Wagner, Falko Jens; Poulsen, Mikael Zebbelin
1999-01-01
When trying to solve a DAE problem of high index with more traditional methods, it often causes instability in some of the variables, and finally leads to breakdown of convergence and integration of the solution. This is nicely shown in [ESF98, p. 152 ff.].This chapter will introduce projection...... methods as a way of handling these special problems. It is assumed that we have methods for solving normal ODE systems and index-1 systems....
Dephasing-assisted selective incoherent quantum transport.
Behzadi, Naghi; Ahansaz, Bahram; Kasani, Hadi
2015-10-01
Selective energy transport throughout a quantum network connected to more than one reaction center can play an important role in many natural and technological considerations in photosystems. In this work, we propose a method in which an excitation can be transported from the original site of the network to one of the reaction centers arbitrarily using independent sources of dephasing noises. We demonstrate that in the absence of dephasing noises, the coherent evolution of the system does not have any role in energy transport in the network. Therefore, incoherent evolution via application of dephasing noises throughout a selected path of the network leads to complete transferring of the excitation to a desired reaction center.
Dephasing in InAs/GaAs quantum dots
Borri, Paola; Langbein, Wolfgang Werner; Mørk, Jesper;
1999-01-01
The room-temperature dephasing in InAs/GaAs self-assembled quantum dots is measured using two independent methods: spectal-hole burning and four-wave mixing. Dephasing times weakly dependent on the excitation density are found, with a low density value of 290+/-80 fs from spectal-hole burning...
Measurement of geometric dephasing using a superconducting qubit
Berger, S.; Pechal, M.; Kurpiers, P.; Abdumalikov, A. A.; Eichler, C.; Mlynek, J. A.; Shnirman, A.; Gefen, Yuval; Wallraff, A.; Filipp, S.
2015-01-01
A quantum system interacting with its environment is subject to dephasing, which ultimately destroys the information it holds. Here we use a superconducting qubit to experimentally show that this dephasing has both dynamic and geometric origins. It is found that geometric dephasing, which is present even in the adiabatic limit and when no geometric phase is acquired, can either reduce or restore coherence depending on the orientation of the path the qubit traces out in its projective Hilbert space. It accompanies the evolution of any system in Hilbert space subjected to noise. PMID:26515812
Coherent Detection of Electron Dephasing
Strambini, E.; Chirolli, L.; Giovanetti, V.; Taddei, F.; Fazio, R.; Piazza, V.
2010-01-01
We show that an Aharonov-Bohm ring with asymmetric electron injection can act as a coherent detector of electron dephasing. The presence of a dephasing source in one of the two arms of a moderately-to-highly asymmetric ring changes the response of the system from total reflection to complete transmi
Michael E. Goerndt; W. Keith Moser; Patrick D. Miles; Dave Wear; Ryan D. DeSantis; Robert J. Huggett; Stephen R. Shifley; Francisco X. Aguilar; Kenneth E. Skog
2016-01-01
One purpose of the Northern Forest Futures Project is to predict change in future forest attributes across the 20 States in the U.S. North for the period that extends from 2010 to 2060. The forest attributes of primary interest are the 54 indicators of forest sustainability identified in the Montreal Process Criteria and Indicators (Montreal Process Working Group, n.d...
Room-Temperature Dephasing in InAs Quantum Dots
Borri, Paola; Langbein, Wolfgang; Mørk, Jesper;
2000-01-01
The room temperature dephasing in InAs/InGaAs/GaAs self-assembled quantum dots, embedded in a waveguide for laser applications, is measured using two independent methods: spectral hole burning and four-wave mixing. Without the application of bias current for electrical carrier injection......, a dephasing time of ~260 fs, weakly dependent on the optical excitation density, is found and attributed to phonon interaction. The application of bias current, leading to population inversion in the dot ground state and optical gain, strongly decreases the dephasing time to less than 50 fs, likely due...
meta-DENSE complex acquisition for reduced intravoxel dephasing
Aletras, Anthony H.; Arai, Andrew E.
2004-08-01
Displacement encoding with stimulated echoes (DENSE) with a meta-DENSE readout and RF phase cycling to suppress the STEAM anti-echo is described for reducing intravoxel dephasing signal loss. This RF phase cycling scheme, when combined with existing meta-DENSE suppression of the T1 recovering signal, yields higher quality DENSE myocardial strain maps. Phantom and human images are provided to demonstrate the technique, which is capable of acquiring phase contrast displacement encoded images at low encoding gradient strengths providing better spatial resolution and less signal loss due to intravoxel dephasing than prior methods.
Control of dephasing in rotationally hot molecules
Bartram, David; Ivanov, Misha
2010-04-01
We consider a rotationally hot diatomic molecule as an example of an open quantum system, where molecular vibrational wave packets are subject to dephasing due to rovibrational coupling. We report analytical and numerical results addressing whether the dephasing rate can be controlled by adjustment of the initial wave packet phases. It appears that over long time scales, phase-only control is not possible, but for earlier time scales the possibility of phase-only control of dephasing remains. In addition, we point out that the time dependence of the dephasing process depends significantly upon the degeneracy of the rotational environment states.
John C Pfeiffer
2004-01-01
In the design/build (D/B) method of implementing plant construction projects, the owner contracts with the engineer/contractor or contractor/engineer company or team-depending upon who takes the lead in the project to develop...
Li, S B; Li, S B; Xu, J B; Li, Shang-Bin; Xu, Jing-Bo; Li, Shang-Bin; Xu, Jing-Bo
2005-01-01
We investigate the concurrence and Bell violation of the Werner or Werner-like states in the presence of collective dephasing. It is shown that the Werner and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the Werner state is given. The influence of external driving field on the finite-time disentanglement of Werner states is discussed. Finally, we present a simple method to control the stationary state entanglement of two qubits. We investigate the concurrence and Bell violation of the Werner or Werner-like states in the presence of collective dephasing. It is shown that the Werner and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the Werner ...
Influence of collisional dephasing processes on superfluorescence
Maki, Jeffery J.; Malcuit, Michelle S.; Raymer, Michael G.; Boyd, Robert W.; Drummond, Peter D.
1989-11-01
We present a quantum-mechanical treatment of the influence of collisional dephasing processes on the statistical properties of superfluorescence (SF). The theory, which treats nonlinear propagation effects as well as quantum noise, shows how the nature of the cooperative emission process changes from that of SF to that of amplified spontaneous emission as the collisional dephasing rate is varied. The predictions of how the SF delay time varies with the collisional dephasing rate are in good agreement with the results of a recent experiment [M. S. Malcuit, J. J. Maki, D. J. Simkin, and R. W. Boyd, Phys. Rev. Lett. 59, 1189 (1987)].
Effects of Electric and Magnetic Fields on Pure Dephasing of Exciton Qubits
LIU Yun-Fei; XIAO Jing-Lin
2009-01-01
In a two-dimensional quantum dot (QD) with parabolic confinement potential, we investigate pure dephasing due to deformation potential exciton-bulk longitudinal acoustic phonons (LAP) interaction for exciton qubits under the influence of external static electric and magnetic fields by adopting the full quantum-mechanical method of Kunihiro Kojima and Akihisa Tomita. The wave function is found and the dependence of the pure dephusing factor on the confinement length of the QD and time and temperature is discussed. We find the external electric and magnetic fields have important effects on pure dephasing of exciton qubits because exciton-LAP interaction increases, leading to more pure dephasing.
Vempala, Santosh S
2005-01-01
Random projection is a simple geometric technique for reducing the dimensionality of a set of points in Euclidean space while preserving pairwise distances approximately. The technique plays a key role in several breakthrough developments in the field of algorithms. In other cases, it provides elegant alternative proofs. The book begins with an elementary description of the technique and its basic properties. Then it develops the method in the context of applications, which are divided into three groups. The first group consists of combinatorial optimization problems such as maxcut, graph coloring, minimum multicut, graph bandwidth and VLSI layout. Presented in this context is the theory of Euclidean embeddings of graphs. The next group is machine learning problems, specifically, learning intersections of halfspaces and learning large margin hypotheses. The projection method is further refined for the latter application. The last set consists of problems inspired by information retrieval, namely, nearest neig...
Geometry of quantum transport for dephasing Lindbladians
Avron, J E; Graf, G M; Kenneth, O
2010-01-01
We develop a geometric theory of adiabatic transport in driven open systems governed by dephasing Lindbladians. The coefficients of dissipative transport are determined by the Fubini-Study metric and the coefficients of non-dissipative transport by the adiabatic curvature. This gives a possible mechanism for residual resistance for gapped systems at low temperatures. When the metric and symplectic form are compatible non-dissipative terms in the inverse matrix of transport coefficients are immune to dephasing. We give three examples of compatible systems: The qubit, coherent states for the Harmonic oscillator and the lowest Landau level on a torus.
Dephasing of quantum tunnelling in molecular nanomagnets
Zhang Shu-Qun; Chen Zhi-De
2008-01-01
Dephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherentstate path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fee and Mn12.
Ultrafast dephasing of interband transitions in semiconductors
ZHANG; Haichao
2001-01-01
［1］Becker, P. C., Fragnito, H. L., Brito, C. C. H. et al., Femtosecond photon echoes from band-to-band transitions in GaAs, Phys. Rev. Lett., 1988, 61: 1647—1649.［2］Lin, W. Z., Schoenlein, R. W., Fujimoto, J. G. et al., Femtosecond absorption saturation of hot carriers in GaAs and AlGaAs, IEEE JQE, 1988, 24: 267—275.［3］Gurevich, V. L., Muradov, M. I., Parshin, D. A., On the theory of femtosecond photon echoes from band-to -band transitions in semiconductors, Europhys. Lett., 1990, 12(4): 375—379.［4］Sayed, K. E., Bányai, L., Haug, H., Coulomb quantum kinetics and optical dephasing on the femtosecond time scale, Phys. Rev. B, 1994, 50:1541—1550.［5］Arlt, S., Siegner, U., Kunde, J. et al., Ultrafast dephasing of continuum transitions in bulk semiconductors, Phys. Rev. B, 1999, 59: 14860—14863.［6］Hügel, W. A., Heinrich, M. F., Wegener, M. et al., Photon echoes from semiconductor band-to -band continuum transitions in the regime of Coulomb quantum kinetics, Phys. Rev. Lett., 1999, 83(16): 3313—3316.［7］Scott, D. C., Binder, R., Koch, S. W., Ultrafast dephasing through acoustic plasmon undamping in nonequilibrium electron-hole plasmas, Phys. Rev. Lett., 1992, 69(2): 347—350.［8］Binder, R., Scott, D., Paul, A. E. et al., Carrier-carrier scattering and optical dephasing in highly excited semiconductors, Phys. Rev., B 1991, 45: 1107—1114.［9］Schilp, J., Kuhn, T., Mahler, G., Electron-phonon quantum kinetics in pulse-excited semiconductors: Memory and renormalization effects, Phys. Rev. B, 1994, 50: 5435—5447.［10］Snoke, D. W., Density dependence of electron scattering at low density, Phys. Rev., B 1994, 50: 11583—11591.［11］Leitenstorfer, A., Lohner, A., Rick, K. et al., Excitonic and free-carrier polarizations of bulk GaAs studied by femtosecond coherent spectroscopy, Phys. Rev., 1994B 49: 16372—16380.［12］Zhang, H. C., Wen, J. H., Guo, B. Hole-hole scattering of photoexcited heavy-holes in GaAs, Acta Physica
Evaluation methods for hospital projects.
Buelow, Janet R; Zuckweiler, Kathryn M; Rosacker, Kirsten M
2010-01-01
The authors report the findings of a survey of hospital managers on the utilization of various project selection and evaluation methodologies. The focus of the analysis was the empirical relationship between a portfolio of project evaluation(1) methods actually utilized for a given project and several measures of perceived project success. The analysis revealed that cost-benefit analysis and top management support were the two project evaluation methods used most often by the hospital managers. The authors' empirical assessment provides evidence that top management support is associated with overall project success.
Models of decoherence with negative dephasing rate
Pernice, Ansgar; Strunz, Walter T
2012-01-01
We determine the total state dynamics of a dephasing open quantum system using the standard environment of harmonic oscillators. Of particular interest are random unitary approaches to the same reduced dynamics and system-environment correlations in the full model. Concentrating on a model with an at times negative dephasing rate, the issue of "non-Markovianity" will also be addressed with the emphasis on information obtained from the dynamics of the total state of system and environment: making use of criteria that allow us to distinguish between classically correlated and entangled total states, we employ a simple measure for the correlations emerging from the increase of the two local entropies, and relate it the nature of the correlations.
Dephasing and diffusion on the alveolar surface
Buschle, L. R.; Kurz, F. T.; Kampf, T.; Wagner, W. L.; Duerr, J.; Stiller, W.; Konietzke, P.; Wünnemann, F.; Mall, M. A.; Wielpütz, M. O.; Schlemmer, H. P.; Ziener, C. H.
2017-02-01
We propose a surface model of spin dephasing in lung tissue that includes both susceptibility and diffusion effects to provide a closed-form solution of the Bloch-Torrey equation on the alveolar surface. The nonlocal susceptibility effects of the model are validated against numerical simulations of spin dephasing in a realistic lung tissue geometry acquired from synchotron-based μ CT data sets of mouse lung tissue, and against simulations in the well-known Wigner-Seitz model geometry. The free induction decay is obtained in dependence on microscopic tissue parameters and agrees very well with in vivo lung measurements at 1.5 Tesla to allow a quantification of the local mean alveolar radius. Our results are therefore potentially relevant for the clinical diagnosis and therapy of pulmonary diseases.
Anharmonic quantum contribution to vibrational dephasing
Barik, Debashis; Ray, Deb Shankar
2004-01-01
Based on a quantum Langevin equation and its corresponding Hamiltonian within a c-number formalism we calculate the vibrational dephasing rate of a cubic oscillator. It is shown that leading order quantum correction due to anharmonicity of the potential makes a significant contribution to the rate and the frequency shift. We compare our theoretical estimates with those obtained from experiments for small diatomics $N_2$, $O_2$ and $CO$.
Optical dephasing in doped solids
Molenkamp, Laurens Wigbolt
1985-01-01
Het doel van mijn promotie onderzoek was in de eerste plaats te bekijken hoe algemeen toepasbaar deze zgn. geaccumuleerde foton echo methode is, Bovendien wilden we proberen sluitende bewijzen te vinden voor de geldigheid van een door onze werkgroep ontwikkelde theorie over optische defasering. Tens
Activated and non-activated dephasing in a spin bath
Torrontegui, E.; Kosloff, R.
2016-09-01
We analyze different decoherence processes in a system coupled to a bath. Apart from the well known standard dephasing mechanism which is temperature dependent an alternative mechanism is presented, the spin-swap dephasing which does not need initial bath activation and is temperature independent. We show that for dipole interaction in the weak coupling regime the separation of time scales between system and bath can not produce pure dephasing, the process being accompanied by dissipation. Activated and non-activated dephasing processes are analyzed in a diamond nitrogen-vacancy center.
Model discrimination for dephasing two-level systems
Gong, Er-ling [Department of Automatic Control, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China); College of Science (Physics), Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Zhou, Weiwei [Department of Automatic Control, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China); Schirmer, Sophie, E-mail: sgs29@swan.ac.uk [College of Science (Physics), Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)
2015-02-06
The problem of model discriminability and parameter identifiability for dephasing two-level systems subject to Hamiltonian control is studied. Analytic solutions of the Bloch equations are used to derive explicit expressions for observables as functions of time for different models. This information is used to give criteria for model discrimination and parameter estimation based on simple experimental paradigms. - Highlights: • Analytic expressions for observables of driven, dephasing two-level systems. • Distinguishability of dephasing models via Rabi-oscillation experiments. • General identifiability of model parameters and cases of failure. • Application to empirically determine of effect of driving on dephasing basis. • Importance for optimal design of coherent controls for qubits subject to dephasing.
Thermodynamics of a qubit undergoing dephasing
Marcantoni, S.
2017-05-01
The thermodynamics of a qubit undergoing dephasing due to the coupling with the external environment is discussed. First of all, we assume the dynamics of the system to be described by a master equation in Lindblad form. In this framework, we review a standard formulation of the first and second law of thermodynamics that has been known in literature for a long time. After that, we explicitly model the environment with a set of quantum harmonic oscillators choosing the interaction such that the global dynamics of system and bath is analytically solvable and the Lindblad master equation is recovered in the weak-coupling limit. In this generalized setting, we can show that the correlations between system and bath play a fundamental role in the heat exchange. Moreover, the internal entropy production of the qubit is proven to be positive for arbitrary coupling strength.
Spacetime Conformal Fluctuations and Quantum Dephasing
Bonifacio, Paolo M
Any quantum system interacting with a complex environment undergoes decoherence. Empty space is filled with vacuum energy due to matter fields in their ground state and represents an underlying environment that any quantum particle has to cope with. In particular quantum gravity vacuum fluctuations should represent a universal source of decoherence. To study this problem we employ a stochastic approach that models spacetime fluctuations close to the Planck scale by means of a classical, randomly fluctuating metric (random gravity framework). We enrich the classical scheme for metric perturbations over a curved background by also including matter fields and metric conformal fluctuations. We show in general that a conformally modulated metric induces dephasing as a result of an effective nonlinear newtonian potential obtained in the appropriate nonrelativistic limit of a minimally coupled Klein-Gordon field. The special case of vacuum fluctuations is considered and a quantitative estimate of the expected effect...
Spacetime Conformal Fluctuations and Quantum Dephasing
Bonifacio, Paolo M.
2009-06-01
Any quantum system interacting with a complex environment undergoes decoherence. Empty space is filled with vacuum energy due to matter fields in their ground state and represents an underlying environment that any quantum particle has to cope with. In particular quantum gravity vacuum fluctuations should represent a universal source of decoherence. To study this problem we employ a stochastic approach that models spacetime fluctuations close to the Planck scale by means of a classical, randomly fluctuating metric (random gravity framework). We enrich the classical scheme for metric perturbations over a curved background by also including matter fields and metric conformal fluctuations. We show in general that a conformally modulated metric induces dephasing as a result of an effective nonlinear newtonian potential obtained in the appropriate nonrelativistic limit of a minimally coupled Klein-Gordon field. The special case of vacuum fluctuations is considered and a quantitative estimate of the expected effect deduced. Secondly we address the question of how conformal fluctuations could physically arise. By applying the random gravity framework we first show that standard GR seems to forbid spontaneous conformal metric modulations. Finally we argue that a different result follows within scalar-tensor theories of gravity such as e.g. Brans-Dicke theory. In this case a conformal modulation of the metric arises naturally as a result of the fluctuations in the Brans-Dicke field and quantum dephasing of a test particle is expected to occur. For large negative values of the coupling parameter the conformal fluctuations may also contribute to alleviate the well known problem of the large zero point energy due to quantum matter fields.
Geometric dephasing in zero-field magnetic resonance
Jones, J.A. [Oxford Centre for Molecular Sciences, University of Oxford, New Chemistry Laboratory, South Parks Road, Oxford OX1 3QT]|[Merton College, Oxford OX1 4JD (United Kingdom); Pines, A. [Lawrence Berkeley Laboratory and Department of Chemistry, University of California, Berkeley, California 94720 (United States)
1997-02-01
Geometric phases acquired randomly can give rise to coherence dephasing in nuclear spin systems, equivalent to spin relaxation. We calculate the form and extent of this geometric dephasing in a number of model systems involving the motion of {sup 131}Xe nuclei in shaped containers. The dephasing is calculated in two ways: first, using an analytical treatment of the diffusive motion of individual nuclei, and second, using ensemble averaged propagators. The effects of applying additional magnetic fields to these systems are discussed briefly. {copyright} {ital 1997 American Institute of Physics.}
Control of interaction-induced dephasing of Bloch oscillations.
Gustavsson, M; Haller, E; Mark, M J; Danzl, J G; Rojas-Kopeinig, G; Nägerl, H-C
2008-02-29
We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice. We quantify the dephasing in terms of the width of the quasimomentum distribution and measure its dependence on time for different interaction strengths which we control by means of a Feshbach resonance. For minimal interaction, the dephasing time is increased from a few to more than 20 thousand Bloch oscillation periods, allowing us to realize a BEC-based atom interferometer in the noninteracting limit.
Coherence and dephasing in self-assembled quantum dots
Hvam, Jørn Märcher; Leosson, K.; Birkedal, Dan
2003-01-01
We measured dephasing times in InGaAl/As self-assembled quantum dots at low temperature using degenerate four-wave mixing. At 0K, the coherence time of the quantum dots is lifetime limited, whereas at finite temperatures pure dephasing by exciton-phonon interactions governs the quantum dot...... coherence. The inferred homogeneous line widths are significantly smaller than the line widths usually observed in the photoluminescence from single quantum dots indicating an additional inhomogeneours broadening mechanism in the latter....
[SENTIERI Project: materials and methods].
Conti, Susanna; Crocetti, Emanuele; Buzzoni, Carlotta; Comba, Pietro; Fazzo, Lucia; Iavarone, Ivano; Manno, Valerio; Minelli, Giada; Pasetto, Roberto; Pirastu, Roberta; Ricci, Paolo; Zona, Amerigo; Fusco, Mario
2014-01-01
The Report considers three health outcomes - mortality, cancer incidence and hospital discharges - studied using homogenous methods and using data from official sources, namely the National Institute of Statistics (Istat), Italian Network of Cancer Registries (AIRTUM) and the Health Ministry. The timeframes of observation are: 2003-2010 for mortality, 1996-2005 for cancer incidence and 2005-2010 for hospital discharges. The causes of death are those examined by the SENTIERI Project. Hospital discharges are analysed with reference to the main diagnosis. The study of cancer incidence applies to the sites selected by AIRTUM. Statistical parameters (SMR, Standardized Mortality Ratio; SIR, Standardized Incidence Ratio; SHR, Standardized Hospitalization Ratio) were computed with a 90% confidence interval; the estimators were adjusted for age and socioeconomic status.
Enhanced electron dephasing in three-dimensional topological insulators
Liao, Jian; Ou, Yunbo; Liu, Haiwen; He, Ke; Ma, Xucun; Xue, Qi-Kun; Li, Yongqing
2017-07-01
Study of the dephasing in electronic systems is not only important for probing the nature of their ground states, but also crucial to harnessing the quantum coherence for information processing. In contrast to well-studied conventional metals and semiconductors, it remains unclear which mechanism is mainly responsible for electron dephasing in three-dimensional topological insulators (TIs). Here, we report on using weak antilocalization effect to measure the dephasing rates in highly tunable (Bi,Sb)2Te3 thin films. As the transport is varied from a bulk-conducting regime to surface-dominant transport, the dephasing rate is observed to evolve from a linear temperature dependence to a sublinear power-law dependence. Although the former is consistent with the Nyquist electron-electron interactions commonly seen in ordinary 2D systems, the latter leads to enhanced electron dephasing at low temperatures and is attributed to the coupling between the surface states and the localized charge puddles in the bulk of 3D TIs.
Dephasing time of a positron accelerated by a laser pulse
杜春光; 李师群
2002-01-01
The dephasing time of a positron in the total field associated with a laser pulse in a plasma is studied numerically.It is shown that the dynamics of the positron is quite different from that of an electron due to the electrostatic potential in the body of the pulse. The dephasing time of the positron increases with the pulse length and decreases with the pulse intensity nonlinearly. In the long pulse case (L> λp) the dephasing time is proportional to the pulse length. These results provide a scientific basis for experiments to observe the positron acceleration scheme, and may be important to the physics of laser-particle interactions in multi-component plasmas.
Effect of dephasing on DNA sequencing via transverse electronic transport
Zwolak, Michael [Los Alamos National Laboratory; Krems, Matt [NON LANL; Pershin, Yuriy V [NON LANL; Di Ventra, Massimiliano [NON LANL
2009-01-01
We study theoretically the effects of dephasing on DNA sequencing in a nanopore via transverse electronic transport. To do this, we couple classical molecular dynamics simulations with transport calculations using scattering theory. Previous studies, which did not include dephasing, have shown that by measuring the transverse current of a particular base multiple times, one can get distributions of currents for each base that are distinguishable. We introduce a dephasing parameter into transport calculations to simulate the effects of the ions and other fluctuations. These effects lower the overall magnitude of the current, but have little effect on the current distributions themselves. The results of this work further implicate that distinguishing DNA bases via transverse electronic transport has potential as a sequencing tool.
Dimensional crossover of the dephasing time in disordered mesoscopic rings
Treiber, M.; Yevtushenko, O. M.; Marquardt, F.; von Delft, J.; Lerner, I. V.
2009-11-01
We study dephasing by electron interactions in a small disordered quasi-one-dimensional (1D) ring weakly coupled to leads. We use an influence functional for quantum Nyquist noise to describe the crossover for the dephasing time τφ(T) from diffusive or ergodic 1D (τφ-1∝T2/3,T1) to zero-dimensional (0D) behavior (τφ-1∝T2) as T drops below the Thouless energy. The crossover to 0D, predicted earlier for two-dimensional and three-dimensional systems, has so far eluded experimental observation. The ring geometry holds promise of meeting this long-standing challenge, since the crossover manifests itself not only in the smooth part of the magnetoconductivity but also in the amplitude of Altshuler-Aronov-Spivak oscillations. This allows signatures of dephasing in the ring to be cleanly extracted by filtering out those of the leads.
Pure dephasing of single Mn spin in semiconductor quantum dots
Liu, Dingyang; Lai, Wenxi; Yang, Wen
2017-08-01
We present comprehensive analytical and numerical studies on the pure dephasing of a single Mn spin in a semiconductor quantum dot due to (i) its sp-d exchange interaction with an electronic environment, and (ii) its hyperfine interaction with the nuclear spin environment. For (i), by modeling the electronic environment by an open two-level system, we provide exact analytical expressions and present detailed analysis for the Mn spin pure dephasing in both the Markovian and non-Markovian regimes. This provides a clear physical picture and a general theoretical framework based on which we estimate the Mn spin pure dephasing due to various fluctuations (such as thermal excitation, optical pumping, tunneling, or electron/hole spin relaxation) of the electronic environment and reveals a series of interesting behaviors, such as thermal, optical, and electrical control of the crossover between the Markov and non-Markov regimes. In particular, we find rapid Mn spin pure dephasing on a nanosecond time scale by the thermal fluctuation and optical pumping, but these mechanisms can be strongly suppressed by shifting the electron envelope function relative to the Mn atom with an external electric field through the quantum-confined Stark effect. The thermal fluctuation mechanism is also exponentially suppressed at low temperature. For (ii), we find that the Mn spin dephasing time is limited by the thermal fluctuation of the nuclear spins to a few microseconds even at low temperature and its value varies from sample to sample, depending on the distribution of spinful isotopes on the nearest-neighbor sites surrounding the substitutional Mn atom. Our findings may be useful to understand and suppress the Mn spin pure dephasing for its applications in quantum information processing.
Manufacturing Methods and Technology Project Summary Reports.
1980-12-01
as high speed machining. Except for the abrasive aluminum alloys like A356 which must be machined with carbide, either carbide or high speed steel...Shear Forging Processes for Missile 82 Primary Structure Project 376 3230 - Manufacturing Methods for High Speed Machining of 85 Aluminum Project 376 3231...Production Methods for Squeeze Castings 88 Projects 471 4312 and 472 4312 - Hard Face Coating to Aluminum Com- 91 ponents Project 576 6759
Intersublevel polaron dephasing in self-assembled quantum dots
E.A. Zibik,; Grange, T.; Carpenter, B. A.; Ferreira, R.; Bastard, G.; Vinh, N. Q.; Phillips, P. J.; Steer, M. J.; M. Hopkinson,; J.W. Cockburn,; Skolnick, M. S.; L.R. Wilson,
2008-01-01
Polaron dephasing processes are investigated in InAs/GaAs dots using far-infrared transient four wave mixing (FWM) spectroscopy. We observe an oscillatory behavior in the FWM signal shortly (< 5 ps) after resonant excitation of the lowest energy conduction band transition due to coherent acoustic
Exciton dephasing in ZnSe quantum wires
Wagner, Hans Peter; Langbein, Wolfgang Werner; Hvam, Jørn Märcher
1998-01-01
The homogeneous linewidths of excitons in wet-etched ZnSe quantum wires of lateral sizes down to 23 nm are studied by transient four-wave mixing. The low-density dephasing time is found to increase with decreasing wire width. This is attributed mainly to a reduction of electron-exciton scattering...
