was administered at baseline and 1.5, 3, 6, 12, and 24 mo. Multivariate linear regression modelled the difference in quality of life (QOL) domains against case number; logistic and Cox regression modelled the differences in PSM and biochemical recurrence (BCR) hazard ratios (HR), respectively. A total of 2206 men were included in BCR/PSM analysis and 1045 consented for QOL analysis. Superior pT2 surgical margins, early and late sexual outcomes, and early urinary outcomes were upheld and became more robust (narrowing of 95% confidence intervals [CIs]). The risk of BCR was initially higher for RARP, improved after 191 RARPs, and was 35% lower (hazard ratio [HR] 0.65, 95% CI 0.47-0.90) at final RARP, plateauing after 226 RARPs. Improved late (12-24 mo) urinary bother scores (adjusted mean difference [AMD]=4.7, 95% CI 1.3-8.0) and irritative-obstructive scores (AMD=3.8, 95% CI 0.9-5.6) at final RARP were demonstrated. Limitations include observational single surgeon data, possible residual confounding, and short follow-up. The results from this updated analysis demonstrate that RARP can be beneficial for patients of high-volume surgeons, although more randomised studies and studies with
Indian Academy of Sciences (India)
In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the Hilbert curve approximately is given. 1. Introduction. A 'continuous curve' in the plane is usually defined as the path traced by a moving point (x (t), Y (t)) as t runs over an interval of the real line, ...
Indian Academy of Sciences (India)
Institute, Calcutta. Apart from mathematics, he likes painting and reading. Unlike most others he dislikes computers. Ritabrata Munshi. Introduction. In this two-part article we will consider one of the classi- cal theorems of mathematics, the Jordan curve theorem. It states that a simple closed curve (i.e., a closed curve which.
DEFF Research Database (Denmark)
Bernstein, Daniel J.; Birkner, Peter; Lange, Tanja
2013-01-01
This paper introduces EECM-MPFQ, a fast implementation of the elliptic-curve method of factoring integers. EECM-MPFQ uses fewer modular multiplications than the well-known GMP-ECM software, takes less time than GMP-ECM, and finds more primes than GMP-ECM. The main improvements above the modular......-arithmetic level are as follows: (1) use Edwards curves instead of Montgomery curves; (2) use extended Edwards coordinates; (3) use signed-sliding-window addition-subtraction chains; (4) batch primes to increase the window size; (5) choose curves with small parameters and base points; (6) choose curves with large...
Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD
Directory of Open Access Journals (Sweden)
Ackermann Martin
2011-05-01
Full Text Available Abstract Background The essential Escherichia coli gene ygjD belongs to a universally conserved group of genes whose function has been the focus of a number of recent studies. Here, we put ygjD under control of an inducible promoter, and used time-lapse microscopy and single cell analysis to investigate the phenotypic consequences of the depletion of YgjD protein from growing cells. Results We show that loss of YgjD leads to a marked decrease in cell size and termination of cell division. The transition towards smaller size occurs in a controlled manner: cell elongation and cell division remain coupled, but cell size at division decreases. We also find evidence that depletion of YgjD leads to the synthesis of the intracellular signaling molecule (pppGpp, inducing a cellular reaction resembling the stringent response. Concomitant deletion of the relA and spoT genes - leading to a strain that is uncapable of synthesizing (pppGpp - abrogates the decrease in cell size, but does not prevent termination of cell division upon YgjD depletion. Conclusions Depletion of YgjD protein from growing cells leads to a decrease in cell size that is contingent on (pppGpp, and to a termination of cell division. The combination of single-cell timelapse microscopy and statistical analysis can give detailed insights into the phenotypic consequences of the loss of essential genes, and can thus serve as a new tool to study the function of essential genes.
Functional dynamic factor models with application to yield curve forecasting
Hays, Spencer
2012-09-01
Accurate forecasting of zero coupon bond yields for a continuum of maturities is paramount to bond portfolio management and derivative security pricing. Yet a universal model for yield curve forecasting has been elusive, and prior attempts often resulted in a trade-off between goodness of fit and consistency with economic theory. To address this, herein we propose a novel formulation which connects the dynamic factor model (DFM) framework with concepts from functional data analysis: a DFM with functional factor loading curves. This results in a model capable of forecasting functional time series. Further, in the yield curve context we show that the model retains economic interpretation. Model estimation is achieved through an expectation- maximization algorithm, where the time series parameters and factor loading curves are simultaneously estimated in a single step. Efficient computing is implemented and a data-driven smoothing parameter is nicely incorporated. We show that our model performs very well on forecasting actual yield data compared with existing approaches, especially in regard to profit-based assessment for an innovative trading exercise. We further illustrate the viability of our model to applications outside of yield forecasting.
Archaeomagnetic SV curve for Belgium
Ech-chakrouni, Souad; Hus, Jozef
2017-04-01
Archaeomagnetic secular variation curves have been established for different countries in Europe, especially when different archeological sites are more or less uniformly distributed in time are available. The disadvantage in that case is that data had to be relocated to a single reference site. The proximity of the reference locality Paris to Belgium makes that we used the French archaeomagnetic SV curve for the last three millennia up to the present for archaeomagnetic dating undated baked structures. In total, 85 baked structures have been examined, unearthed in 24 archaeological sites of the territory of Belgium. The ChRM of each sample was obtained by principal component analysis for at least three demagnetisation steps (Kirschvink 1980). Except for some outliers, the ChRM directions are very coherent with a high confidence factor (α95archaeomagnetism. At present, only six baked structures were dated radiometrically and may be considered as reference data for a limited area about 30500 km2 in Western Europe. The ultimate aim is to construct an archaeomagnetic SV curve for Belgium with Uccle as reference locality, where the first measurement of the geomagnetic field was done in 1895. This curve would include all the available reference data in a radius of about 500 km around Uccle. Keywords: secular variation, archaeomagnetic dating, Belgium.
Indian Academy of Sciences (India)
mathematics and computer applications for the last 20 years. He has been a National Science. Talent awardee of. NCERT in mathematics. GENERAL I ARTICLE. Space-filling Curves. ReMittal. In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the ...
Simulating Supernova Light Curves
Energy Technology Data Exchange (ETDEWEB)
Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-05-05
This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.
Tempo curves considered harmful
Desain, P.; Honing, H.
1993-01-01
In the literature of musicology, computer music research and the psychology of music, timing or tempo measurements are mostly presented in the form of continuous curves. The notion of these tempo curves is dangerous, despite its widespread use, because it lulls its users into the false impression
DEFF Research Database (Denmark)
Federici, Paolo; Georgieva Yankova, Ginka
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to a draft of IEC 61400-12-1 Ed.2.......The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to a draft of IEC 61400-12-1 Ed.2....
GEOMETRIC PROGRESSIONS ON ELLIPTIC CURVES.
Ciss, Abdoul Aziz; Moody, Dustin
2017-01-01
In this paper, we look at long geometric progressions on different model of elliptic curves, namely Weierstrass curves, Edwards and twisted Edwards curves, Huff curves and general quartics curves. By a geometric progression on an elliptic curve, we mean the existence of rational points on the curve whose x -coordinate (or y -coordinate) are in geometric progression. We find infinite families of twisted Edwards curves and Huff curves with geometric progressions of length 5, an infinite family of Weierstrass curves with 8 term progressions, as well as infinite families of quartic curves containing 10-term geometric progressions.
On the Quaternionic Focal Curves
Directory of Open Access Journals (Sweden)
Nurten (BAYRAK GÜRSES
2017-06-01
Full Text Available In this study, a brief summary about quaternions and quaternionic curves are firstly presented. Also, the definition of focal curve is given. The focal curve of a smooth curve consists of the centers of its osculating hypersphere. By using this definition and the quaternionic osculating hyperspheres of these curves, the quaternionic focal curves in the spaces $\\Q$ and $\\Q_\
Directory of Open Access Journals (Sweden)
Paulo Prochno
2004-07-01
Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.
Energy Technology Data Exchange (ETDEWEB)
Thanh, Tran Dang, E-mail: thanhxraylab@yahoo.com [Institute of Materials Science, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi (Viet Nam); Manh, T.V.; Ho, T.A. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Telegin, Andrey [Department of Magnetic Semiconductors, Institute of Metal Physics, RAS (Russian Federation); Phan, T.L. [Department of Physics and Oxide Research Center, Hankuk University of Foreign Studies, Yongin 449-791 (Korea, Republic of); Yu, S.C., E-mail: scyu@chungbuk.ac.kr [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
2016-04-01
In this paper, we present a detailed analysis on temperature and magnetic field dependences of the magnetic entropy change (ΔS{sub m}) near the ferromagnetic (FM)–paramagnetic (PM) phase transition of a La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} single crystal. Experimental results reveal the material exhibiting a FM–PM phase transition at T{sub C}=85 K, and belongs to a second-order phase transition (SOPT). Around T{sub C}, −ΔS{sub m} reaches the maximum value (|ΔS{sub max}|), which increases with increasing an applied magnetic field change, ΔH. The |ΔS{sub max}| values found are about 0.93, 1.73, 2.38, 2.91, and 3.33 J kg{sup −1} K{sup −1} for ΔH=10, 20, 30, 40, and 50 kOe, respectively. However, the peak position of the −ΔS{sub m}(T) curves is effectively shifted to higher temperatures when ΔH increases. Additionally, the ΔS{sub m}(T) curves measured at different ΔH values do not collapse into a universal curve when they are normalized to their respective ΔS{sub max} value, and Prod. Type: rescaled the temperature axis with θ{sub 1}=(T−T{sub C})/(T{sub r}−T{sub C}) for a reference temperature T{sub r}>T{sub C} or T{sub r}
U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation. This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...
Directory of Open Access Journals (Sweden)
Kožul Nataša
2014-01-01
Full Text Available In the broadest sense, yield curve indicates the market's view of the evolution of interest rates over time. However, given that cost of borrowing it closely linked to creditworthiness (ability to repay, different yield curves will apply to different currencies, market sectors, or even individual issuers. As government borrowing is indicative of interest rate levels available to other market players in a particular country, and considering that bond issuance still remains the dominant form of sovereign debt, this paper describes yield curve construction using bonds. The relationship between zero-coupon yield, par yield and yield to maturity is given and their usage in determining curve discount factors is described. Their usage in deriving forward rates and pricing related derivative instruments is also discussed.
Indian Academy of Sciences (India)
We had defined when an arc is said to cross a circle. We broaden the definition of crossing as follows: Definition: Suppose f is a piece-wise circular simple closed curve and, is a piece-wise circular arc. Suppose ..... curve formed by p' pp", q' qq", part of r between p' and q' and part of r between pI! and q", as shown (Figures 6 ...
DEFF Research Database (Denmark)
Georgieva Yankova, Ginka; Federici, Paolo
This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2.......This report describes power curve measurements carried out on a given turbine in a chosen period. The measurements are carried out in accordance to IEC 61400-12-1 Ed. 1 and FGW Teil 2....
Polar representation of centrifugal pump homologous curves
International Nuclear Information System (INIS)
Veloso, Marcelo Antonio; Mattos, Joao Roberto Loureiro de
2008-01-01
Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic parameters: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. Any one of these quantities can be expressed as a function of any two others. The curves showing the relationships between these four variables are called the pump characteristic curves, also referred to as four-quadrant curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, the four-quadrant configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the polar form appears as the simplest way to represent the homologous curves. In the polar method, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a
Heterozygote PCR product melting curve prediction.
Dwight, Zachary L; Palais, Robert; Kent, Jana; Wittwer, Carl T
2014-03-01
Melting curve prediction of PCR products is limited to perfectly complementary strands. Multiple domains are calculated by recursive nearest neighbor thermodynamics. However, the melting curve of an amplicon containing a heterozygous single-nucleotide variant (SNV) after PCR is the composite of four duplexes: two matched homoduplexes and two mismatched heteroduplexes. To better predict the shape of composite heterozygote melting curves, 52 experimental curves were compared with brute force in silico predictions varying two parameters simultaneously: the relative contribution of heteroduplex products and an ionic scaling factor for mismatched tetrads. Heteroduplex products contributed 25.7 ± 6.7% to the composite melting curve, varying from 23%-28% for different SNV classes. The effect of ions on mismatch tetrads scaled to 76%-96% of normal (depending on SNV class) and averaged 88 ± 16.4%. Based on uMelt (www.dna.utah.edu/umelt/umelt.html) with an expanded nearest neighbor thermodynamic set that includes mismatched base pairs, uMelt HETS calculates helicity as a function of temperature for homoduplex and heteroduplex products, as well as the composite curve expected from heterozygotes. It is an interactive Web tool for efficient genotyping design, heterozygote melting curve prediction, and quality control of melting curve experiments. The application was developed in Actionscript and can be found online at http://www.dna.utah.edu/hets/. © 2013 WILEY PERIODICALS, INC.
DEFF Research Database (Denmark)
Gómez Arranz, Paula; Vesth, Allan
This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere......This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here......, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...
Algebraic curves and cryptography
Murty, V Kumar
2010-01-01
It is by now a well-known paradigm that public-key cryptosystems can be built using finite Abelian groups and that algebraic geometry provides a supply of such groups through Abelian varieties over finite fields. Of special interest are the Abelian varieties that are Jacobians of algebraic curves. All of the articles in this volume are centered on the theme of point counting and explicit arithmetic on the Jacobians of curves over finite fields. The topics covered include Schoof's \\ell-adic point counting algorithm, the p-adic algorithms of Kedlaya and Denef-Vercauteren, explicit arithmetic on
Complementary curves of descent
Mungan, Carl E.; Lipscombe, Trevor C.
2013-01-01
The shapes of two wires in a vertical plane with the same starting and ending points are described as complementary curves of descent if beads frictionlessly slide down both of them in the same time, starting from rest. Every analytic curve has a unique complement, except for a cycloid (solution of the brachistochrone problem), which is self complementary. A striking example is a straight wire whose complement is a lemniscate of Bernoulli. Alternatively, the wires can be tracks down which round objects undergo a rolling race. The level of presentation is appropriate for an intermediate undergraduate course in classical mechanics.
Parametric representation of centrifugal pump homologous curves
International Nuclear Information System (INIS)
Veloso, Marcelo A.; Mattos, Joao R.L. de
2015-01-01
Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)
Parametric representation of centrifugal pump homologous curves
Energy Technology Data Exchange (ETDEWEB)
Veloso, Marcelo A.; Mattos, Joao R.L. de, E-mail: velosom@cdtn.br, E-mail: jrmattos@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)
2015-07-01
Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)
Groot, L.F.M.|info:eu-repo/dai/nl/073642398
2008-01-01
The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across
Paulton, Richard J. L.
1991-01-01
A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)
DEFF Research Database (Denmark)
Kock, Carsten Weber; Vesth, Allan
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....
DEFF Research Database (Denmark)
Federici, Paolo; Kock, Carsten Weber
This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...
DEFF Research Database (Denmark)
Gómez Arranz, Paula; Villanueva, Héctor
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...
DEFF Research Database (Denmark)
Gómez Arranz, Paula; Kock, Carsten Weber
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....
DEFF Research Database (Denmark)
Georgieva Yankova, Ginka; Villanueva, Héctor
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present anal...
DEFF Research Database (Denmark)
Villanueva, Héctor; Vesth, Allan
This report describes the power curve measurements carried out on a given wind turbine in a chosen period. The measurements were carried out following the measurement procedure in the draft of IEC 61400-12-1 Ed.2 [1], with some deviations mostly regarding uncertainty calculation. Here, the refere...
DEFF Research Database (Denmark)
Gómez Arranz, Paula; Villanueva, Héctor
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present anal...
Textbook Factor Demand Curves.
Davis, Joe C.
1994-01-01
Maintains that teachers and textbook graphics follow the same basic pattern in illustrating changes in demand curves when product prices increase. Asserts that the use of computer graphics will enable teachers to be more precise in their graphic presentation of price elasticity. (CFR)
DEFF Research Database (Denmark)
Vesth, Allan; Kock, Carsten Weber
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine....
DEFF Research Database (Denmark)
Villanueva, Héctor; Gómez Arranz, Paula
, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...
Power Curve Measurements, REWS
DEFF Research Database (Denmark)
Villanueva, Héctor; Gómez Arranz, Paula
, the reference wind speed used in the power curve is the equivalent wind speed obtained from lidar measurements at several heights between lower and upper blade tip, in combination with a hub height meteorological mast. The measurements have been performed using DTU’s measurement equipment, the analysis...
DEFF Research Database (Denmark)
Federici, Paolo; Kock, Carsten Weber
The report describes power curve measurements carried out on a given wind turbine. The measurements are carried out in accordance to Ref. [1]. A site calibration has been carried out; see Ref. [2], and the measured flow correction factors for different wind directions are used in the present...... analyze of power performance of the turbine...
DEFF Research Database (Denmark)
Gómez Arranz, Paula; Wagner, Rozenn
This report describes the power curve measurements performed with a nacelle LIDAR on a given wind turbine in a wind farm and during a chosen measurement period. The measurements and analysis are carried out in accordance to the guidelines in the procedure “DTU Wind Energy-E-0019” [1]. The reporting...
2012-10-23
.... Statutory Authority: Section 105 of the Child Abuse Prevention and Treatment Act, as amended (42 U.S.C... Abuse & Neglect AGENCY: Children's Bureau, ACF, HHS. ACTION: Announcement of the award of a single... Treatment of Child Abuse & Neglect. SUMMARY: The Administration for Children and Families, Administration on...
MulensModel: Microlensing light curves modeling
Poleski, Radoslaw; Yee, Jennifer
2018-03-01
MulensModel calculates light curves of microlensing events. Both single and binary lens events are modeled and various higher-order effects can be included: extended source (with limb-darkening), annual microlensing parallax, and satellite microlensing parallax. The code is object-oriented and written in Python3, and requires AstroPy (ascl:1304.002).
Approximation by planar elastic curves
DEFF Research Database (Denmark)
Brander, David; Gravesen, Jens; Nørbjerg, Toke Bjerge
2016-01-01
We give an algorithm for approximating a given plane curve segment by a planar elastic curve. The method depends on an analytic representation of the space of elastic curve segments, together with a geometric method for obtaining a good initial guess for the approximating curve. A gradient-driven...
DEFF Research Database (Denmark)
Villanueva, Héctor; Gómez Arranz, Paula
This report describes the analysis carried out with data from a given turbine in a wind farm and a chosen period. The purpose of the analysis is to correlate the power output of the wind turbine to the wind speed measured by a nacelle-mounted anemometer. The measurements and analysis are not perf......This report describes the analysis carried out with data from a given turbine in a wind farm and a chosen period. The purpose of the analysis is to correlate the power output of the wind turbine to the wind speed measured by a nacelle-mounted anemometer. The measurements and analysis...... are not performed according to IEC 61400-12-1 [1]. Therefore, the results presented in this report cannot be considered a power curve according to the reference standard, and are referred to as “power curve investigation” instead. The measurements have been performed by a customer and the data analysis has been...
Directory of Open Access Journals (Sweden)
Iram Ansari
2012-01-01
Full Text Available Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth. Dilaceration can be seen in both the permanent and deciduous dentitions, and is more commonly found in posterior teeth and in maxilla. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations. The controlled regularly tapered preparation of the curved canals is the ultimate challenge in endodontics. Careful and meticulous technique will yield a safe and sufficient enlargement of the curved canals. This article gives a review of the literature and three interesting case reports of root dilacerations.
Kronberg, Max; Soomro, Muhammad Afzal; Top, Jaap
2017-10-01
In this note we extend the theory of twists of elliptic curves as presented in various standard texts for characteristic not equal to two or three to the remaining characteristics. For this, we make explicit use of the correspondence between the twists and the Galois cohomology set H^1\\big({G}_{\\overline{K}/K}, \\operatorname{Aut}_{\\overline{K}}(E)\\big). The results are illustrated by examples.
Transvaginal cholecystectomy learning curve.
Wood, Stephanie G; Dai, Feng; Dabu-Bondoc, Susan; Mikhael, Hosni; Vadivelu, Nalini; Duffy, Andrew; Roberts, Kurt E
2015-07-01
There are few surgeons in the United States, within private practice and academic centers, currently performing transvaginal cholecystectomies (TVC). The lack of exposure to TVC during residency or fellowship training, coupled with a poorly defined learning curve, further limits interested surgeons who want to apply this technique to their practice. This study describes the learning curve encountered during the introduction of TVC to our academic facility. This study is an analysis of consecutive TVCs performed between August 14, 2009 and August 3, 2012 at an academic center. The TVC patients were divided into sequential quartiles (n = 15/16). The learning curve outcome was measured as the operative time of TVC patients and compared to the operative time of female laparoscopic cholecystectomy (LC) patients performed during the same time period. Sixty-one patients underwent a TVC with a mean age of 38 ± 12 years and mean BMI was 29 ± 6 kg/m(2). Sixty-seven female patients who underwent a LC with average age 41 ± 15 years and average BMI 33 ± 12 kg/m(2). The average operative time of LC patients and TVC patients was 48 ± 20 and 60 ± 17 min, respectively. Significant improvement in TVC operative times was seen between the first (n = 15 TVCs) and second quartiles (p = 0.04) and stayed relatively constant for third quartile, during which there was no statistically significant difference between the mean LC operative time for the second and third TVC quartiles The learning curve of a fellowship-trained surgeon introducing TVC to their surgical repertoire, as measured by improved operative times, can be achieved with approximately 15 cases.
Pelce, Pierre
1989-01-01
In recent years, much progress has been made in the understanding of interface dynamics of various systems: hydrodynamics, crystal growth, chemical reactions, and combustion. Dynamics of Curved Fronts is an important contribution to this field and will be an indispensable reference work for researchers and graduate students in physics, applied mathematics, and chemical engineering. The book consist of a 100 page introduction by the editor and 33 seminal articles from various disciplines.
Vo, Martin
2017-08-01
Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio). Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.
Hammer, A
2017-11-01
It was 140 years ago that George von Meyer presented his anatomical diagrams of human bones to a meeting in Zurich. There he was told by Prof. Karl Culmann that the trabecular lines shown within the diagram of the upper femur closely resembled those lines of force which Culmann had determined with Graphic Statics to be passing through a curved, loaded Fairbairn crane. This drew the attention of Julius Wolff, who used this as the basis for his 'Trajectorial theory' which was widely accepted and, to date, has been the underlying basis for all biomechanical investigations of this region. Following Wolff and Culmann, the upper femur is considered to be a curved structure and is investigated as such. Unfortunately, this concept is wrong. The upper femur is not curved but is angular. It is formed by the junction of two straight bones, the femoral neck and the femoral shaft, as may be simply seen as the neck/shaft angle constructed on the antero-posterior radiograph of any normal femur. The internal trabecular bone forms only part of the load bearing structure of the femoral neck. The configuration of this trabecular substance in this region suggests that it is related specifically to the force present during flexion and extension movements of the hip joint. This being so, combined with the delayed timing of the appearance of the trabecular columns, it must be questioned as to whether the remodelling of the upper femur is in response to one or to two distinct forces.
Flow characteristics of curved ducts
Directory of Open Access Journals (Sweden)
Rudolf P.
2007-10-01
Full Text Available Curved channels are very often present in real hydraulic systems, e.g. curved diffusers of hydraulic turbines, S-shaped bulb turbines, fittings, etc. Curvature brings change of velocity profile, generation of vortices and production of hydraulic losses. Flow simulation using CFD techniques were performed to understand these phenomena. Cases ranging from single elbow to coupled elbows in shapes of U, S and spatial right angle position with circular cross-section were modeled for Re = 60000. Spatial development of the flow was studied and consequently it was deduced that minor losses are connected with the transformation of pressure energy into kinetic energy and vice versa. This transformation is a dissipative process and is reflected in the amount of the energy irreversibly lost. Least loss coefficient is connected with flow in U-shape elbows, biggest one with flow in Sshape elbows. Finally, the extent of the flow domain influenced by presence of curvature was examined. This isimportant for proper placement of mano- and flowmeters during experimental tests. Simulations were verified with experimental results presented in literature.
Geometric invariant theory for polarized curves
Bini, Gilberto; Melo, Margarida; Viviani, Filippo
2014-01-01
We investigate GIT quotients of polarized curves. More specifically, we study the GIT problem for the Hilbert and Chow schemes of curves of degree d and genus g in a projective space of dimension d-g, as d decreases with respect to g. We prove that the first three values of d at which the GIT quotients change are given by d=a(2g-2) where a=2, 3.5, 4. We show that, for a>4, L. Caporaso's results hold true for both Hilbert and Chow semistability. If 3.5curves. If 2curves. We also analyze in detail the critical values a=3.5 and a=4, where the Hilbert semistable locus is strictly smaller than the Chow semistable locus. As an application, we obtain three compactications of the universal Jacobian over the moduli space of stable curves, weakly-pseudo-stable curves and pseu...
Fay, Pearse; Adamson, Lynne
2017-12-01
Within the context of growing concerns about a potential oversupply of occupational therapist, this research examines when, where and how long new graduates take to gain employment and identifies influences upon the health and university systems. A mixed method research design, using an online survey was adopted to investigate the topic. Two consecutive cohorts of graduates from a single university program were invited to participate. Seventy-five (58%) responses were received, with 63 (84%) currently employed in an occupational therapy role. Of the 12 (16%) not employed, only 3 (4%) described themselves as actively seeking employment in an occupational therapy role. A wide spread of employment settings and scope of practice areas was reported. Findings suggest that occupational therapy graduates are gaining employment in a range of settings and practice areas, relatively quickly. This research adds evidence to the conversation around graduate employment within a region of Australia. The Australian population, health system and university changes are possible factors influencing employment. The research reveals the difficulties in understanding the current situation with limitations in data collected, varied terminology and an ever changing job seeking environment. The research provides a starting point for the occupational therapy profession to further understand the directions the profession is taking. University programs may also benefit by using the research to tailor course content to assist graduates in gaining employment or to present students with the prospects of new employment opportunities. © 2017 Occupational Therapy Australia.
International Nuclear Information System (INIS)
Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.
1990-05-01
In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data
Wu, Xiaowei; Abe, Tetsuo; Chen, Huaibi; Higo, Toshiyasu; Shi, Jiaru; Wuensch, Walter; Zha, Hao
2016-01-01
As an alternative design for CLIC main accelerating structures, X-band choke-mode damped structures had been studied for several years. However, the performance of choke-mode cavity under high power is still in lack of research. Two standing wave single cell choke-mode damped accelerating structures with different choke dimensions which are working at 11.424 GHz were designed, manufactured and bench tested by accelerator group in Tsinghua University. High power test was carried out on it to s...
Piecewise power laws in individual learning curves.
Donner, Yoni; Hardy, Joseph L
2015-10-01
The notion that human learning follows a smooth power law (PL) of diminishing gains is well-established in psychology. This characteristic is observed when multiple curves are averaged, potentially masking more complex dynamics underpinning the curves of individual learners. Here, we analyzed 25,280 individual learning curves, each comprising 500 measurements of cognitive performance taken from four cognitive tasks. A piecewise PL (PPL) model explained the individual learning curves significantly better than a single PL, controlling for model complexity. The PPL model allows for multiple PLs connected at different points in the learning process. We also explored the transition dynamics between PL curve component pieces. Performance in later pieces typically surpassed that in earlier pieces, after a brief drop in performance at the transition point. The transition rate was negatively associated with age, even after controlling for overall performance. Our results suggest at least two processes at work in individual learning curves: locally, a gradual, smooth improvement, with diminishing gains within a specific strategy, which is modeled well as a PL; and globally, a discrete sequence of strategy shifts, in which each strategy is better in the long term than the ones preceding it. The piecewise extension of the classic PL of practice has implications for both individual skill acquisition and theories of learning.
Sadek, Mohammad
2012-01-01
In this paper we consider genus one equations of degree $n$, namely a (generalised) binary quartic when $n=2$, a ternary cubic when $n=3$, and a pair of quaternary quadrics when $n=4$. A new definition for the minimality of genus one equations of degree $n$ over local fields is introduced. The advantage of this definition is that it does not depend on invariant theory of genus one curves. We prove that this definition coincides with the classical definition of minimality for all $n\\le4$. As a...
Learning from uncertain curves
DEFF Research Database (Denmark)
Mallasto, Anton; Feragen, Aasa
2017-01-01
We introduce a novel framework for statistical analysis of populations of nondegenerate Gaussian processes (GPs), which are natural representations of uncertain curves. This allows inherent variation or uncertainty in function-valued data to be properly incorporated in the population analysis....... Using the 2-Wasserstein metric we geometrize the space of GPs with L2 mean and covariance functions over compact index spaces. We prove uniqueness of the barycenter of a population of GPs, as well as convergence of the metric and the barycenter of their finite-dimensional counterparts. This justifies...
Learning curves in health professions education.
Pusic, Martin V; Boutis, Kathy; Hatala, Rose; Cook, David A
2015-08-01
Learning curves, which graphically show the relationship between learning effort and achievement, are common in published education research but are not often used in day-to-day educational activities. The purpose of this article is to describe the generation and analysis of learning curves and their applicability to health professions education. The authors argue that the time is right for a closer look at using learning curves-given their desirable properties-to inform both self-directed instruction by individuals and education management by instructors.A typical learning curve is made up of a measure of learning (y-axis), a measure of effort (x-axis), and a mathematical linking function. At the individual level, learning curves make manifest a single person's progress towards competence including his/her rate of learning, the inflection point where learning becomes more effortful, and the remaining distance to mastery attainment. At the group level, overlaid learning curves show the full variation of a group of learners' paths through a given learning domain. Specifically, they make overt the difference between time-based and competency-based approaches to instruction. Additionally, instructors can use learning curve information to more accurately target educational resources to those who most require them.The learning curve approach requires a fine-grained collection of data that will not be possible in all educational settings; however, the increased use of an assessment paradigm that explicitly includes effort and its link to individual achievement could result in increased learner engagement and more effective instructional design.
Ersev, H; Yilmaz, B; Dinçol, M E; Dağlaroğlu, R
2012-08-01
To evaluate residual root filling material following removal of three newly developed root canal sealers used with a matched-taper single-cone root filling technique and to compare the efficacy of ProTaper Universal rotary retreatment instruments with that of a conventional manual technique. The canals of 120 palatal roots in maxillary molar teeth were instrumented with EndoWave nickel-titanium rotary instruments and filled using Hybrid Root SEAL, EndoSequence BC Sealer, Activ GP system or AH Plus with matched-taper single gutta-percha cones. The root fillings were then removed with ProTaper Universal retreatment rotary instruments or a manual technique. Buccolingual and proximal digital radiographs of the roots were exposed to determine the area of remaining filling material in the coronal, middle and apical thirds. The area percentages of remaining filling material in each third and total canal area were calculated. Data were analysed statistically with Kruskal-Wallis and Mann-Whitney U-tests. The level of significance was set at Pretreatment technique, filling material could not be removed completely from the root canals. Significantly, more remaining filling material was observed in the apical third (Pretreatment instruments were as safe and effective as hand instruments in reaching the working length. © 2012 International Endodontic Journal.
Schulz, Christian; Schlieper, Daniel; Altreuther, Christiane; Schallenburger, Manuela; Fetz, Katharina; Schmitz, Andrea
2015-12-07
End-of-life integrated care plans are used as structuring tools for the care of the dying. A widely adopted example is the Liverpool Care Pathway for the Dying Patient (LCP). Recently, several concerns were raised about LCP care, such as a worry that diagnosis of dying might be leading to a self-fulfilling trajectory, including hastening of death. However, data on rates of discontinuation of LCP care are lacking. In an observational study, we therefore investigated the incidence, features and trajectory of patients who were discontinued from the LCP. We hypothesised that (1) it is common to discontinue patients from the LCP, (2) quality of life does not decrease for discontinued LCP patients, and (3) discontinued patients live longer than patients who remain within LCP care. All adult patients who were diagnosed as dying in a German university hospital specialized palliative care unit were included in 2013 and 2014. Actuarial estimation of survival prognostication tools and a number of quality of life indicators were used for data collection. Survival time was analysed using Kaplan-Meier estimates. Group differences in quality of life were tested using multivariate analysis of variance. 159 patients were included in a digital version of the LCP. 15 patients (9.4 %) were discontinued later. Quality of life did not decrease for discontinued patients during LCP care (p = 0.16). LCP discontinued patients lived significantly longer than the remaining LCP subgroup (difference of means 296 hours, 95 % confidence interval 105.5 to 451.5 hours; difference of survival function estimates p dying, death is not the inevitable outcome of an end-of-life integrated care plan such as the LCP. Instead, it is common to discontinue the LCP care. Regular careful interprofessional assessments are important for identifying those patients who need to be discontinued from their end-of-life care plan. In this study, we found no evidence for harm by the LCP. We conclude that a
Directory of Open Access Journals (Sweden)
M. Siripruchyanun
2007-01-01
Full Text Available This article presents a dual-mode (voltage-mode and current-mode universal biquadratic filter performing completely standard functions: lowpass, highpass, bandpass, band-reject, and allpass functions, based on plus-type dual-output second-generation, current controlled, current conveyor (DO-CCCII+. The features of the circuit are that the bandwidth and natural frequency can be tuned electronically via the input bias currents: the circuit description is very simple, consisting of merely 2 DO-CCCIIs and 2 capacitors: the circuit can provide either the voltage-mode or current-mode filter without changing circuit topology. Additionally, each function response can be selected by suitably selecting input signals with digital method. Without any external resistors, the proposed circuit is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation. The maximum power consumption is approximately 1.81 mW at ±1.5 V supply voltages.
The Characteristic Curves of Water
Neumaier, Arnold; Deiters, Ulrich K.
2016-09-01
In 1960, E. H. Brown defined a set of characteristic curves (also known as ideal curves) of pure fluids, along which some thermodynamic properties match those of an ideal gas. These curves are used for testing the extrapolation behaviour of equations of state. This work is revisited, and an elegant representation of the first-order characteristic curves as level curves of a master function is proposed. It is shown that Brown's postulate—that these curves are unique and dome-shaped in a double-logarithmic p, T representation—may fail for fluids exhibiting a density anomaly. A careful study of the Amagat curve (Joule inversion curve) generated from the IAPWS-95 reference equation of state for water reveals the existence of an additional branch.
Some issues using the master curve concept
International Nuclear Information System (INIS)
Viehrig, H.W.; Boehmert, J.
2000-01-01
The state-of-the-art structural integrity assessment of reactor pressure vessels (RPV) is based on the Reference Temperature Concept, initially proposed by the American Society of Mechanical Engineers (ASME). An experimentally ensured fracture toughness curve was constructed as the lower boundary of the available fracture toughness, K IC , of RPV steels. This conservative curve describing K IC as a function of temperature is used as a universal curve. For different RPV steels the curve is placed on the temperature axis over a reference temperature. In the initial state the nil-ductility-transition temperature (RT NDT ) is applied as reference temperature. The ductile to brittle transition temperature (DBTT) shift caused by the neutron irradiation is determined by Charpy V impact tests. The Charpy V DBTT shift is one of the results of the RPV surveillance programmes. The concept based on the ASME curve has the following disadvantages: - it is not consistent since it links fracture mechanical and technological parameters and - margins of safety and uncertainties cannot be quantified. (orig.)
Directory of Open Access Journals (Sweden)
Huang Shang-Yi
2011-09-01
Full Text Available Abstract Background Risk factors and outcomes in hematological patients who acquire invasive fungal sinusitis (IFS are infrequently reported in the modern medical era. Method A retrospective study of hospitalized patients with hematological disease was conducted at National Taiwan University Hospital between January 1995 and December 2009. Results Clinical characteristics and outcomes with their associated radiographic and microbiological findings were analyzed. Forty-six patients with IFS and 64 patients with chronic non-invasive sinusitis were enrolled as comparsion. IFS developed more commonly in patients with acute myeloid leukemia (AML and with prolonged neutropenia (absolute neutrophil count less than 500/mm3 for more than 10 days (p Aspergillus flavus was the most common pathogen isolated (44%. Serum Aspergillus galactomannan antigen was elevated in seven of eleven patients (64% with IFS caused by aspergillosis but negative for all three patients with mucormycosis. Bony erosion and extra-sinus infiltration was found in 15 of 46 (33% patients on imaging. Overall, 19 of 46 patients (41.3% died within 6 weeks. Patients with disease subtype of AML (p = 0.044; Odds Ratio [OR], 5.84; 95% confidence interval [95% CI], 1.02-30.56 and refractory leukemia status (p = 0.05; OR, 4.27; 95% CI, 1.003-18.15 had worse prognosis. Multivariate analysis identified surgical debridement as an independent good prognostic factor (p = 0.047 in patients with IFS. Conclusions Patients of AML with prolonged neutropenia (> 10 days had significantly higher risk of IFS. Early introduction of anti-fungal agent and aggressive surgical debridement potentially decrease morbidity and mortality in high risk patients with IFS.
Andrews, T C; Conaway, E P; Zhao, J; Dolan, E L
2016-01-01
Relationships with colleagues have the potential to be a source of support for faculty to make meaningful change in how they teach, but the impact of these relationships is poorly understood. We used a mixed-methods approach to investigate the characteristics of faculty who provide colleagues with teaching resources and facilitate change in teaching, how faculty influence one another. Our exploratory investigation was informed by social network theory and research on the impact of opinion leaders within organizations. We used surveys and interviews to examine collegial interactions about undergraduate teaching in life sciences departments at one research university. Each department included discipline-based education researchers (DBERs). Quantitative and qualitative analyses indicate that DBERs promote changes in teaching to a greater degree than other departmental colleagues. The influence of DBERs derives, at least partly, from a perception that they have unique professional expertise in education. DBERs facilitated change through coteaching, offering ready and approachable access to education research, and providing teaching training and mentoring. Faculty who had participated in a team based-teaching professional development program were also credited with providing more support for teaching than nonparticipants. Further research will be necessary to determine whether these results generalize beyond the studied institution. © 2016 T. C. Andrews et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
Directory of Open Access Journals (Sweden)
Je Hyun Baekt
2000-01-01
Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.
Magnetism in curved geometries
Streubel, Robert
Deterministically bending and twisting two-dimensional structures in the three-dimensional (3D) space provide means to modify conventional or to launch novel functionalities by tailoring curvature and 3D shape. The recent developments of 3D curved magnetic geometries, ranging from theoretical predictions over fabrication to characterization using integral means as well as advanced magnetic tomography, will be reviewed. Theoretical works predict a curvature-induced effective anisotropy and effective Dzyaloshinskii-Moriya interaction resulting in a vast of novel effects including magnetochiral effects (chirality symmetry breaking) and topologically induced magnetization patterning. The remarkable development of nanotechnology, e.g. preparation of high-quality extended thin films, nanowires and frameworks via chemical and physical deposition as well as 3D nano printing, has granted first insights into the fundamental properties of 3D shaped magnetic objects. Optimizing magnetic and structural properties of these novel 3D architectures demands new investigation methods, particularly those based on vector tomographic imaging. Magnetic neutron tomography and electron-based 3D imaging, such as electron holography and vector field electron tomography, are well-established techniques to investigate macroscopic and nanoscopic samples, respectively. At the mesoscale, the curved objects can be investigated using the novel method of magnetic X-ray tomography. In spite of experimental challenges to address the appealing theoretical predictions of curvature-induced effects, those 3D magnetic architectures have already proven their application potential for life sciences, targeted delivery, realization of 3D spin-wave filters, and magneto-encephalography devices, to name just a few. DOE BES MSED (DE-AC02-05-CH11231).
Titration Curves: Fact and Fiction.
Chamberlain, John
1997-01-01
Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…
Non-linear Behavior of Curved Sandwich Panels
DEFF Research Database (Denmark)
Berggreen, Carl Christian; Jolma, P.; Karjalainen, J. P.
2003-01-01
In this paper the non-linear behavior of curved sandwich panels is investigated both numerically and experimentally. Focus is on various aspects of finite element modeling and calculation procedures. A simply supported, singly curved, CFRP/PVC sandwich panel is analyzed under uniform pressure load...
Directory of Open Access Journals (Sweden)
Sergey A. Cherkis
2007-03-01
Full Text Available A typical solution of an integrable system is described in terms of a holomorphic curve and a line bundle over it. The curve provides the action variables while the time evolution is a linear flow on the curve's Jacobian. Even though the system of Nahm equations is closely related to the Hitchin system, the curves appearing in these two cases have very different nature. The former can be described in terms of some classical scattering problem while the latter provides a solution to some Seiberg-Witten gauge theory. This note identifies the setup in which one can formulate the question of relating the two curves.
International Nuclear Information System (INIS)
Kraft, O.
2006-01-01
This paper presents the results of I-131 therapy in patients suffering from various types of functional autonomies of the thyroid gland. The efficacy and adverse effects of radioiodine therapy are presented. Seven hundred ninety-nine patients (age range= 33 to 86 years; average age= 58.7 years; Male: Female = 7.4:1) with unifocal, multifocal and disseminated functional autonomies of thyroid gland were treated with at least one therapeutic dose of I-131. Baseline Tc-99m pertechnetate thyroid scans, radioactive iodine uptake studies and ultrasonography were performed in all cases prior to radio iodine therapy. Baseline serum total and free thyroxine (T-T4 and F-T4), total triiodothyronine (T-T3) and TSH levels were estimated in all cases. Effective half life of radio iodine in the thyroids was also determined in all patients prior to therapy and a few patients were subjected to TRH stimulation tests. Following treatment all patients were evaluated after a period of 4-6 months. Further follow up evaluations were done at one year in 545 patients and at two years in 254 patients. Complete elimination of functional autonomy was achieved in 733 (91.74%) patients with a single therapeutic dose of I-131, while 62 (7.76%) patients required two doses of I-131 and only 4 (0.5%) patients required three therapeutic doses of I-131. Following I-131 therapy, the suppression of TSH levels in serum disappeared in 607 (76%) of treated patients. An average volume reduction of 38% was noted in the thyroid gland following I-131. Side effects were minimal and only a few patients complained of transient neck pressure, pain and neck swelling. Postradiation hypothyroidism was diagnosed in 36 patients (4.5%). We conclude that radio iodine treatment is the most comfortable and economical approach to the treatment of the thyroid functional autonomies. The results of our approach show that the radioiodine therapy of the thyroid functional autonomies is safe, with low incidence of adverse effects
Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.
2016-12-01
Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first
Page curves for tripartite systems
International Nuclear Information System (INIS)
Hwang, Junha; Lee, Deok Sang; Nho, Dongju; Oh, Jeonghun; Park, Hyosub; Zoe, Heeseung; Yeom, Dong-han
2017-01-01
We investigate information flow and Page curves for tripartite systems. We prepare a tripartite system (say, A , B , and C ) of a given number of states and calculate information and entropy contents by assuming random states. Initially, every particle was in A (this means a black hole), and as time goes on, particles move to either B (this means Hawking radiation) or C (this means a broadly defined remnant, including a non-local transport of information, the last burst, an interior large volume, or a bubble universe, etc). If the final number of states of the remnant is smaller than that of Hawking radiation, then information will be stored by both the radiation and the mutual information between the radiation and the remnant, while the remnant itself does not contain information. On the other hand, if the final number of states of the remnant is greater than that of Hawking radiation, then the radiation contains negligible information, while the remnant and the mutual information between the radiation and the remnant contain information. Unless the number of states of the remnant is large enough compared to the entropy of the black hole, Hawking radiation must contain information; and we meet the menace of black hole complementarity again. Therefore, this contrasts the tension between various assumptions and candidates of the resolution of the information loss problem. (paper)
Directory of Open Access Journals (Sweden)
Manish Gupta
2017-01-01
Full Text Available The manuscript presents a circuit that can act as a universal filter as well as a single resistence controlled oscillator by unpretentiously changing the switch positions. The circuit employs only two active devices and all grounded passive elements. The utilization of only grounded passive components makes this circuit a better choice for integrated circuit implementation. The current mode biquadratic filter offers all the five basic responses along with independent tunability of its quality factor. The dual-mode quadrature sinusoidal oscillator offers explicit current outputs along with voltage outputs. The circuit also offers a simple and uncoupled condition of oscillation and frequency of oscillation. The typical analysis such as non-ideal, sensitivity and parasitic analysis along with the regular simulation results as well as experimental results are exposed here, to strengthen the design idea.
Development of Rating Curve for Ofu River at Oforachi Hydrometric ...
African Journals Online (AJOL)
OLUWASOGO
Development of Rating Curve for Ofu River at. Oforachi Hydrometric Station. 1Department of Water Resources and Environmental Engineering, University of Ilorin, Ilorin, Kwara State, Nigeria. 1Department of Civil Engineering, University of Jos, Jos, Nigeria. 2 Department of Water Resources & Environmental Engineering, ...
Intersection numbers of spectral curves
Eynard, B
2011-01-01
We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined by the laplace transform of the spectral curve. This is a hint to the key role of Laplace transform in mirror symmetry. When the spectral curve is y=\\sqrt{x}, the formula gives Kontsevich--Witten intersection numbers, when the spectral curve is chosen to be the Lambert function \\exp{x}=y\\exp{-y}, the formula gives the ELSV formula for Hurwitz numbers, and when one chooses the mirror of C^3 with framing f, i.e. \\exp{-x}=\\exp{-yf}(1-\\exp{-y}), the formula gives the topological vertex formula, i.e. the generating function of Gromov-Witten invariants of C^3. In some sense this formula generalizes ELSV formula, and Mumford formula.
Optimization on Spaces of Curves
DEFF Research Database (Denmark)
Møller-Andersen, Jakob
This thesis is concerned with computational and theoretical aspects of Riemannian metrics on spaces of regular curves, and their applications. It was recently proved that second order constant coefficient Sobolev metrics on curves are geodesically complete. We extend this result to the case...... of Sobolev metrics with coefficient functions depending on the length of the curve. We show how to apply this result to analyse a wide range of metrics on the submanifold of unit and constant speed curves. We present a numerical discretization of second order Sobolev metrics on the space of regular curves...... of cardiac deformations. Finally we investigate a new application of Riemannian shape analysis in shape optimization. We setup a simple elliptic model problem, and describe how to apply shape calculus to obtain directional derivatives in the manifold of planar curves. We present an implementation based...
Asymptotic learning curve and renormalizable condition in statistical learning theory
International Nuclear Information System (INIS)
Watanabe, Sumio
2010-01-01
Bayes statistics and statistical physics have the common mathematical structure, where the log likelihood function corresponds to the random Hamiltonian. Recently, it was discovered that the asymptotic learning curves in Bayes estimation are subject to a universal law, even if the log likelihood function can not be approximated by any quadratic form. However, it is left unknown what mathematical property ensures such a universal law. In this paper, we define a renormalizable condition of the statistical estimation problem, and show that, under such a condition, the asymptotic learning curves are ensured to be subject to the universal law, even if the true distribution is unrealizable and singular for a statistical model. Also we study a nonrenormalizable case, in which the learning curves have the different asymptotic behaviors from the universal law.
International Nuclear Information System (INIS)
Schwarz, Marcus R
2010-01-01
The setup for and first experiences and results with a newly established lab-course on multianvil pressure calibration is reported. In order to provide a challenging and multidisciplinary task, as well as motivating results and an acceptable time scale, an assembly containing four different calibrants with consecutive phase transformations was adopted, thus making it possible for each group (3-4 students) to measure the entire pressure-versus-ram force range of the press in a single run. The course was performed by students of the subject 'applied natural sciences' in their seventh term.
Describing the learning curve for bulbar urethroplasty.
Spilotros, Marco; Malde, Sachin; Greenwell, Tamsin J
2017-12-01
Learning curves have been described for a number of urological procedures including radical prostatectomy and laparoscopic nephrectomy but rarely for urethroplasty. We describe the learning curve for bulbar urethroplasty in a single surgeon series. A retrospective case note review was performed of 91 consecutive men median age 32 years (range, 15-66 years) having bulbar urethroplasty performed by a single surgeon. Data was collected on type of urethroplasty, restricture rate (as defined by urethrogram and/or flow rate) and duration of follow up. The restricture rates were compared by quartiles and statistical analysis was by ¦Ö 2 between the first and fourth quartiles. The 91 men had 42 dorsal onlay buccal mucosal graft (Dorsal BMG), 20 BMG augmented bulbobulbar anastomotic (Augmented Rooftop) and 29 bulbobulbar anastomotic (BBA) urethroplasties performed. Median follow up was 39 months for the first quartile, 42 months for the second, 36 months for the third, and 35 months for the fourth. The restricture rate was 17% in the first quartile, 8.7% in the second and third quartiles and 4.5% in the fourth quartile. There were no restrictures noted after 24 months. There were 4 restrictures in the first quartile and 1 restricture in the fourth quartile (¦Ö 2 Plearning curve for bulbar urethroplasty with a reduced restricture rate each quartile and it may take as many as 90 cases to reach optimum restricture rates.
Regular homotopy of Hurwitz curves
International Nuclear Information System (INIS)
Auroux, D; Kulikov, Vik S; Shevchishin, V V
2004-01-01
We prove that any two irreducible cuspidal Hurwitz curves C 0 adn C 1 (or, more generally, two curves with A-type singularities) in the Hirzebruch surface F N with the same homology classes and sets of singularities are regular homotopic. Moreover, they are symplectically regular homotopic if C 0 and C 1 are symplectic with respect to a compatible symplectic form
Space curves, anholonomy and nonlinearity
Indian Academy of Sciences (India)
Walker parallel transport [14] of any vector P moved ... of Fermi–Walker parallel transport to the case of a moving space curve. 4. General curve evolution equations .... ear term of the Lamb equation (eq. (34)) is just the time derivative of the total.
Energy Technology Data Exchange (ETDEWEB)
Barenboim, Gabriela; /Valencia U.; Mena, Olga; Quigg, Chris; /Fermilab
2004-12-01
If the equation of state for ''dark energy'' varies periodically, the expansion of the Universe may have undergone alternating eras of acceleration and deceleration. We examine a specific form that survives existing observational tests, does not single out the present state of the Universe as exceptional, and suggests a future much like the matter-dominated past: a smooth expansion without a final inflationary epoch.
Vizzotti, C; González, J; Rearte, A; Urueña, A; Pérez Carrega, M; Calli, R; Gentile, A; Uboldi, A; Ramonet, M; Cañero-Velasco, M; Diosque, M
2015-12-01
Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = ≥10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation. © The Author 2014. Published by Oxford University Press on behalf of the Pediatric
Torii, Sho; Fujii, Toshiharu; Murakami, Tsutomu; Nakazawa, Gaku; Ijichi, Takeshi; Nakano, Masataka; Ohno, Yohei; Shinozaki, Norihiko; Yoshimachi, Fuminobu; Ikari, Yuji
2017-04-01
The purpose of this study is to determine reduction of door-to-balloon (D2B) time using a single universal guiding catheter (Ikari-Left catheter) in transradial approach. In this procedure, we can skip a total of five steps compared with a conventional procedure (two catheter insertions, two catheter removals, and one catheter engagement). Reducing total ischemic time is important to achieving a better outcome in primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI). We retrospectively compared 30 consecutive STEMI patients who underwent transradial primary PCI with a single guiding catheter (IL group) with 30 consecutive patients with conventional transradial primary PCI. Patients with cardiogenic shock, heart failure, or need for intra-aortic balloon pumping support before primary PCI were excluded. Baseline characteristics were not different between the two groups. The D2B time was significantly shorter in the IL group (55 ± 16 vs. 63 ± 17 min, respectively; p = 0.01). Puncture-to-balloon time was also significantly shorter in the IL group (15 ± 11 min vs. 25 ± 11 min, respectively; p = 0.001). The total number of diagnostic and guiding catheters was significantly less in IL group (1 (IQR 1-1) vs. 3 (IQR 3-3), respectively; p guiding catheter reduced D2B time by skipping several procedural steps, and reduced the total number of catheters needed. This technique could reduce patient mortality as well as total medical cost.
Light Curve Solution of the Contact Binary AW UMa
Directory of Open Access Journals (Sweden)
J. H. Jeong
1997-12-01
Full Text Available A total of 1088 observations (272 in B,272 in V, 272 in R, and 272 in I were made from January to February in 1995 at Chungbuk National University observatory(CbNUO. We constructed BVRI light curves with our data. The photometric solution of these light curves was obtained by means of the Wilson-Devinney method. Our result was compared with those by previous investigators.
TELECOMMUNICATIONS INFRASTRUCTURE AND GDP /JIPP CURVE/
Directory of Open Access Journals (Sweden)
Mariana Kaneva
2016-07-01
Full Text Available The relationship between telecommunications infrastructure and economic activity is under discussion in many scientific papers. Most of the authors use for research and analysis the Jipp curve. A lot of doubts about the correctness of the Jipp curve appear in terms of applying econometric models. The aim of this study is a review of the Jipp curve, refining the possibility of its application in modern conditions. The methodology used in the study is based on dynamic econometric models, including tests for nonstationarity and tests for causality. The focus of this study is directed to methodological problems in measuring the local density types of telecommunication networks. This study offers a specific methodology for assessing the Jipp law, through VAR-approach and Granger causality tests. It is proved that mechanical substitution of momentary aggregated variables (such as the number of subscribers of a telecommunication network at the end of the year and periodically aggregated variables (such as GDP per capita in the Jipp�s curve is methodologically wrong. Researchers have to reconsider the relationship set in the Jipp�s curve by including additional variables that characterize the Telecommunications sector and the economic activity in a particular country within a specified time period. GDP per capita should not be regarded as a single factor for the local density of telecommunications infrastructure. New econometric models studying the relationship between the investments in telecommunications infrastructure and economic development may be not only linear regression models, but also other econometric models. New econometric models should be proposed after testing and validating with sound economic theory and econometric methodology.
Barris, E. C.; Batzloff, R. M.; Smirnov, A. V.; Sergeev, A. V.; Kulakov, E.
2011-12-01
Data on the long-term changes of Earth's magnetic field strength are crucial for understanding the mechanisms of geomagnetic field generation and constraining models of planetary evolution. However, conventional paleointensity methods, based on thermal treatments of bulk rock samples, have low success rate due to heating-induced alteration of samples. In order to avoid this problem, a new technique has been recently developed at the University of Rochester that uses individual rock-forming crystals, heated by a laser, to measure paleointensity. Single crystals are less susceptible to natural and experimental alterations, which results in significantly higher experimental success rates. We report on the implementation of a laser-based system to be used for paleomagnetic and paleointensity analyses at the Michigan Tech's Earth Magnetism Laboratory. The system consists of a water-cooled 10W CO2 laser and a beam delivering system mounted on an optical bench, a field coil, and associated monitoring equipment. The system is integrated with a 2G Enterprises Superconducting Rock Magnetometer with automated sample handling and is located inside of a magnetically shielded room. Our preliminary experiments on several silicate crystals separated from recent and Precambrian rocks have indicated that the system provides a stable and repeatable thermal demagnetization of both natural and saturation isothermal remanent magnetization in the crystals. Pilot paleointensity experiments are in progress.
Computational aspects of algebraic curves
Shaska, Tanush
2005-01-01
The development of new computational techniques and better computing power has made it possible to attack some classical problems of algebraic geometry. The main goal of this book is to highlight such computational techniques related to algebraic curves. The area of research in algebraic curves is receiving more interest not only from the mathematics community, but also from engineers and computer scientists, because of the importance of algebraic curves in applications including cryptography, coding theory, error-correcting codes, digital imaging, computer vision, and many more.This book cove
CYCLING CURVES AND THEIR APPLICATIONS
Directory of Open Access Journals (Sweden)
RAICU Lucian
2015-06-01
Full Text Available This paper proposes an analysis of the cyclic curves that can be considered as some of the most important regarding their applications in science, technique, design, architecture and art. These curves include the following: cycloid, epicycloid, hypocycloid, spherical cycloid and special cases thereof. In the first part of the paper the main curves of cycloids family are presented with their methods of generating and setting parametric equations. In the last part some of cycloid applications are highlighted in different areas of science, technology and art.
Elliptic Curves and Number Theory
Indian Academy of Sciences (India)
R. Sujatha, School of Mathematics, Tata Institute of Fundamental Research, Mumbai, INDIA
1. Aim: To explain the connection between a simple ancient problem in number theory and a deep sophisticated conjecture about Elliptic Curves. ('arithmetic Geometry'). Notation: N : set of natural numbers (1,2,3,...) ...
51Cr - erythrocyte survival curves
International Nuclear Information System (INIS)
Paiva Costa, J. de.
1982-07-01
Sixteen patients were studied, being fifteen patients in hemolytic state, and a normal individual as a witness. The aim was to obtain better techniques for the analysis of the erythrocytes, survival curves, according to the recommendations of the International Committee of Hematology. It was used the radiochromatic method as a tracer. Previously a revisional study of the International Literature was made in its aspects inherent to the work in execution, rendering possible to establish comparisons and clarify phonomena observed in cur investigation. Several parameters were considered in this study, hindering both the exponential and the linear curves. The analysis of the survival curves of the erythrocytes in the studied group, revealed that the elution factor did not present a homogeneous answer quantitatively to all, though, the result of the analysis of these curves have been established, through listed programs in the electronic calculator. (Author) [pt
Management of the learning curve
DEFF Research Database (Denmark)
Pedersen, Peter-Christian; Slepniov, Dmitrij
2016-01-01
Purpose – This paper focuses on the management of the learning curve in overseas capacity expansions. The purpose of this paper is to unravel the direct as well as indirect influences on the learning curve and to advance the understanding of how these affect its management. Design/methodology...... the dimensions of the learning process involved in a capacity expansion project and identified the direct and indirect labour influences on the production learning curve. On this basis, the study proposes solutions to managing learning curves in overseas capacity expansions. Furthermore, the paper concludes...... employs qualitative methodology and draws on a longitudinal, factory-level analysis of an in-depth case study of a Danish wind turbine manufacturer. Findings – This study goes beyond a simplistic treatment of the lead time and learning required to establish a new capacity. The authors examined...
Nonlinear mechanics of rigidifying curves.
Al Mosleh, Salem; Santangelo, Christian
2017-07-01
Thin shells are characterized by a high cost of stretching compared to bending. As a result isometries of the midsurface of a shell play a crucial role in their mechanics. In turn, curves on the midsurface with zero normal curvature play a critical role in determining the number and behavior of isometries. In this paper, we show how the presence of these curves results in a decrease in the number of linear isometries. Paradoxically, shells are also known to continuously fold more easily across these rigidifying curves than other curves on the surface. We show how including nonlinearities in the strain can explain these phenomena and demonstrate folding isometries with explicit solutions to the nonlinear isometry equations. In addition to explicit solutions, exact geometric arguments are given to validate and guide our analysis in a coordinate-free way.
Learning curve for radical retropubic prostatectomy
Directory of Open Access Journals (Sweden)
Fernando J. A. Saito
2011-02-01
Full Text Available PURPOSE: The learning curve is a period in which the surgical procedure is performed with difficulty and slowness, leading to a higher risk of complications and reduced effectiveness due the surgeon's inexperience. We sought to analyze the residents' learning curve for open radical prostatectomy (RP in a training program. MATERIALS AND METHODS: We conducted a prospective study from June 2006 to January 2008 in the academic environment of the University of São Paulo. Five residents operated on 184 patients during a four-month rotation in the urologic oncology division, mentored by the same physician assistants. We performed sequential analyses according to the number of surgeries, as follows: = 10, 11 to 19, 20 to 28, and = 29. RESULTS: The residents performed an average of 37 RP each. The average psa was 9.3 ng/mL and clinical stage T1c in 71% of the patients. The pathological stage was pT2 (73%, pT3 (23%, pT4 (4%, and 46% of the patients had a Gleason score 7 or higher. In all surgeries, the average operative time and estimated blood loss was 140 minutes and 488 mL. Overall, 7.2% of patients required blood transfusion, and 23% had positive surgical margins. CONCLUSION: During the initial RP learning curve, we found a significant reduction in the operative time; blood transfusion during the procedures and positive surgical margin rate were stable in our series.
International Nuclear Information System (INIS)
Haverkamp, U.; Wiezorek, C.; Poetter, R.
1990-01-01
Lyoluminescence dosimetry is based upon light emission during dissolution of previously irradiated dosimetric materials. The lyoluminescence signal is expressed in the dissolution glow curve. These curves begin, depending on the dissolution system, with a high peak followed by an exponentially decreasing intensity. System parameters that influence the graph of the dissolution glow curve, are, for example, injection speed, temperature and pH value of the solution and the design of the dissolution cell. The initial peak does not significantly correlate with the absorbed dose, it is mainly an effect of the injection. The decay of the curve consists of two exponential components: one fast and one slow. The components depend on the absorbed dose and the dosimetric materials used. In particular, the slow component correlates with the absorbed dose. In contrast to the fast component the argument of the exponential function of the slow component is independent of the dosimetric materials investigated: trehalose, glucose and mannitol. The maximum value, following the peak of the curve, and the integral light output are a measure of the absorbed dose. The reason for the different light outputs of various dosimetric materials after irradiation with the same dose is the differing solubility. The character of the dissolution glow curves is the same following irradiation with photons, electrons or neutrons. (author)
Prospects for PV: a learning curve analysis
International Nuclear Information System (INIS)
Zwaan, Bob van der; Rabi, A.
2003-01-01
This article gives an overview of the current state-of-the-art of photovoltaic electricity technology, and addresses its potential for cost reductions over the first few decades of the 21st century. Current PV production cost ranges are presented, both in terms of capacity installation and electricity generation, of single crystalline silicon, multi-crystalline silicon, amorphous silicon and other thin film technologies. Possible decreases of these costs are assessed, as expected according to the learning-curve methodology. We also estimate how much PV could gain if external costs (due to environmental and health damage) of energy were internalised, for example by an energy tax. Our conclusions are that, (1) mainly due its high costs, PV electricity is unlikely to play a major role in global energy supply and carbon emissions abatement before 2020, (2) extrapolating learning curves observed in the past, one can expect its costs to decrease significantly over the coming years, so that a considerable PV electricity share world-wide could materialise after 2020, (3) niche-market applications, e.g. using stand-alone systems in remote areas, are crucial for continuing 'the ride along the learning curve', (4) damage costs of conventional (fossil) power sources are considerable, and their internalisation would improve the competitiveness of PV, although probably not enough to close the current cost gap. (author)
Creating A Light Curve Using Gathered Data
Wiggs, Joseph; Stolarz, S. A.; DePorto, R. W.; Shake, W. J.; Piper, M.; Linder, T. R.; Holmes, R.; Conwell, J.
2012-01-01
Our group of students with the support of educators and astronomers carried out a program to do astrometric and photometric analysis on the asteroid 2000 SO1 with the objective of obtaining a more in depth analysis of this asteroid and publishing light curve data describing the period of the asteroid. We chose our target asteroid using the minor planet center database, choosing an object that would have an acceptable Right Ascension, Declination, magnitude, and air mass for the ARO (Astronomical Research Observatory)-30 inch telescope operated by the SKYNET program. Our journey began with using Astrometrica for the IASC/WISE Program to identify and find new asteroids in the sky and add data to the Minor Planet Center Database. We then used MPO (Minor Planet Observatory) Canopus to form a light curve and conduct a fourier analysis on an example asteroid to familiarize ourselves with the program and used the program again to conduct fourier analysis on asteroid 2000 SO1. The educational goal in mind was to (a) learn the process of collecting and analyzing data using Astrometrica, MPO Canopus, the Minor Planet Center, and SKYNET and (b) create a poster to display the steps used in the process of surveying taken images and the production of a light curve. We collected 300 images a night, while discarding all the corrupted images, until we had enough data to accurately represent the object.Our work was successful due to resources from; Eastern Illinois University's Physics Department, the Astronomical Research Observatory, the University of Chicago's Yerkes Observatory, the SKYNET network, NASA's IASC/WISE (International Astronomical Search Collaboration/ Wide-Field Infrared Survey Explorer), NITARP (NASA/IPAC Teacher Archive Research Program) and Lincoln-Way North High School.
Directory of Open Access Journals (Sweden)
Janus Ruel T. Cabazares
2016-12-01
Full Text Available In the Filipino version of the Universal Declaration of Human Rights (UDHR, only a single deontic modal marker is found, a curious absence given that such a category conveys the performative function crucial to the language used in laws. Regardless of the current attitude against seeking equivalence in translation analysis, questioning the semantics of the target text (TT is a necessary endeavour for the translation of legal texts, whether or not the relevant linguistic features of the TT language contribute to or facilitate the expression of any of the properties of deontic modality (DM. To this end, the paper analyzes the Filipino translation of the UDHR to look for this type of semantic category. The analysis of the TT focuses on three important points: [1] use of the prospective aspect does not contribute to the expression of the necessary features of DM, notwithstanding their shared notion of futurity; [2] volition, an essential part of DM, is implied by the transitivity triggered by the TT verb voice, but the source and perspective of the volition is different; and [3] use of the modal marker dapat (i.e., necessary carries the primary features of DM. The paper suggests that the consistent use of this modal marker can assign a performative function to the TT, a trait that helps define the source text (ST as a legal text. The study can offer helpful points to translators of legal documents and other forms of technical translation. The methods used can help future translation analyses by providing conceptual tools for the semantic comparison of the linguistic traits of an ST and TT, particularly the semantic representation of Filipino sentences including the transitivity of the verb and modality. Ultimately, the study hopes to contribute to quality translations of text as part of promoting the intellectualization of Filipino and other Philippine languages.
Considerations for reference pump curves
International Nuclear Information System (INIS)
Stockton, N.B.
1992-01-01
This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point
Curve Digitizer – A software for multiple curves digitizing
Directory of Open Access Journals (Sweden)
Florentin ŞPERLEA
2010-06-01
Full Text Available The Curve Digitizer is software that extracts data from an image file representing a graphicand returns them as pairs of numbers which can then be used for further analysis and applications.Numbers can be read on a computer screen stored in files or copied on paper. The final result is adata set that can be used with other tools such as MSEXCEL. Curve Digitizer provides a useful toolfor any researcher or engineer interested in quantifying the data displayed graphically. The image filecan be obtained by scanning a document
A universal model of ontogenetic growth
Martyushev, Leonid M.; Terentiev, Pavel S.