Binding-energy distribution and dephasing of localized biexcitons
Langbein, Wolfgang Werner; Hvam, Jørn Märcher; Umlauff, M.
1997-01-01
We report on the binding energy and dephasing of localized biexciton states in narrow ZnSe multiple quantum wells. The measured binding-energy distribution of the localized biexcitons shows a width of 2.2 meV centered at 8.5 meV, and is fairly independent of the exciton localization energy. In four...
Methods for Project Tracking in Creative Environment
Eva Šviráková
2017-06-01
Full Text Available The objective of this paper is to design new alternative methods for project tracking in creative industry environment. One of the research method is system dynamics modelling. A dynamics model accepts problems which were identified based on qualitative research and assessed using the system thinking method. A system dynamics model contains a project reference mode which correctly and provably expresses the planned and actual project development in terms of scope and budget. Reference mode of the project was discovered on the basis of Earned Value Management method modification. System dynamics modelling suitability is demonstrated on a case study of a creative project called “Water for Everyone”. If the project is behind schedule, the simulation explains why it happened and forecasts further project development. Managers can use the modelling process to evaluate the impact of their decisions on the next stages of the project life cycle and adopt new management practices using scenarios. The published research is valuable for key stakeholders as it is practically focused on ascertaining essential information about the project progress.
Wave attenuation model for dephasing and measurement of conditional times
A M Jayannavar; Colin Benjamin
2002-08-01
Inelastic scattering induces dephasing in mesoscopic systems. An analysis of previous models to simulate inelastic scattering in such systems is presented and a relatively new model based on wave attenuation is introduced. The problem of Aharonov–Bohm (AB) oscillations in conductance of a mesoscopic ring is studied. We show that the conductance is symmetric under ﬂux reversal and the visibility of AB oscillations decays to zero as a function of the incoherence parameter, signaling dephasing. Further the wave attenuation model is applied to a fundamental problem in quantum mechanics, that of the conditional (reﬂection/transmission) times spent in a given region of space by a quantum particle before scattering off from that region.
Dephasing and hyperfine interaction in carbon nanotubes double quantum dots
Reynoso, Andres Alejandro; Flensberg, Karsten
2012-01-01
We study theoretically the return probability experiment, which is used to measure the dephasing time T-2*, in a double quantum dot (DQD) in semiconducting carbon nanotubes with spin-orbit coupling and disorder-induced valley mixing. Dephasing is due to hyperfine interaction with the spins of the C......-13 nuclei. Due to the valley and spin degrees of freedom, four bounded states exist for any given longitudinal mode in the quantum dot. At zero magnetic field, the spin-orbit coupling and the valley mixing split those four states into two Kramers doublets. The valley-mixing term for a given dot...... is determined by the intradot disorder; this leads to (i) states in the Kramers doublets belonging to different dots being different, and (ii) nonzero interdot tunneling amplitudes between states belonging to different doublets. We show that these amplitudes give rise to new avoided crossings, as a function...
Project Management Concepts, Methods, and Techniques
Maley, Claude H
2011-01-01
In order to succeed in today's increasingly competitive environment, corporations, companies, governments, and nonprofit organizations must be conversant with modern project management techniques. This is especially true for individuals looking to remain professionally competitive. Illustrating the why, what, and how of project management, Project Management Concepts, Methods, and Techniques will help readers develop and refine the skills needed to achieve strategic objectives. It presents a balanced blend of detailed explanatory texts and more than 200 illustrations to supply readers with act
Langbein, Wolfgang Werner; Hvam, Jørn Märcher; Zimmermann, R.
1999-01-01
A new method to measure the time-dependent coherence of both homogeneously and inhomogeneously broadened optical excitations in solids is presented. The coherence degree of resonantly excited light emission is deduced from the intensity fluctuations over the emission directions (speckles......). This method determines the decays of intensity and coherence separately, thus distinguishing lifetime from pure dephasing. The secondary emission of excitons in semiconductor quantum wells is investigated. Here the combination of static disorder and inelastic scattering leads to a partially coherent emission...
Numerical Methods through Open-Ended Projects
Cline, Kelly S.
2005-01-01
We present a design for a junior level numerical methods course that focuses on a series of five open-ended projects in applied mathematics. These projects were deliberately designed to present many of the ambiguities and complexities that appear any time we use mathematics in the real world, and so they offered the students a variety of possible…
Using Replication Projects in Teaching Research Methods
Standing, Lionel G.; Grenier, Manuel; Lane, Erica A.; Roberts, Meigan S.; Sykes, Sarah J.
2014-01-01
It is suggested that replication projects may be valuable in teaching research methods, and also address the current need in psychology for more independent verification of published studies. Their use in an undergraduate methods course is described, involving student teams who performed direct replications of four well-known experiments, yielding…
Seiderer, M.; Laub, G.; Staebler, A.; Yousry, P.; Lauterjung, L.
1988-03-01
With rephasing and dephasing sequences the vascular system is imaged with high or low signal intensity whereas stationary tissue is imaged with identical signal intensity. With images recorded in systole and diastole followed by image subtraction separate imaging of arteries or veins without background superposition is possible. 13 patients with vascular lesions of the lower extremities and 7 volunteers were examined. Vascular stenosis, aneurysm, dilatation, occlusion and collateral vessels could be imaged similar to digital subtraction angiography. Vessels with a diameter down to 1 mm could be imaged. The large slice thickness up to 80 mm results in projection type images where the vascular tree is imaged over the whole field of view and without partial volume effects.
Multiple Methods: Research Methods in Education Projects at NSF
Suter, Larry E.
2005-01-01
Projects on science and mathematics education research supported by the National Science Foundation (US government) rarely employ a single method of study. Studies of educational practices that use experimental design are very rare. The most common research method is the case study method and the second most common is some form of experimental…
Projection preconditioning for Lanczos-type methods
Bielawski, S.S.; Mulyarchik, S.G.; Popov, A.V. [Belarusian State Univ., Minsk (Belarus)
1996-12-31
We show how auxiliary subspaces and related projectors may be used for preconditioning nonsymmetric system of linear equations. It is shown that preconditioned in such a way (or projected) system is better conditioned than original system (at least if the coefficient matrix of the system to be solved is symmetrizable). Two approaches for solving projected system are outlined. The first one implies straightforward computation of the projected matrix and consequent using some direct or iterative method. The second approach is the projection preconditioning of conjugate gradient-type solver. The latter approach is developed here in context with biconjugate gradient iteration and some related Lanczos-type algorithms. Some possible particular choices of auxiliary subspaces are discussed. It is shown that one of them is equivalent to using colorings. Some results of numerical experiments are reported.
Dephasing-assisted transport: quantum networks and biomolecules
Plenio, M B [QOLS, Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Huelga, S F [School of Physics, Astronomy and Mathematics, University of Hertfordshire, Hatfield, Herts AL10 9AB (United Kingdom)], E-mail: m.plenio@imperial.ac.uk
2008-11-15
Transport phenomena are fundamental in physics. They allow for information and energy to be exchanged between individual constituents of communication systems, networks or even biological entities. Environmental noise will generally hinder the efficiency of the transport process. However, and contrary to intuition, there are situations in classical systems where thermal fluctuations are actually instrumental in assisting transport phenomena. Here we show that, even at zero temperature, transport of excitations across dissipative quantum networks can be enhanced by local dephasing noise. We explain the underlying physical mechanisms behind this phenomenon and propose possible experimental demonstrations in quantum optics. Our results suggest that the presence of entanglement does not play an essential role for energy transport and may even hinder it. We argue that Nature may be routinely exploiting dephasing noise and show that the transport of excitations in simplified models of light harvesting molecules does benefit from such noise assisted processes. These results point toward the possibility for designing optimized structures for transport, for example in artificial nanostructures, assisted by noise.
Suppression of dephasing by qubit motion in superconducting circuits
Averin, D. V.; Hu, K.; Zhong, Y. P.; Song, C.; Wang, H.; Han, S.
We suggest and demonstrate a protocol which suppresses dephasing due to the low-frequency noise by qubit motion, i.e., transfer of the logical qubit of information in a system of n >= 2 physical qubits. The protocol requires only the nearest-neighbor coupling and is applicable to different qubit structures. Motion of a logical qubit limits the correlation time of the effective noise seen by this qubit and suppresses its decoherence rate. This effect is qualitatively similar to the dynamic decoupling, but relies on the different resource: additional physical qubits, not extra control pulses. In this respect, suggested protocol can serve as the basis for an alternative approach to scalable quantum circuits. We further analyze its effectiveness against noises with arbitrary correlations. Our analysis, together with experiments using up to three superconducting qubits, shows that for the realistic uncorrelated noises, qubit motion increases the dephasing time of the logical qubit as √{ n}. In general, the protocol provides a diagnostic tool for measurements of the noise correlations. This work was supported by the National Basic Research Program of China (2014CB921200, 2012CB927404), US NSF Grants PHY-1314758 and PHY-1314861, the National Natural Science Foundation of China, and Zhejiang Provincial Natural Science Foundation.
Extended abstract: Partial row projection methods
Bramley, R.; Lee, Y. [Indiana Univ., Bloomington, IN (United States)
1996-12-31
Accelerated row projection (RP) algorithms for solving linear systems Ax = b are a class of iterative methods which in theory converge for any nonsingular matrix. RP methods are by definition ones that require finding the orthogonal projection of vectors onto the null space of block rows of the matrix. The Kaczmarz form, considered here because it has a better spectrum for iterative methods, has an iteration matrix that is the product of such projectors. Because straightforward Kaczmarz method converges slowly for practical problems, typically an outer CG acceleration is applied. Definiteness, symmetry, or localization of the eigenvalues, of the coefficient matrix is not required. In spite of this robustness, work has generally been limited to structured systems such as block tridiagonal matrices because unlike many iterative solvers, RP methods cannot be implemented by simply supplying a matrix-vector multiplication routine. Finding the orthogonal projection of vectors onto the null space of block rows of the matrix in practice requires accessing the actual entries in the matrix. This report introduces a new partial RP algorithm which retains advantages of the RP methods.
Dephasing times in quantum dots due to elastic LO phonon-carrier collisions
Uskov, A. V.; Jauho, Antti-Pekka; Tromborg, Bjarne
2000-01-01
Interpretation of experiments on quantum dot (QD) lasers presents a challenge: the phonon bottleneck, which should strongly suppress relaxation and dephasing of the discrete energy states, often seems to be inoperative. We suggest and develop a theory for an intrinsic mechanism for dephasing in Q...
Dephasing and interaction of excitons CdSe/ZnSe islands
Wagner, H. P.; Tranitz, H.-P.; Preis, H.;
2000-01-01
The dephasing of excitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of dephasing times is observed, indicating the existence of localized excitons with different relaxation times at comparable...
Dephasing in semiconductor-superconductor structures by coupling to a voltage probe
Mortensen, Niels Asger; Jauho, Antti-Pekka; Flensberg, Karsten
2000-01-01
We study dephasing in semiconductor-superconductor structures caused by coupling to a voltage probe. We consider structures where the semiconductor consists of two scattering regions between which partial dephasing is possible. As a particular example we consider a situation with a double barrier...... of the conductance when a finite coupling to the voltage probe is taken into account....
Exciton dephasing and biexciton binding in CdSe/ZnSe islands
Wagner, Hans Peter; Tranitz, H.-P.; Preis, H;
1999-01-01
The dephasing of excitons and the formation of biexcitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of exciton-exciton scattering efficiencies and dephasing times in the range of 0.5-10 ps...
Dephasing and interaction of excitons CdSe/ZnSe islands
Wagner, H. P.; Tranitz, H.-P.; Preis, H.
2000-01-01
The dephasing of excitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of dephasing times is observed, indicating the existence of localized excitons with different relaxation times at comparable...
Nonlinear Response of Localized Excitons: Effects of the Excitation-Induced Dephasing
Borri, Paola; Langbein, Wolfgang Werner; Birkedal, Dan;
1997-01-01
. In particular, we show experimentally that the excitation-induced dephasing gives rise to a photon echo in inhomogeneous systems. We develop a simple analytical model for the delay dependence of the signal, which enables us to deduce the dephasing time from the four-wave mixing decay....
Influence of pure dephasing on emission spectra from single photon sources
Næsby Rasmussen, Andreas; Skovgård, Troels Suhr; Kristensen, Philip Trøst
2008-01-01
We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate the char...
Phonon induced pure dephasing process of excitonic state in colloidal semiconductor quantum dots
Huang, Tongyun; Han, Peng; Wang, Xinke; Feng, Shengfei; Sun, Wenfeng; Ye, Jiasheng; Zhang, Yan
2016-04-01
We present a theoretical study on the pure dephasing process of colloidal semiconductor quantum dots induced by lattice vibrations using continuum model calculations. By solving the time dependent Liouville-von Neumann equation, we present the ultrafast Rabi oscillations between excitonic state and virtual state via exciton-phonon interaction and obtain the pure dephasing time from the fast decayed envelope of the Rabi oscillations. The interaction between exciton and longitudinal optical phonon vibration is found to dominate the pure dephasing process and the dephasing time increases nonlinearly with the reduction of exciton-phonon coupling strength. We further find that the pure dephasing time of large quantum dots is more sensitive to temperature than small quantum dots.
Second derivatives for approximate spin projection methods.
Thompson, Lee M; Hratchian, Hrant P
2015-02-07
The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives.
Methods for the Drug Effectiveness Review Project
McDonagh Marian S
2012-09-01
Full Text Available Abstract The Drug Effectiveness Review Project was initiated in 2003 in response to dramatic increases in the cost of pharmaceuticals, which lessened the purchasing power of state Medicaid budgets. A collaborative group of state Medicaid agencies and other organizations formed to commission high-quality comparative effectiveness reviews to inform evidence-based decisions about drugs that would be available to Medicaid recipients. The Project is coordinated by the Center for Evidence-based Policy (CEbP at Oregon Health & Science University (OHSU, and the systematic reviews are undertaken by the Evidence-based Practice Centers (EPCs at OHSU and at the University of North Carolina. The reviews adhere to high standards for comparative effectiveness reviews. Because the investigators have direct, regular communication with policy-makers, the reports have direct impact on policy and decision-making, unlike many systematic reviews. The Project was an innovator of methods to involve stakeholders and continues to develop its methods in conducting reviews that are highly relevant to policy-makers. The methods used for selecting topics, developing key questions, searching, determining eligibility of studies, assessing study quality, conducting qualitative and quantitative syntheses, rating the strength of evidence, and summarizing findings are described. In addition, our on-going interactions with the policy-makers that use the reports are described.
The effect of dephasing on edge state transport through p-n junctions in HgTe/CdTe quantum wells.
Zhang, Ying-Tao; Song, Juntao; Sun, Qing-Feng
2014-02-26
Using the Landauer-Büttiker formula, we study the effect of dephasing on the transport properties of the HgTe/CdTe p-n junction. It is found that in the HgTe/CdTe p-n junction the topologically protected gapless helical edge states manifest a quantized 2e²/h plateau robust against dephasing, in sharp contrast to the case for the normal HgTe/CdTe quantum well. This robustness of the transport properties of the edge states against dephasing should be attributed to the special construction of the HgTe/CdTe p-n junction, which limits the gapless helical edge states to a very narrow region and thus weakens the influence of the dephasing on the gapless edge states to a large extent. Our results demonstrate that the p-n junction could be a substitute device for use in experimentally observing the robust edge states and quantized plateau. Finally, we present a feasible scheme based on current experimental methods.
Simple Weighting Methods to Combine Multimodel Projections
Lorenz, R.; Sedlacek, J.; Knutti, R.
2016-12-01
Multimodel ensembles of global climate models are very heterogeneous and some models perform better than others for a certain purpose. Nevertheless, weighting of models is rarely performed and there is a debate about whether and how to weight model projections when combining simulations. We argue that the growing number of models with different characteristics and considerable interdependence, at least for cases where relevant metrics of model performance are clear, requires to make use of model constraints to decrease uncertainties in model projections. Steps towards this should involve a) showing unweighted results along with weighted ones, b) testing the robustness of the results towards different metrics or constraints to maximize transparency and comparability across studies, c) an explicit discussion of the choice of metrics, including the physical reasoning why those quantities matter, d) an assessment of the uncertainties in observations, e) testing the sensitivity towards different datasets, time periods, seasonal vs. annual mean values, grid point vs. spatially aggregated data, etc., and f) exploring whether the choice of metric may lead to overconfident results. Several prerequisites need to be met for such approaches to work. For instance, we need available observations, a certain degree of model skill as well as observable relationships that relate to the projections in question. Here we explore projections of summer temperature over central North America. Many CMIP5 models show a pronounced bias of summer temperature over central North America in present climate. We investigate possible causes for this bias and possibilities to constrain the CMIP5 ensemble. We will show if and how uncertainties of projections change depending on weighting method, observational dataset and constraint used.
Han, Jingshan; Li, Wenhui
2016-01-01
We perform spectroscopic measurements of electromagnetically induced transparency (EIT) in a strongly interacting Rydberg gas, and observe a significant spectral shift of the transparency from the single-atom EIT resonance as well as a spectral dephasing of the same order. We characterize the shift and dephasing as a function of atomic density, probe Rabi frequency, and principal quantum number of Rydberg states, and demonstrate that the observed spectral shift and dephasing are reduced if the size of a Gaussian atomic cloud is increased. We simulate our experiment with a semi-analytical model, which gives results in good agreement with our experimental data.
Dephasing in self-organized InAlGaAs quantum dots
Leosson, K.; Birkedal, Dan; Hvam, Jørn Märcher
2002-01-01
temperatures. We observe a striking discrepancy between the homogenous linewidth derived from the dephasing times and the measured photoluminescene linewidth of individual quantum dots, indicating the presence of an additional inhomogenous broadening mechanism in photoluminescence measurements of single......We report the first direct measurements of dephasing in III-V semiconductor quantum dots at low temperature using degenerate four-wave mixing. At OK, the coherence time is limited by the population lifetime whereas pure dephasing due to exciton-phonon interactions appears only at finite...... quantum dots....
Lee, Seungwon; vonAllmen, Paul; Oyafuso, Fabiano; Klimeck, Gerhard; Whale, K. Birgitta
2004-01-01
Electron spin dephasing and decoherence by its interaction with nuclear spins in self-assembled quantum dots are investigated in the framework of the empirical tight-binding model. Electron spin dephasing in an ensemble of dots is induced by the inhomogeneous precession frequencies of the electron among dots, while electron spin decoherence in a single dot arises from the inhomogeneous precession frequencies of nuclear spins in the dot. For In(x)Ga(1-x) As self-assembled dots containing 30000 nuclei, the dephasing and decoherence times are predicted to be on the order of 100 ps and 1 (micro)s.
Transverse azimuthal dephasing of vortex spin wave in a hot atomic gas
Shi, Shuai; Zhang, Wei; Zhou, Zhi-Yuan; Dong, Ming-Xin; Liu, Shi-Long; Shi, Bao-Sen; Guo, Guang-Can
2016-01-01
Optical fields with orbital angular momentum (OAM) interact with medium have many remarkable properties with its unique azimuthal phase, showing many potential applications in high capacity information processing, high precision measurement etc. The dephasing mechanics of optical fields with OAM in an interface between light and matter plays a vital role in many areas of physics. In this work, we study the transverse azimuthal dephasing of OAM spin wave in a hot atomic gas via OAM storage. The transverse azimuthal phase difference between the control and probe beams is mapped onto the spin wave, which essentially results in dephasing of atomic spin wave. The dephasing of OAM spin wave can be controlled by the parameters of OAM topological charge and beam waist. Our results are helpful for studying OAM light interaction with matter, maybe hold a promise in OAM-based quantum information processing.
Optical Bloch Equations Modified with Phonon-Induced Intensity-Dependent Dephasing
无
2007-01-01
We extend the exciton population equations of a two-level quantum dot system with weak excitation to the ones with strong excitations, in which, the phonon-induced intensity-dependent dephasing time and decay rate are involved. The straightforward calculated populations from the modified population equations demonstrate the damping behavior of Rabi oscillation as the external field increasing. The effect of the intensity-dependent dephasing time and the intensity-dependent decay rate are also discussed.
Applying a life cycle approach to project management methods
Biggins, David; Trollsund, F.; Høiby, A.L.
2016-01-01
Project management is increasingly important to organisations because projects are the method\\ud by which organisations respond to their environment. A key element within project management\\ud is the standards and methods that are used to control and conduct projects, collectively known as\\ud project management methods (PMMs) and exemplified by PRINCE2, the Project Management\\ud Institute’s and the Association for Project Management’s Bodies of Knowledge (PMBOK and\\ud APMBOK. The purpose of t...
Dyakonov-Perel Effect on Spin Dephasing in n-Type GaAs
Ning, C. Z.; Wu, M. W.
2003-01-01
A paper presents a study of the contribution of the Dyakonov-Perel (DP) effect to spin dephasing in electron-donor-doped bulk GaAs in the presence of an applied steady, moderate magnetic field perpendicular to the growth axis of the GaAs crystal. (The DP effect is an electron-wave-vector-dependent spin-state splitting of the conduction band, caused by a spin/orbit interaction in a crystal without an inversion center.) The applicable Bloch equations of kinetics were constructed to include terms accounting for longitudinal optical and acoustic phonon scattering as well as impurity scattering. The contributions of the aforementioned scattering mechanisms to spin-dephasing time in the presence of DP effect were examined by solving the equations numerically. Spin-dephasing time was obtained from the temporal evolution of the incoherently summed spin coherence. Effects of temperature, impurity level, magnetic field, and electron density on spin-dephasing time were investigated. Spin-dephasing time was found to increase with increasing magnetic field. Contrary to predictions of previous simplified treatments of the DP effect, spin-dephasing time was found to increase with temperature in the presence of impurity scattering. These results were found to agree qualitatively with results of recent experiments.
Commutative algebra constructive methods finite projective modules
Lombardi, Henri
2015-01-01
Translated from the popular French edition, this book offers a detailed introduction to various basic concepts, methods, principles, and results of commutative algebra. It takes a constructive viewpoint in commutative algebra and studies algorithmic approaches alongside several abstract classical theories. Indeed, it revisits these traditional topics with a new and simplifying manner, making the subject both accessible and innovative. The algorithmic aspects of such naturally abstract topics as Galois theory, Dedekind rings, Prüfer rings, finitely generated projective modules, dimension theory of commutative rings, and others in the current treatise, are all analysed in the spirit of the great developers of constructive algebra in the nineteenth century. This updated and revised edition contains over 350 well-arranged exercises, together with their helpful hints for solution. A basic knowledge of linear algebra, group theory, elementary number theory as well as the fundamentals of ring and module theory is r...
An Alternative Method to Project Wind Patterns
Fadillioglu, Cagla; Kiyisuren, I. Cagatay; Collu, Kamil; Turp, M. Tufan; Kurnaz, M. Levent; Ozturk, Tugba
2016-04-01
Wind energy is one of the major clean and sustainable energy sources. Beside its various advantages, wind energy has a downside that its performance cannot be projected very accurately in the long-term. In this study, we offer an alternative method which can be used to determine the best location to install a wind turbine in a large area aiming maximum energy performance in the long run. For this purpose, a regional climate model (i.e. RegCM4.4) is combined with a software called Winds on Critical Streamline Surfaces (WOCSS) in order to identify wind patterns for any domains even in a changing climate. As a special case, Çanakkale region is examined due to the terrain profile having both coastal and mountainous features. WOCSS program was run twice for each month in the sample years in a double nested fashion, using the provisional RegCM4.4 wind data between years 2020 and 2040. Modified version of WOCSS provides terrain following flow surfaces and by processing those data, it makes a wind profile output for certain heights specified by the user. The computational time of WOCSS is also in reasonable range. Considering the lack of alternative methods for long-term wind performance projection, the model used in this study is a very good way for obtaining quick indications for wind performance taking the impact of the terrain effects into account. This research has been supported by Boǧaziçi University Research Fund Grant Number 10421.
Multi-Role Project (MRP): A New Project-Based Learning Method for STEM
Warin, Bruno; Talbi, Omar; Kolski, Christophe; Hoogstoel, Frédéric
2016-01-01
This paper presents the "Multi-Role Project" method (MRP), a broadly applicable project-based learning method, and describes its implementation and evaluation in the context of a Science, Technology, Engineering, and Mathematics (STEM) course. The MRP method is designed around a meta-principle that considers the project learning activity…
Pure Optical Dephasing Dynamics in Semiconducting Single-Walled Carbon Nanotubes
Graham, Matt [University of California, Berkeley; Fleming, Graham [University of California, Berkeley; Ma, Yingzhong [ORNL; Green, Alexander A. [Northwestern University, Evanston; Hersam, Mark C. [Northwestern University, Evanston
2011-01-01
We report a detailed study of ultrafast exciton dephasing processes in semiconducting single-walled carbon nanotubes (SWNTs) employing a sample highly enriched in a single tube species, the (6,5) tube. Systematic measurements of femtosecond pump-probe, two-pulse photon echo and three-pulse photon echo peak shift over a broad range of excitation intensities and lattice temperature (from 4.4 to 292 K) enable us to quantify the timescales of pure optical dephasing (T 2 ), along with exciton-exciton and exciton-phonon scattering, environmental effects as well as spectral diffusion. While the exciton dephasing time (T2 ) increases from 205 fs at room temperature to 320 fs at 70 K, we found that further decrease of the lattice temperature leads to a shortening of the T2 times. This complex temperature dependence was found to arise from an enhanced relaxation of exciton population at lattice temperatures below 80 K. By quantitatively accounting the contribution from the population relaxation, the corresponding pure optical dephasing times increase monotonically from 225 fs at room temperature to 508 fs at 4.4 K. We further found that below 180 K, the inverse of the pure dephasing time (1/T 2 ) scales linearly with temperature with a slope of 6.7 0.6 eV/K, which suggests dephasing arising from one-phonon scattering (i.e. acoustic phonons). In view ofthe large dynamic disorder of the surrounding environment, the origin of the long room temperature pure dephasing time is proposed to result from reduced strength of exciton-phonon coupling by motional narrowing over nuclear fluctuations. This consideration further suggests the occurrence of remarkable initial exciton delocalization, and makes nanotubes ideal to study many-body effects in spatially confined systems.
How Agile Methods Conquers General Project Management - The Project Half Double Initiative
Tordrup Heeager, Lise; Svejvig, Per; Schlichter, Bjarne Rerup
2016-01-01
Increased complexity in projects has forced new project management initiatives. In software development several agile methods have emerged and methods such as Scrum are today highly implemented in practice. General project management practice has been inspired by agile software development....... But in order to fully understand and to provide suggestions for future practice on how agility can be incorporated in general project management, this paper addresses how agile methods have inspired general project management practices. To answer the research question, the paper provides an analysis which...... compares ten characteristics of agile software development (identified in theory) and the general project management method developed by the Danish Project Half Double (PHD) initiative. The method consists of 10 leading stars for rethinking project management the impact, flow and leadership (ILF) method...