2015-06-01
The assumption that a single growth equation can be used to describe all biological objects on different organizational levels and a dimensional analysis are applied in order to substantiate universal model of ontogenetic growth. This model (the mass of a growing organism is a power function of time) is valid only in the initial period of growth. For the whole period of growth, a generalization of the model is advanced; it provides the same accuracy as previously known models of quantitative description of kinetic curves. Within the scope of the developed model, a number of interesting results related to allometry and biological time are obtained.
universal specific energy curve for para- bolic open channels
African Journals Online (AJOL)
DEPT OF AGRICULTURAL ENGINEERING
where A is the flow cross-sectional area, Q is the discharge and g is acceleration due to grav- ity. In parabolic open channels (illustrated in. Figure 1) by definition, the relationship be- tween flow depth y varies with the square of the water surface width b, i.e.. 2 cby. (1). (2) by. A. 3. 2. (compared to A =½by for a triangular open.
Calibration curves for biological dosimetry
International Nuclear Information System (INIS)
Guerrero C, C.; Brena V, M. . E-mail cgc@nuclear.inin.mx
2004-01-01
The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of 60 Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)
Laffer Curves and Home Production
Directory of Open Access Journals (Sweden)
Kotamäki Mauri
2017-06-01
Full Text Available In the earlier related literature, consumption tax rate Laffer curve is found to be strictly increasing (see Trabandt and Uhlig (2011. In this paper, a general equilibrium macro model is augmented by introducing a substitute for private consumption in the form of home production. The introduction of home production brings about an additional margin of adjustment – an increase in consumption tax rate not only decreases labor supply and reduces the consumption tax base but also allows a substitution of market goods with home-produced goods. The main objective of this paper is to show that, after the introduction of home production, the consumption tax Laffer curve exhibits an inverse U-shape. Also the income tax Laffer curves are significantly altered. The result shown in this paper casts doubt on some of the earlier results in the literature.
Rational points on elliptic curves
Silverman, Joseph H
2015-01-01
The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...
The New Keynesian Phillips Curve
DEFF Research Database (Denmark)
Ólafsson, Tjörvi
This paper provides a survey on the recent literature on the new Keynesian Phillips curve: the controversies surrounding its microfoundation and estimation, the approaches that have been tried to improve its empirical fit and the challenges it faces adapting to the open-economy framework. The new...... Keynesian Phillips curve has been severely criticized for poor empirical dynamics. Suggested improvements involve making some adjustments to the standard sticky price framework, e.g. introducing backwardness and real rigidities, or abandoning the sticky price model and relying on models of inattentiveness......, learning or state-dependant pricing. The introduction of openeconomy factors into the new Keynesian Phillips curve complicate matters further as it must capture the nexus between price setting, inflation and the exchange rate. This is nevertheless a crucial feature for any model to be used for inflation...
A NURBS approximation of experimental stress-strain curves
International Nuclear Information System (INIS)
Fedorov, Timofey V.; Morrev, Pavel G.
2016-01-01
A compact universal representation of monotonic experimental stress-strain curves of metals and alloys is proposed. It is based on the nonuniform rational Bezier splines (NURBS) of second order and may be used in a computer library of materials. Only six parameters per curve are needed; this is equivalent to a specification of only three points in a stress-strain plane. NURBS-functions of higher order prove to be surplus. Explicit expressions for both yield stress and hardening modulus are given. Two types of curves are considered: at a finite interval of strain and at infinite one. A broad class of metals and alloys of various chemical compositions subjected to various types of preliminary thermo-mechanical working is selected from a comprehensive data base in order to test the methodology proposed. The results demonstrate excellent correspondence to the experimental data. Keywords: work hardening, stress-strain curve, spline approximation, nonuniform rational B-spline, NURBS.
Electro-Mechanical Resonance Curves
Greenslade, Thomas B.
2018-03-01
Recently I have been investigating the frequency response of galvanometers. These are direct-current devices used to measure small currents. By using a low-frequency function generator to supply the alternating-current signal and a stopwatch smartphone app to measure the period, I was able to take data to allow a resonance curve to be drawn. This is the sort of project that should provide a fascinating research experience for the introductory physics student. In this article I will discuss the galvanometers that I used in this work, and will show a resonance curve for one of them.
DEFF Research Database (Denmark)
Brücker, Herbert; Jahn, Elke J.
Based on a wage curve approach we examine the labor market effects of migration in Germany. The wage curve relies on the assumption that wages respond to a change in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously...... with a vocational degree. The wage and employment effects of migration are moderate: a 1 percent increase in the German labor force through immigration increases the aggregate unemployment rate by less than 0.1 percentage points and reduces average wages by less 0.1 percent. While native workers benefit from...... increased wages and lower unemployment, foreign workers are adversely affected....
Shock detachment from curved wedges
Mölder, S.
2017-09-01
Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.
Photometric Observation and Light Curve Analysis of Binary System ...
Indian Academy of Sciences (India)
Abstract. Photometric observations of the over-contact binary ER ORI were performed during November 2007 and February to April 2008 with the 51cm telescope of Biruni Observatory of Shiraz University in U, B and V filters (Johnson system) and an RCA 4509 photomultiplier. We used these data to obtain the light curves ...
Nishina, Makoto; Yanagi, Hidetaka; Kakuta, Takatoshi; Endoh, Masayuki; Fukagawa, Masafumi; Takagi, Atsushi
2014-08-01
Common outcomes of peritoneal dialysis (PD)-related peritonitis include catheter removal and transition to hemodialysis (HD). According to recent data, the incidence of PD-related peritonitis in Japan is not low, and peritonitis is the most common cause of withdrawal from PD. Against this backdrop, the purpose of this study is to determine the incidence of PD-related peritonitis at the Outpatient Nephrology Clinic of Tokai University Hospital (hereafter "the Clinic") and to examine causative bacteria and the risk factors related to the development of peritonitis. We investigated all PD-related peritonitis episodes of 192 PD patients who visited the Clinic during the period from April 1, 2001 to March 31, 2011 and established the incidence of PD-related peritonitis, along with culture-negative peritonitis rates. Regarding the risk factors that are associated with the development of peritonitis, we examined patient backgrounds, whether an automated peritoneal dialysis (APD) device was used, and which type of connection system was employed. The incidence of peritonitis was one episode per 64.5 patient-months, and the culture-negative peritonitis rate was 16.4 %. Of the cultured bacterial isolates 71.3 % were Gram-positive cocci, including 25.0 % of coagulase-negative staphylococci, 13.2 % of methicillin-susceptible Staphylococcus aureus (MSSA), and 6.6 % of methicillin-resistant Staphylococcus aureus (MRSA). Gram-negative rods were 19.1 %. Risk factors associated with the development of peritonitis included age at the start of PD [odds ratio 1.042, 95 % confidence interval (CI) 1.016-1.069, p value = 0.001], diabetes mellitus nephropathy (DMN) (odds ratio 22.003, 95 % CI 2.101-230.452, p value = 0.010), and the use of a sterile tubing welder device (STWD) (odds ratio 2.399, 95 % CI 1.043-5.521, p value = 0.040). Regarding the situation of peritonitis at a single center during the 10-year period of this study, risk factors associated with the development of peritonitis
Dayton, Paul; Ferguson, Joe; Hatch, Daniel; Santrock, Robert; Scanlan, Sean; Smith, Bret
2016-01-01
To better understand the mechanical characteristics of biplane locked plating in small bone fixation, the present study compared the stability under cyclic cantilever loading of a 2-plate locked biplane (BPP) construct without interfragmentary compression with that of a single-plate locked construct with an additional interfragmentary screw (SPS) using surrogate bone models simulating Lapidus arthrodesis. In static ultimate plantar bending, the BPP construct failed at significantly greater load than did the SPS construct (556.2 ± 37.1 N versus 241.6 ± 6.3 N, p = .007). For cyclic failure testing in plantar bending at a 180-N starting load, the BPP construct failed at a significantly greater number of cycles (158,322 ± 50,609 versus 13,718 ± 10,471 cycles) and failure load (242.5 ± 25.0 N versus 180.0 ± 0.0 N) than the SPS construct (p = .002). For cyclic failure testing in plantar bending at a 120-N starting load, the results were not significantly different between the BPP and SPS constructs for the number of cycles (207,646 ± 45,253 versus 159,334 ± 69,430) or failure load (205.0 ± 22.4 N versus 185.0 ± 33.5 N; p = .300). For cyclic testing with 90° offset loading (i.e., medial to lateral bending) at a 120-N starting load, all 5 BPP constructs (tension side) and 2 of the 5 SPS constructs reached 250,000 cycles without failure. Overall, the present study found the BPP construct to have superior or equivalent stability in multiplanar orientations of force application in both static and fatigue testing. Thus, the concept of biplane locked plating, using 2 low profile plates and unicortical screw insertion, shows promise in small bone fixation, because it provides consistent stability in multiplanar orientations, making it universally adaptable to many clinical situations. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere
Kahraman, Tanju; Hüseyin Ugurlu, Hasan
2016-01-01
In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.
The aeolian dust accumulation curve
Goossens, D.
2001-01-01
This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. The concept is tested in an aeolian dust wind tunnel. The agreement between the accumulation curve predicted by the model and the accumulation
Indian Academy of Sciences (India)
The cause-effect relationship for a wide variety of biologi- cal processes from molecular to ecosystem levels can be described by a curvilinear function called the rectangular hyperbola. Although a simple algebraic equation adequately describes this curve, biological models have generated different equations incorporating ...
Survival curves for irradiated cells
International Nuclear Information System (INIS)
Gibson, D.K.
1975-01-01
The subject of the lecture is the probability of survival of biological cells which have been subjected to ionising radiation. The basic mathematical theories of cell survival as a function of radiation dose are developed. A brief comparison with observed survival curves is made. (author)
2013-01-01
This software can be used to assist with the assessment of margin of safety for a horizontal curve. It is intended for use by engineers and technicians responsible for safety analysis or management of rural highway pavement or traffic control devices...
Ultrasonic Fetal Cephalometry: Percentiles Curve
Flamme, P.
1972-01-01
Measurements by ultrasound of the biparietal diameter of the fetal head during pregnancy are a reliable guide to fetal growth. As a ready means of comparison with the normal we constructed from 4,170 measurements in 1,394 cases a curve showing the percentiles distribution of biparietal diameters for each week of gestation. PMID:5070162
Interpolation and Polynomial Curve Fitting
Yang, Yajun; Gordon, Sheldon P.
2014-01-01
Two points determine a line. Three noncollinear points determine a quadratic function. Four points that do not lie on a lower-degree polynomial curve determine a cubic function. In general, n + 1 points uniquely determine a polynomial of degree n, presuming that they do not fall onto a polynomial of lower degree. The process of finding such a…
Automatic processing of isotopic dilution curves obtained by precordial detection
International Nuclear Information System (INIS)
Verite, J.C.
1973-01-01
Dilution curves pose two distinct problems: that of their acquisition and that of their processing. A study devoted to the latter aspect only was presented. It was necessary to satisfy two important conditions: the treatment procedure, although applied to a single category of curves (isotopic dilution curves obtained by precordial detection), had to be as general as possible; to allow dissemination of the method the equipment used had to be relatively modest and inexpensive. A simple method, considering the curve processing as a process identification, was developed and should enable the mean heart cavity volume and certain pulmonary circulation parameters to be determined. Considerable difficulties were encountered, limiting the value of the results obtained though not condemning the method itself. The curve processing question raised the problem of their acquisition, i.e. the number of these curves and their meaning. A list of the difficulties encountered is followed by a set of possible solutions, a solution being understood to mean a curve processing combination where the overlapping between the two aspects of the problem is accounted for [fr
Progress Report on Alloy 617 Isochronous Stress-Strain Curves
Energy Technology Data Exchange (ETDEWEB)
Jill K. Wright; Richard N. Wright; Nancy J. Lybeck
2014-03-01
Isochronous stress-strain curves for Alloy 617 up to a temperature of 1000°C will be required to qualify the material for elevated temperature design in Section III, Division 1, Subsection NH of the ASME Boiler and Pressure Vessel Code. Several potential methods for developing these curves are reviewed in this report. It is shown that in general power-law creep is the rate controlling deformation mechanism for a wide range of alloy heats, test temperatures and stresses. Measurement of the strain rate sensitivity of Alloy 617 indicates that the material is highly strain rate sensitive in the tensile deformation range above about 750°C. This suggests that the concept of a hot tensile curve as a bounding case on the isochronous stress-strain diagrams is problematic. The impact of strain rate on the hot tensile curves is examined and it is concluded that incorporating such a curve is only meaningful if a single tensile strain rate (typically the ASTM standard rate of 0.5%/min) is arbitrarily defined. Current experimentally determined creep data are compared to isochronous stress-strain curves proposed previously by the German programs in the 1980s and by the 1990 draft ASME Code Case. Variability in how well the experimental data are represented by the proposed design curves that suggests further analysis is necessary prior to completing a new draft Code Case.
Leptogenesis from loop effects in curved spacetime
Energy Technology Data Exchange (ETDEWEB)
McDonald, Jamie I.; Shore, Graham M. [Department of Physics, Swansea University,Singleton Park, Swansea, SA2 8PP (United Kingdom)
2016-04-05
We describe a new mechanism — radiatively-induced gravitational leptogenesis — for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C and CP violating theories cause matter and antimatter to propagate differently in the presence of gravity, and prove this is forbidden in flat space by CPT and translation symmetry. This generates a curvature-dependent chemical potential for leptons, allowing a matter-antimatter asymmetry to be generated in thermal equilibrium in the early Universe. The time-dependent dynamics necessary for leptogenesis is provided by the interaction of the virtual self-energy cloud of the leptons with the expanding curved spacetime background, which violates the strong equivalence principle and allows a distinction between matter and antimatter. We show here how this mechanism is realised in a particular BSM theory, the see-saw model, where the quantum loops involve the heavy sterile neutrinos responsible for light neutrino masses. We demonstrate by explicit computation of the relevant two-loop Feynman diagrams how the size of the radiative corrections relevant for leptogenesis becomes enhanced by increasing the mass hierarchy of the sterile neutrinos, and show how the induced lepton asymmetry may be sufficiently large to play an important rôle in determining the baryon-to-photon ratio of the Universe.
New NIR light-curve templates for classical Cepheids
Inno, L.; Matsunaga, N.; Romaniello, M.; Bono, G.; Monson, A.; Ferraro, I.; Iannicola, G.; Persson, E.; Buonanno, R.; Freedman, W.; Gieren, W.; Groenewegen, M.A.T.; Ita, Y.; Laney, C.D.; Lemasle, B.; Madore, B.F.; Nagayama, T.; Nakada, Y.; Nonino, M.; Pietrzyński, G.; Primas, F.; Scowcroft, V.; Soszyński, I.; Tanabé, T.; Udalski, A.
2015-01-01
Aims. We present new near-infrared (NIR) light-curve templates for fundamental (FU, J, H, KS) and first overtone (FO, J) classical Cepheids. The new templates together with period-luminosity and period-Wesenheit (PW) relations provide Cepheid distances from single-epoch observations with a precision
Interim Site-index Curves for Longleaf Pine Plantations
William D. Boyer
1980-01-01
No single set of site-index curves can be uniformly applied to young longleaf pine plantations without a sacrifice in reliability. A recent study using plantation remeasurement data indicated that planting-site condition (old fields and mechanically prepared or unprepared cutover forest sites) has a major impact on early plantation height growth. Stand density (...
A catalog of special plane curves
Lawrence, J Dennis
2014-01-01
Among the largest, finest collections available-illustrated not only once for each curve, but also for various values of any parameters present. Covers general properties of curves and types of derived curves. Curves illustrated by a CalComp digital incremental plotter. 12 illustrations.
Computation of undulator tuning curves
International Nuclear Information System (INIS)
Dejus, Roger J.
1997-01-01
Computer codes for fast computation of on-axis brilliance tuning curves and flux tuning curves have been developed. They are valid for an ideal device (regular planar device or a helical device) using the Bessel function formalism. The effects of the particle beam emittance and the beam energy spread on the spectrum are taken into account. The applicability of the codes and the importance of magnetic field errors of real insertion devices are addressed. The validity of the codes has been experimentally verified at the APS and observed discrepancies are in agreement with predicted reduction of intensities due to magnetic field errors. The codes are distributed as part of the graphical user interface XOP (X-ray OPtics utilities), which simplifies execution and viewing of the results
A curved resonant flexoelectric actuator
Zhang, Shuwen; Liu, Kaiyuan; Xu, Minglong; Shen, Shengping
2017-08-01
Flexoelectricity is an electro-mechanical coupling effect that exists in all dielectrics and has the potential to replace piezoelectric actuating on the microscale. In this letter, a curved flexoelectric actuator with non-polarized polyvinylidene fluoride is presented and shown to exhibit good electro-mechanical properties. This provides experimental support for a body of theoretical research into converse flexoelectricity in polymeric materials. In addition, this work demonstrates the feasibility of lead-free microscale actuating without piezoelectricity.
Active Particles on Curved Surfaces
Fily, Yaouen; Baskaran, Aparna; Hagan, Michael F.
2016-01-01
Recent studies have highlighted the sensitivity of active matter to boundaries and their geometries. Here we develop a general theory for the dynamics and statistics of active particles on curved surfaces and illustrate it on two examples. We first show that active particles moving on a surface with no ability to probe its curvature only exhibit steady-state inhomogeneities in the presence of orientational order. We then consider a strongly confined 3D ideal active gas and compute its steady-...
Growth curves for Laron syndrome.
Laron, Z; Lilos, P; Klinger, B
1993-06-01
Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls completed their growth between the age of 16-19 years to a final mean (SD) height of 119 (8.5) cm whereas the boys continued growing beyond the age of 20 years, achieving a final height of 124 (8.5) cm. At all ages the upper to lower body segment ratio was more than 2 SD above the normal mean. These growth curves constitute a model not only for primary, hereditary insulin-like growth factor-I (IGF-I) deficiency (Laron syndrome) but also for untreated secondary IGF-I deficiencies such as growth hormone gene deletion and idiopathic congenital isolated growth hormone deficiency. They should also be useful in the follow up of children with Laron syndrome treated with biosynthetic recombinant IGF-I.
Projection-based curve clustering
International Nuclear Information System (INIS)
Auder, Benjamin; Fischer, Aurelie
2012-01-01
This paper focuses on unsupervised curve classification in the context of nuclear industry. At the Commissariat a l'Energie Atomique (CEA), Cadarache (France), the thermal-hydraulic computer code CATHARE is used to study the reliability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code is quite complex and CPU time-consuming, it has to be approximated by a regression model. This regression process involves a clustering step. In the present paper, the CATHARE output curves are clustered using a k-means scheme, with a projection onto a lower dimensional space. We study the properties of the empirically optimal cluster centres found by the clustering method based on projections, compared with the 'true' ones. The choice of the projection basis is discussed, and an algorithm is implemented to select the best projection basis among a library of orthonormal bases. The approach is illustrated on a simulated example and then applied to the industrial problem. (authors)
Path Integrals and Anomalies in Curved Space
Energy Technology Data Exchange (ETDEWEB)
Louko, Jorma [University of Nottingham (United Kingdom)
2007-04-07
gain from the book a heightened appreciation of the central role of regularization as a defining ingredient of a quantum field theory and will be impressed by the agreement of results arising from different regularization schemes. The readers may in particular enjoy the authors' 'brief history of anomalies' in quantum field theory, as well as a similar historical discussion of path integrals in quantum mechanics. (Book review of Path Integrals and Anomalies in Curved Space, Fiorenzo Bastianelli and Peter van Nieuwenhuizen, 2006 Cambridge: Cambridge University Press, ISBN10: 052-184-761-3)
Analytical extension of curved shock theory
Emanuel, G.
2018-03-01
Curved shock theory (CST) is limited to shock waves in a steady, two-dimensional or axisymmetric (2-Ax) flow of a perfect gas. A unique feature of CST is its use of intrinsic coordinates that result in an elegant and useful formulation for flow properties just downstream of a shock. For instance, the downstream effect of upstream vorticity, shock wave curvature, and the upstream pressure gradient along a streamline is established. There have been several attempts to extend CST, as mentioned in the text. Removal of the steady, 2-Ax, and perfect gas limitations, singly or in combination, requires an appropriate formulation of the shock wave's jump relations and the intrinsic coordinate Euler equations. Issues discussed include flow plane versus osculating plane, unsteady flow, vorticity, an imperfect gas, etc. The extension of CST utilizes concepts from differential geometry, such as the osculating plane, streamline torsion, and the Serret-Frenet equations.
Dual Smarandache Curves and Smarandache Ruled Surfaces
Tanju KAHRAMAN; Mehmet ÖNDER; H. Hüseyin UGURLU
2013-01-01
In this paper, by considering dual geodesic trihedron (dual Darboux frame) we define dual Smarandache curves lying fully on dual unit sphere S^2 and corresponding to ruled surfaces. We obtain the relationships between the elements of curvature of dual spherical curve (ruled surface) x(s) and its dual Smarandache curve (Smarandache ruled surface) x1(s) and we give an example for dual Smarandache curves of a dual spherical curve.
Consideration of uncertainties in CCDF risk curves in safety oriented decision making processes
International Nuclear Information System (INIS)
Stern, E.; Tadmor, J.
1988-01-01
In recent years, some of the results of Probabilistic Risk Assessment (i.e. the magnitudes of the various adverse health effects and other effects of potential accidents in nuclear power plants) have usually been presented in Complementary Cumulative Distribution Function curves, widely known as CCDF risk curves. CCDF curves are characteristic of probabilistic accident analyses and consequence calculations, although, in many cases, the codes producing the CCDF curves consist of a mixture of both probabilistic and deterministic calculations. One of the main difficulties in the process of PRA is the problem of uncertainties associated with the risk assessments. The uncertainties, as expressed in CCDF risk curves can be classified into two main categories: (a) uncertainties expressed by the CCDF risk curve itself due to its probabilistic nature and - (b) the uncertainty band of CCDF risk curves. The band consists of a ''family of CCDF curves'' which represents the risks (e.g. early/late fatalities) evaluated at various levels of confidence for a specific Plant-Site Combination (PSC) i.e. a certain nuclear power plant located at a certain site. The reasons why a family of curves rather than a single curve represents the risk of a certain PSC have been discussed. Generally, the uncertainty band of CCDF curves is limited by the 95% (''conservative'') and the 5% curves. In most cases the 50% (median, ''best estimate'') curve is also shown because scientists tend to believe that it represents the ''realistic'' (or real) risk of the plant
Parametrizations of elliptic curves by Shimura curves and by classical modular curves.
Ribet, K A; Takahashi, S
1997-10-14
Fix an isogeny class of semistable elliptic curves over Q. The elements A of have a common conductor N, which is a square-free positive integer. Let D be a divisor of N which is the product of an even number of primes--i.e., the discriminant of an indefinite quaternion algebra over Q. To D we associate a certain Shimura curve X(0)D(N/D), whose Jacobian is isogenous to an abelian subvariety of J0(N). There is a unique A [symbol; see text] A in for which one has a nonconstant map piD : X(0)D(N/D) --> A whose pullback A --> Pic0(X(0)D(N/D)) is injective. The degree of piD is an integer deltaD which depends only on D (and the fixed isogeny class A). We investigate the behavior of deltaD as D varies.
Li, M; Palais, R A; Zhou, L; Wittwer, C T
2017-12-15
High resolution DNA melting of PCR products is a simple technique for sequence variant detection and analysis. However, sensitivity and specificity vary and depend on many factors that continue to be defined. We introduce the area between normalized melting curves as a metric to quantify genotype discrimination. The effects of amplicon size (51-547 bp), melting rate (0.01-0.64 °C/s) and analysis method (curve shape by overlay vs absolute temperature differences) were qualitatively and quantitatively analyzed. To limit experimental variance, we studied a single nucleotide variant with identical predicted wild type and homozygous variant stabilities by nearest neighbor thermodynamic theory. Heterozygotes were easier to detect in smaller amplicons, at faster melting rates, and after curve overlay (superimposition), with some p-values overlay, PCR product size, and analysis method is complicated for homozygote genotype discrimination and is difficult to predict. Similar to temperature cycling in PCR, if the temperature control and temperature homogeneity of the solution are adequate, faster rates improve melting analysis, just like faster rates improve PCR. Copyright © 2017 Elsevier Inc. All rights reserved.
Finite element analysis of the effect of loading curve shape on brain injury predictors
Post, Andrew; Hoshizaki, Thomas Blaine; Gilchrist, M. D.
2012-01-01
Prediction of traumatic and mild traumatic brain injury is an important factor in managing their prevention. Currently, the prediction of these injuries is limited to peak linear and angular acceleration loading curves derived from laboratory reconstructions. However it remains unclear as to what aspect of these loading curves contributes to brain tissue damage. This research will use the University College Dublin Brain Trauma Model (UCDBTM) to analyze three distinct loading curve shapes mean...
International Nuclear Information System (INIS)
Krasznovszky, S.; Wagner, I.
1987-06-01
A distribution function is proposed for multiplicity in accordance with the stochastic number evolution. This function gives a universal description of inelastic and nondiffractive multiplicity distributions in pp collisions at 250, 360 and 800 GeV/c. The negative binomial distribution fails in the description of inelastic data. (author)
NLINEAR - NONLINEAR CURVE FITTING PROGRAM
Everhart, J. L.
1994-01-01
A common method for fitting data is a least-squares fit. In the least-squares method, a user-specified fitting function is utilized in such a way as to minimize the sum of the squares of distances between the data points and the fitting curve. The Nonlinear Curve Fitting Program, NLINEAR, is an interactive curve fitting routine based on a description of the quadratic expansion of the chi-squared statistic. NLINEAR utilizes a nonlinear optimization algorithm that calculates the best statistically weighted values of the parameters of the fitting function and the chi-square that is to be minimized. The inputs to the program are the mathematical form of the fitting function and the initial values of the parameters to be estimated. This approach provides the user with statistical information such as goodness of fit and estimated values of parameters that produce the highest degree of correlation between the experimental data and the mathematical model. In the mathematical formulation of the algorithm, the Taylor expansion of chi-square is first introduced, and justification for retaining only the first term are presented. From the expansion, a set of n simultaneous linear equations are derived, which are solved by matrix algebra. To achieve convergence, the algorithm requires meaningful initial estimates for the parameters of the fitting function. NLINEAR is written in Fortran 77 for execution on a CDC Cyber 750 under NOS 2.3. It has a central memory requirement of 5K 60 bit words. Optionally, graphical output of the fitting function can be plotted. Tektronix PLOT-10 routines are required for graphics. NLINEAR was developed in 1987.
Differential geometry curves, surfaces, manifolds
Kühnel, Wolfgang
2015-01-01
This carefully written book is an introduction to the beautiful ideas and results of differential geometry. The first half covers the geometry of curves and surfaces, which provide much of the motivation and intuition for the general theory. The second part studies the geometry of general manifolds, with particular emphasis on connections and curvature. The text is illustrated with many figures and examples. The prerequisites are undergraduate analysis and linear algebra. This new edition provides many advancements, including more figures and exercises, and-as a new feature-a good number of so
LINS Curve in Romanian Economy
Directory of Open Access Journals (Sweden)
Emilian Dobrescu
2016-02-01
Full Text Available The paper presents theoretical considerations and empirical evidence to test the validity of the Laffer in Narrower Sense (LINS curve as a parabola with a maximum. Attention is focused on the so-called legal-effective tax gap (letg. The econometric application is based on statistical data (1990-2013 for Romania as an emerging European economy. Three cointegrating regressions (fully modified least squares, canonical cointegrating regression and dynamic least squares and three algorithms, which are based on instrumental variables (two-stage least squares, generalized method of moments, and limited information maximum likelihood, are involved.
Principal Curves on Riemannian Manifolds
DEFF Research Database (Denmark)
Hauberg, Søren
2015-01-01
Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only...... in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimize a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend...
Lightlike contractions in curved spacetime
International Nuclear Information System (INIS)
Aichelburg, P.C.; Embacher, F.
1984-01-01
The technique of lightlike contractions in flat and curved space is described. The method consists in boosting a classical field configuration to the velocity of light by an appropriate generalized Lorentz transformation. Within this framework the gravitational field of a massless neutral particle is a meaningful concept. For electrically charged particles, however, the field equations seem to prevent an analogous procedure. We thus conjecture that general relativity forbids the existance of charged point particles moving with the velocity of light. Further examples for lightlike contractions of a self-dual electromagnetic field and of a linearized Rarita-Schwinger (spin-3/2) field are given. (Author)
An appraisal of the learning curve in robotic general surgery.
Pernar, Luise I M; Robertson, Faith C; Tavakkoli, Ali; Sheu, Eric G; Brooks, David C; Smink, Douglas S
2017-11-01
Robotic-assisted surgery is used with increasing frequency in general surgery for a variety of applications. In spite of this increase in usage, the learning curve is not yet defined. This study reviews the literature on the learning curve in robotic general surgery to inform adopters of the technology. PubMed and EMBASE searches yielded 3690 abstracts published between July 1986 and March 2016. The abstracts were evaluated based on the following inclusion criteria: written in English, reporting original work, focus on general surgery operations, and with explicit statistical methods. Twenty-six full-length articles were included in final analysis. The articles described the learning curves in colorectal (9 articles, 35%), foregut/bariatric (8, 31%), biliary (5, 19%), and solid organ (4, 15%) surgery. Eighteen of 26 (69%) articles report single-surgeon experiences. Time was used as a measure of the learning curve in all studies (100%); outcomes were examined in 10 (38%). In 12 studies (46%), the authors identified three phases of the learning curve. Numbers of cases needed to achieve plateau performance were wide-ranging but overlapping for different kinds of operations: 19-128 cases for colorectal, 8-95 for foregut/bariatric, 20-48 for biliary, and 10-80 for solid organ surgery. Although robotic surgery is increasingly utilized in general surgery, the literature provides few guidelines on the learning curve for adoption. In this heterogeneous sample of reviewed articles, the number of cases needed to achieve plateau performance varies by case type and the learning curve may have multiple phases as surgeons add more complex cases to their case mix with growing experience. Time is the most common determinant for the learning curve. The literature lacks a uniform assessment of outcomes and complications, which would arguably reflect expertise in a more meaningful way than time to perform the operation alone.
Differential geometry and topology of curves
Animov, Yu
2001-01-01
Differential geometry is an actively developing area of modern mathematics. This volume presents a classical approach to the general topics of the geometry of curves, including the theory of curves in n-dimensional Euclidean space. The author investigates problems for special classes of curves and gives the working method used to obtain the conditions for closed polygonal curves. The proof of the Bakel-Werner theorem in conditions of boundedness for curves with periodic curvature and torsion is also presented. This volume also highlights the contributions made by great geometers. past and present, to differential geometry and the topology of curves.
Classical optics and curved spaces
International Nuclear Information System (INIS)
Bailyn, M.; Ragusa, S.
1976-01-01
In the eikonal approximation of classical optics, the unit polarization 3-vector of light satisfies an equation that depends only on the index, n, of refraction. It is known that if the original 3-space line element is d sigma 2 , then this polarization direction propagates parallely in the fictitious space n 2 d sigma 2 . Since the equation depends only on n, it is possible to invent a fictitious curved 4-space in which the light performs a null geodesic, and the polarization 3-vector behaves as the 'shadow' of a parallely propagated 4-vector. The inverse, namely, the reduction of Maxwell's equation, on a curve 'dielectric free) space, to a classical space with dielectric constant n=(-g 00 ) -1 / 2 is well known, but in the latter the dielectric constant epsilon and permeability μ must also equal (-g 00 ) -1 / 2 . The rotation of polarization as light bends around the sun by utilizing the reduction to the classical space, is calculated. This (non-) rotation may then be interpreted as parallel transport in the 3-space n 2 d sigma 2 [pt
Deformation Based Curved Shape Representation.
Demisse, Girum G; Aouada, Djamila; Ottersten, Bjorn
2017-06-02
In this paper, we introduce a deformation based representation space for curved shapes in Rn. Given an ordered set of points sampled from a curved shape, the proposed method represents the set as an element of a finite dimensional matrix Lie group. Variation due to scale and location are filtered in a preprocessing stage, while shapes that vary only in rotation are identified by an equivalence relationship. The use of a finite dimensional matrix Lie group leads to a similarity metric with an explicit geodesic solution. Subsequently, we discuss some of the properties of the metric and its relationship with a deformation by least action. Furthermore, invariance to reparametrization or estimation of point correspondence between shapes is formulated as an estimation of sampling function. Thereafter, two possible approaches are presented to solve the point correspondence estimation problem. Finally, we propose an adaptation of k-means clustering for shape analysis in the proposed representation space. Experimental results show that the proposed representation is robust to uninformative cues, e.g. local shape perturbation and displacement. In comparison to state of the art methods, it achieves a high precision on the Swedish and the Flavia leaf datasets and a comparable result on MPEG-7, Kimia99 and Kimia216 datasets.
Wosnitza, Marold; Volet, Simone
2014-01-01
This paper examines how distinct trajectories of change in students' general views of group work over the duration of one single group assignment could be explained by multidimensional aspects of their experience and the overall instructional context. Science (336) and Education (377) students involved in a semester-long group assignment…
Bhowmik, Dhrubajyoti; Saha, Apu Kr; Dutta, Paramartha; Nandi, Supratim
2017-08-01
Quantum-dot Cellular Automata (QCA) is one of the most substitutes developing nanotechnologies for electronic circuits, as a result of lower force utilization, higher speed and smaller size in correlation with CMOS innovation. The essential devices, a Quantum-dot cell can be utilized to logic gates and wires. As it is the key building block on nanotechnology circuits. By applying simple gates, the hardware requirements for a QCA circuit can be decreased and circuits can be less complex as far as level, delay and cell check. This article exhibits an unobtrusive methodology for actualizing novel upgraded simple and universal gates, which can be connected to outline numerous variations of complex QCA circuits. Proposed gates are straightforward in structure and capable as far as implementing any digital circuits. The main aim is to build all basic and universal gates in a simple circuit with and without crossbar-wire. Simulation results and physical relations affirm its handiness in actualizing each advanced circuit.
Mass transfer and power characteristics of stirred tank with Rushton and curved blade impeller
Directory of Open Access Journals (Sweden)
Thiyam Tamphasana Devi
2017-04-01
Full Text Available Present work compares the mass transfer coefficient (kLa and power draw capability of stirred tank employed with Rushton and curved blade impeller using computational fluid dynamics (CFD techniques in single and double impeller cases. Comparative analysis for different boundary conditions and mass transfer model has been done to assess their suitability. The predicted local kLa has been found higher in curved blade impeller than the Rushton impeller, whereas stirred tank with double impeller does not show variation due to low superficial gas velocity. The global kLa predicted has been found higher in curved blade impeller than the Rushton impeller in double and single cases. Curved blade impeller also exhibits higher power draw capability than the Rushton impeller. Overall, stirred tank with curved blade impeller gives higher efficiency in both single and double cases than the Rushton turbine
Smarandache Curves In Terms of Sabban Frame of Fixed Pole Curve
Directory of Open Access Journals (Sweden)
Süleyman Şenyurt
2016-06-01
Full Text Available In this paper, we study the special Smarandache curve interms of Sabban frame of Fixed Pole curve and we give some characterization of Smarandache curves. Besides, we illustrate examples of our results.
Transition curves for highway geometric design
Kobryń, Andrzej
2017-01-01
This book provides concise descriptions of the various solutions of transition curves, which can be used in geometric design of roads and highways. It presents mathematical methods and curvature functions for defining transition curves. .
2002-01-01
The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...
Integration over Tropical Plane Curves and Ultradiscretization
Iwao, Shinsuke
2008-01-01
In this article we study holomorphic integrals on tropical plane curves in view of ultradiscretization. We prove that the lattice integrals over tropical curves can be obtained as a certain limit of complex integrals over Riemannian surfaces.
A Conjectural Generating Function for Numbers of Curves on Surfaces
Göttsche, Lothar
I give a conjectural generating function for the numbers of δ-nodal curves in a linear system of dimension δ on an algebraic surface. It reproduces the results of Vainsencher [V] for the case δ &\\le 6 and Kleiman-Piene [K-P] for the case δ &\\le 8. The numbers of curves are expressed in terms of five universal power series, three of which I give explicitly as quasimodular forms. This gives in particular the numbers of curves of arbitrary genus on a K3 surface and an abelian surface in terms of quasimodular forms, generalizing the formula of Yau-Zaslow for rational curves on K3 surfaces. The coefficients of the other two power series can be determined by comparing with the recursive formulas of Caporaso-Harris for the Severi degrees in 2. We verify the conjecture for genus 2 curves on an abelian surface. We also discuss a link of this problem with Hilbert schemes of points.
Estimation method of the fracture resistance curve
Energy Technology Data Exchange (ETDEWEB)
Cho, Sung Keun; Lee, Kwang Hyeon; Koo, Jae Mean; Seok, Chang Sung [Sungkyunkwan Univ., Suwon (Korea, Republic of); Park, Jae Sil [Samsung Electric Company, Suwon (Korea, Republic of)
2008-07-01
Fracture resistance curves for concerned materials are required in order to perform elastic-plastic fracture mechanical analysis. Fracture resistance curve is built with J-integral values and crack extension values. The objective of this paper is to propose the estimation method of the fracture resistance curve. The estimation method of the fracture resistance curve for the pipe specimen was proposed by the load ratio method from load - displacement data for the standard specimen.
M-curves and symmetric products
Indian Academy of Sciences (India)
Indranil Biswas
2017-08-03
Aug 3, 2017 ... Since M-curves play a special role in the topology of real algebraic varieties, it is useful to have a criterion for M-curves. It was proved earlier that a curve defined over R is an. M-curve if and only if its Jacobian is an M-variety [5]. We use this result of [5] and the. Picard bundle to prove that the n-th symmetric ...
Modeling fertility curves in Africa
Directory of Open Access Journals (Sweden)
Ezra Gayawan
2010-02-01
Full Text Available The modeling of fertility patterns is an essential method researchers use to understand world-wide population patterns. Various types of fertility models have been reported in the literature to capture the patterns specific to developed countries. While much effort has been put into reducing fertility rates in Africa, models which describe the fertility patterns have not been adequately described. This article presents a flexible parametric model that can adequately capture the varying patterns of the age-specific fertility curves of African countries. The model has parameters that are interpretable in terms of demographic indices. The performance of this model was compared with other commonly used models and Akaike's Information Criterion was used for selecting the model with best fit. The presented model was able to reproduce the empirical fertility data of 11 out of 15 countries better than the other models considered.
Ait-Haddou, Rachid
2013-02-01
We show that the generalized Bernstein bases in Müntz spaces defined by Hirschman and Widder (1949) and extended by Gelfond (1950) can be obtained as pointwise limits of the Chebyshev–Bernstein bases in Müntz spaces with respect to an interval [a,1][a,1] as the positive real number a converges to zero. Such a realization allows for concepts of curve design such as de Casteljau algorithm, blossom, dimension elevation to be transferred from the general theory of Chebyshev blossoms in Müntz spaces to these generalized Bernstein bases that we termed here as Gelfond–Bernstein bases. The advantage of working with Gelfond–Bernstein bases lies in the simplicity of the obtained concepts and algorithms as compared to their Chebyshev–Bernstein bases counterparts.
Euler characteristics and elliptic curves.
Coates, J; Howson, S
1997-10-14
Let E be a modular elliptic curve over [symbol, see text], without complex multiplication; let p be a prime number where E has good ordinary reduction; and let Finfinity be the field obtained by adjoining [symbol, see text] to all p-power division points on E. Write Ginfinity for the Galois group of Finfinity over [symbol, see text]. Assume that the complex L-series of E over [symbol, see text] does not vanish at s = 1. If p >/= 5, we make a precise conjecture about the value of the Ginfinity-Euler characteristic of the Selmer group of E over Finfinity. If one makes a standard conjecture about the behavior of this Selmer group as a module over the Iwasawa algebra, we are able to prove our conjecture. The crucial local calculations in the proof depend on recent joint work of the first author with R. Greenberg.
Separation control on curved boundaries
Kamal Kumar, R.; Mathur, Manikandan
2017-11-01
Flow separation and its characteristics are an important consideration in the field of bluff body aerodynamics. Specifically, the location and slope of the separation, and the size of the re-circulation bubble that forms downstream of the bluff body significantly affect the resulting aerodynamic forces. Recent theories based on dynamical systems (Haller, 2004) have established criteria based on wall-based quantities that identify the location and slope of separation in unsteady flows. In this work, we adapt the closed-loop separation control algorithm proposed by Alam, Liu & Haller (2006) to curved boundaries, and demonstrate the effectiveness of the same via numerical simulations on the flow past a cylinder in the vortex-shedding regime. Using appropriately placed wall-based actuators that use inputs from shear stress sensors placed between the actuators, we demonstrate that the separation characteristics including the re-circulation bubble length, can be desirably modified.
Bacterial streamers in curved microchannels
Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard
2009-11-01
Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.
AKLSQF - LEAST SQUARES CURVE FITTING
Kantak, A. V.
1994-01-01
The Least Squares Curve Fitting program, AKLSQF, computes the polynomial which will least square fit uniformly spaced data easily and efficiently. The program allows the user to specify the tolerable least squares error in the fitting or allows the user to specify the polynomial degree. In both cases AKLSQF returns the polynomial and the actual least squares fit error incurred in the operation. The data may be supplied to the routine either by direct keyboard entry or via a file. AKLSQF produces the least squares polynomial in two steps. First, the data points are least squares fitted using the orthogonal factorial polynomials. The result is then reduced to a regular polynomial using Sterling numbers of the first kind. If an error tolerance is specified, the program starts with a polynomial of degree 1 and computes the least squares fit error. The degree of the polynomial used for fitting is then increased successively until the error criterion specified by the user is met. At every step the polynomial as well as the least squares fitting error is printed to the screen. In general, the program can produce a curve fitting up to a 100 degree polynomial. All computations in the program are carried out under Double Precision format for real numbers and under long integer format for integers to provide the maximum accuracy possible. AKLSQF was written for an IBM PC X/AT or compatible using Microsoft's Quick Basic compiler. It has been implemented under DOS 3.2.1 using 23K of RAM. AKLSQF was developed in 1989.
Endoscopic sleeve gastroplasty: the learning curve.
Hill, Christine; El Zein, Mohamad; Agnihotri, Abhishek; Dunlap, Margo; Chang, Angela; Agrawal, Alison; Barola, Sindhu; Ngamruengphong, Saowanee; Chen, Yen-I; Kalloo, Anthony N; Khashab, Mouen A; Kumbhari, Vivek
2017-09-01
Endoscopic sleeve gastroplasty (ESG) is gaining traction as a minimally invasive bariatric treatment. Concern that the learning curve may be slow, even among those proficient in endoscopic suturing, is a barrier to widespread implementation of the procedure. Therefore, we aimed to define the learning curve for ESG in a single endoscopist experienced in endoscopic suturing who participated in a 1-day ESG training program. Consecutive patients who underwent ESG between February 2016 and November 2016 were included. The performing endoscopist, who is proficient in endoscopic suturing for non-ESG procedures, participated in a 1-day ESG training session before offering ESG to patients. The outcome measurements were length of procedure (LOP) and number of plications per procedure. Nonlinear regression was used to determine the learning plateau and calculate the learning rate. Twenty-one consecutive patients (8 males), with mean age 47.7 ± 11.2 years and mean body mass index 41.8 ± 8.5 kg/m 2 underwent ESG. LOP decreased significantly across consecutive procedures, with a learning plateau at 101.5 minutes and a learning rate of 7 cases ( P = 0.04). The number of plications per procedure also decreased significantly across consecutive procedures, with a plateau at 8 sutures and a learning rate of 9 cases ( P < 0.001). Further, the average time per plication decreased significantly with consecutive procedures, reaching a plateau at 9 procedures ( P < 0.001). Endoscopists experienced in endoscopic suturing are expected to achieve a reduction in LOP and number of plications per procedure in successive cases, with progress plateauing at 7 and 9 cases, respectively.
Sibling curves of quadratic polynomials | Wiggins | Quaestiones ...
African Journals Online (AJOL)
Sibling curves were demonstrated in [1, 2] as a novel way to visualize the zeroes of real valued functions. In [3] it was shown that a polynomial of degree n has n sibling curves. This paper focuses on the algebraic and geometric properites of the sibling curves of real and complex quadratic polynomials. Key words: Quadratic ...
Legendre Elliptic Curves over Finite Fields
Auer, Roland; Top, Jakob
2002-01-01
We show that every elliptic curve over a finite field of odd characteristic whose number of rational points is divisible by 4 is isogenous to an elliptic curve in Legendre form, with the sole exception of a minimal respectively maximal elliptic curve. We also collect some results concerning the
Cubic spline functions for curve fitting
Young, J. D.
1972-01-01
FORTRAN cubic spline routine mathematically fits curve through given ordered set of points so that fitted curve nearly approximates curve generated by passing infinite thin spline through set of points. Generalized formulation includes trigonometric, hyperbolic, and damped cubic spline fits of third order.
Trigonometric Characterization of Some Plane Curves
Indian Academy of Sciences (India)
IAS Admin
(Figure 1). A relation between tan θ and tanψ gives the trigonometric equation of the family of curves. In this article, trigonometric equations of some known plane curves are deduced and it is shown that these equations reveal some geometric characteristics of the families of the curves under consideration. In Section 2,.
Holomorphic curves in exploded manifolds: Kuranishi structure
Parker, Brett
2013-01-01
This paper constructs a Kuranishi structure for the moduli stack of holomorphic curves in exploded manifolds. To avoid some technicalities of abstract Kuranishi structures, we embed our Kuranishi structure inside a moduli stack of curves. The construction also works for the moduli stack of holomorphic curves in any compact symplectic manifold.
Automated Blazar Light Curves Using Machine Learning
Energy Technology Data Exchange (ETDEWEB)
Johnson, Spencer James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-07-27
This presentation describes a problem and methodology pertaining to automated blazar light curves. Namely, optical variability patterns for blazars require the construction of light curves and in order to generate the light curves, data must be filtered before processing to ensure quality.
Analysis of the nonlinear dynamics of a 2-axle freight wagon in curves
DEFF Research Database (Denmark)
Di Gialleonardo, Egidio; Bruni, Stefano; True, Hans
2014-01-01
and bifurcations are identified for some particular values of the curve radius. For the single car case, it is shown that depending on the curve radius and the vehicle speed the carbody may experience severe periodic oscillations at speeds lying in the operating range of the vehicle. For the car-assembly case...
Development of a Charpy master curve-based embrittlement trend curve
International Nuclear Information System (INIS)
Erikson, M.
2011-01-01
Under the current U.S. surveillance programs, the Charpy V-notch energy (CVE), yield strength, and tensile strength are measured (all as a function of test temperature) at various times during the operational life of the reactor vessel. Conventionally, the CVE vs. temperature data are fit using a hyperbolic tangent (tanh) function to determine the temperature at which the mean CVE is equal to 30 ft-lbs (41J). This index temperature, which is designated T30 or T41J, is used to track irradiation damage. Recently an alternative strategy for fitting the CVE vs. temperature data was proposed in which a single CVE vs. temperature relationship appears to well represent the behavior of a very wide variety of ferritic steels for temperatures at and below fracture mode transition. It was demonstrated that when upper shelf data are excluded from a fit of Charpy V-notch energy (CVE) vs. temperature a single exponential function is found that well represents the transition temperature behavior of ferritic steels. The findings suggest that a reanalysis of already tested Charpy surveillance specimens can provide the basis for development of an embrittlement trend curve that is less influenced by the biases that arise from the tanh curve fitting method. Recently, a program was initiated with a goal of using the Charpy MC transition data fit to define a reference temperature, to use instead of the traditionally defined tanh-based T30/T41J reference temperature, in development of an embrittlement trend curve. The existing USLWR database was mined for datasets with sufficient data points within the transition temperature region for use in defining a TCVE reference temperature. These values were then used to define ΔTCVE data with irradiation. This data, along with chemistry, temperature, flux and fluence information, was used to develop the embrittlement trend curve presented herein. Predictions of embrittlement behavior made using this ETC were then compared to predictions made
Method of construction spatial transition curve
Directory of Open Access Journals (Sweden)
S.V. Didanov
2013-04-01
Full Text Available Purpose. The movement of rail transport (speed rolling stock, traffic safety, etc. is largely dependent on the quality of the track. In this case, a special role is the transition curve, which ensures smooth insertion of the transition from linear to circular section of road. The article deals with modeling of spatial transition curve based on the parabolic distribution of the curvature and torsion. This is a continuation of research conducted by the authors regarding the spatial modeling of curved contours. Methodology. Construction of the spatial transition curve is numerical methods for solving nonlinear integral equations, where the initial data are taken coordinate the starting and ending points of the curve of the future, and the inclination of the tangent and the deviation of the curve from the tangent plane at these points. System solutions for the numerical method are the partial derivatives of the equations of the unknown parameters of the law of change of torsion and length of the transition curve. Findings. The parametric equations of the spatial transition curve are calculated by finding the unknown coefficients of the parabolic distribution of the curvature and torsion, as well as the spatial length of the transition curve. Originality. A method for constructing the spatial transition curve is devised, and based on this software geometric modeling spatial transition curves of railway track with specified deviations of the curve from the tangent plane. Practical value. The resulting curve can be applied in any sector of the economy, where it is necessary to ensure a smooth transition from linear to circular section of the curved space bypass. An example is the transition curve in the construction of the railway line, road, pipe, profile, flat section of the working blades of the turbine and compressor, the ship, plane, car, etc.
Dirac equation in 2-dimensional curved spacetime, particle creation, and coupled waveguide arrays
Energy Technology Data Exchange (ETDEWEB)
Koke, Christian, E-mail: christian.koke@stud.uni-heidelberg.de [Institut für theoretische Physik, Philosophenweg 16, D-69120 Heidelberg (Germany); Noh, Changsuk, E-mail: changsuk@kias.re.kr [Korea Institute for Advanced Study, 85 Hoegiro, Seoul 130-722 (Korea, Republic of); Angelakis, Dimitris G., E-mail: dimitris.angelakis@gmail.com [Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3, 117542 (Singapore); School of Electronic and Computer Engineering, Technical University of Crete, Chania, Crete, 73100 (Greece)
2016-11-15
When quantum fields are coupled to gravitational fields, spontaneous particle creation may occur similarly to when they are coupled to external electromagnetic fields. A gravitational field can be incorporated as a background spacetime if the back-action of matter on the field can be neglected, resulting in modifications of the Dirac or Klein–Gordon equations for elementary fermions and bosons respectively. The semi-classical description predicts particle creation in many situations, including the expanding-universe scenario, near the event horizon of a black hole (the Hawking effect), and an accelerating observer in flat spacetime (the Unruh effect). In this work, we give a pedagogical introduction to the Dirac equation in a general 2D spacetime and show examples of spinor wave packet dynamics in flat and curved background spacetimes. In particular, we cover the phenomenon of particle creation in a time-dependent metric. Photonic analogs of these effects are then proposed, where classical light propagating in an array of coupled waveguides provides a visualisation of the Dirac spinor propagating in a curved 2D spacetime background. The extent to which such a single-particle description can be said to mimic particle creation is discussed.
Testing the validity of stock-recruitment curve fits
International Nuclear Information System (INIS)
Christensen, S.W.; Goodyear, C.P.
1988-01-01
The utilities relied heavily on the Ricker stock-recruitment model as the basis for quantifying biological compensation in the Hudson River power case. They presented many fits of the Ricker model to data derived from striped bass catch and effort records compiled by the National Marine Fisheries Service. Based on this curve-fitting exercise, a value of 4 was chosen for the parameter alpha in the Ricker model, and this value was used to derive the utilities' estimates of the long-term impact of power plants on striped bass populations. A technique was developed and applied to address a single fundamental question: if the Ricker model were applicable to the Hudson River striped bass population, could the estimates of alpha from the curve-fitting exercise be considered reliable. The technique involved constructing a simulation model that incorporated the essential biological features of the population and simulated the characteristics of the available actual catch-per-unit-effort data through time. The ability or failure to retrieve the known parameter values underlying the simulation model via the curve-fitting exercise was a direct test of the reliability of the results of fitting stock-recruitment curves to the real data. The results demonstrated that estimates of alpha from the curve-fitting exercise were not reliable. The simulation-modeling technique provides an effective way to identify whether or not particular data are appropriate for use in fitting such models. 39 refs., 2 figs., 3 tabs
Tammaro, Pasquale; Hansel, Boris; Police, Andrea; Kousouri, Marina; Magnan, Christophe; Marmuse, Jean Pierre; Arapis, Konstantinos
2017-08-01
Weight loss and overall outcomes following laparoscopic adjustable gastric banding (LAGB) are more variable than with other bariatric procedures. Our aim was to investigate the predictive value of certain parameters in a cohort of 794 patients with 10 years' minimum follow-up after LAGB. We retrospectively reviewed the records of 794 patients undergoing LAGB performed by the authors between April 1996 and December 2004. We collected patients' data on weight loss and band-related complications and performed logistic regression modelling and calculated Kaplan-Meier curves for band preservation. The follow-up rate at 10 years was 90.4%. The mean follow-up duration was 15.1 years (range, 120-228 months). Overall band removal with or without conversion or replacement was required in 304 (38.2%) patients. The mean survival time of the band was 148.4 months (95% confidence interval: 138.3-167.4), and there was no difference in the rate of removal by operative technique (p = 0.7). The highest rate of band removal occurred in female patients (p = 0.05), those with BMI > 50 kg/m 2 (p = 0.005) and in those success rate was significantly lower in patients with initial BMI > 50 kg/m 2 . Conversely, differences in success rate were not statistically significant for age (using 50 years as the cut-off), technique or sex. Higher rates of removal occurred in women, younger patients and those with BMI > 50 kg/m 2 . Regardless of these criteria, the rate of band removal for complications rose over time. Patients should be informed of the high risk of the need for band removal long-term.
Power forward curves: a managerial perspective
International Nuclear Information System (INIS)
Nagarajan, Shankar
1999-01-01
This chapter concentrates on managerial application of power forward curves, and examines the determinants of electricity prices such as transmission constraints, its inability to be stored in a conventional way, its seasonality and weather dependence, the generation stack, and the swing risk. The electricity forward curve, classical arbitrage, constructing a forward curve, volatilities, and electricity forward curve models such as the jump-diffusion model, the mean-reverting heteroscedastic volatility model, and an econometric model of forward prices are examined. A managerial perspective of the applications of the forward curve is presented covering plant valuation, capital budgeting, performance measurement, product pricing and structuring, asset optimisation, valuation of transmission options, and risk management
Retrograde curves of solidus and solubility
International Nuclear Information System (INIS)
Vasil'ev, M.V.
1979-01-01
The investigation was concerned with the constitutional diagrams of the eutectic type with ''retrograde solidus'' and ''retrograde solubility curve'' which must be considered as diagrams with degenerate monotectic transformation. The solidus and the solubility curves form a retrograde curve with a common retrograde point representing the solubility maximum. The two branches of the Aetrograde curve can be described with the aid of two similar equations. Presented are corresponding equations for the Cd-Zn system and shown is the possibility of predicting the run of the solubility curve
Cox, Brian
2014-01-01
Human life is a staggeringly strange thing. On the surface of a ball of rock falling around a nuclear fireball in the blackness of a vacuum the laws of nature conspired to create a naked ape that can look up at the stars and wonder where it came from. What is a human being? Objectively, nothing of consequence. Particles of dust in an infinite arena, present for an instant in eternity. Clumps of atoms in a universe with more galaxies than people. And yet a human being is necessary for the question itself to exist, and the presence of a question in the universe - any question - is the most wonderful thing. Questions require minds, and minds bring meaning. What is meaning? I don't know, except that the universe and every pointless speck inside it means something to me. I am astonished by the existence of a single atom, and find my civilisation to be an outrageous imprint on reality. I don't understand it. Nobody does, but it makes me smile. This book asks questions about our origins, our destiny, and our place i...
Universality in stochastic exponential growth.
Iyer-Biswas, Srividya; Crooks, Gavin E; Scherer, Norbert F; Dinner, Aaron R
2014-07-11
Recent imaging data for single bacterial cells reveal that their mean sizes grow exponentially in time and that their size distributions collapse to a single curve when rescaled by their means. An analogous result holds for the division-time distributions. A model is needed to delineate the minimal requirements for these scaling behaviors. We formulate a microscopic theory of stochastic exponential growth as a Master Equation that accounts for these observations, in contrast to existing quantitative models of stochastic exponential growth (e.g., the Black-Scholes equation or geometric Brownian motion). Our model, the stochastic Hinshelwood cycle (SHC), is an autocatalytic reaction cycle in which each molecular species catalyzes the production of the next. By finding exact analytical solutions to the SHC and the corresponding first passage time problem, we uncover universal signatures of fluctuations in exponential growth and division. The model makes minimal assumptions, and we describe how more complex reaction networks can reduce to such a cycle. We thus expect similar scalings to be discovered in stochastic processes resulting in exponential growth that appear in diverse contexts such as cosmology, finance, technology, and population growth.
Localized qubits in curved spacetimes
Palmer, Matthew C.; Takahashi, Maki; Westman, Hans F.
2012-04-01
We provide a systematic and self-contained exposition of the subject of localized qubits in curved spacetimes. This research was motivated by a simple experimental question: if we move a spatially localized qubit, initially in a state |ψ1>, along some spacetime path Γ from a spacetime point x1 to another point x2, what will the final quantum state |ψ2> be at point x2? This paper addresses this question for two physical realizations of the qubit: spin of a massive fermion and polarization of a photon. Our starting point is the Dirac and Maxwell equations that describe respectively the one-particle states of localized massive fermions and photons. In the WKB limit we show how one can isolate a two-dimensional quantum state which evolves unitarily along Γ. The quantum states for these two realizations are represented by a left-handed 2-spinor in the case of massive fermions and a four-component complex polarization vector in the case of photons. In addition we show how to obtain from this WKB approach a fully general relativistic description of gravitationally induced phases. We use this formalism to describe the gravitational shift in the Colella-Overhauser-Werner 1975 experiment. In the non-relativistic weak field limit our result reduces to the standard formula in the original paper. We provide a concrete physical model for a Stern-Gerlach measurement of spin and obtain a unique spin operator which can be determined given the orientation and velocity of the Stern-Gerlach device and velocity of the massive fermion. Finally, we consider multipartite states and generalize the formalism to incorporate basic elements from quantum information theory such as quantum entanglement, quantum teleportation, and identical particles. The resulting formalism provides a basis for exploring precision quantum measurements of the gravitational field using techniques from quantum information theory.
Sugimachi, Masaru; Sunagawa, Kenji; Uemura, Kazunori; Kamiya, Atsunori; Shimizu, Shuji; Inagaki, Masashi; Shishido, Toshiaki
2010-01-01
In our extended Guyton's model, the ability of heart to pump blood is characterized by a cardiac output curve and the ability of vasculature to pool blood by a venous return surface. These intersect in a three-dimensional coordinate system at the operating right atrial pressure, left atrial pressure, and cardiac output. The baseline cardiac output curve and venous return surface and their changes after volume change would predict new hemodynamics. The invasive methods needed to precisely characterize cardiac output curve and venous return surface led us to aim at estimating cardiac output curve and venous return surface from a single hemodynamic measurement. Using the average values for two logarithmic function parameters, and for two slopes of a surface, we were able to estimate cardiac output curve and venous return surface. The estimated curve and surface predicted new hemodynamics after volume change precisely.
Construction of calibration curve for accountancy tank
International Nuclear Information System (INIS)
Kato, Takayuki; Goto, Yoshiki; Nidaira, Kazuo
2009-01-01
Tanks are equipped in a reprocessing plant for accounting solution of nuclear material. The careful measurement of volume in tanks is very important to implement rigorous accounting of nuclear material. The calibration curve relating the volume and level of solution needs to be constructed, where the level is determined by differential pressure of dip tubes. Several calibration curves are usually employed, but it's not explicitly decided how many segment are used, where to select segment, or what should be the degree of polynomial curve. These parameters, i.e., segment and degree of polynomial curve are mutually interrelated to give the better performance of calibration curve. Here we present the construction technique of giving optimum calibration curves and their characteristics. (author)
MICA: Multiple interval-based curve alignment
Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf
2018-01-01
MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA
PMAnalyzer: a new web interface for bacterial growth curve analysis.
Cuevas, Daniel A; Edwards, Robert A
2017-06-15
Bacterial growth curves are essential representations for characterizing bacteria metabolism within a variety of media compositions. Using high-throughput, spectrophotometers capable of processing tens of 96-well plates, quantitative phenotypic information can be easily integrated into the current data structures that describe a bacterial organism. The PMAnalyzer pipeline performs a growth curve analysis to parameterize the unique features occurring within microtiter wells containing specific growth media sources. We have expanded the pipeline capabilities and provide a user-friendly, online implementation of this automated pipeline. PMAnalyzer version 2.0 provides fast automatic growth curve parameter analysis, growth identification and high resolution figures of sample-replicate growth curves and several statistical analyses. PMAnalyzer v2.0 can be found at https://edwards.sdsu.edu/pmanalyzer/ . Source code for the pipeline can be found on GitHub at https://github.com/dacuevas/PMAnalyzer . Source code for the online implementation can be found on GitHub at https://github.com/dacuevas/PMAnalyzerWeb . dcuevas08@gmail.com. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.
Regional Marginal Abatement Cost Curves for NOx
U.S. Environmental Protection Agency — Data underlying the figures included in the manuscript "Marginal abatement cost curve for NOx incorporating controls, renewable electricity, energy efficiency and...
Simple discs with flat roatation curves
Evans, N. W.; Collett, J. L.
1993-09-01
The aim of this paper is to understand why the squared axial ratio of the velocity ellipse, σphi_^2^/σ_R_^2^, of old disc stars in the Galaxy is less than 1/2. To this end, two infinitesimally thin steady-state axisymmetric discs with asymptotically flat circular velocity curves are presented. The first model - which we designate the Rybicki disc has surface density decaying inversely with radius. The second model is Freeman's exponential disc, which is immersed in the gravity field of the halo simulated by Mestel's potential. For both discs, we provide an infinite family of simple distribution functions, which form a sequence of increasing pressure support. In the Rybicki disc, the stellar streaming velocity increases outwards with radius, which typically causes σphi_^2^/σ_R_^2^ to be greater than 1/2. For our exponential disc distribution functions, the stellar streaming velocity declines outwards with radius, which typically causes σphi^2^/σ_R_^2^ to be less than 1/2. Our exponential disc distribution functions have the property that σ_R_^2^ decays only inversely with galactocentric radius R. If the diminution is faster, the ratio σphi_^2^/σ_R_^2^ rises above 1/2 at the Sun as the mean streaming velocity declines only in the inner disk. To investigate this, exponential discs with exponentially falling radial velocity dispersion are built. These are in conflict with the observations on the axial ratio, even allowing for a mismatch in the photometric and kinematic scalelengths. There are a number of possible resolutions of the contradiction: (1) the galactic disc is not in a steady state or is non-axisymmetric; (2) the circular velocity curve is locally declining; (3) the description of all stellar populations by a single distribution function is invalid; (4) the radial velocity dispersion does not drop off exponentially fast, but much more slowly; (5) the sampling of moving clusters and transient associations of stars creates a biased data set.
University Internationalization and University Autonomy
DEFF Research Database (Denmark)
Turcan, Romeo V.; Gulieva, Valeria
2016-01-01
Turcan and Gulieva deepen our theoretical understanding of the process of university internationalisation by exploring the relationship between university internationalisation and university autonomy. They conjecture that the process of university internationalisation and its sustainability are d...
Hong Shen
2011-01-01
The concepts of curve profile, curve intercept, curve intercept density, curve profile area density, intersection density in containing intersection (or intersection density relied on intersection reference), curve profile intersection density in surface (or curve intercept intersection density relied on intersection of containing curve), and curve profile area density in surface (AS) were defined. AS expressed the amount of curve profile area of Y phase in the unit containing surface area, S...
Advanced topics in the arithmetic of elliptic curves
Silverman, Joseph H
1994-01-01
In the introduction to the first volume of The Arithmetic of Elliptic Curves (Springer-Verlag, 1986), I observed that "the theory of elliptic curves is rich, varied, and amazingly vast," and as a consequence, "many important topics had to be omitted." I included a brief introduction to ten additional topics as an appendix to the first volume, with the tacit understanding that eventually there might be a second volume containing the details. You are now holding that second volume. it turned out that even those ten topics would not fit Unfortunately, into a single book, so I was forced to make some choices. The following material is covered in this book: I. Elliptic and modular functions for the full modular group. II. Elliptic curves with complex multiplication. III. Elliptic surfaces and specialization theorems. IV. Neron models, Kodaira-Neron classification of special fibers, Tate's algorithm, and Ogg's conductor-discriminant formula. V. Tate's theory of q-curves over p-adic fields. VI. Neron's theory of can...
Curve fitting methods for solar radiation data modeling
Energy Technology Data Exchange (ETDEWEB)
Karim, Samsul Ariffin Abdul, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my; Singh, Balbir Singh Mahinder, E-mail: samsul-ariffin@petronas.com.my, E-mail: balbir@petronas.com.my [Department of Fundamental and Applied Sciences, Faculty of Sciences and Information Technology, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia)
2014-10-24
This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R{sup 2}. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.
Curve fitting methods for solar radiation data modeling
Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder
2014-10-01
This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R2. The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods.
Curve fitting methods for solar radiation data modeling
International Nuclear Information System (INIS)
Karim, Samsul Ariffin Abdul; Singh, Balbir Singh Mahinder
2014-01-01
This paper studies the use of several type of curve fitting method to smooth the global solar radiation data. After the data have been fitted by using curve fitting method, the mathematical model of global solar radiation will be developed. The error measurement was calculated by using goodness-fit statistics such as root mean square error (RMSE) and the value of R 2 . The best fitting methods will be used as a starting point for the construction of mathematical modeling of solar radiation received in Universiti Teknologi PETRONAS (UTP) Malaysia. Numerical results indicated that Gaussian fitting and sine fitting (both with two terms) gives better results as compare with the other fitting methods
General Model for Light Curves of Chromospherically Active Binary Stars
Jetsu, L.; Henry, G. W.; Lehtinen, J.