Zimmermann, Tomas
2010-01-01
We propose an approximate method for evaluating the importance of non-Born-Oppenheimer effects on the quantum dynamics of nuclei. The method uses a generalization of the dephasing representation (DR) of quantum fidelity to several diabatic potential energy surfaces and its computational cost is the cost of dynamics of a classical phase space distribution. It can be implemented easily into any molecular dynamics program and also can utilize on-the-fly ab initio electronic structure information. We test the methodology on three model problems introduced by Tully and on the photodissociation of NaI. The results show that for dynamics close to the diabatic regime the decay of fidelity due to nondiabatic effects is described accurately by the DR. In the nearly diabatic regime, unlike the mixed quantum-classical methods such as surface hopping or Ehrenfest dynamics, the DR can capture more subtle quantum effects than the population transfer between potential energy surfaces. Hence we propose using the DR to estimat...
Distributed Research Project Scheduling Based on Multi-Agent Methods
Constanta Nicoleta Bodea
2011-01-01
Full Text Available Different project planning and scheduling approaches have been developed. The Operational Research (OR provides two major planning techniques: CPM (Critical Path Method and PERT (Program Evaluation and Review Technique. Due to projects complexity and difficulty to use classical methods, new approaches were developed. Artificial Intelligence (AI initially promoted the automatic planner concept, but model-based planning and scheduling methods emerged later on. The paper adresses the project scheduling optimization problem, when projects are seen as Complex Adaptive Systems (CAS. Taken into consideration two different approaches for project scheduling optimization: TCPSP (Time- Constrained Project Scheduling and RCPSP (Resource-Constrained Project Scheduling, the paper focuses on a multiagent implementation in MATLAB for TCSP. Using the research project as a case study, the paper includes a comparison between two multi-agent methods: Genetic Algorithm (GA and Ant Colony Algorithm (ACO.
Developing New Testing Methods for Nanosatellites Project
National Aeronautics and Space Administration — Thermal modeling and Test plan to be carried out and developed by Goddard Space Flight Center. This project will be done in collaboration with partners at MIT and...
Manufacturing Methods and Technology Project Summary Reports
1982-06-01
variation. The goal of this FY78 project was to solve these problems, develop pilot line production of 200 ferrites , and test them. SWITCHING ...WIRES FERRITE HIGH &. DIELECTRIC ^ mm i ii ’&Z2ZL f M Figure 1 - Non-Reciprocal Latching Phase Shifter - Side Loaded Geometry 39 i SUMMARY...Control Manufacturing Modernization Plan 18 ELECTRONICS Project 273 9638 - Integrated Hybrid Transistor Switch for Solid 21 State Converter
Inhomogeneous dephasing masks coherence lifetimes in ensemble measurements.
Pelzer, Kenley M; Griffin, Graham B; Gray, Stephen K; Engel, Gregory S
2012-04-28
broadening in the time domain), this important fact has been left out of recent discussions of spectroscopic measurements of energy transport in photosynthesis. In general, these discussions have compared single-system theoretical models to whole-ensemble laboratory measurements without addressing the effect of inhomogeneous dephasing. Our work addresses this distinction between single system and ensemble averaged observations, and shows that the ensemble averaging inherent in many experiments leads to an underestimation of coherence lifetimes in individual systems.
The Action-Project Method in Counseling Psychology
Young, Richard A.; Valach, Ladislav; Domene, Jose F.
2005-01-01
The qualitative action-project method is described as an appropriate and heuristic qualitative research method for use in counseling psychology. Action theory, which addresses human intentional, goal-directed action, project, and career, provides the conceptual framework for the method. Data gathering and analysis involve multiple procedures to…
A Projection-Programming Method of Combination Weighting
ZeshuiXu; LiLi
2004-01-01
This paper proposes a projection programming method of combination weighting. The method combines subjective weights and objective weights, and derives the weights of attributes by solving a projection-programming model. The method is simple, practical and easy to implement on computer. A numerical example is also given.
The Action-Project Method in Counseling Psychology
Young, Richard A.; Valach, Ladislav; Domene, Jose F.
2005-01-01
The qualitative action-project method is described as an appropriate and heuristic qualitative research method for use in counseling psychology. Action theory, which addresses human intentional, goal-directed action, project, and career, provides the conceptual framework for the method. Data gathering and analysis involve multiple procedures to…
Han, Jingshan; Vogt, Thibault; Li, Wenhui
2016-10-01
We perform spectroscopic measurements of electromagnetically induced transparency (EIT) in a strongly interacting Rydberg gas. We observe a significant spectral shift and attenuation of the transparency resonance due to the presence of interactions between Rydberg atoms. We characterize the attenuation as the result of an effective dephasing and show that the shift and the dephasing rate increase versus atomic density, probe Rabi frequency, and principal quantum number of Rydberg states. Moreover, we find that the spectral shift is reduced if the size of a Gaussian atomic cloud is increased and that the dephasing rate increases with the EIT pulse duration at large-parameter regimes. We simulate our experiment with a semianalytical model, which yields results in good agreement with our experimental data.
Strong spin-orbit fields and Dyakonov-Perel spin dephasing in supported metallic films
Long, Nguyen H.; Mavropoulos, Phivos; Bauer, David S. G.; Zimmermann, Bernd; Mokrousov, Yuriy; Blügel, Stefan
2016-11-01
Spin dephasing by the Dyakonov-Perel mechanism in metallic films deposited on insulating substrates is revealed, and quantitatively examined by means of density functional calculations combined with a kinetic equation. The surface-to-substrate asymmetry, probed by the metal wave functions in thin films, is found to produce strong spin-orbit fields and a fast Larmor precession, giving a dominant contribution to spin decay over the Elliott-Yafet spin relaxation up to a thickness of 70 nm. The spin dephasing is oscillatory in time with a rapid (subpicosecond) initial decay. However, parts of the Fermi surface act as spin traps, causing a persistent tail signal lasting 1000 times longer than the initial decay time. It is also found that the decay depends on the direction of the initial spin polarization, resulting in a spin-dephasing anisotropy of 200% in the examined cases.
Spin dephasing in a magnetic dipole field around large capillaries: Approximative and exact results
Kurz, F. T.; Buschle, L. R.; Kampf, T.; Zhang, K.; Schlemmer, H. P.; Heiland, S.; Bendszus, M.; Ziener, C. H.
2016-12-01
We present an analytical solution of the Bloch-Torrey equation for local spin dephasing in the magnetic dipole field around a capillary and for ensembles of capillaries, and adapt this solution for the study of spin dephasing around large capillaries. In addition, we provide a rigorous mathematical derivation of the slow diffusion approximation for the spin-bearing particles that is used in this regime. We further show that, in analogy to the local magnetization, the transverse magnetization of one MR imaging voxel in the regime of static dephasing (where diffusion effects are not considered) is merely the first term of a series expansion that constitutes the signal in the slow diffusion approximation. Theoretical results are in agreement with experimental data for capillaries in rat muscle at 7 T.
Budgetary Approach to Project Management by Percentage of Completion Method
Leszek Borowiec
2010-06-01
Full Text Available Efficient and effective project management process is made possible by the use of methods and techniques of project management. The aim of this paper is to present the problems of project management by using Percentage of Completion method. The research material was gathered based on the experience in implementing this method by the Johnson Controls International Company. The article attempts to demonstrate the validity of the thesis that the POC project management method, allows for effective implementation and monitoring of the project and thus is an effective tool in the managing of companies which exploit the budgetary approach. The study presents planning process of basic parameters affecting the effectiveness of the project (such as costs, revenue, margin and characterized how the primary measurements used to evaluate it. The present theme is illustrating by numerous examples for showing the essence of the raised problems and the results are presenting by using descriptive methods, graphical and tabular.
Manufacturing Methods and Technology Project Summary Reports
1982-12-01
MORE INFORMATION 1 Additional information can be obtained from the project officer, Mr. Nathaniel Scott, ARRADCOM, AV 880-6945 or Commercial (201...QAM6, Mr. S. R. Caswell Cdr, Hawthorne AAP, Attn: SARHW-CO Cdr, Holston AAP, Attn: SARHO-CO Cdr, Indiana AAP, Attn: SARIN-CO AII-3 DRXIB-MT
Project Oriented Immersion Learning: Method and Results
Icaza, José I.; Heredia, Yolanda; Borch, Ole M.
2005-01-01
house that develops digital products including e-books, tutorials, web sites and so on. The students defined the problem that their product was to solve; choose the type of product and the content; and built the product following a strict project methodology. A wiki server was used as a platform to hold...
YUAN Hao; SONG Jun; HE Qin; HAN Lian-Fang; HOU Kui; HU Xiao-Yuan; SHI Shou-Hua
2008-01-01
We propose two schemes for quantum secure direct communication (QSDC) and deterministic secure quantum communication (DSQC) over collective dephasing noisy channel.In our schemes,four special two-qubit states are used as the quantum channel.Since these states are unchanged through the collective dephasing noisy channel,the effect of the channel noise can be perfectly overcome.Simultaneously,the security against some usual attacks can be ensured by utilizing the various checking procedures.Furthermore,these two schemes are feasible with present-day technique.
Dissipation, dephasing and quantum Darwinism in qubit systems with random unitary interactions
Balaneskovic, Nenad; Mendler, Marc
2016-09-01
We investigate the influence of dissipation and decoherence on quantum Darwinism by generalizing Zurek's original qubit model of decoherence and the establishment of pointer states [W.H. Zurek, Nat. Phys. 5, 181 (2009); see also arXiv: quant-ph/0707.2832v1, pp. 14-19.]. Our model allows for repeated multiple qubit-qubit couplings between system and environment which are described by randomly applied two-qubit quantum operations inducing entanglement, dissipation and dephasing. The resulting stationary qubit states of system and environment are investigated. They exhibit the intricate influence of entanglement generation, dissipation and dephasing on this characteristic quantum phenomenon.
Relaxation and Dephasing in a Two-Electron 13C Nanotube Double Quantum Dot
Churchill, H O H; Kuemmeth, Ferdinand; Harlow, J W
2009-01-01
We use charge sensing of Pauli blockade (including spin and isospin) in a two-electron 13C nanotube double quantum dot to measure relaxation and dephasing times. The relaxation time T1 first decreases with a parallel magnetic field and then goes through a minimum in a field of 1.4 T. We attribute...... both results to the spin-orbit-modified electronic spectrum of carbon nanotubes, which at high field enhances relaxation due to bending-mode phonons. The inhomogeneous dephasing time T2* is consistent with previous data on hyperfine coupling strength in 13C nanotubes....
Optical Dephasing in a Glass-like System : A Photon Echo Study of Pentacene in Benzoic Acid
Duppen, Koos; Molenkamp, Laurens W.; Morsink, Jos B.W.; Wiersma, Douwe A.; Trommsdorff, H.P.
1981-01-01
Optical absorption and picosecond photon echo experiments are used to study the dephasing of pentacene in benzoic acid. It is shown that, while the absorption spectrum of pentacene is effected by proton transfer in the benzoic acid dimer, the dephasing is caused by elastic and inelastic phonon scatt
Overlap Removal Methods for Data Projection Algorithms
Spicker, Marc
2011-01-01
Projection algorithms map high dimensional data points to lower dimensions. However, when adding arbitrary shaped objects as representatives for these data points, they may intersect. The positions of these representatives have to be modi ed in order to remove existing overlaps. There are multiple algorithms designed to deal with this layout adjustment problem, which lead to very di erent results. These adjustment strategies are evaluated according to di erent measures for comparison: euclide...
CHARACTERISTICS OF MIRR METHOD IN EVALUATION OF INVESTMENT PROJECTS' EFFECTIVENESS
P. Kukhta
2014-09-01
Full Text Available There were analyzed characteristics of the Modified Internal Rate of Return method in the evaluation of investment projects, restrictions connected with its application, advantages and disadvantages compared with indicators of the original Internal Rate of Return and Net Present Value for projects with certain baseline characteristics. It was determined opportunities to adapt the method of Modified Internal Rate of Return to alternative computational approaches of the project cash flows evaluation.
How Agile Methods Inspire Project Management - The Half Double Initiative
Heeager, Lise Tordrup; Svejvig, Per; Schlichter, Bjarne Rerup
Increased complexity in projects has forced new project management initiatives. In software development several agile methods have emerged and are today highly implemented in practice. Observations of general project management practice show how it has been inspired by agile software development......, but very little research addresses the issue of agile project management. In order to understand and to provide suggestions for future practice on how agility can be incorporated in general project management, this paper provides an analysis which compares ten characteristics of agile software development...... (identified in theory) and the Half Double Methodology developed by the Danish Project Half Double initiative; a Methodology developed with practitioners and tested in seven Danish case companies. The analysis shows how the general project management to a great extent has been inspired by agile methods...
An Analytical Method for Measuring Competence in Project Management
González-Marcos, Ana; Alba-Elías, Fernando; Ordieres-Meré, Joaquín
2016-01-01
The goal of this paper is to present a competence assessment method in project management that is based on participants' performance and value creation. It seeks to close an existing gap in competence assessment in higher education. The proposed method relies on information and communication technology (ICT) tools and combines Project Management…
Fuzzy Assessment Method and Its Application to Selecting Project Managers
无
2006-01-01
Open competition is a new form of the assessment of candidates and selection of project managers. This has many merits compared to the traditional administrative method of appointment. This article introduces a method of fuzzy assessment of project manager candidates. Fuzzy assessment unifies objective qualitative and quantitative appraisal and can be used for improving decision-making in the selection process.
An update on projection methods for transient incompressible viscous flow
Gresho, P.M.; Chan, S.T.
1995-07-01
Introduced in 1990 was the biharmonic equation (for the pressure) and the concomitant biharmonic miracle when transient incompressible viscous flow is solved approximately by a projection method. Herein is introduced the biharmonic catastrophe that sometimes occurs with these same projection methods.
An Analytical Method for Measuring Competence in Project Management
González-Marcos, Ana; Alba-Elías, Fernando; Ordieres-Meré, Joaquín
2016-01-01
The goal of this paper is to present a competence assessment method in project management that is based on participants' performance and value creation. It seeks to close an existing gap in competence assessment in higher education. The proposed method relies on information and communication technology (ICT) tools and combines Project Management…
Hybrid Prediction Method for Aircraft Interior Noise Project
National Aeronautics and Space Administration — The goal of the project is research and development of methods for application of the Hybrid FE-SEA method to aircraft vibro-acoustic problems. This proposal...
The RISKMED project: philosophy, methods and products
Bartzokas, A.; Azzopardi, J.; Bertotti, L.; Buzzi, A.; Cavaleri, L.; Conte, D.; Davolio, S.; Dietrich, S.; Drago, A.; Drofa, O.; Gkikas, A.; Kotroni, V.; Lagouvardos, K.; Lolis, C. J.; Michaelides, S.; Miglietta, M.; Mugnai, A.; Music, S.; Nikolaides, K.; Porcù, F.; Savvidou, K.; Tsirogianni, M. I.
2010-07-01
This paper presents RISKMED, a project targeted to create an Early Warning System (EWS) in case of severe or extreme weather events in the central and eastern Mediterranean and specifically in southern Italy, northwestern Greece, Malta and Cyprus. As severe or extreme weather events are considered, cases when the values of some meteorological parameters (temperature, wind, precipitation) exceed certain thresholds, and/or a severe weather phenomenon (thunderstorm, snowfall) occurs. For an accurate weather forecast, selected meteorological models have been operated daily, based on a nesting strategy using two or three domains, providing detailed forecasts over the above mentioned areas. The forecast results are further exploited for the evaluation and prediction of human discomfort and fire weather indices. Finally, sea wave models have also been operating daily over the central and eastern Mediterranean Sea. In case a severe or extreme weather event is forecasted within the next 48 or 72 h for selected target areas (sub-regions defined by their morphological and population characteristics), the local authorities and the public are informed via a user-friendly graphic system, the so-called RISK MAP. On the web page of the Project ( http://www.riskmed.net ), additional information is provided about the real-time values of some meteorological parameters, the latest satellite picture and the time and space distribution of lightning during the last 24 h. The RISKMED project was financed by the EU and th Ministries of National Economy of Greece, Italy, Malta and Cyprus, in the frame of INTERREG IIIB/ARCHIMED programme.
Interaction induced dephasing of excitons in wide ZnSe/ZnMgSe single quantum wells
Wagner, Hans Peter; Schätz, A.; Maier, R.;
1998-01-01
The dephasing of excitons in wide ZnSe/Zn0.94Mg0.06Se single quantum wells (SQW) is investigated by spectrally resolved, time integrated four-wave mixing (FWM). Simultaneous excitation of Is center-of-mass quantized heavy-hole and light-hole excition states leads to pronounced quantum beats. Pola...
Relaxation and Dephasing in a Two-Electron 13C Nanotube Double Quantum Dot
Churchill, H O H; Kuemmeth, Ferdinand; Harlow, J W;
2009-01-01
We use charge sensing of Pauli blockade (including spin and isospin) in a two-electron 13C nanotube double quantum dot to measure relaxation and dephasing times. The relaxation time T1 first decreases with a parallel magnetic field and then goes through a minimum in a field of 1.4 T. We attribute...
Many-Body Effect in Spin Dephasing in n-Type GaAs Quantum Wells
WENG Ming-Qi; WU Ming-Wei
2005-01-01
@@ By constructing and numerically solving the kinetic Bloch equations we perform a many-body study of the spin dephasing due to the D'yakonov-Perel' effect in n-type GaAs (100) quantum wells for high temperatures.
Dephasing time and damping mechanisms of surface plasmon polaritons in gold nanoparticles
Borg, Nils; Sanchez Blazquez, David; Hendrich, Christian; Hubenthal, Frank; Traeger, Frank [Institut fuer Physik und Center for Interdisciplinary Nanostructure Science and Technology - CINSaT, Universitaet Kassel, Heinrich-Plett-Strasse 40, D-34132 Kassel (Germany)
2007-07-01
The ultrafast electron dynamics in gold nanoparticles (NPs) was studied by measuring the dephasing time T{sub 2} of the surface plasmon polariton by means of persistent spectral hole burning. The dephasing time of gold grown on sapphire and TiO{sub 2} substrates was measured as a function of photon energy and the particle size. Dephasing times ranging from 5 to 17 fs were extracted. Furthermore, an explicit influence of the reduced dimension of the NPs has been determined, which plays a role for NPs with radii below 12 nm already. Most importantly, a dependence of T{sub 2} on the decreasing particle dimensions which fulfilled a 1/R-dependence was found and we could obtain a damping parameter for gold on sapphire of A=(0.32{+-}0.06) nm/fs. Comparison with other measurements as well as with theoretical predictions could identify surface scattering and Landau-damping as the most important mechanisms. Recent further experiments on gold NPs supported on TiO{sub 2} showed a further reduction of the dephasing time. For example, for NPs with a radius of approximately 13 nm we observed a decrease from T{sub 2}{approx}15 fs for NPs grown on sapphire to T{sub 2}{approx}12 fs for NPs grown on TiO{sub 2} at a photon energy of 1.65 eV. This indicates an additional damping mechanism, i.e. chemical interface damping.
Reducing dephasing in coupled quantum dot-cavity systems by engineering the carrier wavefunctions
Nysteen, Anders; Nielsen, Per Kær; Mørk, Jesper
2012-01-01
We demonstrate theoretically how photon-assisted dephasing by the electron-phonon interaction in a coupled cavity-quantum dot system can be significantly reduced for specific QD-cavity detunings. Our starting point is a recently published theory,1 which considers longitudinal acoustic phonons, de...
Equitable Financial Evaluation Method for Public-Private Partnership Projects
KE Yongjian; LIU Xinping; WANG Shouqing
2008-01-01
The feasibility study of a public-private partnership (PPP) project is regarded as one of the critical factors for successful implementation,but unfortunately the common financial evaluation methods currently used only represent the benefits of the private sector.There is,therefore,an urgent need to develop an equitable financial evaluation method for PPP projects.This paper presents a comprehensive literature review that examines international practices.An equitable financial evaluation method was then developed taking into account the inherent characteristics of PPP projects using six separate indicators and Monte Carlo simulations.The result for a bridge project in Romania shows that the method combines the viewpoints of all the relevant stakeholders to achieve an equitable financial evaluation of PPP projects.
Higher-Order Semi-Implicit Projection Methods
Minion, M L
2001-09-06
A semi-implicit form of the method of spectral deferred corrections is applied to the solution of the incompressible Navier-Stokes equations. A methodology for constructing semi-implicit projection methods with arbitrarily high order of temporal accuracy in both the velocity and pressure is presented. Three variations of projection methods are discussed which differ in the manner in which the auxiliary velocity and the pressure are calculated. The presentation will make clear that project methods in general need not be viewed as fractional step methods as is often the practice. Two simple numerical examples re used to demonstrate fourth-order accuracy in time for an implementation of each variation of projection method.
Lattice Regenerative Cooling Methods (LRCM) Project
National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate a novel cooling concept called Lattice Regenerative Cooling Methods (LRCM) for future high thrust in-space propulsion...
Projected oriented organizations as development of enterprise management methods
S.I. Pavlova
2016-12-01
Full Text Available Dynamic external environment, significant shortage of product life cycle, increase of product technological difficulty, extension of innovative knowledge motivates managers to look for and use in their activities keys that will provide constant, stable development of organizational structures. The methodology of project enterprise management meets the requirements of «preservation through development». The articles researches the integration of methods and procedures of project management into the enterprise management system. Project management philosophy is the efficient way of existence in the competitive environment and the means for internal development of a company. The author conducts an analysis, determines the essence and peculiarities of a project-oriented enterprise, performs comparing characteristics of functional and project management, describes the stages of gradual transformation of an enterprise organizational structure into a project-oriented one. It is defined that a project-oriented enterprise is that one which functions on the base of innovative development and are scientific, creative and widely use the project activity as the means of a steady development. The article describes internal and external instruments of project management, base knowledge systems on project management and possibilities of enterprises on audit of state of system project management in an enterprise according to the IPMA certification program on the territory of Ukraine.
An adaptive projection method for the incompressible Euler equations
Almgren, Ann S.; Bell, John B.; Colella, Phillip; Howell, Louis H.
A new adaptive projection method has been developed for time-dependent incompressible variable density flow. The levels in the adaptive mesh hierarchy are refined in both space and time. The advection step takes place on individual grids in an approach similar to that of the single grid method. The projection at each level is similar to the uniform grid projection but must now incorporate multiple grids per level. A sync projection is introduced which is needed to synchronize the solution at each level l with the data at the levels above it at the end of each level l time step. This adaptive projection method is second-order accurate and provides an accurate and efficient tool for modeling variable density flows.
Effective Teaching Methods--Project-based Learning in Physics
Holubova, Renata
2008-01-01
The paper presents results of the research of new effective teaching methods in physics and science. It is found out that it is necessary to educate pre-service teachers in approaches stressing the importance of the own activity of students, in competences how to create an interdisciplinary project. Project-based physics teaching and learning…
Advanced Bayesian Methods for Lunar Surface Navigation Project
National Aeronautics and Space Administration — The key innovation of this project is the application of advanced Bayesian methods to integrate real-time dense stereo vision and high-speed optical flow with an...
Advanced Bayesian Methods for Lunar Surface Navigation Project
National Aeronautics and Space Administration — The key innovation of this project will be the application of advanced Bayesian methods to integrate real-time dense stereo vision and high-speed optical flow with...
On the accuracy of low-order projection methods
Paul Pichler
2007-01-01
We use low-order projection methods to compute numerical solutions of the basic neoclassical stochastic growth model. We assess the quality of the obtained solutions, and compare them to numerical approximations derived with first and second-order perturbation techniques. We show that projection methods perform surprisingly poor when the degree of approximation is very low, and we provide some intuition behind this finding.
Insurance ratemaking method for risk of construction diversion project
Chen Zhiding; Hu Zhigen
2012-01-01
Based on analyzing risk factors of diversion project, synthetic risk rate and engineering insurance period, the frequency and distribution law of loss are researched on the grounds that foundation pit is submerged after diversion project ceases to be effective. And then, the standpoint that these total loss is subject to non-homogeneous compound Poisson processes is put forward. Furthermore, the collective risk model of the total loss about engineering insurance is established on the basis of construction diversion project risk. Ultimately, insurance ratemaking method for construction engineering risk and its mathematical expression are presented, which provides theoretical method for the insurance ratemaking of hydropower engineering to some extent.
A PROJECTION-TYPE METHOD FOR SOLVING VARIOUS WEBER PROBLEMS
Jian-lin Jiang; Bo Chen
2006-01-01
This paper investigates various Weber problems including unconstrained Weber problems and constrained Weber problems under l1,l2 and l∞-norms. First with a transformation technique various Weber problems are turned into a class of monotone linear variational inequalities. By exploiting the favorable structure of these variational inequalities, we present a new projection-type method for them. Compared with some other projection-type methods which can solve monotone linear variational inequality, this new projection-type method is simple in numerical implementations and more efficient for solving this class of problems; Compared with some popular methods for solving unconstrained Weber problem and constrained Weber problem, a singularity would not happen in this new method and it is more reliable by using this new method to solve various Weber problems.
A Modified Projection Method for Linear Feasibility Problems
Yi-Ju Wang; Hong-Yu Zhang
2009-01-01
In this paper, we present a modified projection method for the linear feasibility problems (LFP). Compared with the existing methods, the new method adopts a surrogate technique to obtain new iteration instead of the line search procedure with fixed stepsize. For the new method, we first show its global convergence under the condition that the solution set is nonempty, and then establish its linear convergence rate. Preliminary numerical experiments show that this method has good performance.
Expanding the Action Project Method to Encompass Comparative Analyses
José F. Domene PhD
2008-03-01
Full Text Available This article is an exploration of the possibility and pragmatics of conducting between-groups comparative analysis in action theory and the action project method of qualitative research. After establishing the need for such a procedure and describing the compatibility of these analyses with the paradigm assumptions of action theory, the authors describe a specific set of procedures for conducting qualitative comparisons within the action project method. They also discuss limitations of the procedure and future directions for continuing the expansion of methods of comparison in qualitative research. Finally, they present a case illustration of the use of this comparative analysis method.
Project-Method Fit: Exploring Factors That Influence Agile Method Use
Young, Diana K.
2013-01-01
While the productivity and quality implications of agile software development methods (SDMs) have been demonstrated, research concerning the project contexts where their use is most appropriate has yielded less definitive results. Most experts agree that agile SDMs are not suited for all project contexts. Several project and team factors have been…
Projection methods for the numerical solution of Markov chain models
Saad, Youcef
1989-01-01
Projection methods for computing stationary probability distributions for Markov chain models are presented. A general projection method is a method which seeks an approximation from a subspace of small dimension to the original problem. Thus, the original matrix problem of size N is approximated by one of dimension m, typically much smaller than N. A particularly successful class of methods based on this principle is that of Krylov subspace methods which utilize subspaces of the form span(v,av,...,A(exp m-1)v). These methods are effective in solving linear systems and eigenvalue problems (Lanczos, Arnoldi,...) as well as nonlinear equations. They can be combined with more traditional iterative methods such as successive overrelaxation, symmetric successive overrelaxation, or with incomplete factorization methods to enhance convergence.
Zheng, Hairong; Zhang, Xiangyu; Gao, Dangli; Meltzer, Richard S
2008-03-01
Optical dephasing of Pr3+ and Tm3+ ions doped in transparent oxyfluoride glass ceramics was studied with the two-pulse photon echo technique. It was found that the dephasing time of rare earth ions is dramatically less in nanocrystals embedded in a glass matrix than in bulk crystals. A quasi-linear temperature dependence obtained at low temperatures proved that the long-range interaction of the ions inside the nanocrystals with the two level systems of the glass matrix dominates the optical dephasing. The local thermal effect in glass ceramics containing nanocrystals elevates the local temperature, which results in the reduction of optical dephasing time. For Tm(3+)-doped glass ceramics, the elevation of local temperature induced by the irradiation of excitation laser even quenched the photon echo signals in the experimental study.