2017-04-01
The starspots on the surface of many chromospherically active binary stars concentrate on long-lived active longitudes separated by 180°. Shifts in activity between these two longitudes, the “flip-flop” events, have been observed in single stars like FK Comae and binary stars like σ Geminorum. Recently, interferometry has revealed that ellipticity may at least partly explain the flip-flop events in σ Geminorum. This idea was supported by the double-peaked shape of the long-term mean light curve of this star. Here we show that the long-term mean light curves of 14 chromospherically active binaries follow a general model that explains the connection between orbital motion, changes in starspot distribution, ellipticity, and flip-flop events. Surface differential rotation is probably weak in these stars, because the interference of two constant period waves may explain the observed light curve changes. These two constant periods are the active longitude period ({P}{act}) and the orbital period ({P}{orb}). We also show how to apply the same model to single stars, where only the value of P act is known. Finally, we present a tentative interference hypothesis about the origin of magnetic fields in all spectral types of stars. The CPS results are available electronically at the Vizier database.
Comparison and evaluation of mathematical lactation curve ...
African Journals Online (AJOL)
p2492989
and on the log of 305-d divided by day in lactation (linear and quadratic) were better than the Gamma function. A study of lactation curves in dairy cattle on farms in central Mexico showed that the Dijkstra function was superior to the Wood, Wilmink and Rook functions for describing the lactation curve (Val-. Arreola et al.
Spectral Curves of Operators with Elliptic Coefficients
Directory of Open Access Journals (Sweden)
J. Chris Eilbeck
2007-03-01
Full Text Available A computer-algebra aided method is carried out, for determining geometric objects associated to differential operators that satisfy the elliptic ansatz. This results in examples of Lamé curves with double reduction and in the explicit reduction of the theta function of a Halphen curve.
Inverse Problem for a Curved Quantum Guide
Directory of Open Access Journals (Sweden)
Laure Cardoulis
2012-01-01
Full Text Available We consider the Dirichlet Laplacian operator −Δ on a curved quantum guide in ℝ n(n=2,3 with an asymptotically straight reference curve. We give uniqueness results for the inverse problem associated to the reconstruction of the curvature by using either observations of spectral data or a boot-strapping method.
Deep-learnt classification of light curves
DEFF Research Database (Denmark)
Mahabal, Ashish; Gieseke, Fabian; Pai, Akshay Sadananda Uppinakudru
2017-01-01
Astronomy light curves are sparse, gappy, and heteroscedastic. As a result standard time series methods regularly used for financial and similar datasets are of little help and astronomers are usually left to their own instruments and techniques to classify light curves. A common approach is to d...
Learning curves in energy planning models
Energy Technology Data Exchange (ETDEWEB)
Barreto, L.; Kypreos, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1999-08-01
This study describes the endogenous representation of investment cost learning curves into the MARKAL energy planning model. A piece-wise representation of the learning curves is implemented using Mixed Integer Programming. The approach is briefly described and some results are presented. (author) 3 figs., 5 refs.
The Koch curve as a smooth manifold
International Nuclear Information System (INIS)
Epstein, Marcelo; Sniatycki, Jedrzej
2008-01-01
We show that there exists a homeomorphism between the closed interval [0,1] is contained in R and the Koch curve endowed with the subset topology of R 2 . We use this homeomorphism to endow the Koch curve with the structure of a smooth manifold with boundary
Trigonometric Characterization of Some Plane Curves
Indian Academy of Sciences (India)
IAS Admin
There is a way to describe a family of plane curves different from that using Cartesian or po- lar co-ordinates. This is a trigonometric equation involving two angles. In this article, we highlight the fact that trigonometric equations are conve- nient to describe certain one-parameter families of plane curves. In some cases, the ...
A minicourse on moduli of curves
International Nuclear Information System (INIS)
Looijenga, E.
2000-01-01
These are notes that accompany a short course given at the School on Algebraic Geometry 1999 at the ICTP, Trieste. A major goal is to outline various approaches to moduli spaces of curves. In the last part I discuss the algebraic classes that naturally live on these spaces; these can be thought of as the characteristic classes for bundles of curves. (author)
Sibling curves of polynomials | Wiggins | Quaestiones Mathematicae
African Journals Online (AJOL)
Sibling curves were demonstrated in papers [2, 3] as a novel way to visualize the zeros of complex valued functions. In this paper, we continue the work done in those papers by focusing solely on polynomials. We proceed to prove that the number of sibling curves of a polynomial is the degree of the polynomial. Keywords: ...
Measuring Model Rocket Engine Thrust Curves
Penn, Kim; Slaton, William V.
2010-01-01
This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…
Curve Matching with Applications in Medical Imaging
DEFF Research Database (Denmark)
Bauer, Martin; Bruveris, Martins; Harms, Philipp
2015-01-01
In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...
Wind Turbine Power Curves Incorporating Turbulence Intensity
DEFF Research Database (Denmark)
Sørensen, Emil Hedevang Lohse
2014-01-01
The performance of a wind turbine in terms of power production (the power curve) is important to the wind energy industry. The current IEC-61400-12-1 standard for power curve evaluation recognizes only the mean wind speed at hub height and the air density as relevant to the power production...
Quantum curves and conformal field theory
Manabe, Masahide; Sułkowski, Piotr
2017-06-01
To a given algebraic curve we assign an infinite family of quantum curves (Schrödinger equations), which are in one-to-one correspondence with, and have the structure of, Virasoro singular vectors. For a spectral curve of a matrix model we build such quantum curves out of an appropriate representation of the Virasoro algebra, encoded in the structure of the α /β -deformed matrix integral and its loop equation. We generalize this construction to a large class of algebraic curves by means of a refined topological recursion. We also specialize this construction to various specific matrix models with polynomial and logarithmic potentials, and among other results, show that various ingredients familiar in the study of conformal field theory (Ward identities, correlation functions and a representation of Virasoro operators acting thereon, Belavin-Polyakov-Zamolodchikov equations) arise upon specialization of our formalism to the multi-Penner matrix model.
Curved and conformal high-pressure vessel
Croteau, Paul F.; Kuczek, Andrzej E.; Zhao, Wenping
2016-10-25
A high-pressure vessel is provided. The high-pressure vessel may comprise a first chamber defined at least partially by a first wall, and a second chamber defined at least partially by the first wall. The first chamber and the second chamber may form a curved contour of the high-pressure vessel. A modular tank assembly is also provided, and may comprise a first mid tube having a convex geometry. The first mid tube may be defined by a first inner wall, a curved wall extending from the first inner wall, and a second inner wall extending from the curved wall. The first inner wall may be disposed at an angle relative to the second inner wall. The first mid tube may further be defined by a short curved wall opposite the curved wall and extending from the second inner wall to the first inner wall.
How curved membranes recruit amphipathic helices and protein anchoring motifs.
Hatzakis, Nikos S; Bhatia, Vikram K; Larsen, Jannik; Madsen, Kenneth L; Bolinger, Pierre-Yves; Kunding, Andreas H; Castillo, John; Gether, Ulrik; Hedegård, Per; Stamou, Dimitrios
2009-11-01
Lipids and several specialized proteins are thought to be able to sense the curvature of membranes (MC). Here we used quantitative fluorescence microscopy to measure curvature-selective binding of amphipathic motifs on single liposomes 50-700 nm in diameter. Our results revealed that sensing is predominantly mediated by a higher density of binding sites on curved membranes instead of higher affinity. We proposed a model based on curvature-induced defects in lipid packing that related these findings to lipid sorting and accurately predicted the existence of a new ubiquitous class of curvature sensors: membrane-anchored proteins. The fact that unrelated structural motifs such as alpha-helices and alkyl chains sense MC led us to propose that MC sensing is a generic property of curved membranes rather than a property of the anchoring molecules. We therefore anticipate that MC will promote the redistribution of proteins that are anchored in membranes through other types of hydrophobic moieties.
A dose-surviving fraction curve for mouse colonic mucosa
International Nuclear Information System (INIS)
Tucker, S.L.; Thames, H.D. Jr.; Withers, H.R.; Mason, K.A.
1983-01-01
A dose-surviving fraction curve representing the response of the mouse colonic mucosa to single doses of 137 Cs gamma radiation was obtained from the results of a multifraction in vivo colony assay. Construction of the curve required an estimated of the average number of clonogens initially present per colonic crypt. The estimated clonogen count (88) was determined by a statistical method based on the use of doses per fraction common to different fractionation protocols. Parameters for the LQ and TC models of cell survival were obtained by weighted least-squares fits to the data. A comparison of the survival characteristics of cells from the mouse colonic and jejunal crypts suggested that the epithelium of the colon is less radiosensitive than that of the jejunum. (author)
Wide steering angle microscanner based on curved surface
Sabry, Yasser; Khalil, Diaa; Saadany, Bassam; Bourouina, Tarik
2013-03-01
Intensive industrial and academic research is oriented towards the design and fabrication of optical beam steering systems based on MEMS technology. In most of these systems, the scanning is achieved by rotating a flat micromirror around a central axis in which the main challenge is achieving a wide mirror rotation angle. In this work, a novel method of optical beam scanning based on reflection from a curved surface is presented. The scanning occurs when the optical axis of the curved surface is displaced with respect to the optical axis of the incident beam. To overcome the possible deformation of the spot with the scanning angle, the curved surface is designed with a specific aspherical profile. Moreover, the scanning exhibits a more linearized scanning angle-displacement relation than the conventional spherical profile. The presented scanner is fabricated using DRIE technology on an SOI wafer. The curved surface (reflector) is metalized and attached to a comb-drive actuator fabricated in the same lithography step. A single-mode fiber, behaving as a Gaussian beam source, is positioned on the substrate facing the mirror. The reflected optical beam angle and spotsize in the far field is recorded versus the relative shift between the fiber and the curved mirror. The spot size is plotted versus the scanning angle and a scanning spot size uniformity of about +/-10% is obtained for optical deflection angles up to 100 degrees. As the optical beam is propagating parallel to the wafer substrate, a completely integrated laser scanner can be achieved with filters and actuators self-aligned on the same chip that allows low cost and mass production of this important product.
International Nuclear Information System (INIS)
Parra Barillas, Adriana; Montoya, Michael
2013-01-01
The formation of the hybrid layer is observed in dental pieces in vitro, using systems of conventional adhesives (Single Bond 2 of 3M and One Coat of Coltene), with different times of acid etching, through the use of atomic force microscopy (AFM). The images of the hybrid layer obtained from samples prepared with adhesive systems are analyzed by AFM. Samples collected have been of dental pieces (molars and premolars) recently extracted and later placed in water. The pieces used have provided more surface to be observed under the microscope, greater accessibility to the be cut for its study, and to the great pieces have facilitated their placement on the Isomet low speed saw. The differences are evaluated between hybrid layers according the adhesive system used and the mode of application of the images obtained in the atomic force microscope. The adhesive system that has allowed the formation of a hybrid layer more appropriate between the adhesive system One Coat and the adhesive system Single Bond Universal is determined. The time of acid etching as variable of procedure is determined and has interfered with the formation of a hybrid layer more stable. The images evaluated that were provided by the atomic force microscope and compared with the images of electron microscopy of other studies, have determined that the AFM is without providing detailed information, as well as the appropriate images to evaluate the hybrid layer of the adhesive systems Single Bond 2 and One Coat of Coltene, or the different times of acid etching. Therefore, for this type of study, the image of choice must be of an electron microscope [es
Estimating Unobservable Inflation Expectations in the New Keynesian Phillips Curve
Directory of Open Access Journals (Sweden)
Francesca Rondina
2018-02-01
Full Text Available This paper uses an econometric model and Bayesian estimation to reverse engineer the path of inflation expectations implied by the New Keynesian Phillips Curve and the data. The estimated expectations roughly track the patterns of a number of common measures of expected inflation available from surveys or computed from financial data. In particular, they exhibit the strongest correlation with the inflation forecasts of the respondents in the University of Michigan Survey of Consumers. The estimated model also shows evidence of the anchoring of long run inflation expectations to a value that is in the range of the target inflation rate.
Aspects of quantum field theory in curved space-time
Energy Technology Data Exchange (ETDEWEB)
Fulling, S.A. (Texas A and M Univ., College Station, TX (USA). Dept. of Mathematics)
1989-01-01
The theory of quantum fields on curved spacetimes has attracted great attention since the discovery, by Stephen Hawking, of black-hole evaporation. It remains an important subject for the understanding of such contemporary topics as inflationary cosmology, quantum gravity and superstring theory. The topics covered include normal-mode expansions for a general elliptic operator, Fock space, the Casimir effect, the Klein 'paradox', particle definition and particle creation in expanding universes, asymptotic expansion of Green's functions and heat kernels, and renormalization of the stress tensor. (author).
Aspects of quantum field theory in curved space-time
International Nuclear Information System (INIS)
Fulling, S.A.
1989-01-01
The theory of quantum fields on curved spacetimes has attracted great attention since the discovery, by Stephen Hawking, of black-hole evaporation. It remains an important subject for the understanding of such contemporary topics as inflationary cosmology, quantum gravity and superstring theory. The topics covered include normal-mode expansions for a general elliptic operator, Fock space, the Casimir effect, the Klein 'paradox', particle definition and particle creation in expanding universes, asymptotic expansion of Green's functions and heat kernels, and renormalization of the stress tensor. (author)
The universal behavior of inverse magnetocaloric effect in antiferromagnetic materials
Biswas, Anis; Chandra, Sayan; Samanta, Tapas; Phan, M. H.; Das, I.; Srikanth, H.
2013-05-01
We report the universal behavior of inverse magnetocaloric effect (IMCE) in antiferromagnetic materials. In contrast to the universal behavior of conventional magnetocaloric effect often observed in ferromagnetic systems, a phenomenological universal master curve can be constructed to describe the temperature dependence of magnetic entropy change for IMCE without rescaling the temperature axis. The proposed universal curve method allows extrapolating the magnetic entropy change of an IMCE material, which would be imperative to judge its suitability in actual magnetic refrigeration devices.
Investigation of learning and experience curves
Energy Technology Data Exchange (ETDEWEB)
Krawiec, F.; Thornton, J.; Edesess, M.
1980-04-01
The applicability of learning and experience curves for predicting future costs of solar technologies is assessed, and the major test case is the production economics of heliostats. Alternative methods for estimating cost reductions in systems manufacture are discussed, and procedures for using learning and experience curves to predict costs are outlined. Because adequate production data often do not exist, production histories of analogous products/processes are analyzed and learning and aggregated cost curves for these surrogates estimated. If the surrogate learning curves apply, they can be used to estimate solar technology costs. The steps involved in generating these cost estimates are given. Second-generation glass-steel and inflated-bubble heliostat design concepts, developed by MDAC and GE, respectively, are described; a costing scenario for 25,000 units/yr is detailed; surrogates for cost analysis are chosen; learning and aggregate cost curves are estimated; and aggregate cost curves for the GE and MDAC designs are estimated. However, an approach that combines a neoclassical production function with a learning-by-doing hypothesis is needed to yield a cost relation compatible with the historical learning curve and the traditional cost function of economic theory.
A gymkhana to discover and generate curves in a cooperative work
Directory of Open Access Journals (Sweden)
Anna Vidal Meló
2014-03-01
Full Text Available The student who access the University understands a curve as a function represented by an equality involving the Cartesian variables x and y. But he does not know another great set of curves such as those described by parametric equations and polar coordinates. We show an experience developed in two consecutive courses in the first course of a bachelor's degree, which allows the students to discover and create many curves in parametric or polar representation, working in group. Also the experience facilitate the students to achieve several generic skills.
Modelling curves of manufacturing feasibilities and demand
Directory of Open Access Journals (Sweden)
Soloninko K.S.
2017-03-01
Full Text Available The authors research the issue of functional properties of curves of manufacturing feasibilities and demand. Settlement of the problem, and its connection with important scientific and practical tasks. According to its nature, the market economy is unstable and is in constant movement. Economy has an effective instrument for explanation of changes in economic environment; this tool is called the modelling of economic processes. The modelling of economic processes depends first and foremost on the building of economic model which is the base for the formalization of economic process, that is, the building of mathematical model. The effective means for formalization of economic process is the creation of the model of hypothetic or imaginary economy. The building of demand model is significant for the market of goods and services. The problem includes the receiving (as the result of modelling definite functional properties of curves of manufacturing feasibilities and demand according to which one can determine their mathematical model. Another problem lies in obtaining majorant properties of curves of joint demand on the market of goods and services. Analysis of the latest researches and publications. Many domestic and foreign scientists dedicated their studies to the researches and building of the models of curves of manufacturing feasibilities and demand. In spite of considerable work of the scientists, such problems as functional properties of the curves and their practical use in modelling. The purpose of the article is to describe functional properties of curves of manufacturing feasibilities and demand on the market of goods and services on the base of modelling of their building. Scientific novelty and practical value. The theoretical regulations (for functional properties of curves of manufacturing feasibilities and demand received as a result of the present research, that is convexity, give extra practical possibilities in a microeconomic
Directory of Open Access Journals (Sweden)
Telichenko Valeriy Ivanovich
2014-06-01
Full Text Available The article gives the analysis of university rankings and defines the differences in evaluation methods and indicators of world ranking agencies, presents new approaches to making global rankings. It defines the position of MGSU in Russian universities TOP-100 ranking. University rankings are not simply information, but the evaluation instrument of quality of education, initiating the improvement of ranking position. It’s important for Russian Universities claiming for higher positions in the world rankings. MGSU position in universities ranking made the University administration consider thoroughly the University positioning in the system of higher education, in the categories of education and science and among possible employers of the university graduates.
Neck curve polynomials in neck rupture model
International Nuclear Information System (INIS)
Kurniadi, Rizal; Perkasa, Yudha S.; Waris, Abdul
2012-01-01
The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of 280 X 90 with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.
CRC standard curves and surfaces with Mathematica
von Seggern, David H
2006-01-01
Since the publication of the first edition, Mathematica® has matured considerably and the computing power of desktop computers has increased greatly. This enables the presentation of more complex curves and surfaces as well as the efficient computation of formerly prohibitive graphical plots. Incorporating both of these aspects, CRC Standard Curves and Surfaces with Mathematica®, Second Edition is a virtual encyclopedia of curves and functions that depicts nearly all of the standard mathematical functions rendered using Mathematica. While the easy-to-use format remains unchanged from the previ
Morse theory on timelike and causal curves
International Nuclear Information System (INIS)
Everson, J.; Talbot, C.J.
1976-01-01
It is shown that the set of timelike curves in a globally hyperbolic space-time manifold can be given the structure of a Hilbert manifold under a suitable definition of 'timelike.' The causal curves are the topological closure of this manifold. The Lorentzian energy (corresponding to Milnor's energy, except that the Lorentzian inner product is used) is shown to be a Morse function for the space of causal curves. A fixed end point index theorem is obtained in which a lower bound for the index of the Hessian of the Lorentzian energy is given in terms of the sum of the orders of the conjugate points between the end points. (author)
Replication and Analysis of Ebbinghaus' Forgetting Curve.
Murre, Jaap M J; Dros, Joeri
2015-01-01
We present a successful replication of Ebbinghaus' classic forgetting curve from 1880 based on the method of savings. One subject spent 70 hours learning lists and relearning them after 20 min, 1 hour, 9 hours, 1 day, 2 days, or 31 days. The results are similar to Ebbinghaus' original data. We analyze the effects of serial position on forgetting and investigate what mathematical equations present a good fit to the Ebbinghaus forgetting curve and its replications. We conclude that the Ebbinghaus forgetting curve has indeed been replicated and that it is not completely smooth but most probably shows a jump upwards starting at the 24 hour data point.
Replication and Analysis of Ebbinghaus’ Forgetting Curve
Murre, Jaap M. J.; Dros, Joeri
2015-01-01
We present a successful replication of Ebbinghaus’ classic forgetting curve from 1880 based on the method of savings. One subject spent 70 hours learning lists and relearning them after 20 min, 1 hour, 9 hours, 1 day, 2 days, or 31 days. The results are similar to Ebbinghaus' original data. We analyze the effects of serial position on forgetting and investigate what mathematical equations present a good fit to the Ebbinghaus forgetting curve and its replications. We conclude that the Ebbinghaus forgetting curve has indeed been replicated and that it is not completely smooth but most probably shows a jump upwards starting at the 24 hour data point. PMID:26148023
Replication and Analysis of Ebbinghaus' Forgetting Curve.
Directory of Open Access Journals (Sweden)
Jaap M J Murre
Full Text Available We present a successful replication of Ebbinghaus' classic forgetting curve from 1880 based on the method of savings. One subject spent 70 hours learning lists and relearning them after 20 min, 1 hour, 9 hours, 1 day, 2 days, or 31 days. The results are similar to Ebbinghaus' original data. We analyze the effects of serial position on forgetting and investigate what mathematical equations present a good fit to the Ebbinghaus forgetting curve and its replications. We conclude that the Ebbinghaus forgetting curve has indeed been replicated and that it is not completely smooth but most probably shows a jump upwards starting at the 24 hour data point.
Growth curves for twins in Slovenia.
Bricelj, Katja; Blickstein, Isaac; Bržan-Šimenc, Gabrijela; Janša, Vid; Lučovnik, Miha; Verdenik, Ivan; Trojner-Bregar, Andreja; Tul, Nataša
2017-02-01
Abnormalities of fetal growth are more common in twins. We introduce the growth curves for monitoring fetal growth in twin pregnancies in Slovenia. Slovenian National Perinatal Information System for the period between 2002 and 2010 was used to calculate birth weight percentiles for all live born twins for each week from 22nd to 40th week. The calculated percentiles of birth weight for all live-born twins in Slovenia served as the basis for drawing 'growth' curves. The calculated growth curves for twins will help accurately diagnose small or large twin fetuses for their gestational age in the native central European population.
Reflected Light Curves of Extrasolar Planets
Green, D.; Matthews, J.; Kuschnig, R.; Seager, S.
The planned launches of ultra-precise photometric satellites such as MOST, COROT and MONS should provide the first opportunity to study the reflected light curves from extrasolar planets. To predict the capabilities of these missions, we have constructed a series of models of such light curves, improving upon the Monte Carlo simulations by Seager et al. (2000). These models include more realistic features such limb darkening of the star and broad band photometry. For specific models, the resulting planet light curves exhibit unique behavior with the variation of radius, inclination and presence or absence of clouds.
Constructing forward price curves in electricity markets
DEFF Research Database (Denmark)
Fleten, S.-E.; Lemming, Jørgen Kjærgaard
2003-01-01
We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available...... to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted...
Constructing forward price curves in electricity markets
International Nuclear Information System (INIS)
Fleten, Stein-Erik; Lemming, Jacob
2003-01-01
We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted on the Nordic power exchange
Curves of restricted type in euclidean spaces
Directory of Open Access Journals (Sweden)
Bengü Kılıç Bayram
2014-01-01
Full Text Available Submanifolds of restricted type were introduced in [7]. In the present study we consider restricted type of curves in Em. We give some special examples. We also show that spherical curve in S2(r C E3 is of restricted type if and only if either ƒ(s is constant or a linear function of s of the form ƒ(s = ±s + b and every closed W - curve of rank k and of length 2(r in E2k is of restricted type.
International Nuclear Information System (INIS)
Pan, Haoran; Koehler, Jonathan
2007-01-01
Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R and D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R and D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does. (author)
Uncovering the skewness news impact curve
Czech Academy of Sciences Publication Activity Database
Anatolyev, Stanislav; Petukhov, A.
2016-01-01
Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: RVO:67985998 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016
Twisted vector bundles on pointed nodal curves
Indian Academy of Sciences (India)
Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.
Safety evaluation of curve warning speed signs.
2011-06-01
This report presents a review of a research effort to evaluate the safety implications of advisory speeds at horizontal curve locations on Oregon rural two-lane highways. The primary goals of this research effort were to characterize driving operatio...
ARC Code TI: ROC Curve Code Augmentation
National Aeronautics and Space Administration — ROC (Receiver Operating Characteristic) curve Code Augmentation was written by Rodney Martin and John Stutz at NASA Ames Research Center and is a modification of ROC...
Twisted Vector Bundles on Pointed Nodal Curves
Indian Academy of Sciences (India)
Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.
Automorphisms of double coverings of curves
International Nuclear Information System (INIS)
Torres, F.
1994-11-01
We study automorphisms of curves that commute with each other. We prove that the order and the number of fixed points of one of them satisfy certain relations involving those of the other. Then, we specialize our results to the case of double coverings of curves. For instance, if the genus of the curve is at least 4γ + 2 and γ >= 1 (γ = the genus of the covered curve) we prove that the order of an automorphism is bounded above by 2γ + 1 (resp. 4γ + 2) provided it is prime (resp. it has at least five fixed points). We also improve Farkas' bound on the number of fixed points namely 4γ + 4 by showing that it involves the order of the automorphism except in the case of even order when such an improvement is obtained provided the automorphism and the γ-involution has at least one common fixed point. (author). 15 refs
On ``minimally curved spacetimes'' in general relativity
Dadhich, Naresh
1997-01-01
We consider a spacetime corresponding to uniform relativistic potential analogus to Newtonian potential as an example of ``minimally curved spacetime''. We also consider a radially symmetric analogue of the Rindler spacetime of uniform proper acceleration relative to infinity.
Quaternion orders, quadratic forms, and Shimura curves
Alsina, Montserrat
2004-01-01
Shimura curves are a far-reaching generalization of the classical modular curves. They lie at the crossroads of many areas, including complex analysis, hyperbolic geometry, algebraic geometry, algebra, and arithmetic. The text provides an introduction to the subject from a theoretic and algorithmic perspective. The main topics covered in it are Shimura curves defined over the rational number field, the construction of their fundamental domains, and the determination of their complex multiplication points. The study of complex multiplication points in Shimura curves leads to the study of families of binary quadratic forms with algebraic coefficients and to their classification by arithmetic Fuchsian groups. In this regard, the authors develop a theory full of new possibilities which parallels Gauss' theory on the classification of binary quadratic forms with integral coefficients by the action of the modular group. Each topic covered in the book begins with a theoretical discussion followed by carefully worked...
Uncovering the skewness news impact curve
Czech Academy of Sciences Publication Activity Database
Anatolyev, Stanislav; Petukhov, A.
2016-01-01
Roč. 14, č. 4 (2016), s. 746-771 ISSN 1479-8409 Institutional support: PRVOUK-P23 Keywords : conditional skewness * news impact curve * stock returns Subject RIV: AH - Economics Impact factor: 1.800, year: 2016
Procedures for setting curve advisory speed.
2009-08-01
The procedures described in this handbook are intended to improve consistency in curve signing and driver compliance with the advisory speed. The handbook describes guidelines for determining when an advisory speed is needed, criteria for identifying...
Liquefaction Probability Curves for Surficial Geologic Units
Holzer, T. L.; Noce, T. E.; Bennett, M. J.
2009-12-01
Liquefaction probability curves that predict the probability of surface manifestations of earthquake-induced liquefaction are developed for 14 different surficial geologic deposits. The geologic units include alluvial fan, beach ridge, river delta, eolian dune, point bar, floodbasin, natural river levee, abandoned river channel, deep-water lake, lagoonal, sandy artificial fill, and valley train deposits. Probability is conditioned on earthquake magnitude and peak ground acceleration. Curves are developed for water table depths of 1.5 and 5.0 m. Probabilities were derived from complementary cumulative frequency distributions of the liquefaction potential index (LPI) that were computed from 935 cone penetration tests. Most of the curves can be fit with a 3-parameter logistic function, which facilitates computations of probability. For natural deposits with a water table at 1.5 m depth and subjected to an M7.5 earthquake with a PGA = 0.25 g, probabilities range from 0.5 for fluvial point bar, barrier island beach ridge, and deltaic deposits. Retrospective predictions of liquefaction during historical earthquakes based on the curves compare favorably to post-earthquake observations. We also have used the curves to assign ranges of liquefaction probabilities to the susceptibility categories proposed by Youd and Perkins (1978) for different geologic deposits. For the earthquake loading and conditions described above, probabilities range from 0-0.08 for low, 0.09-0.30 for moderate, 0.31-0.62 for high, to 0.63-1.00 for very high susceptibility. Liquefaction probability curves have two primary practical applications. First, the curves can be combined with seismic source characterizations to transform surficial geologic maps into probabilistic liquefaction hazard maps. Geographic specific curves are clearly desirable, but in the absence of such information, generic liquefaction probability curves provide a first approximation of liquefaction hazard. Such maps are useful both
Neutron cross sections: Book of curves
International Nuclear Information System (INIS)
McLane, V.; Dunford, C.L.; Rose, P.F.
1988-01-01
Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs
Curves along which plane waves can interfere
Energy Technology Data Exchange (ETDEWEB)
Karp, S.N.; Machover, M.
1977-07-01
Partial results are given on a conjecture in inverse scattering theory concerning the interference of two-dimensional plane waves. The conjecture states that an odd number of plane waves of the same frequency can only cancel each other at isolated points and not along a simple continuous curve. It is partially confirmed here for curves which are nearly flat at some point. An analysis is also made for various possible nodes for an even number of plane waves.
[Biomechanic principles of the sagittal compensating curve].
Kubein-Meesenburg, D; Nägerl, H; Fanghänel, J
1990-07-01
The alignment of the buccal teeth along the compensating curve is of functional importance. It is closely related with the functional gear system of anterior and posterior guidance. Measurements have shown that individual differences between masticatory systems are mainly attributable to functional parameters. Purely skeletal parameters are of comparatively little variability. The compensating curve may be regarded as a guiding element within a master gear systems which includes the gear system of anterior and posterior guidance.
Replication and Analysis of Ebbinghaus? Forgetting Curve
Murre, Jaap M. J.; Dros, Joeri
2015-01-01
We present a successful replication of Ebbinghaus’ classic forgetting curve from 1880 based on the method of savings. One subject spent 70 hours learning lists and relearning them after 20 min, 1 hour, 9 hours, 1 day, 2 days, or 31 days. The results are similar to Ebbinghaus' original data. We analyze the effects of serial position on forgetting and investigate what mathematical equations present a good fit to the Ebbinghaus forgetting curve and its replications. We conclude that the Ebbingha...
Curvature Entropy for Curved Profile Generation
Ujiie, Yoshiki; Kato, Takeo; Sato, Koichiro; Matsuoka, Yoshiyuki
2012-01-01
In a curved surface design, the overall shape features that emerge from combinations of shape elements are important. However, controlling the features of the overall shape in curved profiles is difficult using conventional microscopic shape information such as dimension. Herein two types of macroscopic shape information, curvature entropy and quadrature curvature entropy, quantitatively represent the features of the overall shape. The curvature entropy is calculated by the curvature distribu...
Curved twistor spaces and H-space
International Nuclear Information System (INIS)
Tod, K.P.
1980-01-01
The curved twistor space construction of Penrose for anti-self-dual solutions to the Einstein vacuum equations is described. Curved twistor spaces are defined and it is shown with the aid of an example how to obtain them by deforming the complex structure of regions of flat twistor space. The connection of this procedure with Newman's H-space construction via asymptotic twistor space is outlined. (Auth.)
Potential Energy Curve of N2 Revisited
Czech Academy of Sciences Publication Activity Database
Špirko, Vladimír; Xiangzhu, L.; Paldus, J.
2011-01-01
Roč. 76, č. 4 (2011), s. 327-341 ISSN 0010-0765 R&D Projects: GA MŠk LC512; GA ČR GAP208/11/0436 Institutional research plan: CEZ:AV0Z40550506 Keywords : reduced multireference coupled-cluster method * reduced potential curve method * nitrogen molecule potential energy curves Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.283, year: 2011
Verified Indifferentiable Hashing into Elliptic Curves
Barthe, Gilles; Grégoire, Benjamin; Heraud, Sylvain; Olmedo, Federico; Zanella-Béguelin, Santiago
2012-01-01
International audience; Many cryptographic systems based on elliptic curves are proven secure in the Random Oracle Model, assuming there exist probabilistic functions that map elements in some domain (e.g. bitstrings) onto uniformly and independently distributed points in a curve. When implementing such systems, and in order for the proof to carry over to the implementation, those mappings must be instantiated with concrete constructions whose behavior does not deviate significantly from rand...
Constructing elliptic curves from Galois representations
Snowden, Andrew; Tsimerman, Jacob
2017-01-01
Given a non-isotrivial elliptic curve over an arithmetic surface, one obtains a lisse $\\ell$-adic sheaf of rank two over the surface. This lisse sheaf has a number of straightforward properties: cyclotomic determinant, finite ramification, rational traces of Frobenius, and somewhere not potentially good reduction. We prove that any lisse sheaf of rank two possessing these properties comes from an elliptic curve.
Probing exoplanet clouds with optical phase curves.
Muñoz, Antonio García; Isaak, Kate G
2015-11-03
Kepler-7b is to date the only exoplanet for which clouds have been inferred from the optical phase curve--from visible-wavelength whole-disk brightness measurements as a function of orbital phase. Added to this, the fact that the phase curve appears dominated by reflected starlight makes this close-in giant planet a unique study case. Here we investigate the information on coverage and optical properties of the planet clouds contained in the measured phase curve. We generate cloud maps of Kepler-7b and use a multiple-scattering approach to create synthetic phase curves, thus connecting postulated clouds with measurements. We show that optical phase curves can help constrain the composition and size of the cloud particles. Indeed, model fitting for Kepler-7b requires poorly absorbing particles that scatter with low-to-moderate anisotropic efficiency, conclusions consistent with condensates of silicates, perovskite, and silica of submicron radii. We also show that we are limited in our ability to pin down the extent and location of the clouds. These considerations are relevant to the interpretation of optical phase curves with general circulation models. Finally, we estimate that the spherical albedo of Kepler-7b over the Kepler passband is in the range 0.4-0.5.
Environmental bias and elastic curves on surfaces
International Nuclear Information System (INIS)
Guven, Jemal; María Valencia, Dulce; Vázquez-Montejo, Pablo
2014-01-01
The behavior of an elastic curve bound to a surface will reflect the geometry of its environment. This may occur in an obvious way: the curve may deform freely along directions tangent to the surface, but not along the surface normal. However, even if the energy itself is symmetric in the curve's geodesic and normal curvatures, which control these modes, very distinct roles are played by the two. If the elastic curve binds preferentially on one side, or is itself assembled on the surface, not only would one expect the bending moduli associated with the two modes to differ, binding along specific directions, reflected in spontaneous values of these curvatures, may be favored. The shape equations describing the equilibrium states of a surface curve described by an elastic energy accommodating environmental factors will be identified by adapting the method of Lagrange multipliers to the Darboux frame associated with the curve. The forces transmitted to the surface along the surface normal will be determined. Features associated with a number of different energies, both of physical relevance and of mathematical interest, are described. The conservation laws associated with trajectories on surface geometries exhibiting continuous symmetries are also examined. (paper)
Global experience curves for wind farms
International Nuclear Information System (INIS)
Junginger, M.; Faaij, A.; Turkenburg, W.C.
2005-01-01
In order to forecast the technological development and cost of wind turbines and the production costs of wind electricity, frequent use is made of the so-called experience curve concept. Experience curves of wind turbines are generally based on data describing the development of national markets, which cause a number of problems when applied for global assessments. To analyze global wind energy price development more adequately, we compose a global experience curve. First, underlying factors for past and potential future price reductions of wind turbines are analyzed. Also possible implications and pitfalls when applying the experience curve methodology are assessed. Second, we present and discuss a new approach of establishing a global experience curve and thus a global progress ratio for the investment cost of wind farms. Results show that global progress ratios for wind farms may lie between 77% and 85% (with an average of 81%), which is significantly more optimistic than progress ratios applied in most current scenario studies and integrated assessment models. While the findings are based on a limited amount of data, they may indicate faster price reduction opportunities than so far assumed. With this global experience curve we aim to improve the reliability of describing the speed with which global costs of wind power may decline
Stenting for curved lesions using a novel curved balloon: Preliminary experimental study.
Tomita, Hideshi; Higaki, Takashi; Kobayashi, Toshiki; Fujii, Takanari; Fujimoto, Kazuto
2015-08-01
Stenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. In vitro experiments: A Palmaz Genesis(®) stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku(®) curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express(®) Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express(®) Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. In vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. In the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. This novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Numerical analysis of heat-curved I-girders
Directory of Open Access Journals (Sweden)
Antoine Gergess
2017-10-01
Full Text Available Heat curving is a practical and economical process used by steel fabricators for curving structural steel. In this method, the flange edges of a fabricated straight girder are asymmetrically heated to induce residual curvature on cooling. Available analytical methods for predicting the resulting residual stress, strain and curvature are complex and iterative because of the need to account for material and geometric non-linearity. This paper presents a single-step, non-iterative, numerical procedure for determining the effects of heat-curving on residual stress and strain based on a previously developed simplified analysis. Thermal equilibrium equations for idealized heating profiles are first recast in a general parametric form and then solved numerically for standard heating width and temperature using modern technical computing. The resulting solutions are expressed as polynomial functions to allow the solution space for the residual curvature to be graphically represented. Curvature predictions using this simplified approach are shown to be within 11% of measured values and within 5% of values obtained using more rigorous numerical methods.
Developing a laparoscopic radical prostatectomy service: defining the learning curve.
Vasdev, Nikhil; Kass-Iliyya, Antoine; Patel, Ameet; Bedford, Geoff; O'Riordon, Anna; Johnson, Mark I; Durkan, Garrett C; Soomro, Naeem A
2012-07-01
Laparoscopic radical prostatectomy (LRP) is an established treatment for patients with prostate cancer in selected centers with appropriate expertise. We studied our single-center experience of developing a LRP service and subsequent training of two additional surgeons by the initial surgeon. We assessed the learning curve of the three surgeons with regard to perioperative outcomes and oncologic results. Three hundred consecutive patients underwent a LRP between January 2005 and April 2011. Patients were divided into three equal groups (1-100 group 1], 101-200 [group 2], and 201-300 [group 3]). Age, American Society of Anesthesiologists score, preoperative comorbidities, and indications for LRP were comparable for all three patient groups. Perioperative and oncologic outcomes were compared across all three groups to assess the impact of the learning curve for LRP. All surgical complications were classified using the Clavien-Dindo system (CDS). The mean age was 61.9 years (range 46-74 y). There was a significant reduction in the mean operative time (Plearning curve, perioperative parameters and oncologic outcomes improve. Using a carefully mentored approach, LRP can be safely introduced as a new procedure without compromising patient outcomes.
Defining the learning curve for robotic-assisted esophagogastrectomy.
Hernandez, Jonathan M; Dimou, Francesca; Weber, Jill; Almhanna, Khaldoun; Hoffe, Sarah; Shridhar, Ravi; Karl, Richard; Meredith, Kenneth
2013-08-01
The expansion of robotic-assisted surgery is occurring quickly, though little is generally known about the "learning curve" for the technology with utilization for complex esophageal procedures. The purpose of this study is to define the learning curve for robotic-assisted esophagogastrectomy with respect to operative time, conversion rates, and patient safety. We have prospectively followed all patients undergoing robotic-assisted esophagogastrectomy and compared operations performed at our institutions by a single surgeon in successive cohorts of 10 patients. Our measures of proficiency included: operative times, conversion rates, and complications. Statistical analyses were undertaken utilizing Spearman regression analysis and Mann-Whitney U test. Significance was accepted with 95 % confidence. Fifty-two patients (41 male: 11 female) of mean age 66.2 ± 8.8 years underwent robotic-assisted esophagogastrectomies for malignant esophageal disease. Neoadjuvant chemoradiation was administered to 30 (61 %) patients. A significant reduction in operative times (p learning curve for a robotic-assisted procedure appears to begin near proficiency after 20 cases. Operative complications and conversions were infrequent and unchanged across successive 10-patient cohorts.
Development of the curve of Spee.
Marshall, Steven D; Caspersen, Matthew; Hardinger, Rachel R; Franciscus, Robert G; Aquilino, Steven A; Southard, Thomas E
2008-09-01
Ferdinand Graf von Spee is credited with characterizing human occlusal curvature viewed in the sagittal plane. This naturally occurring phenomenon has clinical importance in orthodontics and restorative dentistry, yet we have little understanding of when, how, or why it develops. The purpose of this study was to expand our understanding by examining the development of the curve of Spee longitudinally in a sample of untreated subjects with normal occlusion from the deciduous dentition to adulthood. Records of 16 male and 17 female subjects from the Iowa Facial Growth Study were selected and examined. The depth of the curve of Spee was measured on their study models at 7 time points from ages 4 (deciduous dentition) to 26 (adult dentition) years. The Wilcoxon signed rank test was used to compare changes in the curve of Spee depth between time points. For each subject, the relative eruption of the mandibular teeth was measured from corresponding cephalometric radiographs, and its contribution to the developing curve of Spee was ascertained. In the deciduous dentition, the curve of Spee is minimal. At mean ages of 4.05 and 5.27 years, the average curve of Spee depths are 0.24 and 0.25 mm, respectively. With change to the transitional dentition, corresponding to the eruption of the mandibular permanent first molars and central incisors (mean age, 6.91 years), the curve of Spee depth increases significantly (P < 0.0001) to a mean maximum depth of 1.32 mm. The curve of Spee then remains essentially unchanged until eruption of the second molars (mean age, 12.38 years), when the depth increases (P < 0.0001) to a mean maximum depth of 2.17 mm. In the adolescent dentition (mean age, 16.21 years), the depth decreases slightly (P = 0.0009) to a mean maximum depth of 1.98 mm, and, in the adult dentition (mean age 26.98 years), the curve remains unchanged (P = 0.66), with a mean maximum depth of 2.02 mm. No significant differences in curve of Spee development were found between
Development of p-y curves of laterally loaded piles in cohesionless soil.
Khari, Mahdy; Kassim, Khairul Anuar; Adnan, Azlan
2014-01-01
The research on damages of structures that are supported by deep foundations has been quite intensive in the past decade. Kinematic interaction in soil-pile interaction is evaluated based on the p-y curve approach. Existing p-y curves have considered the effects of relative density on soil-pile interaction in sandy soil. The roughness influence of the surface wall pile on p-y curves has not been emphasized sufficiently. The presented study was performed to develop a series of p-y curves for single piles through comprehensive experimental investigations. Modification factors were studied, namely, the effects of relative density and roughness of the wall surface of pile. The model tests were subjected to lateral load in Johor Bahru sand. The new p-y curves were evaluated based on the experimental data and were compared to the existing p-y curves. The soil-pile reaction for various relative density (from 30% to 75%) was increased in the range of 40-95% for a smooth pile at a small displacement and 90% at a large displacement. For rough pile, the ratio of dense to loose relative density soil-pile reaction was from 2.0 to 3.0 at a small to large displacement. Direct comparison of the developed p-y curve shows significant differences in the magnitude and shapes with the existing load-transfer curves. Good comparison with the experimental and design studies demonstrates the multidisciplinary applications of the present method.
Ko, William L.; Fleischer, Van Tran
2011-01-01
The Ko displacement theory originally developed for shape predictions of straight beams is extended to shape predictions of curved beams. The surface strains needed for shape predictions were analytically generated from finite-element nodal stress outputs. With the aid of finite-element displacement outputs, mathematical functional forms for curvature-effect correction terms are established and incorporated into straight-beam deflection equations for shape predictions of both cantilever and two-point supported curved beams. The newly established deflection equations for cantilever curved beams could provide quite accurate shape predictions for different cantilever curved beams, including the quarter-circle cantilever beam. Furthermore, the newly formulated deflection equations for two-point supported curved beams could provide accurate shape predictions for a range of two-point supported curved beams, including the full-circular ring. Accuracy of the newly developed curved-beam deflection equations is validated through shape prediction analysis of curved beams embedded in the windward shallow spherical shell of a generic crew exploration vehicle. A single-point collocation method for optimization of shape predictions is discussed in detail
Twists of genus three curves and their Jacobians
Meagher, Stephen
2008-01-01
An algebraic curve is a curve defined over by polynomial equations with coefficients in a given field. This thesis treats problems which arise from genus three curves over finite fields. An important tool for treating such curves is the Jacobian variety of the curve. One problem is how many points
Brachistochrone curve of a fluid filled cylinder
Sarma, Srikanth; Raja, Sharan; Mahapatra, Pallab Sinha; Panchangnula, Mahesh
2017-11-01
The brachistochrone curve for a non-dissipative particle tries to maximize inertia of the particle but for a fluid filled cylinder, increasing inertia would amount to high dissipative losses. Hence the trade off between inertia and dissipation plays a vital role in the dynamics of a fluid filled cylinder. This trade off manifests itself in the form of an integro-differential equation governing the angular acceleration of the cylinder. Here, we compute the brachistochrone curve using optimal control principles and investigate the effect of the fore mentioned trade off on the deviation of the brachistochrone curve from that of a non-dissipative particle. Also, we investigate the effects of the non-dimensional parameters of the problem on the shape of the brachistochrone curve. We analyze the dissipation rate during the cylinder's motion and show that energy based arguments don't hold good for a fluid filled cylinder. We then analyze the stability of the time varying fluid flow in the cylinder and find an admissible region for the terminal point which would ensure the stability of the fluid flow as the cylinder rolls over the brachistochrone curve.
Incorporating experience curves in appliance standards analysis
International Nuclear Information System (INIS)
Desroches, Louis-Benoit; Garbesi, Karina; Kantner, Colleen; Van Buskirk, Robert; Yang, Hung-Chia
2013-01-01
There exists considerable evidence that manufacturing costs and consumer prices of residential appliances have decreased in real terms over the last several decades. This phenomenon is generally attributable to manufacturing efficiency gained with cumulative experience producing a certain good, and is modeled by an empirical experience curve. The technical analyses conducted in support of U.S. energy conservation standards for residential appliances and commercial equipment have, until recently, assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. This assumption does not reflect real market price dynamics. Using price data from the Bureau of Labor Statistics, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These experience curves were incorporated into recent energy conservation standards analyses for these products. Including experience curves increases the national consumer net present value of potential standard levels. In some cases a potential standard level exhibits a net benefit when considering experience, whereas without experience it exhibits a net cost. These results highlight the importance of modeling more representative market prices. - Highlights: ► Past appliance standards analyses have assumed constant equipment prices. ► There is considerable evidence of consistent real price declines. ► We incorporate experience curves for several large appliances into the analysis. ► The revised analyses demonstrate larger net present values of potential standards. ► The results imply that past standards analyses may have undervalued benefits.
Applications for curved glass in buildings
Directory of Open Access Journals (Sweden)
Jürgen Neugebauer
2015-05-01
Full Text Available In the last years an increase of the number of building projects with built-in curved glass can be observed. The applications can principally be curved monolithic glass, laminated safety glass or insulated glass. This fact makes it absolute of interest to make more investigations in this field. The investigations can be focused on e.g. the process of the bending of the glass to bring it into a certain shape, or the very difficult topic of pre-stressing it. The state of the art of the production process of such glass shows some different ways to produce curved glass. The most used way is to bend the glass at a high temperature of more than 550° Celsius. Another kind of curved glass can be achieved in combination with the laminating process. With the cooling down at the end of the laminating process the interlayer becomes stiff enough to hold the shape by activated shear forces between the glass layers. Another possibility is to produce flat glass and bend it while mounting the glass. The question how to pre-stress curved glass is on the very first beginning of investigations. All these different processes are on the first view very easy but very difficult in the detail.
Comparison of power curve monitoring methods
Directory of Open Access Journals (Sweden)
Cambron Philippe
2017-01-01
Full Text Available Performance monitoring is an important aspect of operating wind farms. This can be done through the power curve monitoring (PCM of wind turbines (WT. In the past years, important work has been conducted on PCM. Various methodologies have been proposed, each one with interesting results. However, it is difficult to compare these methods because they have been developed using their respective data sets. The objective of this actual work is to compare some of the proposed PCM methods using common data sets. The metric used to compare the PCM methods is the time needed to detect a change in the power curve. Two power curve models will be covered to establish the effect the model type has on the monitoring outcomes. Each model was tested with two control charts. Other methodologies and metrics proposed in the literature for power curve monitoring such as areas under the power curve and the use of statistical copulas have also been covered. Results demonstrate that model-based PCM methods are more reliable at the detecting a performance change than other methodologies and that the effectiveness of the control chart depends on the types of shift observed.
Critical Factors for Inducing Curved Somatosensory Saccades
Directory of Open Access Journals (Sweden)
Tamami Nakano
2011-10-01
Full Text Available We are able to make a saccade toward a tactile stimuli to one hand, but trajectories of many saccades curved markedly when the arms were crossed (Groh & Sparks, 2006. However, it remains unknown why some curved and others did not. We therefore examined critical factors for inducing the curved somatosensory saccades. Participants made a saccade as soon as possible from a central fixation point toward a tactile stimulus delivered to one of the two hands, and switched between arms-crossed and arms-uncrossed postures every 6 trials. Trajectories were generally straight when the arms were uncrossed, but all participants made curved saccades when the arms were crossed (12–64%. We found that the probability of curved saccades depended critically on the onset latency: the probability was less than 5% when the latency was larger than 250 ms, but the probability increased up to 70–80% when the onset latency was 160 ms. This relationship was shared across participants. The results suggest that a touch in the arms-crossed posture was always mapped to the wrong hand in the initial phase up to 160 ms, and then remapped to the correct hand during the next 100 ms by some fundamental neural mechanisms shared across participants.
Polynuclear Aromatic Hydrocarbons with Curved Surfaces: Buckyballs
Energy Technology Data Exchange (ETDEWEB)
Sygula, Andrzej [Mississippi State Univ., Mississippi State, MS (United States)
2016-08-15
The discovery of a new allotropic form of elemental carbon – the fullerenes – and subsequently other novel forms of elemental carbon with pyramidalized surfaces, most notably single-walled and multi-walled carbon nanotubes, introduced a novel structural motif to the polycyclic aromatic hydrocarbons (PAHs) with nonplanar surfaces. Our research program supported by BES DOE grant DE-FG02-04ER15514 has dealt with the synthesis, structural studies, and chemistry of the novel curved-surface PAHs with carbon frameworks structurally related to fullerenes. They are referred to as “buckybowls”. We prepared several new buckybowls and, even more importantly, developed the efficient, gram-scale synthetic methodologies for the preparation of small buckybowls, most notably corannulene (C20H10) and its derivatives. In addition, the employment of the corannulene-based synthons previously developed in our laboratory led to a number of highly nonplanar molecular architectures with two or more corannulene subunits with a potential for the applications as novel materials in separation sciences, nanoelectronics, photovoltaics and catalysis. In collaboration with Professor Angelici (Iowa State) we prepared and characterized several transition metal complexes of corannulene, providing the first structural characterization of η6 metal complexes of buckybowls by a single crystal X-ray diffraction. In addition to the definitive structural characterization of the complexes we demonstrated that the (η6-C6Me6)Ru2+ unit in some relatively stable complexes activate the corannulene ligand to react with proper nucleophiles suggesting that such complexex may be used in catalysis. (Section C). We have explored the efficiency of the dispersion-based interactions of curved-surface conjugated carbon networks by high-level computational models. We showed that the curvature of such networks does not reduce the van der Waals attractions as compared to the planar systems of similar size. We than
Impact of morphology on diffusive dynamics on curved surfaces.
Kusters, Remy; Storm, Cornelis
2014-03-01
Diffusive processes on nonplanar substrates are deeply relevant for cellular function and transport and increasingly used to probe and characterize the behavior of proteins in membranes. We present analytical and numerical analyses of in-plane diffusion of discrete particles on curved geometries reflecting various generic motifs in biology and explore, in particular, the effect that the shape of the substrate has on the characteristic time scales of diffusive processes. To this end, we consider both collective measures (the relaxation of concentration profiles towards equilibrium) and single-particle measures (escape rates and first passage times of individual diffusing molecules): the first relevant for the correct interpretation of FRAP experiments in curved environments; the second, for single-particle tracking probes. Each of these measures is sensitively affected by the morphology of the substrate, and we find that the exit rate out of a domain is not uniquely set by the size of its boundary, illustrating the general principle we reveal: By varying the shape of a substrate, Nature can control the diffusive time scales in a microenvironment without changing the bare substrate properties.
Phase response curves for models of earthquake fault dynamics
International Nuclear Information System (INIS)
Franović, Igor; Kostić, Srdjan; Perc, Matjaž; Klinshov, Vladimir; Nekorkin, Vladimir; Kurths, Jürgen
2016-01-01
We systematically study effects of external perturbations on models describing earthquake fault dynamics. The latter are based on the framework of the Burridge-Knopoff spring-block system, including the cases of a simple mono-block fault, as well as the paradigmatic complex faults made up of two identical or distinct blocks. The blocks exhibit relaxation oscillations, which are representative for the stick-slip behavior typical for earthquake dynamics. Our analysis is carried out by determining the phase response curves of first and second order. For a mono-block fault, we consider the impact of a single and two successive pulse perturbations, further demonstrating how the profile of phase response curves depends on the fault parameters. For a homogeneous two-block fault, our focus is on the scenario where each of the blocks is influenced by a single pulse, whereas for heterogeneous faults, we analyze how the response of the system depends on whether the stimulus is applied to the block having a shorter or a longer oscillation period.
Impact of morphology on diffusive dynamics on curved surfaces
Kusters, Remy; Storm, Cornelis
2014-03-01
Diffusive processes on nonplanar substrates are deeply relevant for cellular function and transport and increasingly used to probe and characterize the behavior of proteins in membranes. We present analytical and numerical analyses of in-plane diffusion of discrete particles on curved geometries reflecting various generic motifs in biology and explore, in particular, the effect that the shape of the substrate has on the characteristic time scales of diffusive processes. To this end, we consider both collective measures (the relaxation of concentration profiles towards equilibrium) and single-particle measures (escape rates and first passage times of individual diffusing molecules): the first relevant for the correct interpretation of FRAP experiments in curved environments; the second, for single-particle tracking probes. Each of these measures is sensitively affected by the morphology of the substrate, and we find that the exit rate out of a domain is not uniquely set by the size of its boundary, illustrating the general principle we reveal: By varying the shape of a substrate, Nature can control the diffusive time scales in a microenvironment without changing the bare substrate properties.
Experimental simulation of closed timelike curves.
Ringbauer, Martin; Broome, Matthew A; Myers, Casey R; White, Andrew G; Ralph, Timothy C
2014-06-19
Closed timelike curves are among the most controversial features of modern physics. As legitimate solutions to Einstein's field equations, they allow for time travel, which instinctively seems paradoxical. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. The study of these systems therefore provides valuable insight into nonlinearities and the emergence of causal structures in quantum mechanics--essential for any formulation of a quantum theory of gravity. Here we experimentally simulate the nonlinear behaviour of a qubit interacting unitarily with an older version of itself, addressing some of the fascinating effects that arise in systems traversing a closed timelike curve. These include perfect discrimination of non-orthogonal states and, most intriguingly, the ability to distinguish nominally equivalent ways of preparing pure quantum states. Finally, we examine the dependence of these effects on the initial qubit state, the form of the unitary interaction and the influence of decoherence.
Asymmetry dependence of the nuclear caloric curve
International Nuclear Information System (INIS)
McIntosh, A.B.; Bonasera, A.; Cammarata, P.; Hagel, K.; Heilborn, L.; Kohley, Z.; Mabiala, J.; May, L.W.; Marini, P.; Raphelt, A.; Souliotis, G.A.; Wuenschel, S.; Zarrella, A.; Yennello, S.J.
2013-01-01
A basic feature of the nuclear equation of state is not yet understood: the dependence of the nuclear caloric curve on the neutron–proton asymmetry. Predictions of theoretical models differ on the magnitude and even the sign of this dependence. In this work, the nuclear caloric curve is examined for fully reconstructed quasi-projectiles around mass A=50. The caloric curve extracted with the momentum quadrupole fluctuation thermometer shows that the temperature varies linearly with quasi-projectile asymmetry (N−Z)/A . An increase in asymmetry of 0.15 units corresponds to a decrease in temperature on the order of 1 MeV. These results also highlight the importance of a full quasi-projectile reconstruction in the study of thermodynamic properties of hot nuclei
The genus curve of the Abell clusters
Rhoads, James E.; Gott, J. Richard, III; Postman, Marc
1994-01-01
We study the topology of large-scale structure through a genus curve measurement of the recent Abell catalog redshift survey of Postman, Huchra, and Geller (1992). The structure is found to be spongelike near median density and to exhibit isolated superclusters and voids at high and low densities, respectively. The genus curve shows a slight shift toward 'meatball' topology, but remains consistent with the hypothesis of Gaussian random phase initial conditions. The amplitude of the genus curve corresponds to a power-law spectrum with index n = 0.21(sub -0.47 sup +0.43) on scales of 48/h Mpc or to a cold dark matter power spectrum with omega h = 0.36(sub -0.17 sup +0.46).
Energy efficiency and load curve impacts
International Nuclear Information System (INIS)
Feilberg, Nicolai
2002-01-01
One of SINTEF Energy Research's European RTD projects is the two-year EFFLOCOM (Energy EFFiciency and LOad curve impacts of COMmercial development in competitive markets). This project will determine the end-user response of different market-related services offered in deregulated power markets. The project will investigate the possibility of influencing load curves by using different price signals and two-way communications via Internet. The partners are from Denmark. Finland, England, France and Norway. SINTEF Energy Research is in charge of the project management. During the project, the changes in load curves will he studied in the in the participating countries before and after deregulation. Specific issues are the use of ICT, time- and situation-dependent tariffs and smart-house technology. The project will consist of 5 work packages that will give recommendations about new methods, guidelines and tools to promote effective use of energy in the partner countries. The total budget is EUR 692 000. (author)
Differential geometry of curves and surfaces
Banchoff, Thomas F
2010-01-01
Students and professors of an undergraduate course in differential geometry will appreciate the clear exposition and comprehensive exercises in this book that focuses on the geometric properties of curves and surfaces, one- and two-dimensional objects in Euclidean space. The problems generally relate to questions of local properties (the properties observed at a point on the curve or surface) or global properties (the properties of the object as a whole). Some of the more interesting theorems explore relationships between local and global properties. A special feature is the availability of accompanying online interactive java applets coordinated with each section. The applets allow students to investigate and manipulate curves and surfaces to develop intuition and to help analyze geometric phenomena.
The many radial access learning curves.
Hillegass, William B
2017-04-01
The radial approach to endovascular procedures has a series of learning curves: diagnostic heart catheterization, low-risk settings and "straightforward" percutaneous coronary intervention, high-risk settings, and complex coronary intervention, and peripheral vascular angiography and intervention. For diagnostic and low-risk interventional procedures, incremental improvements in technical success and safety are observed in the initial 200 procedures for most operators compared to highly experienced operators. Formal didactic training and ongoing support/review from an experienced radial operator(s) may expedite surmounting the series of radial learning curves while maintaining optimal procedural success and safety. Advances in technology and understanding will require the most experienced radial operators to continually embrace their next learning curve. © 2017 Wiley Periodicals, Inc.
Surface growth kinematics via local curve evolution
Moulton, Derek E.
2012-11-18
A mathematical framework is developed to model the kinematics of surface growth for objects that can be generated by evolving a curve in space, such as seashells and horns. Growth is dictated by a growth velocity vector field defined at every point on a generating curve. A local orthonormal basis is attached to each point of the generating curve and the velocity field is given in terms of the local coordinate directions, leading to a fully local and elegant mathematical structure. Several examples of increasing complexity are provided, and we demonstrate how biologically relevant structures such as logarithmic shells and horns emerge as analytical solutions of the kinematics equations with a small number of parameters that can be linked to the underlying growth process. Direct access to cell tracks and local orientation enables for connections to be made to the underlying growth process. © 2012 Springer-Verlag Berlin Heidelberg.
Minimal families of curves on surfaces
Lubbes, Niels
2014-11-01
A minimal family of curves on an embedded surface is defined as a 1-dimensional family of rational curves of minimal degree, which cover the surface. We classify such minimal families using constructive methods. This allows us to compute the minimal families of a given surface.The classification of minimal families of curves can be reduced to the classification of minimal families which cover weak Del Pezzo surfaces. We classify the minimal families of weak Del Pezzo surfaces and present a table with the number of minimal families of each weak Del Pezzo surface up to Weyl equivalence.As an application of this classification we generalize some results of Schicho. We classify algebraic surfaces that carry a family of conics. We determine the minimal lexicographic degree for the parametrization of a surface that carries at least 2 minimal families. © 2014 Elsevier B.V.
POSSIBLE RECESSION CURVE APPLICATIONS FOR RETENTION EVALUATION
Directory of Open Access Journals (Sweden)
Daniel Liberacki
2015-11-01
Full Text Available The objective of the article was to present possible applications of recession flow curve in a small lowland watershed retention discharge size evaluation. The examined woodland micro catchment area of 0.52 sq km is located in Puszcza Zielonka in central Wielkopolska. The Hutka catchment is typically woody with high retention abilities. The catchment of the Hutka watercourse is forested in 89%, the other 11% is covered by swamps and wasteland. The predominant sites are fresh mixed coniferous forest (BMśw, fresh coniferous forest (Bśw and alder carr forest (Ol. Landscape in catchment is characterized by a large number of interior depressions, filled partly with rainwater or peatbogs, with poorly developed natural drainage. The watercourses do not exceed 1 km in length, the mean width is approx. 0.5 m, while mean depth ranges from 0.2 to 0.3 m. During hydrological research conducted in 1997/1998–1999/2000, 35 major (characteristic raised water stages were observed in Hutka after substantial precipitation. The recession curve dating from 18–24 September 2000 has the α and n rates nearest to average. Comparing the model curve and the curve created by observing watercourse flow, one can notice their resemblance and that they have similar ordinate values as well as shape. In the case of other recession curves, the maximum differences of ordinate values are also about 0.1–0.2 l/s/km2. The measuured α and n rates do not reveal any regularities. There are no significant statistical Horton model parameter (for recession flow curves dependencies between α and n and e.g. initial flows (Qo or the whole period of high water waves (Qp. Consequently, calculated relation between these parameters is only an approximation for the general evaluation of the retention discharge in the catchment area towards retention with flow function.
Nonlinear Oscillations of Elastic Curved Plate Carried to the Associated Masses System
Sysoyev, O. Ye; Dobryshkin, A. Yu; Naing, N. S.
2017-11-01
Curved plates are used in many spheres of our life. Often curved plates have an articulated support. Often, the operation of such structures is associated with fluctuations as well as with the systems of attached masses. The vibrations of such structures have not been fully studied yet. In the laboratory of building structures of Komsomolsk-on-Amur State Technical University a test bench was prepared for testing curved plates hinged at the edges and carrying an attached mass or a system of attached masses. The attached mass is represented by a sensor fixed to the body of a curved plate carrying an attached mass. Experimental and theoretical data correlate with each other. Minimal discrepancies were obtained with the minimum attached mass and the maximum discrepancies at the maximum investigated attached mass. Theoretical calculations were performed using the known equations of plate oscillations.
From Curve Fitting to Machine Learning
Zielesny, Achim
2011-01-01
The analysis of experimental data is at heart of science from its beginnings. But it was the advent of digital computers that allowed the execution of highly non-linear and increasingly complex data analysis procedures - methods that were completely unfeasible before. Non-linear curve fitting, clustering and machine learning belong to these modern techniques which are a further step towards computational intelligence. The goal of this book is to provide an interactive and illustrative guide to these topics. It concentrates on the road from two dimensional curve fitting to multidimensional clus
Computer Controlled Photometer/Planck Curve Experiment
Dupuy, David L.; Peters, Philip B.
2001-11-01
Developed as a demo in our course for computer control of laboratory experiments, this experiment had two goals: to attempt to measure the output of a tungsten bulb over a wide range of wavelengths, and to test the use of LabVIEW as a programming language for teaching experiment control. The brightness readings were corrected for instrumental effects and fitted with a Planck curve. The experiment involved digital input, digital output to a microstepper controller to move the filter wheel, and analog input. Results will be shown for the Planck curve and the LabVIEW program.
Phonon dispersion curves for CsCN
International Nuclear Information System (INIS)
Gaur, N.K.; Singh, Preeti; Rini, E.G.; Galgale, Jyostna; Singh, R.K.
2004-01-01
The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the orientation of cyanide molecules for the description of phonon dispersion curves of CsCN between the temperatures 195 and 295 K. Our results on PDCs in symmetric direction are in good agreement with the experimental data measured with inelastic neutron scattering technique. (author)
Angles between Curves in Metric Measure Spaces
Directory of Open Access Journals (Sweden)
Han Bang-Xian
2017-09-01
Full Text Available The goal of the paper is to study the angle between two curves in the framework of metric (and metric measure spaces. More precisely, we give a new notion of angle between two curves in a metric space. Such a notion has a natural interplay with optimal transportation and is particularly well suited for metric measure spaces satisfying the curvature-dimension condition. Indeed one of the main results is the validity of the cosine formula on RCD*(K, N metric measure spaces. As a consequence, the new introduced notions are compatible with the corresponding classical ones for Riemannian manifolds, Ricci limit spaces and Alexandrov spaces.
Migration and the Wage-Settings Curve
DEFF Research Database (Denmark)
Brücker, Herbert; Jahn, Elke
Germany on basis of a wage-setting curve. The wage-setting curve relies on the assumption that wages respond to a hange in the unemployment rate, albeit imperfectly. This allows one to derive the wage and employment effects of migration simultaneously in a general equilibrium framework. Using...... in the German labor force through immigration increases the aggregate unemployment rate by less than 0.1 percentage points and reduces average wages by 0.1 percent in the short run. While native workers benefit from increased wages and lower unemployment, foreign workers are adversely affected....
Bound states in curved quantum waveguides
International Nuclear Information System (INIS)
Exner, P.; Seba, P.
1987-01-01
We study free quantum particle living on a curved planar strip Ω of a fixed width d with Dirichlet boundary conditions. It can serve as a model for electrons in thin films on a cylindrical-type substrate, or in a curved quantum wire. Assuming that the boundary of Ω is infinitely smooth and its curvature decays fast enough at infinity, we prove that a bound state with energy below the first transversal mode exists for all sufficiently small d. A lower bound on the critical width is obtained using the Birman-Schwinger technique. (orig.)