Freezing motion-induced dephasing in an atomic-ensemble quantum memory
Jiang, Yan; Bao, Xiao-Hui; Pan, Jian-Wei
2016-01-01
Motion-induced dephasing is a dominant decoherence mechanism for atom-gas quantum memories. In this paper, we develop a new coherent manipulation technique which enables arbitrary engineering of the spin-wave momentum with neglectable noise. By zeroing the spin-wave momentum, motion-induced dephasing can be frozen completely. We experimentally demonstrate this scheme with laser-cooled atoms in a DLCZ configuration. By applying the freezing pulses, memory lifetime gets extended significantly to the limit of atom cloud expansion and does not depend on the detection angle anymore. The observed high cross-correlation above 20 proves that high-fidelity memory operation is well preserved after coherent manipulation.
On the non-equilibrium dynamics of dissipative Rydberg gases in the presence of dephasing noise
Levi, Emanuele; Lesanovsky, Igor
2016-01-01
In the presence of strong dephasing noise the dynamics of Rydberg gases becomes effectively classical, due to the rapid decay of quantum superpositions between atomic levels. Recently a great deal of attention has been devoted to the stochastic dynamics that emerges in that limit, revealing several interesting features, including kinetically-constrained glassy behaviour, self-similarity and aggregation effects. However, the non-equilibrium physics of these systems, in particular in the regime where coherent and dissipative processes contribute on equal footing, is yet far from being understood. To explore this we study the dynamics of a small one-dimensional Rydberg lattice gas subject to dephasing noise by numerically integrating the quantum Master equation. We find indications that the main features observed in the strongly dissipative limit persist when the dissipation is not strong enough to annihilate quantum coherences at the dynamically relevant time scales. These features include a power law growth of...
Size dependence of electron spin dephasing in InGaAs quantum dots
Huang, Y. Q.; Puttisong, Y.; Buyanova, I. A.; Chen, W. M. [Department of Physics, Chemistry and Biology, Linköping University, S-581 83 Linköping (Sweden); Yang, X. J.; Subagyo, A.; Sueoka, K.; Murayama, A. [Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo 060-0814 (Japan)
2015-03-02
We investigate ensemble electron spin dephasing in self-assembled InGaAs/GaAs quantum dots (QDs) of different lateral sizes by employing optical Hanle measurements. Using low excitation power, we are able to obtain a spin dephasing time T{sub 2}{sup *} (in the order of ns) of the resident electron after recombination of negative trions in the QDs. We show that T{sub 2}{sup *} is determined by the hyperfine field arising from the frozen fluctuation of nuclear spins, which scales with the size of QDs following the Merkulov-Efros-Rosen model. This scaling no longer holds in large QDs, most likely due to a breakdown in the lateral electron confinement.
Composite orthogonal projection methods for large matrix eigenproblems
贾仲孝
1999-01-01
For classical orthogonal projection methods for large matrix eigenproblems, it may be much more difficult for a Ritz vector to converge than for its corresponding Ritz value when the matrix in question is non-Hermitian. To this end, a class of new refined orthogonal projection methods has been proposed. It is proved that in some sense each refined method is a composite of two classical orthogonal projections, in which each refined approximate eigenvector is obtained by realizing a new one of some Hermitian semipositive definite matrix onto the same subspace. A priori error bounds on the refined approximate eigenvector are established in terms of the sine of acute angle of the normalized eigenvector and the subspace involved. It is shown that the sufficient conditions for convergence of the refined vector and that of the Ritz value are the same, so that the refined methods may be much more efficient than the classical ones.
PRECONDITIONED SPECTRAL PROJECTED GRADIENT METHOD ON CONVEX SETS
Lenys Bello; Marcos Raydan
2005-01-01
The spectral gradient method has proved to be effective for solving large-scale unconstrained optimization problems. It has been recently extended and combined with the projected gradient method for solving optimization problems on convex sets. This combination includes the use of nonmonotone line search techniques to preserve the fast local convergence. In this work we further extend the spectral choice of steplength to accept preconditioned directions when a good preconditioner is available. We present an algorithm that combines the spectral projected gradient method with preconditioning strategies to increase the local speed of convergence while keeping the global properties. We discuss implementation details for solving large-scale problems.
Lin, Shih-Wei; Wu, Yue-Han; Chang, Li; Liang, Chi-Te; Lin, Sheng-Di
2015-01-01
We have successfully grown ultrathin continuous aluminum film by molecular beam epitaxy. This percolative aluminum film is single crystalline and strain free as characterized by transmission electron microscopy and atomic force microscopy. The weak anti-localization effect is observed in the temperature range of 1.4 to 10 K with this sample, and it reveals that, for the first time, the dephasing is purely caused by electron-electron inelastic scattering in aluminum.
Quantum corrections to the polarizability and dephasing in isolated disordered metals
Treiber, M.; Ostrovsky, P. M.; Yevtushenko, O. M.; von Delft, J.; Lerner, I. V.
2013-07-01
We study the quantum corrections to the polarizability of isolated metallic mesoscopic systems using the loop expansion in diffusive propagators. We show that the difference between connected (grand-canonical ensemble) and isolated (canonical ensemble) systems appears only in subleading terms of the expansion, and can be neglected if the frequency of the external field, ω, is of the order of (or even slightly smaller than) the mean level spacing, Δ. If ω≪Δ, the two-loop correction becomes important. We calculate it by systematically evaluating the ballistic parts (the Hikami boxes) of the corresponding diagrams and exploiting electroneutrality. Our theory allows one to take into account a finite dephasing rate, γ, generated by electron interactions, and it is complementary to the nonperturbative results obtained from a combination of random matrix theory (RMT) and the σ-model, valid at γ→0. Remarkably, we find that the two-loop result for isolated systems with moderately weak dephasing, γ˜Δ, is similar to the result of the RMT+σ-model even in the limit ω→0. For smaller γ, we discuss the possibility to interpolate between the perturbative and the nonperturbative results. We compare our results for the temperature dependence of the polarizability of isolated rings to the experimental data of Deblock [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.84.5379 84, 5379 (2000); Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.65.075301 65, 075301 (2002)], and we argue that the elusive 0D regime of dephasing might have manifested itself in the observed magneto-oscillations. Besides, we thoroughly discuss possible future measurements of the polarizability, which could aim to reveal the existence of 0D dephasing and the role of the Pauli blocking at small temperatures.
Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes
Kalampounias, A. G.; Tsilomelekis, G.; Boghosian, S.
2015-01-01
In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are
Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes.
Kalampounias, A G; Tsilomelekis, G; Boghosian, S
2015-01-25
In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are
Selection of renewable energy project using Multicriteria Method
DADDA Afaf1 , OUHBI Brahim1
2015-10-01
Full Text Available Nowadays, many investors are interesting on implementing new renewable energy project around the world. The success of the decision making process regarding the selection of this projects, depends a lot on the effectiveness of the feasibility stage. During last decades, it is observed that many researches had used the Multicriteria Decision Making Methods to assist decision makers. Therefore, this paper proposes a comparative study of a three decision making process, applied in different countries. This study compares the related process in different levels. A new process is also proposed to validate a local renewable energy project
Training two-layered feedforward networks with variable projection method.
Kim, C T; Lee, J J
2008-02-01
The variable projection (VP) method for separable nonlinear least squares (SNLLS) is presented and incorporated into the Levenberg-Marquardt optimization algorithm for training two-layered feedforward neural networks. It is shown that the Jacobian of variable projected networks can be computed by simple modification of the backpropagation algorithm. The suggested algorithm is efficient compared to conventional techniques such as conventional Levenberg-Marquardt algorithm (LMA), hybrid gradient algorithm (HGA), and extreme learning machine (ELM).
Application of Participatory Method to Selection of Project Demonstration Area
无
2011-01-01
The Sino-Japan cooperation project of "Vegetation Rehabilitation Demonstration and Planning in Sandstorm Jeopardized Area around Beijing" introduced participatory method to select the project area. Through investigating the socioeconomic indicators of 9 villages in Beijing and Hebei Province as well as the farmers’ willingness to participate in forestry operation activities, the vegetation restoration demonstration areas were selected, including Hantai Village, Baicaowa Village and Xiabachi Village, respect...
Sun, Qi-C; Ding, Yuchen; Goodman, Samuel M; Funke, Hans H; Nagpal, Prashant
2014-11-07
Copper metal can provide an important alternative for the development of efficient, low-cost and low-loss plasmonic nanoparticles, and selective nanocatalysts. However, poor chemical stability and lack of insight into photophysics and plasmon decay mechanisms has impeded study. Here, we use smooth conformal ALD coating on copper nanoparticles to prevent surface oxidation, and study dephasing time for localized surface plasmons on different sized copper nanoparticles. Using dephasing time as a figure of merit, we elucidate the role of electron-electron, electron-phonon, impurity, surface and grain boundary scattering on the decay of localized surface plasmon waves. Using our quantitative analysis and different temperature dependent measurements, we show that electron-phonon interactions dominate over other scattering mechanisms in dephasing plasmon waves. While interband transitions in copper metal contributes substantially to plasmon losses, tuning surface plasmon modes to infrared frequencies leads to a five-fold enhancement in the quality factor. These findings demonstrate that conformal ALD coatings can improve the chemical stability for copper nanoparticles, even at high temperatures (>300 °C) in ambient atmosphere, and nanoscaled copper is a good alternative material for many potential applications in nanophotonics, plasmonics, catalysis and nanoscale electronics.
Dynamical decoupling sequences for multi-qubit dephasing suppression and long-time quantum memory
Paz-Silva, Gerardo A.; Lee, Seung-Woo; Green, Todd J.; Viola, Lorenza
2016-07-01
We consider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer filter-function framework for open-loop control, we provide an exact representation of the controlled dynamics for arbitrary stationary non-Gaussian classical and quantum noise statistics, with analytical expressions emerging when all dephasing sources are Gaussian. This exact characterization is used to establish two main results. First, we construct multi-qubit sequences that ensure maximum high-order error suppression in both the time and frequency domain and that can be exponentially more efficient than existing ones in terms of total pulse number. Next, we show how long-time multi-qubit storage may be achieved by meeting appropriate conditions for the emergence of a fidelity plateau under sequence repetition, thereby generalizing recent results for single-qubit memory under Gaussian dephasing. In both scenarios, the key step is to endow multi-qubit sequences with a suitable displacement anti-symmetry property, which is of independent interest for applications ranging from environment-assisted entanglement generation to multi-qubit noise spectroscopy protocols.
Lesion insertion in the projection domain: Methods and initial results
Chen, Baiyu; Leng, Shuai; Yu, Lifeng; Yu, Zhicong; Ma, Chi; McCollough, Cynthia, E-mail: mccollough.cynthia@mayo.edu [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)
2015-12-15
Purpose: To perform task-based image quality assessment in CT, it is desirable to have a large number of realistic patient images with known diagnostic truth. One effective way of achieving this objective is to create hybrid images that combine patient images with inserted lesions. Because conventional hybrid images generated in the image domain fails to reflect the impact of scan and reconstruction parameters on lesion appearance, this study explored a projection-domain approach. Methods: Lesions were segmented from patient images and forward projected to acquire lesion projections. The forward-projection geometry was designed according to a commercial CT scanner and accommodated both axial and helical modes with various focal spot movement patterns. The energy employed by the commercial CT scanner for beam hardening correction was measured and used for the forward projection. The lesion projections were inserted into patient projections decoded from commercial CT projection data. The combined projections were formatted to match those of commercial CT raw data, loaded onto a commercial CT scanner, and reconstructed to create the hybrid images. Two validations were performed. First, to validate the accuracy of the forward-projection geometry, images were reconstructed from the forward projections of a virtual ACR phantom and compared to physically acquired ACR phantom images in terms of CT number accuracy and high-contrast resolution. Second, to validate the realism of the lesion in hybrid images, liver lesions were segmented from patient images and inserted back into the same patients, each at a new location specified by a radiologist. The inserted lesions were compared to the original lesions and visually assessed for realism by two experienced radiologists in a blinded fashion. Results: For the validation of the forward-projection geometry, the images reconstructed from the forward projections of the virtual ACR phantom were consistent with the images physically
Extension of moment projection method to the fragmentation process
Wu, Shaohua; Yapp, Edward K. Y.; Akroyd, Jethro; Mosbach, Sebastian; Xu, Rong; Yang, Wenming; Kraft, Markus
2017-04-01
The method of moments is a simple but efficient method of solving the population balance equation which describes particle dynamics. Recently, the moment projection method (MPM) was proposed and validated for particle inception, coagulation, growth and, more importantly, shrinkage; here the method is extended to include the fragmentation process. The performance of MPM is tested for 13 different test cases for different fragmentation kernels, fragment distribution functions and initial conditions. Comparisons are made with the quadrature method of moments (QMOM), hybrid method of moments (HMOM) and a high-precision stochastic solution calculated using the established direct simulation algorithm (DSA) and advantages of MPM are drawn.
Extension of moment projection method to the fragmentation process
Wu, Shaohua [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Yapp, Edward K.Y.; Akroyd, Jethro; Mosbach, Sebastian [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore); Yang, Wenming [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)
2017-04-15
The method of moments is a simple but efficient method of solving the population balance equation which describes particle dynamics. Recently, the moment projection method (MPM) was proposed and validated for particle inception, coagulation, growth and, more importantly, shrinkage; here the method is extended to include the fragmentation process. The performance of MPM is tested for 13 different test cases for different fragmentation kernels, fragment distribution functions and initial conditions. Comparisons are made with the quadrature method of moments (QMOM), hybrid method of moments (HMOM) and a high-precision stochastic solution calculated using the established direct simulation algorithm (DSA) and advantages of MPM are drawn.
Reconstruction of CT images by the Bayes- back projection method
Haruyama, M; Takase, M; Tobita, H
2002-01-01
In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. From the basic theory of Baysian Back Projection method, it can be not only applied to CT types of 1st, 2nd, and 3rd generation. This reported deals with a reconstruction program of cross-section images in the CT of ...
Stochastic number projection method in the pairing-force problem
Capote, R; Capote, Roberto; Gonzalez, Augusto
1999-01-01
A new stochastic number projection method is proposed. The component of the BCS wave function corresponding to the right number of particles is obtained by means of a Metropolis algorithm in which the weight functions are constructed from the single-particle occupation probability. Either standard BCS or Lipkin-Nogami probability distributions can be used, thus the method is applicable for any pairing strength. The accuracy of the method is tested in the computation of pairing energies of model and real systems.
Integrated project delivery methods for energy renovation of social housing
Tadeo Baldiri Salcedo Rahola
2015-11-01
Full Text Available Optimised project delivery methods forsocial housing energy renovationsEuropean Social Housing Organisations (SHOs are currently facing challenging times. The ageing of their housing stock and the economic crisis, which has affected both their finances and the finances of their tenants, are testing their capacity to stick to their aim of providing decent and affordable housing. Housing renovation projects offer the possibility of upgrading the health and comfort levels of their old housing stock to current standards and improve energy efficiency, and this solution also addresses the fuel poverty problems suffered by some tenants. Unfortunately, the limited financial capacity of SHOs is hampering the scale of housing renovation projects and the energy savings achieved. At the same time, the renovation of the existing housing stock is seen as one of the most promising alternative routes to achieving the ambitious CO2 emissions reduction targets set by European authorities – namely, to reduce EU CO2 emissions to 20% below their 1990 levels by 2020. The synergy between European targets and the aims of SHOs has been addressed by the energy policies of the member states, which focus on the potential energy savings achievable by renovating social housing. In fact, the European initiatives have prioritised energy savings in social housing renovations to such an extent that these are referred to as ‘energy renovations’. Energy renovation is therefore a renovation project with higher energy savings target than a regular renovation project.In total, European SHOs own 21.5 million dwellings representing around 9.4% of the total housing stock. Each SHO owns a large number of dwellings, which means there are fewer people to convince of the need to make energy savings through building renovations, maximising the potentially high impact of decisions. Moreover, SHOs are responsible for maintaining and upgrading their properties in order to continue
THEORETICAL AND NUMERICAL COMPARISON ON DOUBLE-PROJECTION METHODS FOR VARIATIONAL INEQUALITIES
WANG Yiju; SUN Wenyu
2003-01-01
Recently, double projection methods for solving variational inequalities have received much attention due to their fewer projection times at each iteration. In this paper, we unify these double projection methods within two unified frameworks, which contain the existing double projection methods as special cases. On the basis of this unification, theoretical and numerical comparison between these double projection methods is presented.
A fast alternating projection method for complex frequency estimation
Andersson, Fredrik; Ivert, Per-Anders
2011-01-01
The problem of approximating a sampled function using sums of a fixed number of complex exponentials is considered. We use alternating projections between fixed rank matrices and Hankel matrices to obtain such an approximation. Convergence, convergence rates and error estimates for this technique are proven, and fast algorithms are developed. We compare the numerical results obtain with the MUSIC and ESPRIT methods.
Implementation of Relevant Methods in Assessing Traffic-Technological Projects
Danijela Barić
2007-09-01
Full Text Available The assessment of investment traffic-technological projectsmeans a set of activities whose basic aim is to determine the justificationand feasibility of the projects. The decision-makingprocess, including the decision-making on investments is an extremelycomplex process, and the decision-maker has to have avision of the future and make decisions accordingly in a modemand flexible manner. Therefore, the decisions need to be theresult of a planning and research process based on relevant scientificmethods. The work includes the selected, analysed andpresented methods of cost-benefit analysis, methods of multi-criteria decision-making and SWOT (Strengths, Weaknesses,Opportunities, and Threats analysis methods. Regarding thebasic characteristics, the mentioned methods have been compared,the order of their implementation has been determined,and then they have been implemented in assessing the traffic-technological projects of reconstmction with the aim of selectingthe optimal variant solution.
Researching on quantitative project management plan and implementation method
Wang, Xin; Ren, Aihua; Liu, Xiangshang
2017-08-01
With the practice of high maturity process improvement, more and more attention has been paid to CMMI and other process improvement frameworks. The key to improve the process of high maturity is to quantify the process. At present, the method of improving the software process of high maturity is lack of specific introduction to the corresponding improvement link or process implementation. In this paper, based on the current improvement in the quantitative management of the framework and statistical analysis technical of the high maturity recommended for the enterprise to improve the process of planning and implementation methods. These methods provide quantitative process management for the enterprise, as well as quantitative management of the project to provide a systematic process, and finally evaluate the effectiveness of quantitative management projects. Finally, this method is used to verify the effectiveness of the framework in guiding the enterprise to improve the process of high maturity.
Study on Method of Comprehensive Evaluating for Information System Projects
无
2000-01-01
In this paper, a new method of evaluation for information system project is propoeed on the basis of the meta-synthesis methodology from qualitative analysis to quantitative analysis. DHGF is an integrated method of improved Delphi, analytic hierarchy process, grey interconnect degree and fuzzy comprehensive evaluating. It gives full play to their advantages and controls theirs disadvantages. The feasibility and effectiveness of DHGF are shown in the practical example.
A General, Mass-Preserving Navier-Stokes Projection Method
Salac, David
2015-01-01
The conservation of mass is common issue with multiphase fluid simulations. In this work a novel projection method is presented which conserves mass both locally and globally. The fluid pressure is augmented with a time-varying component which accounts for any global mass change. The resulting system of equations is solved using an efficient Schur-complement method. Using the proposed method four numerical examples are performed: the evolution of a static bubble, the rise of a bubble, the breakup of a thin fluid thread, and the extension of a droplet in shear flow. The method is capable of conserving the mass even in situations with morphological changes such as droplet breakup.
A decoupled monolithic projection method for natural convection problems
Pan, Xiaomin; Kim, Kyoungyoun; Lee, Changhoon; Choi, Jung-Il
2016-06-01
We propose an efficient monolithic numerical procedure based on a projection method for solving natural convection problems. In the present monolithic method, the buoyancy, linear diffusion, and nonlinear convection terms are implicitly advanced by applying the Crank-Nicolson scheme in time. To avoid an otherwise inevitable iterative procedure in solving the monolithic discretized system, we use a linearization of the nonlinear convection terms and approximate block lower-upper (LU) decompositions along with approximate factorization. Numerical simulations demonstrate that the proposed method is more stable and computationally efficient than other semi-implicit methods, preserving temporal second-order accuracy.
Risk Management Method in IT Project: A Review
Ikhtiar Faahakhododo
2016-09-01
can produce a useful product and make a profit. This article clarified some of the methods of risk management exist. There was two techniques to determine the risks used in this study, those were Metrics of Process Structure and Referential Model or could be referred as the Comparison to the Referential Model technique. That technique will produce Software Process Meta Model, Model of Risk Management, and Manage Risks in Project models. Those models were used to help managers in mapping the risks of the project.
A multilevel adaptive projection method for unsteady incompressible flow
Howell, Louis H.
1993-11-01
There are two main requirements for practical simulation of unsteady flow at high Reynolds number: the algorithm must accurately propagate discontinuous flow fields without excessive artificial viscosity, and it must have some adaptive capability to concentrate computational effort where it is most needed. We satisfy the first of these requirements with a second-order Godunov method similar to those used for high-speed flows with shocks, and the second with a grid-based refinement scheme which avoids some of the drawbacks associated with unstructured meshes. These two features of our algorithm place certain constraints on the projection method used to enforce incompressibility. Velocities are cell-based, leading to a Laplacian stencil for the projection which decouples adjacent grid points. We discuss features of the multigrid and multilevel iteration schemes required for solution of the resulting decoupled problem. Variable-density flows require use of a modified projection operator--we have found a multigrid method for this modified projection that successfully handles density jumps of thousands to one. Numerical results are shown for the 2D adaptive and 3D variable-density algorithms.
A projection method for LES of incompressible turbulent combustion
LIU Yi; GUO Yincheng
2004-01-01
In this paper, the "incompressible" property of a turbulent combustion with Ma<<1 is analyzed, and a projection method for simulation of low Ma number turbulent combustions is discussed. The density is calculated explicitly,and the projection is only applied to the momentum equations and thus greatly saves the calculation cost. Large eddy simulation of methane-air turbulent planar jet combustion is performed using this projection method. A reduced four-step chemical kinetic mechanism is applied for the simulation of methane-air combustion. A dynamic eddy viscosity model is utilized for the sub-grid scales turbulence modulation. The SGS model for the filtered reaction rate is a dynamic similarity model. Simulation results depict the detailed coherent structures in the jet flame along with the vortex-flame interactions in the flow field. Besides, it is found that the chemical reaction has the effect of "energy rearrangement" in the flow field, which may greatly reduce the turbulence. Simulation results show the satisfactory performance of this projection method in simulating turbulent combustion under the condition of Ma<<1.
Fast alternating projection methods for constrained tomographic reconstruction.
Liu, Li; Han, Yongxin; Jin, Mingwu
2017-01-01
The alternating projection algorithms are easy to implement and effective for large-scale complex optimization problems, such as constrained reconstruction of X-ray computed tomography (CT). A typical method is to use projection onto convex sets (POCS) for data fidelity, nonnegative constraints combined with total variation (TV) minimization (so called TV-POCS) for sparse-view CT reconstruction. However, this type of method relies on empirically selected parameters for satisfactory reconstruction and is generally slow and lack of convergence analysis. In this work, we use a convex feasibility set approach to address the problems associated with TV-POCS and propose a framework using full sequential alternating projections or POCS (FS-POCS) to find the solution in the intersection of convex constraints of bounded TV function, bounded data fidelity error and non-negativity. The rationale behind FS-POCS is that the mathematically optimal solution of the constrained objective function may not be the physically optimal solution. The breakdown of constrained reconstruction into an intersection of several feasible sets can lead to faster convergence and better quantification of reconstruction parameters in a physical meaningful way than that in an empirical way of trial-and-error. In addition, for large-scale optimization problems, first order methods are usually used. Not only is the condition for convergence of gradient-based methods derived, but also a primal-dual hybrid gradient (PDHG) method is used for fast convergence of bounded TV. The newly proposed FS-POCS is evaluated and compared with TV-POCS and another convex feasibility projection method (CPTV) using both digital phantom and pseudo-real CT data to show its superior performance on reconstruction speed, image quality and quantification.
Projected discrete ordinates methods for numerical transport problems
Larsen, E.W.
1985-01-01
A class of Projected Discrete-Ordinates (PDO) methods is described for obtaining iterative solutions of discrete-ordinates problems with convergence rates comparable to those observed using Diffusion Synthetic Acceleration (DSA). The spatially discretized PDO solutions are generally not equal to the DSA solutions, but unlike DSA, which requires great care in the use of spatial discretizations to preserve stability, the PDO solutions remain stable and rapidly convergent with essentially arbitrary spatial discretizations. Numerical results are presented which illustrate the rapid convergence and the accuracy of solutions obtained using PDO methods with commonplace differencing methods.
Scrum Method Implementation in a Software Development Project Management
Putu Adi Guna Permana
2015-09-01
Full Text Available To maximize the performance, companies conduct a variety of ways to increase the business profit. The work management between one company and the other company is different, so the differences in the management may cause the software to have a different business process. Software development can be defined as creating a new software or fixing the existing one. Technology developments led to increasing demand for software, Industrial Technology (IT Companies should be able to project well maintenance. The methodology in software development is used in accordance with the company's needs based on the SDLC (Software Development Life Cycle. Scrum method is a part of the Agile method that is expected to increase the speed and flexibility in software development project management.
Modelling of Airship Flight Mechanics by the Projection Equivalent Method
Frantisek Jelenciak; Michael Gerke; Ulrich Borgolte
2015-01-01
This article describes the projection equivalent method (PEM) as a specific and relatively simple approach for the modelling of aircraft dynamics. By the PEM it is possible to obtain a mathematic al model of the aerodynamic forces and momentums acting on different kinds of aircraft during flight. For the PEM, it is a characteristic of it that - in principle - it provides an acceptable regression model of aerodynamic forces and momentums which exhibits reasonable and plausible behaviour from a...
Manufacturing Methods & Technology Project Execution Report. Second Half CY 1980
1981-03-01
U.S. ARMY MATER-IEL DEVELOP AND READINESS COMMAND Lu ti MAANUFACTURING METHODS & 0 ~ ECHNOLOGY ELECTE, hAY 4 19 81 PROJECT EXECUTION REPORTautw w...Armament Materiel Readiness Command (Ammunition) . ... 83 Armament R&D Cormtand Armament Materiel Readiness Command (Weapons) .. . . . 105 Mobility ... MOBILIZATION PRODUCTION RATES ARE ESTIMATED TO BE S1t6 6000 PER YEAR. 5 78 4288 EXPLOSIVE SAFE SEPARATION AND SENSITIVITY CRITERIA ZERO PALLET SPACING
A New Method To Convert the Fischer Projection of a Monosaccharide to the Haworth Projection
Zhang, Qing-Zhi; Zhang, Shen-Song
1999-06-01
This method is based upon the R,S-configuration designation of each asymmetric carbon of a monosaccharide. According to the rule of configurational retention of each original asymmetric carbon, the Fischer projection of a monosaccharide can be converted into different views of the Haworth projection (the carbon-numbering orientation of the Haworth ring can be in either a clockwise or a counterclockwise direction, and the oxygen atom can be written at any corner of the ring). The D,L-configuration of a sugar in Haworth projection can be directly determined by designating the R,S-configuration of the highest-numbered asymmetric carbon; that is, the most distant carbon from the anomeric carbon. The R-configuration at this carbon corresponds to the D-family, and S- to the L-family. By comparing the stereochemistry of the anomeric carbon with that of the highest-numbered asymmetric carbon, the a, b-anomer of a Haworth projection is directly notated. If these two carbons have the same configuration (R,R or S,S), the anomer is b; if different (R,S or S,R), the anomer is a. This method proves to be general and widely applicable.
Successive projection method for solving the unbalanced Procrustes problem
ZHANG Zhenyue; DU Keqin
2006-01-01
We present a successive projection method for solving the unbalanced Procrustes problem: given matrix A ∈ Rn×n and B ∈ Rn×κ, n ＞κ, minimize the residual ‖AQ - B‖F with the orthonormal constraint QTQ = Iκ on the variant Q ∈ Rn×κ. The presented algorithm consists of solving k least squares problems with quadratic constraints and an expanded balance problem at each sweep. We give a detailed convergence analysis. Numerical experiments reported in this paper show that our new algorithm is superior to other existing methods.
Lundeman, Jesper Holm; Jensen, Ole Bjarlin; Andersen, Peter E.;
2009-01-01
We present a measurement series of the efficiency of periodically poled KTP used for second-harmonic generation in an external phase-locked cavity. Due to the high absorption (0.01 cm^−1) in the PPKTP crystal at the pump wavelength a strong thermal dephasing of the periodically poled grating...... is observed for high pump powers. For four different resonator setups, it was experimentally found that a threshold parameter could be defined as the ratio between the focal intensity in the crystal and the single-pass conversion efficiency. The value of this threshold for the onset of strong thermal...... dephasing was found to be 1.41×10^10 W^2 m^-2 in our 30-mm long PPKTP sample. This threshold parameter marks the onset of thermally induced instability that leads to a degradation of the SHG conversion efficiency. Above the threshold the shape of the resonance peaks of the resonator changed from symmetrical...
The role of chaos in quantum communication through a dynamical dephasing channel
Lemos, Gabriela Barreto
2010-01-01
In this article we treat the subject of chaotic environments with few degrees of freedom in quantum communication by investigating a conservative dynamical map as a model of a dephasing quantum channel. When the channel's dynamics is chaotic, we investigate the model's semi-classical limit and show that the entropy exchange grows at a constant rate which depends on a single parameter (the interaction strength), analogous to stochastic models of dephasing channels. We analyze memory effects in the channel and present strong physical arguments to support that the present model is forgetful in the chaotic regime while memory effects in general cannot be ignored when channel dynamics is regular. In order to render the non-chaotic channel forgetful, it becomes necessary to apply a reset to the channel and this reset can efficiently be modeled by application of a chaotic map. We may then refer to encoding theorems (valid in the case of forgetful channels) to present evidence of a transition from noiseless to noisy ...
Role of chaos in quantum communication through a dynamical dephasing channel
Lemos, Gabriela Barreto; Benenti, Giuliano
2010-06-01
In this article we treat the subject of chaotic environments with few degrees of freedom in quantum communication by investigating a conservative dynamical map as a model of a dephasing quantum channel. When the channel’s dynamics is chaotic, we investigate the model’s semi-classical limit and show that the entropy exchange grows at a constant rate which depends on a single parameter (the interaction strength), analogous to stochastic models of dephasing channels. We analyze memory effects in the channel and present strong physical arguments to support that the present model is forgetful in the chaotic regime while memory effects in general cannot be ignored when channel dynamics is regular. In order to render the nonchaotic channel forgetful, it becomes necessary to apply a reset to the channel and this reset can efficiently be modeled by application of a chaotic map. We may then refer to encoding theorems (valid in the case of forgetful channels) to present evidence of a transition from noiseless to noisy channel due to the environment’s transition from regular to chaotic dynamics.
Dephasing mechanisms of optical transitions in rare-earth-doped transparent ceramics
Kunkel, Nathalie; Bartholomew, John; Welinski, Sacha; Ferrier, Alban; Ikesue, Akio; Goldner, Philippe
2016-11-01
We identify and analyze dephasing mechanisms that broaden the optical transitions of rare-earth ions in randomly oriented transparent ceramics. The study examines the narrow F70↔D50 transition of Eu3 + dopants in a series of Y2O3 ceramic samples prepared under varying conditions. We characterize the temperature and magnetic field dependence of the homogeneous linewidth, as well as long-term spectral diffusion on time scales up to 1 s. The results highlight significant differences between samples with differing thermal treatments and Zr4 + additive concentrations. In particular, several distinct magnetic interactions from defect centers are observed, which are clearly distinguished from the broadening due to interactions with two-level systems and phonons. By minimizing the broadening due to the different defect centers, linewidths of the order of 4 kHz are achieved for all samples. The linewidths are limited by temperature-dependent interactions and by an interaction that is yet to be identified. Although the homogeneous linewidth can be narrowed further in these ceramic samples, the broadening is now comparable to the linewidths achieved in rare-earth-ion-doped single crystals. Thus, this work emphasizes the usefulness of studying ceramics to gain insights into dephasing mechanisms relevant to single crystals and suggests that ceramics may be an interesting alternative for applications in classical and quantum information processing.
Diffusion-mediated dephasing in the dipole field around a single spherical magnetic object.
Buschle, Lukas R; Kurz, Felix T; Kampf, Thomas; Triphan, Simon M F; Schlemmer, Heinz-Peter; Ziener, Christian Herbert
2015-11-01
In this work, the time evolution of the free induction decay caused by the local dipole field of a spherical magnetic perturber is analyzed. The complicated treatment of the diffusion process is replaced by the strong-collision-approximation that allows a determination of the free induction decay in dependence of the underlying microscopic tissue parameters such as diffusion coefficient, sphere radius and susceptibility difference. The interplay between susceptibility- and diffusion-mediated effects yields several dephasing regimes of which, so far, only the classical regimes of motional narrowing and static dephasing for dominant and negligible diffusion, respectively, were extensively examined. Due to the asymmetric form of the dipole field for spherical objects, the free induction decay exhibits a complex component in contradiction to the cylindrical case, where the symmetric local dipole field only causes a purely real induction decay. Knowledge of the shape of the corresponding frequency distribution is necessary for the evaluation of more sophisticated pulse sequences and a detailed understanding of the off-resonance distribution allows improved quantification of transverse relaxation.
Methods for cost estimation in software project management
Briciu, C. V.; Filip, I.; Indries, I. I.
2016-02-01
The speed in which the processes used in software development field have changed makes it very difficult the task of forecasting the overall costs for a software project. By many researchers, this task has been considered unachievable, but there is a group of scientist for which this task can be solved using the already known mathematical methods (e.g. multiple linear regressions) and the new techniques as genetic programming and neural networks. The paper presents a solution for building a model for the cost estimation models in the software project management using genetic algorithms starting from the PROMISE datasets related COCOMO 81 model. In the first part of the paper, a summary of the major achievements in the research area of finding a model for estimating the overall project costs is presented together with the description of the existing software development process models. In the last part, a basic proposal of a mathematical model of a genetic programming is proposed including here the description of the chosen fitness function and chromosome representation. The perspective of model described it linked with the current reality of the software development considering as basis the software product life cycle and the current challenges and innovations in the software development area. Based on the author's experiences and the analysis of the existing models and product lifecycle it was concluded that estimation models should be adapted with the new technologies and emerging systems and they depend largely by the chosen software development method.
Galerkin projection methods for solving multiple related linear systems
Chan, T.F.; Ng, M.; Wan, W.L.
1996-12-31
We consider using Galerkin projection methods for solving multiple related linear systems A{sup (i)}x{sup (i)} = b{sup (i)} for 1 {le} i {le} s, where A{sup (i)} and b{sup (i)} are different in general. We start with the special case where A{sup (i)} = A and A is symmetric positive definite. The method generates a Krylov subspace from a set of direction vectors obtained by solving one of the systems, called the seed system, by the CG method and then projects the residuals of other systems orthogonally onto the generated Krylov subspace to get the approximate solutions. The whole process is repeated with another unsolved system as a seed until all the systems are solved. We observe in practice a super-convergence behaviour of the CG process of the seed system when compared with the usual CG process. We also observe that only a small number of restarts is required to solve all the systems if the right-hand sides are close to each other. These two features together make the method particularly effective. In this talk, we give theoretical proof to justify these observations. Furthermore, we combine the advantages of this method and the block CG method and propose a block extension of this single seed method. The above procedure can actually be modified for solving multiple linear systems A{sup (i)}x{sup (i)} = b{sup (i)}, where A{sup (i)} are now different. We can also extend the previous analytical results to this more general case. Applications of this method to multiple related linear systems arising from image restoration and recursive least squares computations are considered as examples.
Wagner, Hans Peter; Schätz, A.; Maier, R.
1998-01-01
We investigate the interaction and dephasing of the excitons in wide ZnSe/Zn0.94Mg0.06Se quantum wells by spectrally resolved, femtosecond four-wave mixing (FWM). Polarization-dependent measurements indicate that excitation-induced dephasing is the dominant FWM process. The biexcitons of the center...
Image processing methods to obtain symmetrical distribution from projection image.
Asano, H; Takenaka, N; Fujii, T; Nakamatsu, E; Tagami, Y; Takeshima, K
2004-10-01
Flow visualization and measurement of cross-sectional liquid distribution is very effective to clarify the effects of obstacles in a conduit on heat transfer and flow characteristics of gas-liquid two-phase flow. In this study, two methods to obtain cross-sectional distribution of void fraction are applied to vertical upward air-water two-phase flow. These methods need projection image only from one direction. Radial distributions of void fraction in a circular tube and a circular-tube annuli with a spacer were calculated by Abel transform based on the assumption of axial symmetry. On the other hand, cross-sectional distributions of void fraction in a circular tube with a wire coil whose conduit configuration rotates about the tube central axis periodically were measured by CT method based on the assumption that the relative distributions of liquid phase against the wire were kept along the flow direction.
Phylogenetic and functional assessment of orthologs inference projects and methods.
Adrian M Altenhoff
2009-01-01
Full Text Available Accurate genome-wide identification of orthologs is a central problem in comparative genomics, a fact reflected by the numerous orthology identification projects developed in recent years. However, only a few reports have compared their accuracy, and indeed, several recent efforts have not yet been systematically evaluated. Furthermore, orthology is typically only assessed in terms of function conservation, despite the phylogeny-based original definition of Fitch. We collected and mapped the results of nine leading orthology projects and methods (COG, KOG, Inparanoid, OrthoMCL, Ensembl Compara, Homologene, RoundUp, EggNOG, and OMA and two standard methods (bidirectional best-hit and reciprocal smallest distance. We systematically compared their predictions with respect to both phylogeny and function, using six different tests. This required the mapping of millions of sequences, the handling of hundreds of millions of predicted pairs of orthologs, and the computation of tens of thousands of trees. In phylogenetic analysis or in functional analysis where high specificity is required, we find that OMA and Homologene perform best. At lower functional specificity but higher coverage level, OrthoMCL outperforms Ensembl Compara, and to a lesser extent Inparanoid. Lastly, the large coverage of the recent EggNOG can be of interest to build broad functional grouping, but the method is not specific enough for phylogenetic or detailed function analyses. In terms of general methodology, we observe that the more sophisticated tree reconstruction/reconciliation approach of Ensembl Compara was at times outperformed by pairwise comparison approaches, even in phylogenetic tests. Furthermore, we show that standard bidirectional best-hit often outperforms projects with more complex algorithms. First, the present study provides guidance for the broad community of orthology data users as to which database best suits their needs. Second, it introduces new methodology
Risk assessment method of major unsafe hydroelectric project
2008-01-01
Based on the characteristics of major unsafe hydroelectric projects and the data from field detection, in situ monitoring, and regular safety inspection, the funda-mental principles of operation risk assessment are proposed in this paper. Mean-while, a three layer hierarchical system is constructed, and an improved analytical hierarchical process combining genetic algorithm and analytical hierarchical process is established, with corresponding program. The operation risk of some unsafe dam was assessed with the principles, method and program presented in this paper and the major factors which would affect the operation of the dam were pointed out.
Theory of secondary vocational English project teaching method
张梅
2016-01-01
Under the impetus of the rapid development of science and technology and economy,Social productivity level and greatly enhance people's quality of life,education level also got further development.Under the influence of the globalization development trend,English gradually become the most widely used foreign language of people daily life. Secondary vocational English is a public basic course of secondary vocational school students, as an important part of secondary vocational students training plan, has received the widespread attention.In this study, secondary vocational English project teaching method is briefly discussed.
Risk assessment method of major unsafe hydroelectric project
WU ZhongRu; SU HuaiZhi; GUO HaiQing
2008-01-01
Based on the characteristics of major unsafe hydroelectric projects and the data from field detection, in situ monitoring, and regular safety inspection, the funda- menial principles of operation risk assessment are proposed in this paper. Mean- while, a three layer hierarchical system is constructed, and an improved analytical hierarchical process combining genetic algorithm and analytical hierarchical process is established, with corresponding program. The operation risk of some unsafe dam was assessed with the principles, method and program presented in this paper and the major factors which would affect the operation of the dam were pointed out.
Sutinen, Ari
2013-01-01
The project method became a famous teaching method when William Heard Kilpatrick published his article "Project Method" in 1918. The key idea in Kilpatrick's project method is to try to explain how pupils learn things when they work in projects toward different common objects. The same idea of pupils learning by work or action in an…
Study on Top-Down Estimation Method of Software Project Planning
ZHANG Jun-guang; L(U) Ting-jie; ZHAO Yu-mei
2006-01-01
This paper studies a new software project planning method under some actual project data in order to make software project plans more effective. From the perspective of system theory, our new method regards a software project plan as an associative unit for study. During a top-down estimation of a software project, Program Evaluation and Review Technique (PERT) method and analogy method are combined to estimate its size, then effort estimation and specific schedules are obtained according to distributions of the phase effort. This allows a set of practical and feasible planning methods to be constructed. Actual data indicate that this set of methods can lead to effective software project planning.
Thermally induced dephasing of high power second harmonic generation in MgO: LiNbO3 waveguides
Guohui Li; Xinye Xu
2011-01-01
High power second harmonic generation (SHG) in MgO-doped LiNbO3 waveguides is investigated using a three-dimensional (3D) coupled thermo-optical model. Simulations performed for a 1111.6-nm fundamental laser show the influence of the absorptions and the thermally induced dephasing on the conversion efficiencies of the different waveguides. The onset of the thermally induced dephasing effect for each waveguide is also indicated. As a result of high light intensity in the waveguide, nonlinear absorptions are identified as the possible main factors in efficiency losses in specific cases.%High power second harmonic generation (SHG) in MgO-doped LiNbO3 waveguides is investigated using a three-dimensional (3D) coupled thermo-optical model.Simulations performed for a 1111.6-nm fundamental laser show the influence of the absorptions and the thermally induced dephasing on the conversion efficiencies of the different waveguides.The onset of the thermally induced dephasing effect for each waveguide is also indicated.As a result of high light intensity in the waveguide,nonlinear absorptions are identified as the possible main factors in efficiency losses in specific cases.
A method to study the management of urban development projects
Heurkens, E.
2011-01-01
The management of urban development projects in the Netherlands has changed significantly in recent years. These projects have become mainly ‘led’ by developers as they manage the entire life cycle of development projects, while public actors mainly facilitate development projects. This changes the
A method to study the management of urban development projects
Heurkens, E.
2011-01-01
The management of urban development projects in the Netherlands has changed significantly in recent years. These projects have become mainly ‘led’ by developers as they manage the entire life cycle of development projects, while public actors mainly facilitate development projects. This changes the
Disorder and dephasing as control knobs for light transport in optical fiber cavity networks
Viciani, Silvia; Gherardini, Stefano; Lima, Manuela; Bellini, Marco; Caruso, Filippo
2016-11-01
Transport phenomena represent a very interdisciplinary topic with applications in many fields of science, such as physics, chemistry, and biology. In this context, the possibility to design a perfectly controllable experimental setup, where to tune and optimize its dynamics parameters, is a challenging but very relevant task to emulate, for instance, the transmission of energy in light harvesting processes. Here, we experimentally build a scalable and controllable transport emulator based on optical fiber cavity networks where the system noise parameters can be finely tuned while maximizing the transfer efficiency. In particular, we demonstrate that disorder and dephasing noise are two control knobs allowing one to play with constructive and destructive interference to optimize the transport paths towards an exit site. These optical setups, on one side, mimic the transport dynamics in natural photosynthetic organisms and, on the other, are very promising platforms to artificially design optimal nanoscale structures for novel, more efficient, clean energy technologies.
High-fidelity gate operations for quantum computing beyond dephasing time limits
Souza, Alexandre M.; Sarthour, Roberto S.; Oliveira, Ivan S.; Suter, Dieter
2015-12-01
The implementation of quantum gates with fidelities that exceed the threshold for reliable quantum computing requires robust gates whose performance is not limited by the precision of the available control fields. The performance of these gates also should not be affected by the noisy environment of the quantum register. Here we use randomized benchmarking of quantum gate operations to compare the performance of different families of gates that compensate errors in the control field amplitudes and decouple the system from the environmental noise. We obtain average fidelities of up to 99.8%, which exceeds the threshold value for some quantum error correction schemes as well as the expected limit from the dephasing induced by the environment.
Nonlocality threshold for entanglement under general dephasing evolutions: a case study
Lo Franco, Rosario
2016-06-01
Determining relationships between different types of quantum correlations in open composite quantum systems is important since it enables the exploitation of a type by knowing the amount of another type. We here review, by giving a formal demonstration, a closed formula of the Bell function, witnessing nonlocality, as a function of the concurrence, quantifying entanglement, valid for a system of two noninteracting qubits initially prepared in extended Werner-like states undergoing any local pure-dephasing evolution. This formula allows for finding nonlocality thresholds for the concurrence depending only on the purity of the initial state. We then utilize these thresholds in a paradigmatic system where the two qubits are locally affected by a quantum environment with an Ohmic class spectrum. We show that steady entanglement can be achieved and provide the lower bound of initial state purity such that this stationary entanglement is above the nonlocality threshold thus guaranteeing the maintenance of nonlocal correlations.
Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method
Wei Xue
2016-08-01
Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.
Various Tunnel Excavation Methods used on the LHC Project
Fielder, R
2000-01-01
Civil Engineering construction work for the LHC Project began in April 1998 and is now well underway. A major part of this work is the construction of the new tunnels, caverns and cavern enlargements for the LHC experiments and machine. Currently, this underground work is being carried out for the two injection tunnels, TI2 and TI8, and at Point 1 for the Atlas Experiment. There are three contractors involved in these tunnelling works and each contactor is using a different technique. This paper will outline the different methods used for excavation and the reasons for these differences. It will also examine the other operations involved in the construction of major underground structures such as supply of materials to the tunnel face, evacuation of excavated material and ventilation.
Xiang Ding
2014-01-01
Full Text Available Project delivery planning is a key stage used by the project owner (or project investor for organizing design, construction, and other operations in a construction project. The main task in this stage is to select an appropriate project delivery method. In order to analyze different factors affecting the PDM selection, this paper establishes a multiagent model mainly to show how project complexity, governance strength, and market environment affect the project owner’s decision on PDM. Experiment results show that project owner usually choose Design-Build method when the project is very complex within a certain range. Besides, this paper points out that Design-Build method will be the prior choice when the potential contractors develop quickly. This paper provides the owners with methods and suggestions in terms of showing how the factors affect PDM selection, and it may improve the project performance.
Investment Lending as a Method Of Investment Projects Financing
Svitlana Urvantseva
2014-01-01
The article deals with the genesis consideration of "investment loan" definition. The author provides comparative characteristics of the main forms of investment projects financing involving credit institution. A generalized definition of the project financing and investment lending essence are suggested.
Investment Lending as a Method Of Investment Projects Financing
Svitlana Urvantseva
2014-01-01
The article deals with the genesis consideration of "investment loan" definition. The author provides comparative characteristics of the main forms of investment projects financing involving credit institution. A generalized definition of the project financing and investment lending essence are suggested.
Modelling of Airship Flight Mechanics by the Projection Equivalent Method
Frantisek Jelenciak
2015-12-01
Full Text Available This article describes the projection equivalent method (PEM as a specific and relatively simple approach for the modelling of aircraft dynamics. By the PEM it is possible to obtain a mathematic al model of the aerodynamic forces and momentums acting on different kinds of aircraft during flight. For the PEM, it is a characteristic of it that - in principle - it provides an acceptable regression model of aerodynamic forces and momentums which exhibits reasonable and plausible behaviour from a dynamics viewpoint. The principle of this method is based on applying Newton's mechanics, which are then combined with a specific form of the finite element method to cover additional effects. The main advantage of the PEM is that it is not necessary to carry out measurements in a wind tunnel for the identification of the model’s parameters. The plausible dynamical behaviour of the model can be achieved by specific correction parameters, which can be determined on the basis of experimental data obtained during the flight of the aircraft. In this article, we present the PEM as applied to an airship as well as a comparison of the data calculated by the PEM and experimental flight data.
Modelling of Airship Flight Mechanics by the Projection Equivalent Method
Frantisek Jelenciak
2015-12-01
Full Text Available This article describes the projection equivalent method (PEM as a specific and relatively simple approach for the modelling of aircraft dynamics. By the PEM it is possible to obtain a mathematic al model of the aerodynamic forces and momentums acting on different kinds of aircraft during flight. For the PEM, it is a characteristic of it that -in principle - it provides an acceptable regression model of aerodynamic forces and momentums which exhibits reasonable and plausible behaviour from a dynamics viewpoint. The principle of this method is based on applying Newton's mechanics, which are then combined with a specific form of the finite element method to cover additional effects. The main advantage of the PEM is that it is not necessary to carry out measurements in a wind tunnel for the identification of the model's parameters. The plausible dynamical behaviour of the model can be achieved by specific correction parameters, which can be determined on the basis of experimental data obtained during the flight of the aircraft. In this article, we present the PEM as applied to an airship as well as a comparison of the data calculated by the PEM and experimental flight data.
Implementing Kernel Methods Incrementally by Incremental Nonlinear Projection Trick.
Kwak, Nojun
2016-05-20
Recently, the nonlinear projection trick (NPT) was introduced enabling direct computation of coordinates of samples in a reproducing kernel Hilbert space. With NPT, any machine learning algorithm can be extended to a kernel version without relying on the so called kernel trick. However, NPT is inherently difficult to be implemented incrementally because an ever increasing kernel matrix should be treated as additional training samples are introduced. In this paper, an incremental version of the NPT (INPT) is proposed based on the observation that the centerization step in NPT is unnecessary. Because the proposed INPT does not change the coordinates of the old data, the coordinates obtained by INPT can directly be used in any incremental methods to implement a kernel version of the incremental methods. The effectiveness of the INPT is shown by applying it to implement incremental versions of kernel methods such as, kernel singular value decomposition, kernel principal component analysis, and kernel discriminant analysis which are utilized for problems of kernel matrix reconstruction, letter classification, and face image retrieval, respectively.
YANG Min; JIN Xu-Ling; LI Bao-Lei
2010-01-01
In order to determine the projected coordinate origin in the cone-beam CT scanning system with respect to the Feldkamp-Davis-Kress(FDK)algorithm,we propose a simple yet feasible method to accurately measure the projected coordinate origin.This method was established on the basis of the theory that the projection of a spherical object in the cone-beam field is an ellipse.We first utilized image processing and the least square estimation method to get each major axis of the elliptical Digital Radiography(DR)projections of a group of spherical objects.Then we determined the intersection point of the group of major axis by solving an over-determined equation set that was composed by the major axis equations of all the elliptical projections.Based on the experimental results,this new method was proved to be easy to implement in practical scanning systems with high accuracy and anti-noise capability.
A projection method for under determined optimal experimental designs
Long, Quan
2014-01-09
A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.
Smagin, V. V.
1997-04-01
We consider a weakly solvable parabolic problem in a separable Hilbert space. We seek approximations to the exact solution by projective and projective-difference methods. In this connection the discretization of the problem with respect to the spatial variables is carried out by the semidiscrete method of Galerkin, and with respect to time by the implicit method of Euler. In this paper we establish a coercive mean-square error estimate for the approximate solutions. We illustrate the effectiveness of these estimates with parabolic equations of second order with Dirichlet or Neumann boundary conditions in projective subspaces of finite element type.
A hybrid incremental projection method for thermal-hydraulics applications
Christon, Mark A.; Bakosi, Jozsef; Nadiga, Balasubramanya T.; Berndt, Markus; Francois, Marianne M.; Stagg, Alan K.; Xia, Yidong; Luo, Hong
2016-07-01
A new second-order accurate, hybrid, incremental projection method for time-dependent incompressible viscous flow is introduced in this paper. The hybrid finite-element/finite-volume discretization circumvents the well-known Ladyzhenskaya-Babuška-Brezzi conditions for stability, and does not require special treatment to filter pressure modes by either Rhie-Chow interpolation or by using a Petrov-Galerkin finite element formulation. The use of a co-velocity with a high-resolution advection method and a linearly consistent edge-based treatment of viscous/diffusive terms yields a robust algorithm for a broad spectrum of incompressible flows. The high-resolution advection method is shown to deliver second-order spatial convergence on mixed element topology meshes, and the implicit advective treatment significantly increases the stable time-step size. The algorithm is robust and extensible, permitting the incorporation of features such as porous media flow, RANS and LES turbulence models, and semi-/fully-implicit time stepping. A series of verification and validation problems are used to illustrate the convergence properties of the algorithm. The temporal stability properties are demonstrated on a range of problems with 2 ≤ CFL ≤ 100. The new flow solver is built using the Hydra multiphysics toolkit. The Hydra toolkit is written in C++ and provides a rich suite of extensible and fully-parallel components that permit rapid application development, supports multiple discretization techniques, provides I/O interfaces, dynamic run-time load balancing and data migration, and interfaces to scalable popular linear solvers, e.g., in open-source packages such as HYPRE, PETSc, and Trilinos.
Utilizing the Project Method for Teaching Culture and Intercultural Competence
Euler, Sasha S.
2017-01-01
This article presents a detailed methodological outline for teaching culture through project work. It is argued that because project work makes it possible to gain transferrable and applicable knowledge and insight, it is the ideal tool for teaching culture with the aim of achieving real intercultural communicative competence (ICC). Preceding the…
Social Science Methods Used in the RESTORE Project
Lynne M. Westphal; Cristy Watkins; Paul H. Gobster; Liam Heneghan; Kristen Ross; Laurel Ross; Madeleine Tudor; Alaka Wali; David H. Wise; Joanne Vining; Moira. Zellner
2014-01-01
The RESTORE (Rethinking Ecological and Social Theories of Restoration Ecology) project is an interdisciplinary, multi-institutional research endeavor funded by the National Science Foundation's Dynamics of Coupled Natural Human Systems program. The goal of the project is to understand the links between organizational type, decision making processes, and...
Sawyer, Brian C; Bollinger, John J
2014-01-01
We employ spin-dependent optical dipole forces to characterize the transverse center-of-mass (COM) motional mode of a two-dimensional Wigner crystal of hundreds of $^9$Be$^+$. By comparing the measured spin dephasing produced by the spin-dependent force with the predictions of a semiclassical dephasing model, we obtain absolute mode temperatures in excellent agreement with both the Doppler laser cooling limit and measurements obtained from a previously published technique (B. C. Sawyer et al. Phys. Rev. Lett. \\textbf{108}, 213003 (2012)). Furthermore, the structure of the dephasing histograms allows for discrimination between initial thermal and coherent states of motion. We also apply the techniques discussed here to measure, for the first time, the ambient heating rate of the COM mode of a 2D Coulomb crystal in a Penning trap. This measurement places an upper limit on the anomalous single-ion heating rate due to electric field noise from the trap electrode surfaces of $\\frac{d\\bar{n}}{dt}\\sim 5$ s$^{-1}$ fo...