Boiling curve in high quality flow boiling
International Nuclear Information System (INIS)
Shiralkar, B.S.; Hein, R.A.; Yadigaroglu, G.
1980-01-01
The post dry-out heat transfer regime of the flow boiling curve was investigated experimentally for high pressure water at high qualities. The test section was a short round tube located downstream of a hot patch created by a temperature controlled segment of tubing. Results from the experiment showed that the distance from the dryout point has a significant effect on the downstream temperatures and there was no unique boiling curve. The heat transfer coefficients measured sufficiently downstream of the dryout point could be correlated using the Heineman correlation for superheated steam, indicating that the droplet deposition effects could be neglected in this region
Multivariate curve-fitting in GAUSS
Bunck, C.M.; Pendleton, G.W.
1988-01-01
Multivariate curve-fitting techniques for repeated measures have been developed and an interactive program has been written in GAUSS. The program implements not only the one-factor design described in Morrison (1967) but also includes pairwise comparisons of curves and rates, a two-factor design, and other options. Strategies for selecting the appropriate degree for the polynomial are provided. The methods and program are illustrated with data from studies of the effects of environmental contaminants on ducklings, nesting kestrels and quail.
Light Curve Analysis of SAO23229
Directory of Open Access Journals (Sweden)
Ho-Il Kim
1993-06-01
Full Text Available We have made UBV light curves of a newly discovered eclipsing binary, SAO23229 at Sobaeksan Astronomy Observatory. We determined a minimum light time of HJD2448636.1170+/-0.0005 that is 3 minutes later than predicted time, and founda peculiar light variation at phase 0.75 that may not be secondary eclipse. Orbital period of SAO23229 would be 4.2 days rather than 2.1 days. Our analysis of the light curves shows that SAO23229 has a detached configuration consisting of two almost identical F type main sequence stars.
Ghandhi, J B
2000-10-20
Single- and dual-fiber fluorescence probes have been utilized to study oil-film behavior in a firing Diesel engine. A detailed analysis of the response characteristics of these probes was performed, and universal response curves have been generated through identification of the appropriate nondimensional parameters. For single-fiber probes a single curve was obtained, and for dual-fiber probes families of curves were identified based on three geometric dimensionless parameters. The complementary response characteristics of the single- and dual-fiber probes allows determination of the oil distribution within the piston-liner gap. The dual-fiber probe is not sensitive at small distances. Thus its signal originates solely from the piston surface, whereas the single-fiber probe is most sensitive at small distances and hence to the wall oil film. The engine data from the dual-fiber probe confirmed the presence of an oil film on the piston and provided a means of quantifying the transport of this oil within the engine.
Analysis of characteristic performance curves in radiodiagnosis by an observer
International Nuclear Information System (INIS)
Kossovoj, A.L.
1988-01-01
Methods and ways of construction of performance characteristic curves (PX-curves) in roentgenology, their qualitative and quantitative estimation are described. Estimation of PX curves application for analysis of scintigraphic and sonographic images is presented
Higher rank BN-theory for curves of genus 4
Lange, H.; Newstead, P. E.
2015-01-01
Higher rank Brill-Noether theory is completely known for curves of genus $\\leq 3$. In this paper, we investigate the theory for curves of genus 4. Some of our results apply to curves of arbitrary genus.
Too far ahead of the IT curve?
Glaser, John P
2007-01-01
Peachtree Healthcare has major IT infrastructure problems, and CEO Max Berndt is struggling to find the right fix. He can go with a single set of systems and applications that will provide consistency across Peachtree's facilities but may not give doctors enough flexibility. Or he can choose service-oriented architecture (SOA), a modular design that will allow Peachtree to standardize incrementally and selectively but poses certain risks as a newer technology. What should he do? Four experts comment on this fictional case study, authored by John P. Glaser, CIO for Partners HealthCare System. George C. Halvorson, the chairman and CEO of Kaiser Permanente, warns against using untested methodologies such as SOA in a health care environment, where lives are at stake. He says Peachtree's management must clarify its overall IT vision before devising a plan to achieve each of its objectives. Monte Ford, the chief information officer at American Airlines, says Peachtree can gradually replace its old systems with SOA. An incremental approach, he points out, would not only minimize risk but also enhance flexibility and control, and would allow IT to shift priorities along the way. Randy Heffner, a vice president at Forrester Research who focuses on technology architectures for computer-based business systems, thinks SOA's modular approach to business design would best meet Peachtree's need for flexibility. He says that Peachtree's CIO sees SOA as a new product category but should instead view it as a methodology. John A. Kastor, a professor at the University of Maryland School of Medicine, questions the goal of standardized care. He argues that it would be difficult to persuade doctors, many of whom are fiercely independent, to follow rigid patterns in their work.
Bijlsma, S.; Boelens, H. F. M.; Hoefsloot, H. C. J.; Smilde, A. K.
2000-01-01
A traditional curve fitting (TCF) algorithm is compared with a classical curve resolution (CCR) approach for estimating reaction rate constants from spectral data obtained in time of a chemical reaction. In the TCF algorithm, reaction rate constants an estimated from the absorbance versus time data
Characterization of Elliptic Curve Traces under FR-reduction
Miyaji, Atsuko; Nakabayashi, Masaki; Takano, Shunzo
2001-01-01
Elliptic curve cryptosystems([19],[25]) are based on the elliptic curve discrete logarithm problem(ECDLP). If elliptic curve cryptosystems avoid FR-reduction([11],[17]) and anomalous elliptic curve over F_q ([34],[3],[36]), then with current knowledge we can construct elliptic curve cryptosystems over a smaller definition field. ECDLP has an interesting property that the security deeply depends on elliptic curve traces rather than definition fields, which does not occur in the case of the dis...
Universality of accelerating change
Eliazar, Iddo; Shlesinger, Michael F.
2018-03-01
On large time scales the progress of human technology follows an exponential growth trend that is termed accelerating change. The exponential growth trend is commonly considered to be the amalgamated effect of consecutive technology revolutions - where the progress carried in by each technology revolution follows an S-curve, and where the aging of each technology revolution drives humanity to push for the next technology revolution. Thus, as a collective, mankind is the 'intelligent designer' of accelerating change. In this paper we establish that the exponential growth trend - and only this trend - emerges universally, on large time scales, from systems that combine together two elements: randomness and amalgamation. Hence, the universal generation of accelerating change can be attained by systems with no 'intelligent designer'.
Some genus 3 curves with many points
Auer, R; Top, J; Fieker, C; Kohel, DR
2002-01-01
We explain a naive approach towards the problem of finding genus 3 curves C over any given finite field F-q of odd characteristic, with a number of rational points close to the Hasse-Weil-Serre upper bound q+1+3[2rootq]. The method turns out to be successful at least in characteristic 3.
Meromorphic connections on vector bundles over curves
Indian Academy of Sciences (India)
Descartes,. 67084 Strasbourg Cedex, France. *Correspond author. E-mail: indranil@math.tifr.res.in; heu@math.unistra.fr. MS received 17 July 2013; revised 20 October 2013. Abstract. We give a criterion for filtered vector bundles over curves to admit a ...
Phonon dispersion curves of CsCN
Indian Academy of Sciences (India)
Abstract. The motivation for the present work was gained from the recent publication on phonon dispersion curves (PDCs) of CsCN from the neutron scattering technique. We have applied the extended three-body force shell model (ETSM) by incorporating the effect of coupling between the translation modes and the ...
A Probabilistic Framework for Curve Evolution
DEFF Research Database (Denmark)
Dahl, Vedrana Andersen
2017-01-01
approach include ability to handle textured images, simple generalization to multiple regions, and efficiency in computation. We test our probabilistic framework in combination with parametric (snakes) and geometric (level-sets) curves. The experimental results on composed and natural images demonstrate...
Replication and analysis of Ebbinghaus' forgetting curve
Murre, J.M.J.; Dros, J.
2015-01-01
We present a successful replication of Ebbinghaus’ classic forgetting curve from 1880 based on the method of savings. One subject spent 70 hours learning lists and relearning them after 20 min, 1 hour, 9 hours, 1 day, 2 days, or 31 days. The results are similar to Ebbinghaus' original data. We
Steady turbulent flow in curved rectangular channels
De Vriend, H.J.
1979-01-01
After the study of fully developed and developing steady laminar flow in curved channels of shallow rectangular wet cross-section (see earlier reports in this series), steady turbulent flow in such channels is investigated as a next step towards a mathematical model of the flow in shallow river
Developing laminar flow in curved rectangular channels
De Vriend, H.J.
1978-01-01
As an intermediate step between earlier investigations on fully developed laminar flow in curved channels of shallow rectancular wet cross-section and the mathematical modeling of turbulent flow in river bends, a mathematical model of developing laminar flow in such channels is investigated. The
Covariant quantizations in plane and curved spaces
Energy Technology Data Exchange (ETDEWEB)
Assirati, J.L.M. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P.N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil)
2017-07-15
We present covariant quantization rules for nonsingular finite-dimensional classical theories with flat and curved configuration spaces. In the beginning, we construct a family of covariant quantizations in flat spaces and Cartesian coordinates. This family is parametrized by a function ω(θ), θ element of (1,0), which describes an ambiguity of the quantization. We generalize this construction presenting covariant quantizations of theories with flat configuration spaces but already with arbitrary curvilinear coordinates. Then we construct a so-called minimal family of covariant quantizations for theories with curved configuration spaces. This family of quantizations is parametrized by the same function ω(θ). Finally, we describe a more wide family of covariant quantizations in curved spaces. This family is already parametrized by two functions, the previous one ω(θ) and by an additional function Θ(x,ξ). The above mentioned minimal family is a part at Θ = 1 of the wide family of quantizations. We study constructed quantizations in detail, proving their consistency and covariance. As a physical application, we consider a quantization of a non-relativistic particle moving in a curved space, discussing the problem of a quantum potential. Applying the covariant quantizations in flat spaces to an old problem of constructing quantum Hamiltonian in polar coordinates, we directly obtain a correct result. (orig.)
Covariant quantizations in plane and curved spaces
International Nuclear Information System (INIS)
Assirati, J.L.M.; Gitman, D.M.
2017-01-01
We present covariant quantization rules for nonsingular finite-dimensional classical theories with flat and curved configuration spaces. In the beginning, we construct a family of covariant quantizations in flat spaces and Cartesian coordinates. This family is parametrized by a function ω(θ), θ element of (1,0), which describes an ambiguity of the quantization. We generalize this construction presenting covariant quantizations of theories with flat configuration spaces but already with arbitrary curvilinear coordinates. Then we construct a so-called minimal family of covariant quantizations for theories with curved configuration spaces. This family of quantizations is parametrized by the same function ω(θ). Finally, we describe a more wide family of covariant quantizations in curved spaces. This family is already parametrized by two functions, the previous one ω(θ) and by an additional function Θ(x,ξ). The above mentioned minimal family is a part at Θ = 1 of the wide family of quantizations. We study constructed quantizations in detail, proving their consistency and covariance. As a physical application, we consider a quantization of a non-relativistic particle moving in a curved space, discussing the problem of a quantum potential. Applying the covariant quantizations in flat spaces to an old problem of constructing quantum Hamiltonian in polar coordinates, we directly obtain a correct result. (orig.)
Designing the Alluvial Riverbeds in Curved Paths
Macura, Viliam; Škrinár, Andrej; Štefunková, Zuzana; Muchová, Zlatica; Majorošová, Martina
2017-10-01
The paper presents the method of determining the shape of the riverbed in curves of the watercourse, which is based on the method of Ikeda (1975) developed for a slightly curved path in sandy riverbed. Regulated rivers have essentially slightly and smoothly curved paths; therefore, this methodology provides the appropriate basis for river restoration. Based on the research in the experimental reach of the Holeška Brook and several alluvial mountain streams the methodology was adjusted. The method also takes into account other important characteristics of bottom material - the shape and orientation of the particles, settling velocity and drag coefficients. Thus, the method is mainly meant for the natural sand-gravel material, which is heterogeneous and the particle shape of the bottom material is very different from spherical. The calculation of the river channel in the curved path provides the basis for the design of optimal habitat, but also for the design of foundations of armouring of the bankside of the channel. The input data is adapted to the conditions of design practice.
Electronic properties of curved graphene sheets
Cortijo, Alberto; Vozmediano, Maria A. H.
2006-01-01
A model is proposed to study the electronic structure of slightly curved graphene sheets with an arbitrary number of pentagon-heptagon pairs and Stone-Wales defects based on a cosmological analogy. The disorder induced by curvature produces characteristic patterns in the local density of states that can be observed in scanning tunnel and transmission electron microscopy.
A Mean Value Formula for Elliptic Curves
Directory of Open Access Journals (Sweden)
Rongquan Feng
2014-01-01
Full Text Available It is proved in this paper that, for any point on an elliptic curve, the mean value of x-coordinates of its n-division points is the same as its x-coordinate and that of y-coordinates of its n-division points is n times that of its y-coordinate.
Bayesian Estimation of Item Response Curves.
Tsutakawa, Robert K.; Lin, Hsin Ying
1986-01-01
Item response curves for a set of binary responses are studied from a Bayesian viewpoint of estimating the item parameters. For the two-parameter logistic model with normally distributed ability, restricted bivariate beta priors are used to illustrate the computation of the posterior mode via the EM algorithm. (Author/LMO)
Numerical analysis of thermoluminescence glow curves
International Nuclear Information System (INIS)
Gomez Ros, J. M.; Delgado, A.
1989-01-01
This report presents a method for the numerical analysis of complex thermoluminescence glow curves resolving the individual glow peak components. The method employs first order kinetics analytical expressions and is based In a Marquart-Levenberg minimization procedure. A simplified version of this method for thermoluminescence dosimetry (TLD) is also described and specifically developed to operate whit Lithium Fluoride TLD-100. (Author). 36 refs
Light extraction block with curved surface
Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.
2016-03-22
Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.
Tempo curves considered harmful (part 2)
Desain, P.; Honing, H.
1991-01-01
A column (the second of a series of three) constitutes an abridged and adapted version of Tempo curves considered harmful . M (an amateur mathematician) and P (a would-be psychologist) incorporated some generative models for expressive timing in their sequencer program. This proved partially
Morphological modelling of strongly curved islands
Roelvink, D.; Den Heijer, C.; Van Thiel De Vries, J.S.M.
2013-01-01
Land reclamations and island coasts often involve strongly curved shorelines, which are challenging to be properly modeled by numerical morphological models. Evaluation of the long term development of these types of coasts as well as their response to storm conditions requires proper representation
Spherical images and inextensible curved folding
Seffen, Keith A.
2018-02-01
In their study, Duncan and Duncan [Proc. R. Soc. London A 383, 191 (1982), 10.1098/rspa.1982.0126] calculate the shape of an inextensible surface folded in two about a general curve. They find the analytical relationships between pairs of generators linked across the fold curve, the shape of the original path, and the fold angle variation along it. They present two special cases of generator layouts for which the fold angle is uniform or the folded curve remains planar, for simplifying practical folding in sheet-metal processes. We verify their special cases by a graphical treatment according to a method of Gauss. We replace the fold curve by a piecewise linear path, which connects vertices of intersecting pairs of hinge lines. Inspired by the d-cone analysis by Farmer and Calladine [Int. J. Mech. Sci. 47, 509 (2005), 10.1016/j.ijmecsci.2005.02.013], we construct the spherical images for developable folding of successive vertices: the operating conditions of the special cases in Duncan and Duncan are then revealed straightforwardly by the geometric relationships between the images. Our approach may be used to synthesize folding patterns for novel deployable and shape-changing surfaces without need of complex calculation.
Electron conductance in curved quantum structures
DEFF Research Database (Denmark)
Willatzen, Morten; Gravesen, Jens
2010-01-01
A differential-geometry analysis is employed to investigate the transmission of electrons through a curved quantum-wire structure. Although the problem is a three-dimensional spatial problem, the Schrodinger equation can be separated into three general coordinates. Hence, the proposed method...
Principal normal indicatrices of closed space curves
DEFF Research Database (Denmark)
Røgen, Peter
1999-01-01
A theorem due to J. Weiner, which is also proven by B. Solomon, implies that a principal normal indicatrix of a closed space curve with nonvanishing curvature has integrated geodesic curvature zero and contains no subarc with integrated geodesic curvature pi. We prove that the inverse problem alw...
Yield stress independent column buckling curves
DEFF Research Database (Denmark)
Stan, Tudor‐Cristian; Jönsson, Jeppe
2017-01-01
Using GMNIA and shell finite element modelling of steel columns it is ascertained that the buckling curves for given imperfections and residual stresses are not only dependent on the relative slenderness ratio and the cross section shape but also on the magnitude of the yield stress. The influence...
Theoretical Magnon Dispersion Curves for Gd
DEFF Research Database (Denmark)
Lindgård, Per-Anker; Harmon, B. N.; Freeman, A. J.
1975-01-01
The magnon dispersion curve of Gd metal has been determined from first principles by use of augmented-plane-wave energy bands and wave functions. The exchange matrix elements I(k⃗, k⃗′) between the 4f electrons and the conduction electrons from the first six energy bands were calculated under...
ATLAS detector records its first curved muon
2007-01-01
The barrel muon spectrometer of the ATLAS detector has acquired its first cosmic event in a magnetic field produced by the barrel toroid magnet. This was an important test of the chambers in their final configurations, and marked the first triggering and measurement of curved cosmic ray muons in ATLAS.
Discrete groups, Mumford curves and Theta functions
Put, Marius van der
1992-01-01
A discrete group Γ given over some complete non archimedean valued field defines a curve X. The theta functions for Γ provide an analytic construction for the Jacobian variety of X. A theory of theta functions is developed with the help of currents on trees and graphs and the cohomology for Γ. In
Comparison and evaluation of mathematical lactation curve ...
African Journals Online (AJOL)
Using the General Linear Model procedure in SAS, the effect of herd, calving year, age at calving, season of production, age and days in milk were found to be significant on daily milk yield. The suitability of seven mathematical models (with three, four and five parameters) for describing the 305-day milk yield lactation curve ...
Affine LIBOR Models with Multiple Curves
DEFF Research Database (Denmark)
Grbac, Zorana; Papapantoleon, Antonis; Schoenmakers, John
2015-01-01
We introduce a multiple curve framework that combines tractable dynamics and semianalytic pricing formulas with positive interest rates and basis spreads. Negative rates and positive spreads can also be accommodated in this framework. The dynamics of overnight indexed swap and LIBOR rates...
Measuring Systematic Error with Curve Fits
Rupright, Mark E.
2011-01-01
Systematic errors are often unavoidable in the introductory physics laboratory. As has been demonstrated in many papers in this journal, such errors can present a fundamental problem for data analysis, particularly when comparing the data to a given model. In this paper I give three examples in which my students use popular curve-fitting software…
Principal G-bundles on nodal curves
Indian Academy of Sciences (India)
Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45
If Y is reducible these notions depend on parameters a = (a1,...,aI ). The study of G-bundles on Y is done by extending the notion of (generalized) parabolic vector bundles [U1] to generalized parabolic principal G-bundles (called GPGs in short) on the curve C and using the correspondence between them and principal ...
Growth Curves for Girls with Turner Syndrome
Directory of Open Access Journals (Sweden)
Fabio Bertapelli
2014-01-01
Full Text Available The objective of this study was to review the growth curves for Turner syndrome, evaluate the methodological and statistical quality, and suggest potential growth curves for clinical practice guidelines. The search was carried out in the databases Medline and Embase. Of 1006 references identified, 15 were included. Studies constructed curves for weight, height, weight/height, body mass index, head circumference, height velocity, leg length, and sitting height. The sample ranged between 47 and 1,565 (total = 6,273 girls aged 0 to 24 y, born between 1950 and 2006. The number of measures ranged from 580 to 9,011 (total = 28,915. Most studies showed strengths such as sample size, exclusion of the use of growth hormone and androgen, and analysis of confounding variables. However, the growth curves were restricted to height, lack of information about selection bias, limited distributional properties, and smoothing aspects. In conclusion, we observe the need to construct an international growth reference for girls with Turner syndrome, in order to provide support for clinical practice guidelines.
Principal normal indicatrices of closed space curves
DEFF Research Database (Denmark)
Røgen, Peter
1997-01-01
A theorem due to J. Weiner, which also is proven by B. Solomon, implies that a principal normal indicatrix of a closed space curve with non-vanishing curvature has integrated geodesic curvature zero and contains no sub arc with integrated geodesic curvature Pi. We prove that the inverse problem...
Tropical count of curves on abelian varieties
DEFF Research Database (Denmark)
Halle, Lars Halvard; Rose, Simon Charles Florian
2017-01-01
We investigate the problem of counting tropical genus g curves ing-dimensional tropical abelian varieties. We do this by studyingmaps from principally polarized tropical abelian varieties into afixed abelian variety. For g = 2, 3, we prove that the tropical countmatches the count provided in [Göt98...
Remote sensing used for power curves
DEFF Research Database (Denmark)
Wagner, Rozenn; Ejsing Jørgensen, Hans; Schmidt Paulsen, Uwe
2008-01-01
Power curve measurement for large wind turbines requires taking into account more parameters than only the wind speed at hub height. Based on results from aerodynamic simulations, an equivalent wind speed taking the wind shear into account was defined and found to reduce the power standard deviat...
Tempo curves considered harmful (part 1)
Desain, P.; Honing, H.
1991-01-01
A column (the first of a series of three) constitutes an abridged and adapted version of Tempo curves considered harmful . Two friends, an amateur mathematician (M) and a would-be psychologist (P), invited a retired pianist to do some experiments with their new sequencer program. As musical material
Visualizing Nonlinear Narratives with Story Curves.
Kim, Nam Wook; Bach, Benjamin; Im, Hyejin; Schriber, Sasha; Gross, Markus; Pfister, Hanspeter
2018-01-01
In this paper, we present story curves, a visualization technique for exploring and communicating nonlinear narratives in movies. A nonlinear narrative is a storytelling device that portrays events of a story out of chronological order, e.g., in reverse order or going back and forth between past and future events. Many acclaimed movies employ unique narrative patterns which in turn have inspired other movies and contributed to the broader analysis of narrative patterns in movies. However, understanding and communicating nonlinear narratives is a difficult task due to complex temporal disruptions in the order of events as well as no explicit records specifying the actual temporal order of the underlying story. Story curves visualize the nonlinear narrative of a movie by showing the order in which events are told in the movie and comparing them to their actual chronological order, resulting in possibly meandering visual patterns in the curve. We also present Story Explorer, an interactive tool that visualizes a story curve together with complementary information such as characters and settings. Story Explorer further provides a script curation interface that allows users to specify the chronological order of events in movies. We used Story Explorer to analyze 10 popular nonlinear movies and describe the spectrum of narrative patterns that we discovered, including some novel patterns not previously described in the literature. Feedback from experts highlights potential use cases in screenplay writing and analysis, education and film production. A controlled user study shows that users with no expertise are able to understand visual patterns of nonlinear narratives using story curves.
Curved bones: An adaptation to habitual loading.
Milne, Nick
2016-10-21
Why are long bones curved? It has long been considered a paradox that many long bones supporting mammalian bodies are curved, since this curvature results in the bone undergoing greater bending, with higher strains and so greater fracture risk under load. This study develops a theoretical model wherein the curvature is a response to bending strains imposed by the requirements of locomotion. In particular the radioulna of obligate quadrupeds is a lever operated by the triceps muscle, and the bending strains induced by the triceps muscle counter the bending resulting from longitudinal loads acting on the curved bone. Indeed the theoretical model reverses this logic and suggests that the curvature is itself a response to the predictable bending strains induced by the triceps muscle. This, in turn, results in anatomical arrangements of bone, muscle and tendon that create a simple physiological mechanism whereby the bone can resist the bending due to the action of triceps in supporting and moving the body. The model is illustrated by contrasting the behaviour of a finite element model of a llama radioulna to that of a straightened version of the same bone. The results show that longitudinal and flexor muscle forces produce bending strains that effectively counter strains due to the pull of the triceps muscle in the curved but not in the straightened model. It is concluded that the curvature of these and other curved bones adds resilience to the skeleton by acting as pre-stressed beams or strainable pre-buckled struts. It is also proposed that the cranial bending strains that result from triceps, acting on the lever that is the radioulna, can explain the development of the curvature of such bones. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.
Trend analyses with river sediment rating curves
Warrick, Jonathan A.
2015-01-01
Sediment rating curves, which are fitted relationships between river discharge (Q) and suspended-sediment concentration (C), are commonly used to assess patterns and trends in river water quality. In many of these studies it is assumed that rating curves have a power-law form (i.e., C = aQb, where a and b are fitted parameters). Two fundamental questions about the utility of these techniques are assessed in this paper: (i) How well to the parameters, a and b, characterize trends in the data? (ii) Are trends in rating curves diagnostic of changes to river water or sediment discharge? As noted in previous research, the offset parameter, a, is not an independent variable for most rivers, but rather strongly dependent on b and Q. Here it is shown that a is a poor metric for trends in the vertical offset of a rating curve, and a new parameter, â, as determined by the discharge-normalized power function [C = â (Q/QGM)b], where QGM is the geometric mean of the Q values sampled, provides a better characterization of trends. However, these techniques must be applied carefully, because curvature in the relationship between log(Q) and log(C), which exists for many rivers, can produce false trends in â and b. Also, it is shown that trends in â and b are not uniquely diagnostic of river water or sediment supply conditions. For example, an increase in â can be caused by an increase in sediment supply, a decrease in water supply, or a combination of these conditions. Large changes in water and sediment supplies can occur without any change in the parameters, â and b. Thus, trend analyses using sediment rating curves must include additional assessments of the time-dependent rates and trends of river water, sediment concentrations, and sediment discharge.
ULTRA: Universal Grammar as a Universal Parser.
Medeiros, David P
2018-01-01
A central concern of generative grammar is the relationship between hierarchy and word order, traditionally understood as two dimensions of a single syntactic representation. A related concern is directionality in the grammar. Traditional approaches posit process-neutral grammars, embodying knowledge of language, put to use with infinite facility both for production and comprehension. This has crystallized in the view of Merge as the central property of syntax, perhaps its only novel feature. A growing number of approaches explore grammars with different directionalities, often with more direct connections to performance mechanisms. This paper describes a novel model of universal grammar as a one-directional, universal parser. Mismatch between word order and interpretation order is pervasive in comprehension; in the present model, word order is language-particular and interpretation order (i.e., hierarchy) is universal. These orders are not two dimensions of a unified abstract object (e.g., precedence and dominance in a single tree); rather, both are temporal sequences, and UG is an invariant real-time procedure (based on Knuth's stack-sorting algorithm) transforming word order into hierarchical order. This shift in perspective has several desirable consequences. It collapses linearization, displacement, and composition into a single performance process. The architecture provides a novel source of brackets (labeled unambiguously and without search), which are understood not as part-whole constituency relations, but as storage and retrieval routines in parsing. It also explains why neutral word order within single syntactic cycles avoids 213-like permutations. The model identifies cycles as extended projections of lexical heads, grounding the notion of phase. This is achieved with a universal processor, dispensing with parameters. The empirical focus is word order in noun phrases. This domain provides some of the clearest evidence for 213-avoidance as a cross
A computational approach to the twin paradox in curved spacetime
Fung, Kenneth K. H.; Clark, Hamish A.; Lewis, Geraint F.; Wu, Xiaofeng
2016-09-01
Despite being a major component in the teaching of special relativity, the twin ‘paradox’ is generally not examined in courses on general relativity. Due to the complexity of analytical solutions to the problem, the paradox is often neglected entirely, and students are left with an incomplete understanding of the relativistic behaviour of time. This article outlines a project, undertaken by undergraduate physics students at the University of Sydney, in which a novel computational method was derived in order to predict the time experienced by a twin following a number of paths between two given spacetime coordinates. By utilising this method, it is possible to make clear to students that following a geodesic in curved spacetime does not always result in the greatest experienced proper time.
Chain propagator, mass, and universality in polymer solutions from Brownian relativity
International Nuclear Information System (INIS)
Mezzasalma, Stefano A.
2005-01-01
A Lagrangian theory for single chains in polymer solutions is addressed via a recent Brownian relativity. By employing generalized diffusive coordinates, statements of covariance and diffusivity invariance result into free particle Lagrangians, where mass turns out to rise as a universal spacetime property. It descends from lowering diffusivity (or curving spacetime), so identifying a mechanism which conceptually resemble those ruling macromolecular scaling laws. An extended chain propagator recovers the Gaussian end-to-end distribution and, in the limits of time-like and space-like orbits, the dualism for diffusive paths and polymer random-walks
The host galaxy and optical light curve of the gamma-ray burst GRB 980703
DEFF Research Database (Denmark)
Holland, S.; Fynbo, J.P.U.; Hjorth, J.
2001-01-01
980703 with any special features in the host. The host galaxy appears to be a typical example of a compact star forming galaxy similar to those found in the Hubble Deep Field North. The R-band light curve of the optical afterglow associated with this gamma-ray burst is consistent with a single power...
Time course of attentional modulation in the frontal eye field during curve tracing
Khayat, P. S.; Pooresmaeili, A.; Roelfsema, P. R.
2009-01-01
Neurons in the frontal eye fields (FEFs) register incoming visual information and select visual stimuli that are relevant for behavior. Here we investigated the timing of the visual response and the timing of selection by recording from single FEF neurons in a curve-tracing task that requires shifts
Time Course of Attentional Modulation in the Frontal Eye Field During Curve Tracing
Khayat, P.S.; Pooresmaeili, A.; Roelfsema, P.R.
2009-01-01
Neurons in the frontal eye fields (FEFs) register incoming visual information and select visual stimuli that are relevant for behavior. Here we investigated the timing of the visual response and the timing of selection by recording from single FEF neurons in a curve-tracing task that requires shifts
Computer aided cooling curve analysis for Al-5Si and Al-11Si alloys ...
African Journals Online (AJOL)
The effect of grain refiner, modifier, and combination of grain refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both grain refiner and modifier.
Navigating the Social Media Learning Curve
Pikalek, Amy J.
2010-01-01
In recent years, terms such as "social media" and "social networking" have become staples in the university continuing education marketer's vocabulary. This article provides both a working knowledge of the social media landscape and practical applications of the concepts using a case study approach from a Midwestern university.…
Optimal time travel in the Godel universe
Natario, Jose
2011-01-01
Using the theory of optimal rocket trajectories in general relativity, recently developed in arXiv:1105.5235, we present a candidate for the minimum total integrated acceleration closed timelike curve in the Godel universe, and give evidence for its minimality. The total integrated acceleration of this curve is lower than Malament's conjectured value (Malament, 1984), as was already implicit in the work of Manchak (Manchak, 2011); however, Malament's conjecture does seem to hold for periodic ...
Approximate Implicitization of Parametric Curves Using Cubic Algebraic Splines
Directory of Open Access Journals (Sweden)
Xiaolei Zhang
2009-01-01
Full Text Available This paper presents an algorithm to solve the approximate implicitization of planar parametric curves using cubic algebraic splines. It applies piecewise cubic algebraic curves to give a global G2 continuity approximation to planar parametric curves. Approximation error on approximate implicitization of rational curves is given. Several examples are provided to prove that the proposed method is flexible and efficient.
Evaluation of the water retention curve of Abidjan Quaternary aquifer ...
African Journals Online (AJOL)
Methods and Results: The water retention curve is difficult to measure in situ on large sites like this aquifer. Kovac's modified model to predict the water retention curve is tested. Predicted curves are compared with in situ measurements points. The results show that, overall, the model predicts well the water retention curves.
Curvature Entropy for Curved Profile Generation
Directory of Open Access Journals (Sweden)
Koichiro Sato
2012-03-01
Full Text Available In a curved surface design, the overall shape features that emerge from combinations of shape elements are important. However, controlling the features of the overall shape in curved profiles is difficult using conventional microscopic shape information such as dimension. Herein two types of macroscopic shape information, curvature entropy and quadrature curvature entropy, quantitatively represent the features of the overall shape. The curvature entropy is calculated by the curvature distribution, and represents the complexity of a shape (one of the overall shape features. The quadrature curvature entropy is an improvement of the curvature entropy by introducing a Markov process to evaluate the continuity of a curvature and to approximate human cognition of the shape. Additionally, a shape generation method using a genetic algorithm as a calculator and the entropy as a shape generation index is presented. Finally, the applicability of the proposed method is demonstrated using the side view of an automobile as a design example.
Cell Proliferation on Planar and Curved Substrates
Gaines, Michelle; Chang, Ya Wen; Cruz, Ricardo; Fragkopoulos, Alexandros; Garcia, Andres; Fernandez-Nieves, Alberto
Aberrant epithelial collective cell growth is one of the major challenges to be addressed in order to treat diseases such as cancer and organ fibrosis. The conditions of the extracellular microenvironment, properties of the cells' cytoskeleton, and interfacial properties of the substratum (the surface in contact with epithelial cells) have a significant influence on the migratory behavior of epithelial cells, cell proliferation and migration. This work focuses on understanding the impact the substratum curvature has on cell behavior. We focus on cell proliferation first and study MDCK cells on both planar and curved hydrogel substrates. The curved hydrogels are based on polyacrylamide and have toroidal shape, with tube radius 200 um and an aspect ratio in the rage between 2 and 9. Proliferation is measured using the Click-it EDU assay (Invitrogen), which measures cells that are synthesizing DNA. Funding Source is Childrens Healthcare of Atlanta.