Jakubczyk, Tomasz; Delmonte, Valentin; Koperski, Maciej; Nogajewski, Karol; Faugeras, Clément; Langbein, Wolfgang; Potemski, Marek; Kasprzak, Jacek
2016-09-14
By implementing four-wave mixing (FWM) microspectroscopy, we measure coherence and population dynamics of the exciton transitions in monolayers of MoSe2. We reveal their dephasing times T2 and radiative lifetime T1 in a subpicosecond (ps) range, approaching T2 = 2T1 and thus indicating radiatively limited dephasing at a temperature of 6 K. We elucidate the dephasing mechanisms by varying the temperature and by probing various locations on the flake exhibiting a different local disorder. At the nanosecond range, we observe the residual FWM produced by the incoherent excitons, which initially disperse toward the dark states but then relax back to the optically active states within the light cone. By introducing polarization-resolved excitation, we infer intervalley exciton dynamics, revealing an initial polarization degree of around 30%, constant during the initial subpicosecond decay, followed by the depolarization on a picosecond time scale. The FWM hyperspectral imaging reveals the doped and undoped areas of the sample, allowing us to investigate the neutral exciton, the charged one, or both transitions at the same time. In the latter, we observe the exciton-trion beating in the coherence evolution indicating their coherent coupling.
Song, Ya-Ju; Tan, Qing-Shou; Kuang, Le-Man
2017-01-01
We investigate the possibility to control quantum evolution speed of a single dephasing qubit for arbitrary initial states by the use of periodic dynamical decoupling (PDD) pulses. It is indicated that the quantum speed limit time (QSLT) is determined by initial and final quantum coherence of the qubit, as well as the non-Markovianity of the system under consideration during the evolution when the qubit is subjected to a zero-temperature Ohmic-like dephasing reservoir. It is shown that final quantum coherence of the qubit and the non-Markovianity of the system can be modulated by PDD pulses. Our results show that for arbitrary initial states of the dephasing qubit with non-vanishing quantum coherence, PDD pulses can be used to induce potential acceleration of the quantum evolution in the short-time regime, while PDD pulses can lead to potential speedup and slow down in the long-time regime. We demonstrate that the effect of PDD on the QSLT for the Ohmic or sub-Ohmic spectrum (Markovian reservoir) is much different from that for the super-Ohmic spectrum (non-Markovian reservoir). PMID:28272546
Levi, Emanuele; Gutiérrez, Ricardo; Lesanovsky, Igor
2016-09-01
In the presence of strong dephasing noise the dynamics of Rydberg gases becomes effectively classical, due to the rapid decay of quantum superpositions between atomic levels. Recently a great deal of attention has been devoted to the stochastic dynamics that emerges in that limit, revealing several interesting features, including kinetically constrained glassy behaviour, self-similarity and aggregation effects. However, the non-equilibrium physics of these systems, in particular in the regime where coherent and dissipative processes contribute on equal footing, is yet far from being understood. To explore this we study the dynamics of a small one-dimensional Rydberg lattice gas subject to dephasing noise by numerically integrating the quantum master equation. We interpolate between the coherent and the strongly dephased regime by defining a generalised concept of a blockade length. We find indications that the main features observed in the strongly dissipative limit persist when the dissipation is not strong enough to annihilate quantum coherences at the dynamically relevant time scales. These features include the existence of a time-dependent Rydberg blockade radius, and a growth of the density of excitations which is compatible with the power-law behaviour expected in the classical limit.
Song, Ya-Ju; Tan, Qing-Shou; Kuang, Le-Man
2017-03-01
We investigate the possibility to control quantum evolution speed of a single dephasing qubit for arbitrary initial states by the use of periodic dynamical decoupling (PDD) pulses. It is indicated that the quantum speed limit time (QSLT) is determined by initial and final quantum coherence of the qubit, as well as the non-Markovianity of the system under consideration during the evolution when the qubit is subjected to a zero-temperature Ohmic-like dephasing reservoir. It is shown that final quantum coherence of the qubit and the non-Markovianity of the system can be modulated by PDD pulses. Our results show that for arbitrary initial states of the dephasing qubit with non-vanishing quantum coherence, PDD pulses can be used to induce potential acceleration of the quantum evolution in the short-time regime, while PDD pulses can lead to potential speedup and slow down in the long-time regime. We demonstrate that the effect of PDD on the QSLT for the Ohmic or sub-Ohmic spectrum (Markovian reservoir) is much different from that for the super-Ohmic spectrum (non-Markovian reservoir).
Phonon mechanisms of nonlinear decay and dephasing of mesoscopic vibrational systems
Atalaya, Juan; Kenny, Thomas W.; Dykman, Mark I.
2015-03-01
The frequencies and the decay rates of mesoscopic oscillators depend on vibration amplitudes. Nonlinear decay has been seen recently in various nano- and micro-mechanical systems. Here we consider a microscopic mechanism of nonlinear decay, the nonlinear coupling of the vibrational mode of interest, for example, a flexural mode, to other vibrations. Typically, the modes of interest have low eigenfrequencies ω0. Their decay comes from the coupling to acoustic-phonon type vibrations with much higher frequency and density of states. Thus, nonlinear decay requires quartic anharmonic coupling or cubic anharmonicity in the higher order. We find the decay rate for the inverse lifetime of the involved phonons, which is determined by the internal nonlinearity and the boundary scattering, being either much larger or smaller than ω0. The results extend the thermo-elastic, Akhiezer, and Landau-Rumer decay theory to nonlinear decay of mesoscopic modes and make specific predictions on the temperature and frequency dependence of the decay rate for different types of systems. We show that nonlinear decay is invariably accompanied by dephasing. We also show that in nano-electro-mechanical systems the decay rate can be electrostatically controlled.
Characterization of alkyl carbon in forest soils by CPMAS 13C NMR spectroscopy and dipolar dephasing
Kogel-Knabner, I.; Hatcher, P.G.
1989-01-01
Samples obtained from forest soils at different stages of decomposition were treated sequentially with chloroform/methanol (extraction of lipids), sulfuric acid (hydrolysis), and sodium chlorite (delignification) to enrich them in refractory alkyl carbon. As revealed by NMR spectroscopy, this treatment yielded residues with high contents of alkyl carbon. In the NMR spectra of residues obtained from litter samples, resonances for carbohydrates are also present, indicating that these carbohydrates are tightly bound to the alkyl carbon structures. During decomposition in the soils this resistant carbohydrate fraction is lost almost completely. In the litter samples the alkyl carbon shows a dipolar dephasing behavior indicative of two structural components, a rigid and a more mobile component. As depth and decomposition increase, only the rigid component is observed. This fact could be due to selective degradation of the mobile component or to changes in molecular mobility during decomposition, e.g., because of an increase in cross linking or contact with the mineral matter of the soil.
Pulsed Rydberg four-wave mixing with motion-induced dephasing in a thermal vapor
Chen, Yi-Hsin; Löw, Robert; Pfau, Tilman
2015-01-01
We report on time-resolved pulsed four-wave mixing (FWM) signals in a thermal Rubidium vapor involving a Rydberg state. We observe FWM signals with dephasing times up to 7 ns, strongly dependent on the excitation bandwidth to the Rydberg state. The excitation to the Rydberg state is driven by a pulsed two-photon transition on ns time scales. Combined with a third cw de-excitation laser, a strongly directional and collective emission is generated according to a combination of the phase matching effect and averaging over Doppler classes. In contrast to a previous report [1] using off-resonant FWM, at a resonant FWM scheme we observe additional revivals of the signal shortly after the incident pulse has ended. We infer that this is a revival of motion-induced constructive interference between the coherent emissions of the thermal atoms. The resonant FWM scheme reveals a richer temporal structure of the signals, compared to similar, but off-resonant excitation schemes. A simple explanation lies in the selectivity...
Pulsed Rydberg four-wave mixing with motion-induced dephasing in a thermal vapor.
Chen, Yi-Hsin; Ripka, Fabian; Löw, Robert; Pfau, Tilman
We report on time-resolved pulsed four-wave mixing (FWM) signals in a thermal Rubidium vapor involving a Rydberg state. We observe FWM signals with dephasing times up to 7 ns, strongly dependent on the excitation bandwidth to the Rydberg state. The excitation to the Rydberg state is driven by a pulsed two-photon transition on ns timescales. Combined with a cw de-excitation laser, a strongly directional and collective emission is generated according to a combination of the phase matching effect and averaging over Doppler classes. In contrast to a previous report (Huber et al. in Phys Rev A 90: 053806, 2014) using off-resonant FWM, at a resonant FWM scheme we observe additional revivals of the signal shortly after the incident pulse has ended. We infer that this is a revival of motion-induced constructive interference between the coherent emissions of the thermal atoms. The resonant FWM scheme reveals a richer temporal structure of the signals, compared to similar, but off-resonant excitation schemes. A simple explanation lies in the selectivity of Doppler classes. Our numerical simulations based on a four-level model including a whole Doppler ensemble can qualitatively describe the data.
Influence of pure-dephasing by phonons on exciton-photon interfaces: Quantum microscopic theory
Kojima, K; Kojima, Kunihiro; Tomita, Akihisa
2006-01-01
We have developed a full quantum microscopic theory to analyze the time evolution of transversal and longitudinal components of an exciton-single photon system coupled to bulk acoustic phonons. These components are subjected to two decay processes. One is radiative relaxation and the other is pure-dephasing due to exciton-phonon interaction. The former results in a decay with an exponent linear to time, while the latter causes a faster initial decay than the radiative decay. We analyzed the dependence of the components on the duration of the input one-photon pulse, temperature, and radiative relaxation rates. Such a quantitative analysis is important for the developments of atom-photon interfaces which enable coherent transfer of quantum information between photons and atomic systems. We found that, for a GaAs spherical quantum dot in which the exciton interacts with bulk phonons, the maximal probability of the excited state can be increased up to 75 %. This probability can be considered as the efficiency for...
Kenfack, Lionel Tenemeza; Tchoffo, Martin; Fai, Lukong Cornelius
2017-02-01
We address the dynamics of quantum correlations, including entanglement and quantum discord of a three-qubit system interacting with a classical pure dephasing random telegraph noise (RTN) in three different physical environmental situations (independent, mixed and common environments). Two initial entangled states of the system are examined, namely the Greenberger-Horne-Zeilinger (GHZ)- and Werner (W)-type states. The classical noise is introduced as a stochastic process affecting the energy splitting of the qubits. With the help of suitable measures of tripartite entanglement (entanglement witnesses and lower bound of concurrence) and quantum discord (global quantum discord and quantum dissension), we show that the evolution of quantum correlations is not only affected by the type of the system-environment interaction but also by the input configuration of the qubits and the memory properties of the environmental noise. Indeed, depending on the memory properties of the environmental noise and the initial state considered, we find that independent, common and mixed environments can play opposite roles in preserving quantum correlations, and that the sudden death and revival phenomena or the survival of quantum correlations may occur. On the other hand, we also show that the W-type state has strong dynamics under this noise than the GHZ-type ones.
System-environment correlations for dephasing two-qubit states coupled to thermal baths
Costa, A. C. S.; Beims, M. W.; Strunz, W. T.
2016-05-01
Based on the exact dynamics of a two-qubit system and environment, we investigate system-environment (SE) quantum and classical correlations. The coupling is chosen to represent a dephasing channel for one of the qubits and the environment is a proper thermal bath. First we discuss the general issue of dilation for qubit phase damping. Based on the usual thermal bath of harmonic oscillators, we derive criteria of separability and entanglement between an initial X state and the environment. Applying these criteria to initial Werner states, we find that entanglement between the system and environment is built up in time for temperatures below a certain critical temperature Tcrit. On the other hand, the total state remains separable during those short times that are relevant for decoherence and loss of entanglement in the two-qubit state. Close to Tcrit the SE correlations oscillate between separable and entangled. Even though these oscillations are also observed in the entanglement between the two qubits, no simple relation between the loss of entanglement in the two-qubit system and the build-up of entanglement between the system and environment is found.
Orbital hyperfine interaction and qubit dephasing in carbon nanotube quantum dots
Palyi, Andras; Csiszar, Gabor
2015-03-01
Hyperfine interaction (HF) is of key importance for the functionality of solid-state quantum information processing, as it affects qubit coherence and enables nuclear-spin quantum memories. In this work, we complete the theory of the basic hyperfine interaction mechanisms (Fermi contact, dipolar, orbital) in carbon nanotube quantum dots by providing a theoretical description of the orbital HF. We find that orbital HF induces an interaction between the nuclear spins of the nanotube lattice and the valley degree of freedom of the electrons confined in the quantum dot. We show that the resulting nuclear-spin-electron-valley interaction (i) is approximately of Ising type, (ii) is essentially local, in the sense that an effective atomic interaction strength can be defined, and (iii) has a strength that is comparable to the combined strength of Fermi contact and dipolar interactions. We argue that orbital HF provides a new decoherence mechanism for single-electron valley qubits and spin-valley qubits in a range of multi-valley materials. We explicitly evaluate the corresponding inhomogeneous dephasing time T2* for a nanotube-based valley qubit. We acknowledge funding from the EU Marie Curie CIG-293834, OTKA Grant PD 100373, and EU ERC Starting Grant CooPairEnt 258789. AP is supported by the Janos Bolyai Scholarship of the Hungarian Academy of Sciences.
Quantum dynamics of a driven two-level molecule with variable dephasing
Grandi, Samuele; Major, Kyle D.; Polisseni, Claudio; Boissier, Sebastien; Clark, Alex S.; Hinds, E. A.
2016-12-01
The longitudinal (Γ1) and transverse (Γ2) decay rates of a two-level quantum system have a profound influence on its evolution. Atomic systems with Γ2=1/2 Γ1 have been studied extensively, but with the rise of solid-state quantum devices it is also important to consider the effect of stronger transverse relaxation due to interactions with the solid environment. Here we study the quantum dynamics of a single organic dye molecule driven by a laser. We measure the variation of Γ2 with temperature and determine the activation energy for thermal dephasing of the optical dipole. Then we measure the second-order correlation function g(2 )(τ ) of the light emitted by the molecule for various ratios Γ2/Γ1 and saturation parameters S . We show that the general solution to the optical Bloch equations accurately describes the observed quantum dynamics over a wide range of these parameters, and we discuss the limitations of the various approximate expressions for g(2 )(τ ) that appear in the literature.
Van Dyke, John S.; Morr, Dirk K.
2017-01-01
Using the nonequilibrium Keldysh Green's function formalism, we investigate the effect of defects on the electronic structure and transport properties of two-dimensional topological insulators (TI). We demonstrate how the spatial flow of charge changes between the topologically protected edge and bulk states and show that elastically and inelastically scattering defects that preserve the time-reversal symmetry of the TI lead to qualitatively different effects on the TI's local electronic structure and its transport properties. Moreover, we show that the recently predicted ability to create highly spin-polarized currents by breaking the time-reversal symmetry of the TI via magnetic defects [J. S. Van Dyke and D. K. Morr, Phys. Rev. B 93, 081401 (2016), 10.1103/PhysRevB.93.081401] is robust against the inclusion of a Rashba spin-orbit interaction and the effects of dephasing, and remains unaffected by changes over a wide range of the TI's parameters. We discuss how the sign of the induced spin currents changes under symmetry operations, such as reversal of bias and gate voltages, or spatial reflections. Finally, we show that the insight into the interplay between topology and symmetry of the magnetic defects can be employed for the creation of intriguing quantum phenomena, such as highly localized magnetic fields inside the TI.
Prolonged spontaneous emission and dephasing of localized excitons in air-bridged carbon nanotubes
Sarpkaya, Ibrahim; Zhang, Zhengyi; Walden-Newman, William; Wang, Xuesi; Hone, James; Wong, Chee W.; Strauf, Stefan
2013-07-01
The bright exciton emission of carbon nanotubes is appealing for optoelectronic devices and fundamental studies of light-matter interaction in one-dimensional nanostructures. However, to date, the photophysics of excitons in carbon nanotubes is largely affected by extrinsic effects. Here we perform time-resolved photoluminescence measurements over 14 orders of magnitude for ultra-clean carbon nanotubes bridging an air gap over pillar posts. Our measurements demonstrate a new regime of intrinsic exciton photophysics with prolonged spontaneous emission times up to T1=18 ns, about two orders of magnitude better than prior measurements and in agreement with values hypothesized by theorists about a decade ago. Furthermore, we establish for the first time exciton decoherence times of individual nanotubes in the time domain and find fourfold prolonged values up to T2=2.1 ps compared with ensemble measurements. These first observations motivate new discussions about the magnitude of the intrinsic dephasing mechanism while the prolonged exciton dynamics is promising for applications.
Weiss, Emily A; Katz, Gil; Goldsmith, Randall H; Wasielewski, Michael R; Ratner, Mark A; Kosloff, Ronnie; Nitzan, Abraham
2006-02-21
We simulate the effects of two types of dephasing processes, a nonlocal dephasing of system eigenstates and a dephasing of semilocal eigenstates, on the rate and mechanism of electron transfer (eT) through a series of donor-bridge-acceptor systems, D-B(N)-A, where N is the number of identical bridge units. Our analytical and numerical results show that pure dephasing, defined as the perturbation of system eigenstates through the system-bath interaction, does not disrupt coherent eT because it induces no localization; electron transfer may proceed through superexchange in a system undergoing only pure dephasing. A more physically reasonable description may be obtained via a system-bath interaction that reflects the perturbation of more local electronic structure by local nuclear distortions and dipole interactions. The degree of locality of this interaction is guided by the structure of the system Hamiltonian and by the nature of the measurement performed on the system (i.e., the nature of the environment). We compare our result from this "semilocal" model with an even more local phenomenological dephasing model. We calculate electron transfer rate by obtaining nonequilibrium steady-state solutions for the elements of a reduced density matrix; a semigroup formalism is used to write down the dissipative part of the equation of motion.
On multigrid methods for image reconstruction from projections
Henson, V.E.; Robinson, B.T. [Naval Postgraduate School, Monterey, CA (United States); Limber, M. [Simon Fraser Univ., Burnaby, British Columbia (Canada)
1994-12-31
The sampled Radon transform of a 2D function can be represented as a continuous linear map R : L{sup 1} {yields} R{sup N}. The image reconstruction problem is: given a vector b {element_of} R{sup N}, find an image (or density function) u(x, y) such that Ru = b. Since in general there are infinitely many solutions, the authors pick the solution with minimal 2-norm. Numerous proposals have been made regarding how best to discretize this problem. One can, for example, select a set of functions {phi}{sub j} that span a particular subspace {Omega} {contained_in} L{sup 1}, and model R : {Omega} {yields} R{sup N}. The subspace {Omega} may be chosen as a member of a sequence of subspaces whose limit is dense in L{sup 1}. One approach to the choice of {Omega} gives rise to a natural pixel discretization of the image space. Two possible choices of the set {phi}{sub j} are the set of characteristic functions of finite-width `strips` representing energy transmission paths and the set of intersections of such strips. The authors have studied the eigenstructure of the matrices B resulting from these choices and the effect of applying a Gauss-Seidel iteration to the problem Bw = b. There exists a near null space into which the error vectors migrate with iteration, after which Gauss-Seidel iteration stalls. The authors attempt to accelerate convergence via a multilevel scheme, based on the principles of McCormick`s Multilevel Projection Method (PML). Coarsening is achieved by thickening the rays which results in a much smaller discretization of an optimal grid, and a halving of the number of variables. This approach satisfies all the requirements of the PML scheme. They have observed that a multilevel approach based on this idea accelerates convergence at least to the point where noise in the data dominates.
Inverse Finite Element Method Investigation for Adaptive Structures Project
National Aeronautics and Space Administration — This research project is evaluating an innovative technique that uses fiber optic strain sensors to measure structural deformations and full field strains. An...
Low Cost Method of Manufacturing Space Optics Project
National Aeronautics and Space Administration — The Phase I project successfully demonstrated the feasibility of developing a technology that will reduce cost and manufacturing time, broaden design options, and...
About Shape Identification Methods of Objects Invariant to Projective Transformations
Gostev Ivan M.
2016-01-01
Full Text Available Diffculties concerning the choice of the invariants of the projective transformation groups used for the identification of the shapes of planar objects are illustrated and solutions allowing the derivation of robust identification criteria are discussed.
Nahri, Davoud G.; Mathkoor, Faisal H. A.; Ooi, C. H. Raymond
2017-02-01
A dissipative quantum dot (QD)-cavity system, where the QD is initially prepared in the excited state with no photon in the cavity, coupled to a longitudinal acoustic (LA) phonon reservoir is studied using a numerically exact real-time path-integral approach. Three distinct dynamical regimes of weak (WC), strong (SC), and coherent coupling (CC) are discussed and more accurate conditions identifying them are presented. Our results show that to have the CC regime, which is characterized by clear vacuum Rabi oscillation (VRO), vacuum Rabi splitting (VRS) should be larger than the sum of the widths of the corresponding peaks. In order to distinguish between contributions of population decay and impure dephasing, induced by LA phonon bath and the dissipations, we propose a two-part phenomenological expression, corresponding to the population decay and impure dephasing, which fits the QD-cavity decay curves perfectly and is used to calculate the corresponding spectra. We demonstrate that the effective population decay rate (the emission rate) increases from the carrier recombination rate to a maximum value, which is the mean of the QD and cavity dissipation rates, with QD-cavity coupling strength. To study the role of the effective impure dephasing rate on the width of the central peak of the spectra we introduce a quantity that can also be applied in determining the distinct coupling regimes. This quantity enables us to identify the onset of the SC regime as the point where the impure dephasing term begins to contribute to the central band of the spectrum significantly, as a result of the existence of VRO with a very small frequency (unclear VRO) at the corresponding decay curve. Its contribution to the width of the central peak increases with the coupling strength up to the onset of the CC regime, then reduces as a result of the appearance of sidebands in the spectra, which originates from clear VRO. The effective population decay and impure dephasing rate contribute
Analysis of Conflict Centers in Projects Procured with Traditional and Integrated Methods in Nigeria
Martin O. Dada
2012-07-01
Full Text Available Conflicts in any organization can either be functional or dysfunctional and can contribute to or detract from the achievement of organizational or project objectives. This study investigated the frequency and intensity of conflicts, using five conflict centers, on projects executed with either the integrated or traditional method in Nigeria. Questionnaires were administered through purposive and snowballing techniques on 274 projects located in twelve states of Nigeria and Abuja. 94 usable responses were obtained. The collected data were subjected to both descriptive and inferential statistical analysis. In projects procured with traditional methods, conflicts relating to resources for project execution had the greatest frequency, while conflicts around project/client goals had the least frequency. For projects executed with integrated methods, conflicts due to administrative procedures were ranked highest while conflicts due to project/client goals were ranked least. Regarding seriousness of conflict, conflicts due to administrative procedures and resources for project execution were ranked highest respectively for projects procured with traditional and integrated methods. Additionally, in terms of seriousness, personality issues and project/client goals were the least sources of conflict in projects executed with traditional and integrated methods. There were no significant differences in the incidence of conflicts, using the selected conflict centers, between the traditional and integrated procurement methods. There was however significant difference in the intensity or seriousness of conflicts between projects executed with the traditional method and those executed with integrated methods in the following areas: technical issues, administrative matters and personality issues. The study recommends that conscious efforts should be made at teambuilding on projects executed with integrated methods.
Aleksius Madu
2016-10-01
Full Text Available The purpose of this study is to predict the number of traffic accident victims who died in Timor Tengah Regency with Trend Projection method and Backpropagation method, and compare the two methods based on the degree of guilt and predict the number traffic accident victims in the Timor Tengah Regency for the coming year. This research was conducted in Timor Tengah Regency where data used in this study was obtained from Police Unit in Timor Tengah Regency. The data is on the number of traffic accidents in Timor Tengah Regency from 2000 – 2013, which is obtained by a quantitative analysis with Trend Projection and Backpropagation method. The results of the data analysis predicting the number of traffic accidents victims using Trend Projection method obtained the best model which is the quadratic trend model with equation Yk = 39.786 + (3.297 X + (0.13 X2. Whereas by using back propagation method, it is obtained the optimum network that consists of 2 inputs, 3 hidden screens, and 1 output. Based on the error rates obtained, Back propagation method is better than the Trend Projection method which means that the predicting accuracy with Back propagation method is the best method to predict the number of traffic accidents victims in Timor Tengah Regency. Thus obtained predicting the numbers of traffic accident victims for the next 5 years (Years 2014-2018 respectively - are 106 person, 115 person, 115 person, 119 person and 120 person. Keywords: Trend Projection, Back propagation, Predicting.
Arnault, Denise Saint; Fetters, Michael D.
2011-01-01
Mixed methods research has made significant in-roads in the effort to examine complex health related phenomenon. However, little has been published on the funding of mixed methods research projects. This paper addresses that gap by presenting an example of an NIMH funded project using a mixed methods QUAL-QUAN triangulation design entitled “The Mixed-Method Analysis of Japanese Depression.” We present the Cultural Determinants of Health Seeking model that framed the study, the specific aims, ...
Jayaweera, T.; Haeri, H.
2013-04-01
Under the Uniform Methods Project, DOE is developing a framework and a set of protocols for determining the energy savings from specific energy efficiency measures and programs. The protocols provide a straightforward method for evaluating gross energy savings for common residential and commercial measures offered in ratepayer-funded initiatives in the United States. They represent a refinement of the body of knowledge supporting energy efficiency evaluation, measurement, and verification (EM&V) activities. This document deals with savings from the following measures: commercial and industrial lighting, commercial and industrial lighting controls, small commercial and residential unitary and split system HVAC cooling equipment, residential furnaces and boilers, residential lighting, refrigerator recycling, whole-building retrofit using billing analysis, metering, peak demand and time-differentiated energy savings, sample design, survey design and implementation, and assessing persistence and other evaluation issues.
Methods and Management of the Healthy Brain Study: A Large Multisite Qualitative Research Project
Laditka, Sarah B.; Corwin, Sara J.; Laditka, James N.; Liu, Rui; Friedman, Daniela B.; Mathews, Anna E.; Wilcox, Sara
2009-01-01
Purpose of the study: To describe processes used in the Healthy Brain project to manage data collection, coding, and data distribution in a large qualitative project, conducted by researchers at 9 universities in 9 states. Design and Methods: Project management protocols included: (a) managing audiotapes and surveys to ensure data confidentiality,…
Methods and Management of the Healthy Brain Study: A Large Multisite Qualitative Research Project
Laditka, Sarah B.; Corwin, Sara J.; Laditka, James N.; Liu, Rui; Friedman, Daniela B.; Mathews, Anna E.; Wilcox, Sara
2009-01-01
Purpose of the study: To describe processes used in the Healthy Brain project to manage data collection, coding, and data distribution in a large qualitative project, conducted by researchers at 9 universities in 9 states. Design and Methods: Project management protocols included: (a) managing audiotapes and surveys to ensure data confidentiality,…
A Novel Method for Assessing and Optimizing Software Project Process Based Risk Control
无
2006-01-01
A new approach for assessing and optimizing software project process based on software risk control pre-sented, which evaluates and optimizes software project process from the view of controlling the software project risks. A model for optimizing software risk control is given, a discrete optimization algorithm based on dynamic programming is proposed and an example of using above method to solve a problem is also included in this paper. By improving the old passive post-project control into an active effective pre-action, this new method can greatly promote the possibility of success of software projects.
Harmonizing and Optimizing Fish Testing Methods: The OECD Framework Project
The Organisation for Economic Cooperation and Development (OECD) serves a key role in the international harmonization of testing of a wide variety of chemicals. An integrated fish testing framework project was initiated in mid-2009 through the OECD with the US as the lead country...
MINRES Seed Projection Methods for Solving Symmetric Linear Systems with Multiple Right-Hand Sides
Xin Li
2014-01-01
Full Text Available We consider the MINRES seed projection method for solving multiple right-hand side linear systems AX=B, where A∈Rn×n is a nonsingular symmetric matrix, B∈Rn×p. In general, GMRES seed projection method is one of the effective methods for solving multiple right-hand side linear systems. However, when the coefficient matrix is symmetric, the efficiency of this method would be weak. MINRES seed projection method for solving symmetric systems with multiple right-hand sides is proposed in this paper, and the residual estimation is analyzed. The numerical examples show the efficiency of this method.
Vinayaka : A Semi-Supervised Projected Clustering Method Using Differential Evolution
Satish Gajawada; Durga Toshniwal
2012-01-01
Differential Evolution (DE) is an algorithm for evolutionary optimization. Clustering problems have beensolved by using DE based clustering methods but these methods may fail to find clusters hidden insubspaces of high dimensional datasets. Subspace and projected clustering methods have been proposed inliterature to find subspace clusters that are present in subspaces of dataset. In this paper we proposeVINAYAKA, a semi-supervised projected clustering method based on DE. In this method DE opt...
Lin Zhenghua
2005-01-01
In this paper, we discuss the relationship between the sparse symmetric Broyden (SPSB) method [1, 2] and m-time secant-like multi-projection (SMP) method [3] and prove that when m goes to infinity, the SMP method is corresponding to the SPSB method.
Proposed Project Selection Method for Human Support Research and Technology Development (HSR&TD)
Jones, Harry
2005-01-01
The purpose of HSR&TD is to deliver human support technologies to the Exploration Systems Mission Directorate (ESMD) that will be selected for future missions. This requires identifying promising candidate technologies and advancing them in technology readiness until they are acceptable. HSR&TD must select an may of technology development projects, guide them, and either terminate or continue them, so as to maximize the resulting number of usable advanced human support technologies. This paper proposes an effective project scoring methodology to support managing the HSR&TD project portfolio. Researchers strongly disagree as to what are the best technology project selection methods, or even if there are any proven ones. Technology development is risky and outstanding achievements are rare and unpredictable. There is no simple formula for success. Organizations that are satisfied with their project selection approach typically use a mix of financial, strategic, and scoring methods in an open, established, explicit, formal process. This approach helps to build consensus and develop management insight. It encourages better project proposals by clarifying the desired project attributes. We propose a project scoring technique based on a method previously used in a federal laboratory and supported by recent research. Projects are ranked by their perceived relevance, risk, and return - a new 3 R's. Relevance is the degree to which the project objective supports the HSR&TD goal of developing usable advanced human support technologies. Risk is the estimated probability that the project will achieve its specific objective. Return is the reduction in mission life cycle cost obtained if the project is successful. If the project objective technology performs a new function with no current cost, its return is the estimated cash value of performing the new function. The proposed project selection scoring method includes definitions of the criteria, a project evaluation
Project Management Optimistic (GPO): A Method that Integra Pert / CPM to CCPM
Novais, Igor Fontes; Jorge, Eduardo Manoel de Freitas; Junior, Carlos Pereira Costa; Souza, Daniele Tavares
2011-01-01
The time factor for project managers is one of the most worrisome because of difficulties in keeping projects on time, making interesting use of traditional techniques such as PERT/CPM. Another interesting technique that supports the management of time is the Critical Chain (CCPM) based on the Theory of Constraints (TOC). This article presents the method Optimistic Project Management (GPO) that is based on PERT/CPM and CCPM. The method GPO brings as differential a new way of assembling a sche...
Risk Determination in Projects. The Advantages and Disadvantages of Stochastic Methods
Leonard Lepadatu
2009-10-01
Full Text Available This paper is a comparative study about the principal stochastic methods that is used in Project Management. Risk determination is a mustfor every Project Manager worldwide, but the methods have, of course, advantages and disadvantages. Further, many Project Managers work withdeterministic methods, but they see only the advantages or disadvantages of those methods. In Subject of this paper it is Risk determination inprojects. The advantages and disadvantages of stochastic methods. Choosing the theme of this paper is not randomly, it continues a series of articlespublished for strengthen of scientific research in the Doctorate studies that I followed since 2005.
Monotone projected gradient methods for large-scale box-constrained quadratic programming
ZHOU Bin; GAO Li; DAI Yuhong
2006-01-01
Inspired by the success of the projected Barzilai-Borwein (PBB) method for largescale box-constrained quadratic programming, we propose and analyze the monotone projected gradient methods in this paper. We show by experiments and analyses that for the new methods,it is generally a bad option to compute steplengths based on the negative gradients. Thus in our algorithms, some continuous or discontinuous projected gradients are used instead to compute the steplengths. Numerical experiments on a wide variety of test problems are presented, indicating that the new methods usually outperform the PBB method.
Ossai, Peter Agbadobi Uloku
2016-01-01
This study examined the relationship between students' scores on Research Methods and statistics, and undergraduate project at the final year. The purpose was to find out whether students matched knowledge of research with project-writing skill. The study adopted an expost facto correlational design. Scores on Research Methods and Statistics for…
Prioritizing sewer rehabilitation projects using AHP-PROMETHEE II ranking method.
Kessili, Abdelhak; Benmamar, Saadia
2016-01-01
The aim of this paper is to develop a methodology for the prioritization of sewer rehabilitation projects for Algiers (Algeria) sewer networks to support the National Sanitation Office in its challenge to make decisions on prioritization of sewer rehabilitation projects. The methodology applies multiple-criteria decision making. The study includes 47 projects (collectors) and 12 criteria to evaluate them. These criteria represent the different issues considered in the prioritization of the projects, which are structural, hydraulic, environmental, financial, social and technical. The analytic hierarchy process (AHP) is used to determine weights of the criteria and the Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE II) method is used to obtain the final ranking of the projects. The model was verified using the sewer data of Algiers. The results have shown that the method can be used for prioritizing sewer rehabilitation projects.
Height projection methods and sensitivity study. Technical report
Mikhail, A. S.; Justus, C. G.
1979-06-01
A brief description is given of the different techniques for height projection of wind speed that have been developed at Georgia Tech. One of these techniques, the similarity model, is based on Monin-Obukhov similarity theory. Other models examined are the empirical velocity-dependent power law model (power law model) and the semi-empirical modified velocity-dependent power law model (modified power law model). A detailed description of the methodologies is given and example applications are illustrated, with all the necessary input parameters to the models.
A Projected Conjugate Gradient Method for Sparse Minimax Problems
Madsen, Kaj; Jonasson, Kristjan
1993-01-01
A new method for nonlinear minimax problems is presented. The method is of the trust region type and based on sequential linear programming. It is a first order method that only uses first derivatives and does not approximate Hessians. The new method is well suited for large sparse problems...... as it only requires that software for sparse linear programming and a sparse symmetric positive definite equation solver are available. On each iteration a special linear/quadratic model of the function is minimized, but contrary to the usual practice in trust region methods the quadratic model is only...
Gupta, Manish K.; Dowling, Jonathan P.
2016-06-01
We analytically derive a decoherence model for orbital angular momentum states of a photon in a multimode optical fiber and show that the rate of decoherence scales approximately exponentially with l2, where l is the azimuthal mode order. We also show numerically that for large values of l the orbital angular momentum photon state completely dephases. However, for lower values of l the decoherence can be minimized by using dynamical decoupling to allow for qudit high-bandwidth quantum communication and similar applications.
Risk management for engineering projects procedures, methods and tools
Munier, Nolberto
2014-01-01
Many people see risk in engineering projects as an imprecise and nebulous problem - something that exists, is feared and is impossible to deal with. Nothing could be further from the truth. While risk is certainly ubiquitous, sometimes difficult to detect, and cannot always be completely avoided, it can generally be mitigated, reduced or prevented through timely analysis and action. This book covers the entire process of risk management by providing methodologies for determining the sources of project risk, and once threats have been identified, managing them through: · identification and assessment (probability, relative importance, variables, risk breakdown structure, etc.) · implementation of measures for their prevention, reduction or mitigation · evaluation of impacts and quantification of risks · establishment of control measures It also considers sensitivity analysis to determine the influence of uncertain parameters values ...
Projection and quasi-compressibility methods for solving the incompressible Navier-Stokes equations
Prohl, Andreas
1997-01-01
Projection methods had been introduced in the late sixties by A. Chorin and R. Teman to decouple the computation of velocity and pressure within the time-stepping for solving the nonstationary Navier-Stokes equations. Despite the good performance of projection methods in practical computations, their success remained somewhat mysterious as the operator splitting implicitly introduces a nonphysical boundary condition for the pressure. The objectives of this monograph are twofold. First, a rigorous error analysis is presented for existing projection methods by means of relating them to so-called quasi-compressibility methods (e.g. penalty method, pressure stabilzation method, etc.). This approach highlights the intrinsic error mechanisms of these schemes and explains the reasons for their limitations. Then, in the second part, more sophisticated new schemes are constructed and analyzed which are exempted from most of the deficiencies of the classical projection and quasi-compressibility methods. "... this book ...
Project scheduling method with time using MRP system – A case study: Construction project in Libya
Abdallah Ali Imetieg
2015-04-01
Full Text Available Materials Requirements and Planning (MRP is a system of production planning and inventory control, which is used to manage manufacturing processes. Most MRP systems are software-based and are used to ensure that the materials are available for production, that the products are available for delivery to customers, that the lowest possible material and product level is maintained in store, as well as to plan delivery schedules and purchasing activities. Upon completion of scheduling, begins the process of follow-up, which includes the achievement of the project goals in terms of quantity, quality and costs in accordance with deadlines. MRP system was applied to project of 5000 housing units in Solug area, which is close to Benghazi city, Libya, with the aim to provide necessary cash flow to pay dues on time without delay to all involved project sub-contractors and material suppliers, to ensure the smooth flow of operations, as well as to diminish costs by reduction of temporary storages and rented areas. There is a correlation between time and cost of each activity. If the required time is shorter than the scheduled time of the certain activity, it would demand more resources, which further leads to the increase in direct costs of the given activity. Therefore, the output of MRP is important since commands are issued through planning in order to launch the suggested orders with the required quantities and within the limited time period.
Advanced Aqueous Phase Catalyst Development using Combinatorial Methods Project
National Aeronautics and Space Administration — Combinatorial methods are proposed to develop advanced Aqueous Oxidation Catalysts (AOCs) with the capability to mineralize organic contaminants present in effluents...
HOMES - Holographic Optical Method for Exoplanet Spectroscopy Project
National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope designed for exoplanet discovery. Its double dispersion architecture employs a...
Discounted Cash Flow and Modern Asset Pricing Methods - Project Selection and Policy Implications
Emhjellen, Magne; Alaouze, Chris M.
2002-07-01
We examine the differences in the net present values (NPV's) of North Sea oil projects obtained using the Weighted Average Cost of Capital (WACC) and a Modern Asset Pricing (MAP) method which involves the separate discounting of project cash flow components. NPV differences of more than $1 Om were found for some oil projects. Thus, the choice of valuation method will affect the development decisions of oil companies. The results of the MAP method are very sensitive to the choice of parameter values for the stochastic process used to model oil prices. Further research is recommended before the MAP method is used as the sole valuation model. (author)
Discounted Cash Flow and Modern Asset Pricing Methods - Project Selection and Policy Implications
Emhjellen, Magne; Alaouze, Chris M.
2002-07-01
We examine the differences in the net present values (NPV's) of North Sea oil projects obtained using the Weighted Average Cost of Capital (WACC) and a Modern Asset Pricing (MAP) method which involves the separate discounting of project cash flow components. NPV differences of more than $1 Om were found for some oil projects. Thus, the choice of valuation method will affect the development decisions of oil companies. The results of the MAP method are very sensitive to the choice of parameter values for the stochastic process used to model oil prices. Further research is recommended before the MAP method is used as the sole valuation model. (author)
ORBAN Magdalena
2015-06-01
Full Text Available The paper presents a comparative graphical and analytical study concerning the possibility of applying methods of transforming the projection – rotation and change of projection planes - for determination of spatial image of some machine parts whose edges or plane faces form imposed angles with the projection planes. An analysis of the existing relation between the two methods respectively with the axonometric representation realized by the coordinate’s method is also performed, highlighting the advantages presented by each of the considered methods. In both cases, the double rotation, respectively the double change of projection planes will be applied, equivalent to an intuitive axonometric representation which will meet, at the same time, some concrete requirements of a project.
Real Option Method and Escalation of Commitment in the Evaluation of Investment Projects
Mehrdad Karami
2011-01-01
Full Text Available Problem statement: This study applies an experimental method to find out whether using the real option method along with the discounted cash flow techniques can reduce the decision-makers Escalation of Commitment (EC hereafter or their desire to keep up their commitment to a failed project. Approach: The real option method used for the evaluation of long-term projects also measures the flexibility value which may be produced during the implementation of the project. Results: The results indicate that those who use the real option method show lower EC to a failed project than those who merely use the net present value method. Conclusion/Recommendations: The major conclusion might be that using the real option method in capital budgeting can affect the users behavior and decisions and lead to better decision-making in the long-term projects. In view of the fact that longterm investment projects are costly and time-consuming, a greater need is felt for better methods of evaluating such projects and, in consequence, researchers should also consider the other affective aspects of using real method options on the users' behavior and decisions.
Sumikura, Hisashi; Kuramochi, Eiichi; Taniyama, Hideaki; Notomi, Masaya
2016-11-01
We have observed electron-hole droplet emission enhanced by silicon photonic crystal nanocavities with different Q values and simulated their Purcell effect using a semiclassical theory considering the temporal dephasing of the emission. When the photon loss rate of the nanocavities is smaller than the dephasing rate of the emission, the cavity-enhanced integrated photoluminescence (PL) intensity is unchanged by the cavity Q value. This is because the Purcell enhancement of the spontaneous emission rate is saturated in a high-Q region. In contrast, the peak intensity of the cavity-enhanced PL is proportional to the cavity Q value without saturation. These results suggest that a high-Q nanocavity is suitable for fabricating bright narrowband light emitting devices that concentrate the broadband emission energy of fast-dephasing emitters in a narrowband cavity resonance.
Joint Projection Filling method for occlusion handling in Depth-Image-Based Rendering
Jantet, Vincent; Guillemot, Christine; Morin, Luce
2011-01-01
International audience; This paper addresses the disocclusion problem which may occur when using Depth-Image-Based Rendering (DIBR) techniques in 3DTV and Free-Viewpoint TV applications. A new DIBR technique is proposed, which combines three methods: a Joint Projection Filling (JPF) method to handle disocclusions in synthesized depth maps; a backward projection to synthesize virtual views; and a full-Z depth-aided inpainting to fill in disoccluded areas in textures. The JPF method performs th...
Advanced Aqueous Phase Catalyst Development using Combinatorial Methods Project
National Aeronautics and Space Administration — The use of combinatorial methods is proposed to rapidly screen catalyst formulations for the advanced development of aqueous phase oxidation catalysts with greater...
Hybrid Prediction Method for Aircraft Interior Noise Project
National Aeronautics and Space Administration — This proposal discusses the development and application of new methods of structural-acoustic analysis in order to address existing problems in aircraft interior...
Jobelin, M
2006-10-15
This thesis treats of time resolution methods for the Navier-Stokes equations. Based on the well-known projection method of Chorin and Temam, an original pressure correction method, named 'projection-penalty' is developed. Its specificity concerns the addition of a penalty term in the prediction step, which constrains the predicted velocity to fit with the mass balance. The precision improvements added by this method are demonstrated by some analysis results and by some numerical experiments of incompressible or dilatable flows. Finally, the potentialities offered by the use of the joint finite elements method in this type of fractionary step scheme is studied. Two applications are presented, one for local refinement purpose, the other for the resolution of a multi-physics problem. (J.S.)
Projection operator method CPA to single-particle excitation spectra
Kakehashi, Yoshiro
2005-03-01
Single-site theories for electron correlations such as the many-body CPA, the dynamical CPA, and the dynamical-mean field theory are useful as a starting point to describe strongly correlated electron systems. Nevertheless, simple and useful treatments of correlations being applicable to the realistic system has not yet been well developed. We propose here the projection operator technique combined with the many-body CPA which allows us to calculate the excitation spectrum directly from the retarded Green function. The basic idea is to introduce an energy dependent Liouville operator for the description of the dynamics of correlated electrons. The self-energy obtained by a renormalized perturbation scheme describes the overall features of excitation spectra. The quasiparticle weight for a half-filled band in infinite dimensions show a simple analytic form Z=[1-(U/Uc2)^2]/[1+(U/U2)^2] with Uc2=3.705 and U2=2.522 (hypercubic lattice) which reproduces well the result of the numerical renormalization group calculations. The critical Coulomb interaction Uc1 for a gap formation is 3.69 when the Hartree-Fock wave function is used for the evaluation of the static average, and 3.24 when the correlated wave function is used. The latter agrees with the result of the NRG within 1% error.
A method for weighted projections to the positive definite cone
Valkonen, Tuomo
2014-06-24
© 2014 Taylor & Francis. We study the numerical solution of the problem (Formula presented.) , where (Formula presented.) is a symmetric square matrix, and (Formula presented.) is a linear operator, such that (Formula presented.) is invertible. With (Formula presented.) the desired fractional duality gap, and (Formula presented.) the condition number of (Formula presented.) , we prove (Formula presented.) iteration complexity for a simple primal-dual interior point method directly based on those for linear programs with semi-definite constraints. We do not, however, require the numerically expensive scalings inherent in these methods to force fast convergence. For low-dimensional problems (Formula presented.), our numerical experiments indicate excellent performance and only a very slowly growing dependence of the convergence rate on (Formula presented.). While our algorithm requires somewhat more iterations than existing interior point methods, the iterations are cheaper. This gives better computational times.
Pla Puigvert, Mònica
2009-01-01
UniReserach is a company that assists companies and research institutes with their project management. For this company an assignment could be done in which an inventory will be made on the monitoring and control methods during project execution, based on which recommendations for improvement have to be generated.
Using Single-Case Design and Personalized Behavior Change Projects to Teach Research Methods
Morgan, David L.
2009-01-01
Students in research methods courses, especially those taught in an intense format, might be hard pressed to actually conduct research studies due to logistics and time constraints. I describe the use of single-case research design and a personalized behavior project as an alternative research project for students in an undergraduate psychology…
A New Group-Formation Method for Student Projects
Borges, Jose; Dias, Teresa Galvao; Cunha, Joao Falcao E.
2009-01-01
In BSc/MSc engineering programmes at Faculty of Engineering of the University of Porto (FEUP), the need to provide students with teamwork experiences close to a real world environment was identified as an important issue. A new group-formation method that aims to provide an enriching teamwork experience is proposed. Students are asked to answer a…
A New Group-Formation Method for Student Projects
Borges, Jose; Dias, Teresa Galvao; Cunha, Joao Falcao E.
2009-01-01
In BSc/MSc engineering programmes at Faculty of Engineering of the University of Porto (FEUP), the need to provide students with teamwork experiences close to a real world environment was identified as an important issue. A new group-formation method that aims to provide an enriching teamwork experience is proposed. Students are asked to answer a…
The use of discrete orthogonal projections in boundary element methods
Brandts, J.
2001-01-01
In recent papers by Sloan and Wendland Grigorie and Sloan and Grigorie Sloan and Brandts a formalismwas developed that serves many important and interesting applications in boundary element methods the commutator property for splines Based on superapproximation results this property is for exam
Mengle, Vinod G. (Inventor); Thomas, Russell H. (Inventor)
2012-01-01
Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter. Projections near a support pylon and/or associated heat shield can have particular configurations, including greater flow immersion than other projections.
Method for assigning sites to projected generic nuclear power plants
Holter, G.M.; Purcell, W.L.; Shutz, M.E.; Young, J.R.
1986-07-01
Pacific Northwest Laboratory developed a method for forecasting potential locations and startup sequences of nuclear power plants that will be required in the future but have not yet been specifically identified by electric utilities. Use of the method results in numerical ratings for potential nuclear power plant sites located in each of the 10 federal energy regions. The rating for each potential site is obtained from numerical factors assigned to each of 5 primary siting characteristics: (1) cooling water availability, (2) site land area, (3) power transmission land area, (4) proximity to metropolitan areas, and (5) utility plans for the site. The sequence of plant startups in each federal energy region is obtained by use of the numerical ratings and the forecasts of generic nuclear power plant startups obtained from the EIA Middle Case electricity forecast. Sites are assigned to generic plants in chronological order according to startup date.
Davis, Eric J.; Pauls, Steve; Dick, Jonathan
2017-01-01
Presented is a project-based learning (PBL) laboratory approach for an upper-division environmental chemistry or quantitative analysis course. In this work, a combined laboratory class of 11 environmental chemistry students developed a method based on published EPA methods for the extraction of dichlorodiphenyltrichloroethane (DDT) and its…
The Hip Impact Protection Project: design and methods.
Barton, Bruce A; Birge, Stanley J; Magaziner, Jay; Zimmerman, Sheryl; Ball, Linda; Brown, Kathleen M; Kiel, Douglas P
2008-01-01
Nearly 340,000 hip fractures occur each year in the U.S. With current demographic trends, the number of hip fractures is expected to double at least in the next 40 years. The Hip Impact Protection Project (HIP PRO) was designed to investigate the efficacy and safety of hip protectors in an elderly nursing home population. This paper describes the innovative clustered matched-pair research design used in HIP PRO to overcome the inherent limitations of clustered randomization. Three clinical centers recruited 37 nursing homes to participate in HIP PRO. They were randomized so that the participating residents in that home received hip protectors for either the right or left hip. Informed consent was obtained from either the resident or the resident's responsible party. The target sample size was 580 residents with replacement if they dropped out, had a hip fracture, or died. One of the advantages of the HIP PRO study design was that each resident was his/her own case and control, eliminating imbalances, and there was no confusion over which residents wore pads (or on which hip). Generalizability of the findings may be limited. Adherence was higher in this study than in other studies because of: (1) the use of a run-in period, (2) staff incentives, and (3) the frequency of adherence assessments. The use of a single pad is not analogous to pad use in the real world and may have caused unanticipated changes in behavior. Fall assessment was not feasible, limiting the ability to analyze fractures as a function of falls. Finally, hip protector designs continue to evolve so that the results generated using this pad may not be applicable to other pad designs. However, information about factors related to adherence will be useful for future studies. The clustered matched-pair study design avoided the major problem with previous cluster-randomized investigations of this question - unbalanced risk factors between the experimental group and the control group. Because each
Hamzah Abdul-Rahman
2011-01-01
Full Text Available Problem statement: Learning from project is vital for organizations to achieve competition and to survive in a dynamic environment. However, learning is not an easy task because there is no specific way for learning from projects. Besides, the practice of project learning and transfer knowledge to the firms level is still vague, specifically in the construction milieu. Approach: A questionnaire survey was conducted targeted quantity surveying firms in Malaysia, attempted to identify methods of learning from projects and implement this approach successfully. Interviews with experts in construction projects were conducted to expand and validate the results of the survey. Results: The findings indicated that on-the-job training is the preferable method to learn from construction project in quantity surveying firms. In addition, top management support and employee participants are the main enablers/barriers of project learning implementation. While, top management support found to be the main key success factor of project learning implementation. Conclusion/Recommendations: Determining barriers and enablers of learning showed how construction organization could implement learning from project successfully. This adds a practical tool of promoting learning in the field of organizational learning in construction. Results can be replicated in different industries to observe the disparity in each setting.
Nonlinear Time Reversal Acoustic Method of Friction Stir Weld Assessment Project
National Aeronautics and Space Administration — The goal of the project is demonstration of the feasibility of Friction Stir Weld (FSW) assessment by novel Nonlinear Time Reversal Acoustic (TRA) method. Time...
Feng, Qing-Hua
2014-08-01
In this paper, a new fractional projective Riccati equation method is proposed to establish exact solutions for fractional partial differential equations in the sense of modified Riemann—Liouville derivative. This method can be seen as the fractional version of the known projective Riccati equation method. For illustrating the validity of this method, we apply this method to solve the space-time fractional Whitham—Broer—Kaup (WBK) equations and the nonlinear fractional Sharma—Tasso—Olever (STO) equation, and as a result, some new exact solutions for them are obtained.
Liu, Wei; Wang, Wei D.; Wang, Wei; Bai, Shi; Dybowski, Cecil
2010-09-01
A modified 2D-SUPER technique is demonstrated to allow independent measurement of the principal values of the chemical-shift tensors of overlapping protonated and unprotonated carbons. The insertion of a dipolar-dephasing period into the sequence causes loss of signal from protonated carbons. The spectrum obtained with this modification allows one to determine the principal values of the unprotonated carbons with high precision. Subsequent fitting of the usual 2D-SUPER spectrum, with the chemical-shift parameters of the unprotonated carbons fixed, gives the parameters of the overlapped resonances of the protonated carbons. As an example, we report the determination of the 13C chemical-shift parameters of the carbons of form II of piroxicam. The experimental results are compared with those obtained from calculations using the DFT/GIAO method. Potential applications of this method are discussed.
Manufacturing Methods and Technology Project Execution Report, Second CY 81
1982-03-15
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Developing and executing quality improvement projects (concept, methods, and evaluation).
Likosky, Donald S
2014-03-01
Continuous quality improvement, quality assurance, cycles of change--these words of often used to express the process of using data to inform and improve clinical care. Although many of us have been exposed to theories and practice of experimental work (e.g., randomized trial), few of us have been similarly exposed to the science underlying quality improvement. Through the lens of a single-center quality improvement study, this article exposes the reader to methodology for conducting such studies. The reader will gain an understanding of these methods required to embark on such a study.
New Method of Selecting Efficient Project Portfolios in the Presence of Hybrid Uncertainty
Bogdan Rębiasz
2016-01-01
Full Text Available A new methods of selecting efficient project portfolios in the presence of hybrid uncertainty has been presented. Pareto optimal solutions have been defined by an algorithm for generating project portfolios. The method presented allows us to select efficient project portfolios taking into account statistical and economic dependencies between projects when some of the parameters used in the calculation of effectiveness can be expressed in the form of an interactive possibility distribution and some in the form of a probability distribution. The procedure for processing such hybrid data combines stochastic simulation with nonlinear programming. The interaction between data are modeled by correlation matrices and the interval regression. Economic dependences are taken into account by the equations balancing the production capacity of the company. The practical example presented indicates that an interaction between projects has a significant impact on the results of calculations. (original abstract
A projection and density estimation method for knowledge discovery.
Stanski, Adam; Hellwich, Olaf
2012-01-01
A key ingredient to modern data analysis is probability density estimation. However, it is well known that the curse of dimensionality prevents a proper estimation of densities in high dimensions. The problem is typically circumvented by using a fixed set of assumptions about the data, e.g., by assuming partial independence of features, data on a manifold or a customized kernel. These fixed assumptions limit the applicability of a method. In this paper we propose a framework that uses a flexible set of assumptions instead. It allows to tailor a model to various problems by means of 1d-decompositions. The approach achieves a fast runtime and is not limited by the curse of dimensionality as all estimations are performed in 1d-space. The wide range of applications is demonstrated at two very different real world examples. The first is a data mining software that allows the fully automatic discovery of patterns. The software is publicly available for evaluation. As a second example an image segmentation method is realized. It achieves state of the art performance on a benchmark dataset although it uses only a fraction of the training data and very simple features.
A projection and density estimation method for knowledge discovery.
Adam Stanski
Full Text Available A key ingredient to modern data analysis is probability density estimation. However, it is well known that the curse of dimensionality prevents a proper estimation of densities in high dimensions. The problem is typically circumvented by using a fixed set of assumptions about the data, e.g., by assuming partial independence of features, data on a manifold or a customized kernel. These fixed assumptions limit the applicability of a method. In this paper we propose a framework that uses a flexible set of assumptions instead. It allows to tailor a model to various problems by means of 1d-decompositions. The approach achieves a fast runtime and is not limited by the curse of dimensionality as all estimations are performed in 1d-space. The wide range of applications is demonstrated at two very different real world examples. The first is a data mining software that allows the fully automatic discovery of patterns. The software is publicly available for evaluation. As a second example an image segmentation method is realized. It achieves state of the art performance on a benchmark dataset although it uses only a fraction of the training data and very simple features.