Gauge field configurations in curved spacetimes (II)
International Nuclear Information System (INIS)
Boutaleb-Joutei, H.; Chakrabarti, A.; Comtet, A.
1979-05-01
One continues the study of gauge field configurations in curved spaces, using the formalism and results of a previous paper. A class of static, finite action, selfdual solutions of SU(2) gauge fields on a Euclidean section of de Sitter space is presented. The action depends on a continuous parameter. The spin connection solution is obtained as a particular case and a certain passage to the limiting case of a flat space is shown to reproduce the Euclidean Prasad-Sommerfield solution. The significance and possible interest of such solutions are discussed. The results are then generalized to a non-Einstein but conformally flat space, including de Sitter space as an Einstein limit. Next Baecklund type transformations are constructed starting from selfduality constraints for such curved spaces. These transformations are applied to the above mentioned solutions. The last two sections contain remarks on solutions with a background Robinson-Bertotti metric and on static, axially symmetric solutions respectively
Inferring cardiac phase response curve in vivo
Pikovsky, Arkady; Kralemann, Bjoern; Fruehwirth, Matthias; Rosenblum, Michael; Kenner, Thomas; Schaefer, Jochen; Moser, Maximilian
2014-03-01
Characterizing properties of biological oscillators with phase response cirves (PRC) is one of main theoretical tools in neuroscience, cardio-respiratory physiology, and chronobiology. We present a technique that allows the extraction of the PRC from a non-invasive observation of a system consisting of two interacting oscillators, in this case heartbeat and respiration, in its natural environment and under free-running conditions. We use this method to obtain the phase coupling functions describing cardio-respiratory interactions and the phase response curve of 17 healthy humans. We show at which phase the cardiac beat is susceptible to respiratory drive and extract the respiratory-related component of heart rate variability. This non-invasive method of bivariate data analysis for the determination of phase response curves of coupled oscillators may find application in other biological and physical systems.
Geometry of curves and surfaces with Maple
Rovenski, Vladimir
2000-01-01
This concise text on geometry with computer modeling presents some elementary methods for analytical modeling and visualization of curves and surfaces. The author systematically examines such powerful tools as 2-D and 3-D animation of geometric images, transformations, shadows, and colors, and then further studies more complex problems in differential geometry. Well-illustrated with more than 350 figures---reproducible using Maple programs in the book---the work is devoted to three main areas: curves, surfaces, and polyhedra. Pedagogical benefits can be found in the large number of Maple programs, some of which are analogous to C++ programs, including those for splines and fractals. To avoid tedious typing, readers will be able to download many of the programs from the Birkhauser web site. Aimed at a broad audience of students, instructors of mathematics, computer scientists, and engineers who have knowledge of analytical geometry, i.e., method of coordinates, this text will be an excellent classroom resource...
Point- and curve-based geometric conflation
López-Vázquez, C.
2013-01-01
Geometric conflation is the process undertaken to modify the coordinates of features in dataset A in order to match corresponding ones in dataset B. The overwhelming majority of the literature considers the use of points as features to define the transformation. In this article we present a procedure to consider one-dimensional curves also, which are commonly available as Global Navigation Satellite System (GNSS) tracks, routes, coastlines, and so on, in order to define the estimate of the displacements to be applied to each object in A. The procedure involves three steps, including the partial matching of corresponding curves, the computation of some analytical expression, and the addition of a correction term in order to satisfy basic cartographic rules. A numerical example is presented. © 2013 Copyright Taylor and Francis Group, LLC.
Energy Technology Data Exchange (ETDEWEB)
L Moya, Sara; Aragon, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)
1997-12-31
The proposed methodology described ahead (Moya et al.,1996; Moya et al.,1997a, 1997b and 1997c) simplifies the construction of production characteristic curves of geothermal wells and of its associated thermal productivity, in requiring one single measurement of mass flow-pressure-enthalpy (W-P-h) at the wellhead. Therefore it is an ecological option, technically and economically more feasible. On the other hand, the methodology also allows to diagnose the rocky formation absolute permeability in the well feeding zone. This permeability is usually determined through well bottom pressure tests, than in some cases are difficult to interpret. The permeability inferred by means of the proposed technology represents a complementary tool for these field tests and for the laboratory measurements on drilling cores. [Espanol] La metodologia propuesta que se describe a continuacion [Moya et al., 1995d; Moya et al., 1996; Moya et al., 1997a, 1997b y 1997c] simplifica la construccion de curvas caracteristicas de produccion de pozos geotermicos y de su productividad termica asociada al requerir solo una medicion de flujo masico-presion-entalpia (W-P-h) a boca de pozo. Es por tanto una alternativa ecologica, tecnica y economicamente mas factible. Por otra parte, la metodologia tambien permite diagnosticar el valor de la permeabilidad absoluta de la formacion rocosa en la zona de alimentacion al pozo. Esta permeabilidad se determina usualmente a partir de pruebas de presion a fondo de pozo que en algunos casos son dificiles de interpretar. La permeabilidad inferida mediante la metodologia propuesta representa una herramienta complementaria a estas pruebas de campo y a las mediciones de laboratorio sobre nucleos de perforacion.
String field theory in curved space
International Nuclear Information System (INIS)
Kikkawa, Keiji; Maeno, Masahiro; Sawada, Shiro
1988-01-01
The purely cubic action in the string field theory is shown to provide a set of equations of motion for background fields which agree to those obtained by the vanishing condition of β-functions in the non-linear sigma model. Using the sigma model as an auxiliary tool, a systematic method for solving the string field theory in curved space is proposed. (author)
Growth curve models and statistical diagnostics
Pan, Jian-Xin
2002-01-01
Growth-curve models are generalized multivariate analysis-of-variance models. These models are especially useful for investigating growth problems on short times in economics, biology, medical research, and epidemiology. This book systematically introduces the theory of the GCM with particular emphasis on their multivariate statistical diagnostics, which are based mainly on recent developments made by the authors and their collaborators. The authors provide complete proofs of theorems as well as practical data sets and MATLAB code.
Quantum field theory in curved spacetime
International Nuclear Information System (INIS)
Gibbons, G.W.
1978-04-01
The purpose of this article is to outline what the extension of such a treatment to curved space entails and to discuss what essentially new features arise when one takes into account the quantum mechanical nature of gravitating systems. I shall throughout assume a classical, unquantized gravitational field and confine the discussion to matter fields although similar techniques and ideas may be applied to 'gravitons' - that is linearized perturbations of the metric propagating on some fixed, unperturbed, background. (orig./WL) [de
The Green functions in curved spacetime
International Nuclear Information System (INIS)
Buchbinder, I.L.; Kirillova, E.N.; Odinstov, S.D.
1987-01-01
The theory of a free scalar field with conformal coupling in curved spacetime with some special metrics is considered. The integral representations for the green function G-tilde in the form of integrals with Schwinger-De Witt kernel over contours in the complex plane of proper time are obtained. It is shown how the transitions from a unique Green function in Euclidean space to different Green functions in Minkowski space and vice versa can be carried out. (author)
Twisted vector bundles on pointed nodal curves
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
is an element different from the identity and u is a geometric point of U fixed by γ, then the automorphism of the fiber ηu induced by γ is not trivial. 3. An essential action of a finite group on (η,U) is called tame, if the action of on. (U → S, i) is tame. DEFINITION 2.3. Let S be a k-scheme. Let C → S be an n-pointed nodal curve ...
Bezier Curve Modeling for Neutrosophic Data Problem
Directory of Open Access Journals (Sweden)
Ferhat Tas
2017-02-01
Full Text Available Neutrosophic set concept is defined with membership, non-membership and indeterminacy degrees. This concept is the solution and representation of the problems with various fields. In this paper, a geometric model is introduced for Neutrosophic data problem for the first time. This model is based on neutrosophic sets and neutrosophic relations. Neutrosophic control points are defined according to these points, resulting in neutrosophic Bezier curves.
Hydrogen technologies and the technology learning curve
International Nuclear Information System (INIS)
Rogner, H.-H.
1998-01-01
On their bumpy road to commercialization, hydrogen production, delivery and conversion technologies not only require dedicated research, development and demonstration efforts, but also protected niche markets and early adopters. While niche markets utilize the unique technological properties of hydrogen, adopters exhibit a willingness to pay a premium for hydrogen fueled energy services. The concept of the technology learning curve is applied to estimate the capital requirements associated with the commercialization process of several hydrogen technologies. (author)
Stable curves and screens on fatgraphs
DEFF Research Database (Denmark)
Penner, Robert; McShane, Greg
The mapping class group invariant ideal cell decomposition of the Teichmueller space of a punctured surface times an open simplex has been used in a number of computations. This paper answers a question about the asymptotics of this decomposition, namely, in a given cell of the decomposition, whi...... curves can be short? Screens are a new combinatorial structure which provide an answer to this question. The heart of the calculation here involves Ptolemy transformations and the triangle inequalities on lambda lengths....
Feynman propagator in curved space-time
International Nuclear Information System (INIS)
Candelas, P.; Raine, D.J.
1977-01-01
The Wick rotation is generalized in a covariant manner so as to apply to curved manifolds in a way that is independent of the analytic properties of the manifold. This enables us to show that various methods for defining a Feynman propagator to be found in the literature are equivalent where they are applicable. We are also able to discuss the relation between certain regularization methods that have been employed
Numerical Characterization of Piezoceramics Using Resonance Curves
Directory of Open Access Journals (Sweden)
Nicolás Pérez
2016-01-01
Full Text Available Piezoelectric materials characterization is a challenging problem involving physical concepts, electrical and mechanical measurements and numerical optimization techniques. Piezoelectric ceramics such as Lead Zirconate Titanate (PZT belong to the 6 mm symmetry class, which requires five elastic, three piezoelectric and two dielectric constants to fully represent the material properties. If losses are considered, the material properties can be represented by complex numbers. In this case, 20 independent material constants are required to obtain the full model. Several numerical methods have been used to adjust the theoretical models to the experimental results. The continuous improvement of the computer processing ability has allowed the use of a specific numerical method, the Finite Element Method (FEM, to iteratively solve the problem of finding the piezoelectric constants. This review presents the recent advances in the numerical characterization of 6 mm piezoelectric materials from experimental electrical impedance curves. The basic strategy consists in measuring the electrical impedance curve of a piezoelectric disk, and then combining the Finite Element Method with an iterative algorithm to find a set of material properties that minimizes the difference between the numerical impedance curve and the experimental one. Different methods to validate the results are also discussed. Examples of characterization of some common piezoelectric ceramics are presented to show the practical application of the described methods.
Detection of flaws below curved surfaces
International Nuclear Information System (INIS)
Elsley, R.K.; Addison, R.C.; Graham, L.J.
1983-01-01
A measurement model has been developed to describe ultrasonic measurements made with circular piston transducers in parts with flat or cylindrically curved surfaces. The model includes noise terms to describe electrical noise, scatterer noise and echo noise as well as effects of attenuation, diffraction and Fresnel loss. An experimental procedure for calibrating the noise terms of the model was developed. Experimental measurements were made on a set of known flaws located beneath a cylindrically curved surface. The model was verified by using it to correct the experimental measurements to obtain the absolute scattering amplitude of the flaws. For longitudinal wave propagation within the part, the derived scattering amplitudes were consistent with predictions at internal angles of less than 30 0 . At larger angles, focusing and aberrations caused a lack of agreement; the model needs further refinement in this case. For shear waves, it was found that the frequency for optimum flaw detection in the presence of material noise is lower than that for longitudinal waves; lower frequency measurements are currently in progress. The measurement model was then used to make preliminary predictions of the best experimental measurement technique for the detection of cracks located under cylindrically curved surfaces
Breakthrough curve moments scaling in hyporheic exchange
Bellin, A.; Tonina, D.; Marzadri, A.
2015-02-01
The interaction between stream flow and bed forms creates an uneven distribution of near-bed energy heads, which is the driving force of hyporheic exchange. Owing to the large disparity of advection characteristic times in the stream and within the hyporheic zone, solute mass exchange is often modeled by considering the latter as an immobile region. In a recent contribution Gónzalez-Pinzón et al. (2013) showed that existing models employing this hypothesis are structurally inconsistent with the scaling revealed by the analysis of 384 breakthrough curves collected in 44 streams across five continents. Motivated by this result, we analyze the scaling characteristics of a model that we recently developed by combining the analytical solution of the advective flow within the hyporheic zone with a Lagrangian solute transport model. Results show that similarly to the experimental data our model predicts breakthrough curves with a constant skewness, irrespective of the stream size, and that the scaling of the first three moments observed by Gónzalez-Pinzón et al. (2013) is also respected. Moreover, we propose regression curves that relate the first three moments of the residence time distribution with the alternate bar dimensionless depth (YBM*), a quantity that is easily measurable in the field. The connection between BTC moments and YBM* opens new possibilities for modeling transport processes at the catchment scale.
Numerical Characterization of Piezoceramics Using Resonance Curves
Pérez, Nicolás; Buiochi, Flávio; Brizzotti Andrade, Marco Aurélio; Adamowski, Julio Cezar
2016-01-01
Piezoelectric materials characterization is a challenging problem involving physical concepts, electrical and mechanical measurements and numerical optimization techniques. Piezoelectric ceramics such as Lead Zirconate Titanate (PZT) belong to the 6 mm symmetry class, which requires five elastic, three piezoelectric and two dielectric constants to fully represent the material properties. If losses are considered, the material properties can be represented by complex numbers. In this case, 20 independent material constants are required to obtain the full model. Several numerical methods have been used to adjust the theoretical models to the experimental results. The continuous improvement of the computer processing ability has allowed the use of a specific numerical method, the Finite Element Method (FEM), to iteratively solve the problem of finding the piezoelectric constants. This review presents the recent advances in the numerical characterization of 6 mm piezoelectric materials from experimental electrical impedance curves. The basic strategy consists in measuring the electrical impedance curve of a piezoelectric disk, and then combining the Finite Element Method with an iterative algorithm to find a set of material properties that minimizes the difference between the numerical impedance curve and the experimental one. Different methods to validate the results are also discussed. Examples of characterization of some common piezoelectric ceramics are presented to show the practical application of the described methods. PMID:28787875
Open Timelike Curves Violate Heisenberg's Uncertainty Principle
Pienaar, J. L.; Ralph, T. C.; Myers, C. R.
2013-02-01
Toy models for quantum evolution in the presence of closed timelike curves have gained attention in the recent literature due to the strange effects they predict. The circuits that give rise to these effects appear quite abstract and contrived, as they require nontrivial interactions between the future and past that lead to infinitely recursive equations. We consider the special case in which there is no interaction inside the closed timelike curve, referred to as an open timelike curve (OTC), for which the only local effect is to increase the time elapsed by a clock carried by the system. Remarkably, circuits with access to OTCs are shown to violate Heisenberg’s uncertainty principle, allowing perfect state discrimination and perfect cloning of coherent states. The model is extended to wave packets and smoothly recovers standard quantum mechanics in an appropriate physical limit. The analogy with general relativistic time dilation suggests that OTCs provide a novel alternative to existing proposals for the behavior of quantum systems under gravity.
Open timelike curves violate Heisenberg's uncertainty principle.
Pienaar, J L; Ralph, T C; Myers, C R
2013-02-08
Toy models for quantum evolution in the presence of closed timelike curves have gained attention in the recent literature due to the strange effects they predict. The circuits that give rise to these effects appear quite abstract and contrived, as they require nontrivial interactions between the future and past that lead to infinitely recursive equations. We consider the special case in which there is no interaction inside the closed timelike curve, referred to as an open timelike curve (OTC), for which the only local effect is to increase the time elapsed by a clock carried by the system. Remarkably, circuits with access to OTCs are shown to violate Heisenberg's uncertainty principle, allowing perfect state discrimination and perfect cloning of coherent states. The model is extended to wave packets and smoothly recovers standard quantum mechanics in an appropriate physical limit. The analogy with general relativistic time dilation suggests that OTCs provide a novel alternative to existing proposals for the behavior of quantum systems under gravity.
Incorporating Experience Curves in Appliance Standards Analysis
Energy Technology Data Exchange (ETDEWEB)
Garbesi, Karina; Chan, Peter; Greenblatt, Jeffery; Kantner, Colleen; Lekov, Alex; Meyers, Stephen; Rosenquist, Gregory; Buskirk, Robert Van; Yang, Hung-Chia; Desroches, Louis-Benoit
2011-10-31
The technical analyses in support of U.S. energy conservation standards for residential appliances and commercial equipment have typically assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. There is, however, considerable evidence that this assumption does not reflect real market prices. Costs and prices generally fall in relation to cumulative production, a phenomenon known as experience and modeled by a fairly robust empirical experience curve. Using price data from the Bureau of Labor Statistics, and shipment data obtained as part of the standards analysis process, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These allow us to develop more representative appliance price projections than the assumption-based approach of constant prices. These experience curves were incorporated into recent energy conservation standards for these products. The impact on the national modeling can be significant, often increasing the net present value of potential standard levels in the analysis. In some cases a previously cost-negative potential standard level demonstrates a benefit when incorporating experience. These results imply that past energy conservation standards analyses may have undervalued the economic benefits of potential standard levels.
A theoretical extension of the soil freezing curve paradigm
Amiri, Erfan A.; Craig, James R.; Kurylyk, Barret L.
2018-01-01
Numerical models of permafrost evolution in porous media typically rely upon a smooth continuous relation between pore ice saturation and sub-freezing temperature, rather than the abrupt phase change that occurs in pure media. Soil scientists have known for decades that this function, known as the soil freezing curve (SFC), is related to the soil water characteristic curve (SWCC) for unfrozen soils due to the analogous capillary and sorptive effects experienced during both soil freezing and drying. Herein we demonstrate that other factors beyond the SFC-SWCC relationship can influence the potential range over which pore water phase change occurs. In particular, we provide a theoretical extension for the functional form of the SFC based upon the presence of spatial heterogeneity in both soil thermal conductivity and the freezing point depression of water. We infer the functional form of the SFC from many abrupt-interface 1-D numerical simulations of heterogeneous systems with prescribed statistical distributions of water and soil properties. The proposed SFC paradigm extension has the appealing features that it (1) is determinable from measurable soil and water properties, (2) collapses into an abrupt phase transition for homogeneous media, (3) describes a wide range of heterogeneity within a single functional expression, and (4) replicates the observed hysteretic behavior of freeze-thaw cycles in soils.
Multiple curved descending approaches and the air traffic control problem
Hart, S. G.; Mcpherson, D.; Kreifeldt, J.; Wemple, T. E.
1977-01-01
A terminal area air traffic control simulation was designed to study ways of accommodating increased air traffic density. The concepts that were investigated assumed the availability of the microwave landing system and data link and included: (1) multiple curved descending final approaches; (2) parallel runways certified for independent and simultaneous operation under IFR conditions; (3) closer spacing between successive aircraft; and (4) a distributed management system between the air and ground. Three groups each consisting of three pilots and two air traffic controllers flew a combined total of 350 approaches. Piloted simulators were supplied with computer generated traffic situation displays and flight instruments. The controllers were supplied with a terminal area map and digital status information. Pilots and controllers also reported that the distributed management procedure was somewhat more safe and orderly than the centralized management procedure. Flying precision increased as the amount of turn required to intersect the outer mark decreased. Pilots reported that they preferred the alternative of multiple curved descending approaches with wider spacing between aircraft to closer spacing on single, straight in finals while controllers preferred the latter option. Both pilots and controllers felt that parallel runways are an acceptable way to accommodate increased traffic density safely and expeditiously.
A Novel Elliptic Curve Scalar Multiplication Algorithm against Power Analysis
Directory of Open Access Journals (Sweden)
Hongming Liu
2013-01-01
Full Text Available Nowadays, power analysis attacks are becoming more and more sophisticated. Through power analysis attacks, an attacker can obtain sensitive data stored in smart cards or other embedded devices more efficiently than with any other kind of physical attacks. Among power analysis, simple power analysis (SPA is probably the most effective against elliptic curve cryptosystem, because an attacker can easily distinguish between point addition and point doubling in a single execution of scalar multiplication. To make elliptic curve scalar multiplication secure against SPA attacks, many methods have been proposed using special point representations. In this paper, a simple but efficient SPA-resistant multiscalar multiplication is proposed. The method is to convert the scalar into a nonadjacent form (NAF representation at first and then constitute it in a new signed digit representation. This new representation is undertaken at a small precomputation cost, as each representation needs just one doubling and 1/2 additions for each bit. In addition, when combined with randomization techniques, the proposed method can also guard against differential power analysis (DPA attack.
Inter-University Council for Higher Education Overseas, London (England).
The following articles and reports are presented in this publication of "Overseas Universities:""Appropriate Technology and University Education," by John Twidell; "The Training of Engineering Staff for Higher Education Institutions in Developing Countries," by D. W. Daniel, C. A. Leal, J. H. Maynes and T. Wilmore;…
McKenna, F W; Ahmad, S
2009-03-21
Stereotactic body radiation therapy (SBRT) uses high doses of radiation to treat tumors. The cell survival behavior at these high doses is subject to debate. We investigated this high-dose region by fitting a variety of formulas to cell survival data. Each of the formulas is motivated by a discussion of the theory of cell survival. Fourteen cell lines are examined. These are fit to a variety of equations. Among the equations include the traditional single-hit multi-target and linear quadratic as well as recent proposals such as the universal survival curve (USC). The chi(2)/df of each fit is compared to determine the best fit. While no formula is clearly superior for all cell lines, the newer formulas often provide better fits than the single-hit multi-target and linear quadratic. We recommend that the more recent formula discussed herein be used over the linear quadratic in dealing with the high-dose regions dealt with in SBRT.
Bayat, Hossein; Sedaghat, Azadeh; Safari Sinegani, Ali Akbar; Gregory, Andrew S.
2015-03-01
This study was conducted to estimate the soil unsaturated hydraulic conductivity through the van Genuchten model using easy to measure soil properties by regression and artificial neural networks methods. In this study, 148 soil samples were taken from five provinces of Iran. Basic soil properties (clay, silt/sand and bulk density) and other soil properties were measured. Soil water retention curve was measured to obtain the unsaturated hydraulic conductivity curve using the van Genuchten-Mualem model. Confined compression curve was measured and the modified model of van Genuchten was fitted on its data. Two-thirds and one-third of the data were used for the training and testing steps, respectively. Confined compression curve parameters and other soil properties were used as predictors to estimate unsaturated hydraulic conductivity curve. Pedotransfer functions (PTFs) were developed in two separate parts: in 5 and 6 PTFs basic soil properties were or were not used as predictors, respectively. The artificial neural networks (ANNs) performed better than the regression methods. Among the ANN-developed PTFs which have not used basic soil properties as predictors, PTFa3, with the inputs of the parameters of confined compression curve (n∗, α∗ and e0), performed better than the others. Also, among the ANN-developed PTFs that used basic soil properties as predictors along with the other input variables, PTFb5 that used the σmc (stress at the maximum curvature) and σi (stress at the inflection point) as inputs along with basic soil properties, performed better than the other PTFs. The results showed a successful prediction of the hydraulic conductivity curve using confined compression curve.
EXTRACTION OF CURVED FIBERS FROM 3D DATA
Directory of Open Access Journals (Sweden)
Gerd Gaiselmann
2013-03-01
Full Text Available A segmentation algorithm is proposed which automatically extracts single fibers from tomographic 3D data of fiber-based materials. As an example, the algorithm is applied to a non-woven material used in the gas diffusion layer of polymer electrolyte membrane fuel cells. This porous material consists of a densely packed system of strongly curved carbon fibers. Our algorithm works as follows. In a first step, we focus on the extraction of skeletons, i.e., center lines of fibers. Due to irregularities like noise or other data artefacts, it is only possible to extract fragments of center lines. Thus, in a second step, we consider a stochastic algorithm to adequately connect these parts of center lines to each other, with the general aim to reconstruct the complete fibers such that the curvature properties of real fibers are reflected correctly. The quality of the segmentation algorithm is validated by applying it to simulated test data.
Path integral for the relativistic particle in curved space
International Nuclear Information System (INIS)
Ferraro, R.
1992-01-01
The propagator for a single relativistic particle in a (D+1)-dimensional curved background is obtained by evaluating the canonical path integral in the true 2D-dimensional phase space. Since only paths moving forward in time are integrated, the resulting propagator depends on how the time is chosen; i.e., it depends on the reference system. In order for the propagator to satisfy the properties of a unitary theory, the time must be attached to a Killing vector. Although the measure is unique (it is the Liouville measure), the skeletonization of the phase-space functional action is ambiguous. One such ambiguity is exploited to obtain different propagators obeying the Klein-Gordon equation with different couplings to quantities related to the shape of the reference system (spatial curvature, etc.)
Application of anti-reflection structures on curved surfaces
Yamamoto, Kazuya; Yamamoto, Takeshi; Takaoka, Toshimitsu; Seigo, Masafumi; Kitagawa, Seiichiro
2012-02-01
Conventional lens manufacturing is accomplished by injection molding followed by application of a thin film anti-reflection coating. This requires several production steps, each with the associated constraints. Here we report a technique for production of injection molded lenses with conical sub-wavelength grating anti-reflection structures. While similar structures have been made in the past, our technique allows the sub-wavelength structure to be created on curved surfaces during the injection molding process, reducing the number of steps in the manufacturing process. The advantage of this new technology is that anti-reflection function is created without any additional process(es) conventionally required but by a single injection molding process to make lens normally, through which substantial cost saving will be achieved.
Simulation of time curves in small animal PET using GATE
International Nuclear Information System (INIS)
Simon, Luc; Strul, Daniel; Santin, Giovanni; Krieguer, Magalie; Morel, Christian
2004-01-01
The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for high resolution small animal Positron Emission Tomography (PET). Monte Carlo simulation is essential for optimizing the specifications of these systems with regards to their most important characteristics, such as spatial resolution, sensitivity, or count rate performance. GATE, the Geant4 Application for Tomographic Emission simulates the passing of time during real acquisitions, allowing to handle dynamic systems such as decaying source distributions or moving detectors. GATE output is analyzed on an event-by-event basis. The time associated with each single event allows to sort coincidences and to model dead-time. This leads to the study of time curves for a prospective small animal PET scanner design. The count rates of true, and random coincidences are discussed together with the corresponding Noise Equivalent Count (NEC) rates as a function of some PET scanner specifications such as detector dead time, or coincidence time window
Hypothesized, Directly-Coded Curve Shapes in Growth Curve Analysis: An Example
Directory of Open Access Journals (Sweden)
Patricia M. Herman
2013-02-01
Full Text Available Growth curve analysis provides important informational benefits regarding intervention outcomes over time. Rarely, however, should outcome trajectories be assumed to be linear. Instead, both the shape and the slope of the growth curve can be estimated. Non-linear growth curves are usually modeled by including either higher-order time variables or orthogonal polynomial contrast codes. Each has limitations (multicollinearity with the first, a lack of coefficient interpretability with the second, and a loss of degrees of freedom with both and neither encourages direct testing of alternative hypothesized curve shapes. Especially in studies with relatively small samples it is likely to be useful to preserve as much information as possible at the individual level. This article presents a step-by-step example of the use and testing of hypothesized curve shapes in the estimation of growth curves using hierarchical linear modeling for a small intervention study. DOI: 10.2458/azu_jmmss.v3i2.16476
Granados, I.; Calo, M.; Ramos, V.
2017-12-01
We developed a Matlab suite package (NDCP, Noisy Dispersion Curve Picking) that allows a full control over parameters to identify correctly group velocity dispersion curves in two types of datasets: correlograms between two stations or surface wave records from earthquakes. Using the frequency-time analysis (FTAN), the procedure to obtain the dispersion curves from records with a high noise level becomes difficult, and sometimes, the picked curve result in a misinterpreted character. For correlogram functions, obtained with cross-correlation of noise records or earthquake's coda, a non-homogeneous noise sources distribution yield to a non-symmetric Green's function (GF); to retrieve the complete information contained in there, NDCP allows to pick the dispersion curve in the time domain both in the causal and non-causal part of the GF. Then the picked dispersion curve is displayed on the FTAN diagram to in order to check if it matches with the maximum of the signal energy avoiding confusion with overtones or spike of noise. To illustrate how NDCP performs, we show exemple using: i) local correlograms functions obtained from sensors deployed into a volcanic caldera (Los Humeros, in Puebla, Mexico), ii) regional correlograms functions between two stations of the National Seismological Service (SSN, Servicio Sismológico Nacional in Spanish), and iii) surface wave seismic record for an earthquake located in the Pacific Ocean coast of Mexico and recorded by the SSN. This work is supported by the GEMEX project (Geothermal Europe-Mexico consortium).
What Works Clearinghouse, 2015
2015-01-01
In the 2014 study, "Interactive Online Learning on Campus: Testing MOOCs and Other Platforms in Hybrid Formats in the University System of Maryland," researchers examined the impact of using hybrid forms of interactive online learning in seven undergraduate courses across seven universities in Maryland. Hybrid forms of interactive online…
Directory of Open Access Journals (Sweden)
Marquet P.
2014-10-01
Full Text Available This paper investigates the G ̈odel’s exact solution of the Einstein equations which describes a stationary homogeneous cosmological Universe inducing closed timelike curves CTCs. This model is generally dismissed because it exhibits a rotational sym- metry and it requires a non zero cosmological constant in contradiction with the current astronomical observations. If the cosmological term is assumed to be slightly variable, we show that this metric can be compatible with the Hubble expansion, which makes the G ̈odel model a viable representation of our Universe.
Quantum and classical phenomenological universalities
Molski, Marcin
2018-01-01
The quantum Q2 class of phenomenological universalities (PU) is extended to include exact solutions and minimum uncertainty coherent states of Hulthen, Kratzer-Fues, Tipping and generalized Kratzer-Fues-Tipping oscillators. In the dissociation (quasi-quantum) limit the solutions obtained generate the extended U2 class of PU including West-Brown-Enquist universal growth curve and temporal (spatial) fractal functions widely used in the field of life sciences and physics. It will be shown that the PU concept seems to be a valuable methodology for deriving the new forms of potential energy functions with possible applications in theoretical analysis of molecular spectra.
Modelling of isothermal remanence magnetisation curves for an assembly of macrospins
International Nuclear Information System (INIS)
Tournus, F.
2015-01-01
We present a robust and efficient framework to compute isothermal remanent magnetisation (IRM) curves for magnetic nanoparticle assemblies. The assembly is modelled by independent, randomly oriented, uniaxial macrospins and we use a Néel model to take into account the thermal relaxation. A simple analytic expression is established for a single size, in a sudden switching approximation, and is compared to more evolved models. We show that for realistic samples (necessarily presenting a size dispersion) the simple model is very satisfactory. With this framework, it is then possible to reliably simulate IRM curves, which can be compared to experimental measurements and used in a best fit procedure. We also examine the influence of several parameters on the IRM curves and we discuss the link between the irreversible susceptibility and the switching field distribution. - Highlights: • A framework to compute IRM curves for nanoparticle assemblies is presented. • A simple analytic expression (for a single size) is compared to more evolved models. • The simple expression can reliably simulate IRM curves for realistic samples. • Irreversible susceptibility and the influence of several parameters is discussed
Evaluation of Shape Parameter Effect on the J-R Curve of Curved CT Specimen Using Limit Load Method
Energy Technology Data Exchange (ETDEWEB)
Shin, In Hwan; Park, Chi Yong [Korea Hydro Nuclear Power Corporation, Seoul (Korea, Republic of); Seok, Chang Sung; Koo, Jae Mean [SungKyunKwan University, Suwon (Korea, Republic of)
2014-07-15
In this study, the effect of shape parameters on the J-R curves of curved CT specimens was evaluated using the limit load method. Fracture toughness tests considering the shape factors L/W and Rm/t of the specimens were also performed. Thereafter, the J-R curves of the curved CT specimens were compared using the J-integral equation proposed in the ASTM (American Society for Testing and Materials) and limit load solution. The J-R curves of the curved CT specimens were also compared with those of the CWP (curved wide plate), which is regarded to be similar to real pipe and standard specimens.. Finally, the effectiveness of the J-R curve of each curved CT specimen was evaluated. The results of this study can be used for assessing the applicability of curved CT specimens in the accurate evaluation of the fracture toughness of real pipes.
Quantum field theory of universe
International Nuclear Information System (INIS)
Hosoya, Akio; Morikawa, Masahiro.
1988-08-01
As is well-known, the wave function of universe dictated by the Wheeler-DeWitt equation has a difficulty in its probabilistic interpretation. In order to overcome this difficulty, we explore a theoretical possibility of the second quantization of universe, following the same passage historically taken for the Klein-Gordon particles and the Nambu-Goto strings. It turns out that multiple production of universes is an inevitable consequence even if the initial state is nothing. The problematical interpretation of wave function of universe is circumvented by introducing an internal comoving model detector, which is an analogue of the DeWitt-Unruh detector in the quantum field theory in curved space-time. (author)