Poulsen, Morten; Niebe, Sarah Maria; Erleben, Kenny
2010-01-01
In interactive physical simulation, contact forces are applied to prevent rigid bodies from penetrating and control slipping between bodies. Accurate contact force determination is a computationally hard problem. Thus, in practice one trades accuracy for performance. The result is visual artifact...... and a minimum map reformulation. The resulting model is called the Projected Gauss–Seidel method. Quantitative research results are presented and can be used as a taxonomy for selecting a suitable heuristic when using the Projected Gauss–Seidel method....
Poulsen, Morten; Abel, Sarah Maria Niebe; Erleben, Kenny
2010-01-01
In interactive physical simulation, contact forces are applied to prevent rigid bodies from penetrating and control slipping between bodies. Accurate contact force determination is a computationally hard problem. Thus, in practice one trades accuracy for performance. The result is visual artifact...... and a minimum map reformulation. The resulting model is called the Projected Gauss–Seidel method. Quantitative research results are presented and can be used as a taxonomy for selecting a suitable heuristic when using the Projected Gauss–Seidel method....
Modified Halfspace-Relaxation Projection Methods for Solving the Split Feasibility Problem
Min Li
2012-01-01
Full Text Available This paper presents modified halfspace-relaxation projection (HRP methods for solving the split feasibility problem (SFP. Incorporating with the techniques of identifying the optimal step length with positive lower bounds, the new methods improve the efficiencies of the HRP method (Qu and Xiu (2008. Some numerical results are reported to verify the computational preference.
Peer Assessment in Group Projects Accounting for Assessor Reliability by an Iterative Method
Ko, Sung-Seok
2014-01-01
This study proposes an advanced method to factor in the contributions of individual group members engaged in an integrated group project using peer assessment procedures. Conway et al. proposed the Individual Weight Factor (IWF) method for peer assessment which has been extensively developed over the years. However, most methods associated with…
A versatile method for groundwater vulnerability projections in future scenarios.
Stevenazzi, Stefania; Bonfanti, Marianna; Masetti, Marco; Nghiem, Son V; Sorichetta, Alessandro
2017-02-01
Water scarcity and associated risks are serious societal problems. A major challenge for the future will be to ensure the short-term and long-term provision of accessible and safe freshwater to meet the needs of the rapidly growing human population and changes in land cover and land use, where conservation and protection play a key role. Through a Bayesian spatial statistical method, a time-dependent approach for groundwater vulnerability assessment is developed to account for both the recent status of groundwater contamination and its evolution, as required by the European Union (Groundwater Directive, 2006/118/EC). This approach combines natural and anthropogenic factors to identify areas with a critical combination of high levels and increasing trends of nitrate concentrations, together with a quantitative evaluation of how different future scenarios would impact the quality of groundwater resources in a given area. In particular, the proposed approach can determine potential impacts on groundwater resources if policies are maintained at the status quo or if new measures are implemented for safeguarding groundwater quality, as natural factors are changing under climatic or anthropogenic stresses. Copyright © 2016 Elsevier Ltd. All rights reserved.
Luo, Shouhua; Wu, Huazhen; Sun, Yi; Li, Jing; Li, Guang; Gu, Ning
2017-03-01
The beam hardening effect can induce strong artifacts in CT images, which result in severely deteriorated image quality with incorrect intensities (CT numbers). This paper develops an effective and efficient beam hardening correction algorithm incorporated in a filtered back-projection based maximum a posteriori (BHC-FMAP). In the proposed algorithm, the beam hardening effect is modeled and incorporated into the forward-projection of the MAP to suppress beam hardening induced artifacts, and the image update process is performed by Feldkamp–Davis–Kress method based back-projection to speed up the convergence. The proposed BHC-FMAP approach does not require information about the beam spectrum or the material properties, or any additional segmentation operation. The proposed method was qualitatively and quantitatively evaluated using both phantom and animal projection data. The experimental results demonstrate that the BHC-FMAP method can efficiently provide a good correction of beam hardening induced artefacts.
Implementation of Six Sigma Method to Maintain The Quality of Construction Projects
Yusuf Latief
2010-10-01
Full Text Available Six sigma (6-sigma is a method that widely developed in the world, especially in manufacturing industry to decrease failures in achieving good quality in construction projects. The objective of this research is to explore the existing condition of quality management and the aplication of 6-sigma method in maintaining quality of construction projects. Structured interviews to experienced experts and people who were recommended by their companies were conducted. Non-parametric analysis using frequencies distribution procedures were used for analysis. The result shows that existing condition in quality management of construction project in Indonesia have been implemented 6-sigma method approach, that concern with is how to adapt with either from internal or external condition of that project.
张素英; 邓子辰
2004-01-01
For the constrained generalized Hamiltonian system with dissipation, by introducing Lagrange multiplier and using projection technique, the Lie group integration method was presented, which can preserve the inherent structure of dynamic system and the constraint-invariant. Firstly, the constrained generalized Hamiltonian system with dissipative was converted to the non-constraint generalized Hamiltonian system, then Lie group integration algorithm for the non-constraint generalized Hamiltonian system was discussed, finally the projection method for generalized Hamiltonian system with constraint was given. It is found that the constraint invariant is ensured by projection technique, and after introducing Lagrange multiplier the Lie group character of the dynamic system can't be destroyed while projecting to the constraint manifold. The discussion is restricted to the case of holonomic constraint. A presented numerical example shows the effectiveness of the method.
Risk Evaluation on UHV Power Transmission Construction Project Based on AHP and FCE Method
Huiru Zhao
2014-01-01
Full Text Available Ultra high voltage (UHV power transmission construction project is a high-tech power grid construction project which faces many risks and uncertainty. Identifying the risk of UHV power transmission construction project can help mitigate the risk loss and promote the smooth construction. The risk evaluation on “Zhejiang-Fuzhou” UHV power transmission construction project was performed based on analytic hierarchy process (AHP and fuzzy comprehensive evaluation (FCE method in this paper. After the risk evaluation index system was built, the AHP was used to determine the weights of risk indicators, and the FCE method was to perform the risk evaluation. The evaluation result shows that (1 “Zhejiang-Fuzhou” UHV power transmission construction project has moderate risk, which indicates the occurrence probability of project risk is medium and the risk occurrence will cause general loss for project, (2 “society risk” has the highest level, and the next is “policy and law risk,” “technique risk,” “natural environmental risk,” and “Management risk,” respectively, and it should keep main eye on the social risk, policy and law risk, and technique risk. Finally, according to the risk evaluation result, the specific risk control recommendations were proposed for the smooth construction of this project.
Molenkamp, L.W.; Wiersma, Douwe A.
1984-01-01
We report results of an optical and picosecond photon echo study on the zero-phonon line of photosite I of pentacene in benzoic acid. The results show that optical dephasing in this system proceeds via uncorrelated phonon scattering processes from the ground and optically excited state to singly exc
Nielsen, Per Kær; Nielsen, Torben Roland; Lodahl, Peter;
2010-01-01
We investigate the influence of electron-phonon interactions on the dynamical properties of a quantum-dot-cavity QED system. We show that non-Markovian effects in the phonon reservoir lead to strong changes in the dynamics, arising from photon-assisted dephasing processes, not present in Markovian...
Arnault, Denise Saint; Fetters, Michael D
2011-10-01
Mixed methods research has made significant in-roads in the effort to examine complex health related phenomenon. However, little has been published on the funding of mixed methods research projects. This paper addresses that gap by presenting an example of an NIMH funded project using a mixed methods QUAL-QUAN triangulation design entitled "The Mixed-Method Analysis of Japanese Depression." We present the Cultural Determinants of Health Seeking model that framed the study, the specific aims, the quantitative and qualitative data sources informing the study, and overview of the mixing of the two studies. Finally, we examine reviewer's comments and our insights related to writing mixed method proposal successful for achieving RO1 level funding.
Wei, W. B.; Tan, L.; Jia, M. Q.; Pan, Z. K.
2017-01-01
The variational level set method is one of the main methods of image segmentation. Due to signed distance functions as level sets have to keep the nature of the functions through numerical remedy or additional technology in an evolutionary process, it is not very efficient. In this paper, a normal vector projection method for image segmentation using Chan-Vese model is proposed. An equivalent formulation of Chan-Vese model is used by taking advantage of property of binary level set functions and combining with the concept of convex relaxation. Threshold method and projection formula are applied in the implementation. It can avoid the above problems and obtain a global optimal solution. Experimental results on both synthetic and real images validate the effects of the proposed normal vector projection method, and show advantages over traditional algorithms in terms of computational efficiency.
Investigation of the Relationship between Green Design and Project Delivery Methods
Bilec, Melissa M.; Ries, Robert J.
2008-04-24
The selection of the project delivery method (PDM) for any project is critical--it establishes communication, coordination, and contractual issues between the owner, contractor, and designer. With an increase in the number of green design projects, understanding the relationship between the PDM and green design is paramount to project and contract management. It is reasonable to assume that a positive relationship between green design and design-build (DB) exists since both theoretically are intended to foster an integrated, holistic, and collaborative project. This research examines the relationship between the design-bid-build (DBB), construction management (CM), and DB PDMs and green design with the goal of establishing best practices and identifying potential synergies between them. The research collected information by conducting primarily telephone interviews with approximately twenty-five individuals, including owners, contractors, and designers involved in completed green design projects, mainly in the public sector. The interviews developed a general understanding of the current state of knowledge and experience and not a rigorous quantitative analysis. Upon completion of the interviews, the tabulated results were summarized and green project characteristics and project-PDM interactions emerged. Existing published research was evaluated to reveal aspects of PDMs independent of green design. Best practices were ascertained by combining information from the interviews and published research. Best practices are as follows: (1) Project implementation features--The decision to use DB as PDM on green design or other projects should be based on the specific project features; e.g., well-defined scope and adequate owner staffing. DB will not produce successful results on all projects. (2) Collaboration--Project team collaboration early in the design and construction process is an important aspect of green projects, and collaboration was considered somewhat more
Thoma, A.; Schnauber, P.; Gschrey, M.; Seifried, M.; Wolters, J.; Schulze, J.-H.; Strittmatter, A.; Rodt, S.; Carmele, A.; Knorr, A.; Heindel, T.; Reitzenstein, S.
2016-01-01
We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature-dependent two-photon interference (TPI) experiments. An increase in temporal separation between consecutive photon emission events reveals a decrease in TPI visibility on a nanosecond time scale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from (96 ±4 )% at 10 K to a vanishing visibility at 40 K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter on a nanosecond time scale.
Phase retrieval with the reverse projection method in the presence of object's scattering
Wang, Zhili; Gao, Kun; Wang, Dajiang
2017-08-01
X-ray grating interferometry can provide substantially increased contrast over traditional attenuation-based techniques in biomedical applications, and therefore novel and complementary information. Recently, special attention has been paid to quantitative phase retrieval in X-ray grating interferometry, which is mandatory to perform phase tomography, to achieve material identification, etc. An innovative approach, dubbed ;Reverse Projection; (RP), has been developed for quantitative phase retrieval. The RP method abandons grating scanning completely, and is thus advantageous in terms of higher efficiency and reduced radiation damage. Therefore, it is expected that this novel method would find its potential in preclinical and clinical implementations. Strictly speaking, the reverse projection method is applicable for objects exhibiting only absorption and refraction. In this contribution, we discuss the phase retrieval with the reverse projection method for general objects with absorption, refraction and scattering simultaneously. Especially, we investigate the influence of the object's scattering on the retrieved refraction signal. Both theoretical analysis and numerical experiments are performed. The results show that the retrieved refraction signal is the product of object's refraction and scattering signals for small values. In the case of a strong scattering, the reverse projection method cannot provide reliable phase retrieval. Those presented results will guide the use of the reverse projection method for future practical applications, and help to explain some possible artifacts in the retrieved images and/or reconstructed slices.
A second-order projection method for variable-density flows
Bell, John B.; Marcus, Daniel L.
1992-08-01
The second-order projection method presented for variable-density, incompressible flows is based on a second-order, fractional-step scheme in which diffusion-convection terms are advanced without enforcing the compressibility condition. The resulting, intermediate velocity field is then projected onto the space of discretely divergence-free vector fields. Attention is given to the form taken by the method in the cases of finite-amplitude density variation; simplifications for a Boussinesq approximation are given, in conjunction with numerical results validating the method's convergence properties.
Collaborative decision-making on wind power projects based on AHP method
Badea, A.; Proştean, G.; Tămăşilă, M.; Vârtosu, A.
2017-01-01
The complexity of projects implementation in Renewable Energy Sources (RES) requires finding collaborative alliances between suppliers and project developers in RES. Links activities in supply chain in RES, respectively, transportation of heavy components, processing orders to purchase quality raw materials, storage and materials handling, packaging, and other complex activities requiring a logistics system collaboratively to be permanently dimensioned properly selected and monitored. Requirements imposed by stringency of wind power energy projects implementation inevitably involves constraints in infrastructure, implementation and logistics. Thus, following an extensive research in RES project, to eliminate these constraints were identified alternative collaboration to provide feasible solutions on different levels of performance. The paper presents a critical analysis of different collaboration alternatives in supply chain for RES projects, selecting the ones most suitable for particular situations by using decision-making method Analytic Hierarchy Process (AHP). The role of AHP method was to formulate a decision model by which can be establish the collaboration alternative choice through mathematical calculation to reduce the impact created by constraints encountered. The solution provided through AHP provides a framework for detecting optimal alternative collaboration between suppliers and project developers in RES and avoids some breaks in the chain by resizing safety buffers for leveling orders in RES projects.
Joint Power and Multiple Access Control for Wireless Mesh Network with Rose Projection Method
Tang, Meiqin; Shang, Lili; Xin, Yalin; Liu, Xiaohua; Wei, Xinjiang
2014-01-01
This paper investigates the utility maximization problem for the downlink of the multi-interface multichannel wireless mesh network with orthogonal frequency division multiple access. A cross-layer joint power and multiple access control algorithm are proposed. Rosen projection matrix is combined with Solodov projection techniques to build a three-memory gradient Rosen projection method, which is applied to solve this optimization problem. The convergence analysis is given and simulations show that the proposed solution achieves significant throughput compared with existing approaches. PMID:24883384
Tools and Methods for Risk Management in Multi-Site Engineering Projects
Zhou, Mingwei; Nemes, Laszlo; Reidsema, Carl; Ahmed, Ammar; Kayis, Berman
In today's highly global business environment, engineering and manufacturing projects often involve two or more geographically dispersed units or departments, research centers or companies. This paper attempts to identify the requirements for risk management in a multi-site engineering project environment, and presents a review of the state-of-the-art tools and methods that can be used to manage risks in multi-site engineering projects. This leads to the development of a risk management roadmap, which will underpin the design and implementation of an intelligent risk mapping system.
Joint power and multiple access control for wireless mesh network with Rose projection method.
Tang, Meiqin; Shang, Lili; Xin, Yalin; Liu, Xiaohua; Wei, Xinjiang
2014-01-01
This paper investigates the utility maximization problem for the downlink of the multi-interface multichannel wireless mesh network with orthogonal frequency division multiple access. A cross-layer joint power and multiple access control algorithm are proposed. Rosen projection matrix is combined with Solodov projection techniques to build a three-memory gradient Rosen projection method, which is applied to solve this optimization problem. The convergence analysis is given and simulations show that the proposed solution achieves significant throughput compared with existing approaches.
Aggregation-iterative analogues and generalizations of projection-iterative methods
Shuvar B.F.
2013-06-01
Full Text Available Aggregation-iterative algorithms for linear operator equations are constructed and investigated. These algorithms cover methods of iterative aggregation and projection-iterative methods. In convergence conditions there is neither requirement for the corresponding operator of fixed sign no restriction to the spectral radius to be less than one.
E. M. E. Zayed
2014-01-01
Full Text Available We apply the generalized projective Riccati equations method to find the exact traveling wave solutions of some nonlinear evolution equations with any-order nonlinear terms, namely, the nonlinear Pochhammer-Chree equation, the nonlinear Burgers equation and the generalized, nonlinear Zakharov-Kuznetsov equation. This method presents wider applicability for handling many other nonlinear evolution equations in mathematical physics.
Radeva, Veselka S.
Several interactive methods, applied in the astronomy education during creation of the project about a colony in the Space, are presented. The methods Pyramid, Brainstorm, Snow-slip (Snowball) and Aquarium give the opportunity for schooler to understand and learn well a large packet of astronomical knowledge.
Second-order fully discretized projection method for incompressible Navier-Stokes equations
Daniel X. Guo
2016-03-01
Full Text Available A second-order fully discretized projection method for the incompressible Navier-Stokes equations is proposed. It is an explicit method for updating the pressure field. No extra conditions of immediate velocity fields are needed. The stability and convergence are investigated.
A second-order boundary-fitted projection method for free-surface flow computations
Yang, B.; Prosperetti, A.
2006-01-01
This paper describes a new approach to the high-fidelity simulation of axisymmetric free-surface flows. A boundary-fitted grid is coupled with a new projection method for the solution of the Navier–Stokes equations with second-order accuracy in space and time. Two variants of this new method are dev
Second-order fully discretized projection method for incompressible Navier-Stokes equations
Daniel X. Guo
2016-01-01
A second-order fully discretized projection method for the incompressible Navier-Stokes equations is proposed. It is an explicit method for updating the pressure field. No extra conditions of immediate velocity fields are needed. The stability and convergence are investigated.
Valentyn Chimshir; Anna Chimshir
2014-01-01
This work demonstrates correlation between technical system efficiency criterion and complex system efficiency criterion in which the said technical system operates. Furthermore, the said correlation may be expressed by means of a set of separate particular criteria of a complex system. Methodology of choosing the technical system for project implementation within the framework of project-oriented organization of a complex sociotechnical system is also proposed. The offered method provides fo...
Chen, Zhiwen
2017-01-01
Zhiwen Chen aims to develop advanced fault detection (FD) methods for the monitoring of industrial processes. With the ever increasing demands on reliability and safety in industrial processes, fault detection has become an important issue. Although the model-based fault detection theory has been well studied in the past decades, its applications are limited to large-scale industrial processes because it is difficult to build accurate models. Furthermore, motivated by the limitations of existing data-driven FD methods, novel canonical correlation analysis (CCA) and projection-based methods are proposed from the perspectives of process input and output data, less engineering effort and wide application scope. For performance evaluation of FD methods, a new index is also developed. Contents A New Index for Performance Evaluation of FD Methods CCA-based FD Method for the Monitoring of Stationary Processes Projection-based FD Method for the Monitoring of Dynamic Processes Benchmark Study and Real-Time Implementat...
Zurovac, Jelena; Esposito, Dominick
2014-11-01
The American Recovery and Reinvestment Act of 2009 (ARRA) directed nearly US$29.2 million to comparative effectiveness research (CER) methods development. To help inform future CER methods investments, we describe the ARRA CER methods projects, identify barriers to this research and discuss the alignment of topics with published methods development priorities. We used several existing resources and held discussions with ARRA CER methods investigators. Although funded projects explored many identified priority topics, investigators noted that much work remains. For example, given the considerable investments in CER data infrastructure, the methods development field can benefit from additional efforts to educate researchers about the availability of new data sources and about how best to apply methods to match their research questions and data.
INFORMATION SUPPORT OF THE PROJECT AS A METHOD OF FORMING METASUBJECT KNOWLEDGE
И Ф Зыкова
2016-12-01
Full Text Available One of the fastest growing educational facilities is an online training. it is aimed at the remote receive quality knowledge in different subjects and disciplines. Given the prospects for the development of teaching aids, we have considered the possibility of its integration into the traditional school systems. In particular, we have demonstrated the implementation of this method of learning through project- based learning - students create educational materials that will be posted on the Internet.In the article the different software tools were analyzed, allowing to implement all stages of the project development with the help of cloud computing, that is, providing a collaborative and interactive way to work on the project. There are online boards for the initial stages of project development, software for management and structured storage of documents, as well as platforms that enable aesthetically and creatively presentation of the project.Given the metasubject nature of topology, the integrative component of a method of projects, we have created an online tutorial on “A method of solving mazes.” Which answers our goal - to investigate the possibility of forming metasubject knowledge by studying the topological elements in the school course.
Pechir, Q.V.M.
1972-04-01
In the present work, the importance is pointed out of the physical and economical magnitude of secondary recovery of oil by injection of water. This is for the purpose of emphasizing the urgent necessity of attending to the problems of control and supervision which present themselves during the development of the projects. An example of such a project is cited (Tamaulipas-Constitucion) where the problems and failures gave many opportunities for delay in completion of some of the work. In some instances, there was overspending which might have been avoided in great part, if there had been controls and supervision suitable and adequate in importance to the magnitude and complexity of the project. Because of such situations, and for overcoming the initial deficiencies in control and supervision of these water-injection projects, it was decided to adopt the Visiflex method of control and the Visual Path method of work scheduling. A description of the parts is integrated into the method as well as the techniques of its application n the mentioned project, including a model of the Visual Path Program for the water- injection project in the Caliza San Andres (San Andres Limestone) formations of the Tamaulipas-Constitucion oil field.
Assessment on The Islamic Banking Market Share Projection by Bank Indonesia and Proposed Methods
Raditya Sukmana
2015-08-01
Full Text Available Indonesian Islamic banking market share projected by Bank Indonesia is an integral part in developing the industry in the country. By setting a projection which will then be used as a benchmark / target, Islamic banks can make a necessary program to attract new customers which eventually increase its asset. If the increase of the asset is significant,the Islamic bank market share may increase. The problem is that the current projection by Bank Indonesia seems to be off target. It means that the projection is pretty much above the actual value. This paper attempts to utilize two projection methods namely Spline and Auto-ARIMA which we think can provide a better result. This study uses the monthly data covering period since January 2006 until December 2012. The result shows that our projections, especially using Spline method, are closer to the actual value of the Islamic banking industry market share. It means that the gap between the projection and the actual value of market share is lesser than the gap on the Bank Indonesia calculation. Moreover, this study argue that, the projection of the Islamic banking market share made by BI will not be achieved unless with government support. So far, government has not made any policy which deposit some of the national budget in the Islamic bank. This study calculates that if government regularly depositing 1% of total National Government Budget in Islamic banks, the projection of Islamic banking market share made by BI will be acheived. As a conclusion, the role of government is very significant in developing the Islamic banking industry in Indonesia.
Hundecha, Yeshewatesfa; Sunyer, Maria A.; Lawrence, Deborah; Madsen, Henrik; Willems, Patrick; Bürger, Gerd; Kriaučiūnienė, Jurate; Loukas, Athanasios; Martinkova, Marta; Osuch, Marzena; Vasiliades, Lampros; von Christierson, Birgitte; Vormoor, Klaus; Yücel, Ismail
2016-10-01
The effect of methods of statistical downscaling of daily precipitation on changes in extreme flow indices under a plausible future climate change scenario was investigated in 11 catchments selected from 9 countries in different parts of Europe. The catchments vary from 67 to 6171 km2 in size and cover different climate zones. 15 regional climate model outputs and 8 different statistical downscaling methods, which are broadly categorized as change factor and bias correction based methods, were used for the comparative analyses. Different hydrological models were implemented in different catchments to simulate daily runoff. A set of flood indices were derived from daily flows and their changes have been evaluated by comparing their values derived from simulations corresponding to the current and future climate. Most of the implemented downscaling methods project an increase in the extreme flow indices in most of the catchments. The catchments where the extremes are expected to increase have a rainfall-dominated flood regime. In these catchments, the downscaling methods also project an increase in the extreme precipitation in the seasons when the extreme flows occur. In catchments where the flooding is mainly caused by spring/summer snowmelt, the downscaling methods project a decrease in the extreme flows in three of the four catchments considered. A major portion of the variability in the projected changes in the extreme flow indices is attributable to the variability of the climate model ensemble, although the statistical downscaling methods contribute 35-60% of the total variance.
Kurnik, Charles W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-09-28
This chapter provides a set of model protocols for determining energy and demand savings that result from specific energy efficiency measures implemented through state and utility efficiency programs. The methods described here are approaches that are or are among the most commonly used and accepted in the energy efficiency industry for certain measures or programs. As such, they draw from the existing body of research and best practices for energy efficiency program evaluation, measurement, and verification (EM&V). These protocols were developed as part of the Uniform Methods Project (UMP), funded by the U.S. Department of Energy (DOE). The principal objective for the project was to establish easy-to-follow protocols based on commonly accepted methods for a core set of widely deployed energy efficiency measures.
Hundecha, Yeshewatesfa; Sunyer Pinya, Maria Antonia; Lawrence, Deborah;
2016-01-01
flow indices in most of the catchments. The catchments where the extremes are expected to increase have a rainfall-dominated flood regime. In these catchments, the downscaling methods also project an increase in the extreme precipitation in the seasons when the extreme flows occur. In catchments where...... the flooding is mainly caused by spring/summer snowmelt, the downscaling methods project a decrease in the extreme flows in three of the four catchments considered. A major portion of the variability in the projected changes in the extreme flow indices is attributable to the variability of the climate model......The effect of methods of statistical downscaling of daily precipitation on changes in extreme flow indices under a plausible future climate change scenario was investigated in 11 catchments selected from 9 countries in different parts of Europe. The catchments vary from 67 to 6171km2 in size...
Bai, Xiao-ping; Zhang, Xi-wei
2013-01-01
Selecting construction schemes of the building engineering project is a complex multiobjective optimization decision process, in which many indexes need to be selected to find the optimum scheme. Aiming at this problem, this paper selects cost, progress, quality, and safety as the four first-order evaluation indexes, uses the quantitative method for the cost index, uses integrated qualitative and quantitative methodologies for progress, quality, and safety indexes, and integrates engineering economics, reliability theories, and information entropy theory to present a new evaluation method for building construction project. Combined with a practical case, this paper also presents detailed computing processes and steps, including selecting all order indexes, establishing the index matrix, computing score values of all order indexes, computing the synthesis score, sorting all selected schemes, and making analysis and decision. Presented method can offer valuable references for risk computing of building construction projects. PMID:23533352
Scattering cluster wave functions on the lattice using the adiabatic projection method
Rokash, Alexander; Elhatisari, Serdar; Lee, Dean; Epelbaum, Evgeny; Krebs, Hermann
2015-01-01
The adiabatic projection method is a general framework for studying scattering and reactions on the lattice. It provides a low-energy effective theory for clusters which becomes exact in the limit of large Euclidean projection time. Previous studies have used the adiabatic projection method to extract scattering phase shifts from finite periodic-box energy levels using L\\"uschers method. In this paper we demonstrate that scattering observables can be computed directly from asymptotic cluster wave functions. For a variety of examples in one and three spatial dimensions, we extract elastic phase shifts from asymptotic cluster standing waves corresponding to spherical wall boundary conditions. We find that this approach of extracting scattering wave functions from the adiabatic Hamiltonian to be less sensitive to small stochastic and systematic errors as compared with using periodic-box energy levels.
Xu, Hong-Kun
2017-04-01
Bounded perturbation resilience and superiorization techniques for the projected scaled gradient (PSG) method are studied under the general Hilbert space setting. Weak convergence results of the (superiorized) PSG method and its relaxed version are proved under the assumption that the errors be summable. It is also shown that the PSG method converges in a sublinear rate and can be accelerated to the convergence rate O≤ft(\\tfrac{1}{{n}2}\\right). Applications to linear inverse problems and split feasibility problems are discussed.
Image restoration by the method of convex projections: part 2 applications and numerical results.
Sezan, M I; Stark, H
1982-01-01
The image restoration theory discussed in a previous paper by Youla and Webb [1] is applied to a simulated image and the results compared with the well-known method known as the Gerchberg-Papoulis algorithm. The results show that the method of image restoration by projection onto convex sets, by providing a convenient technique for utilizing a priori information, performs significantly better than the Gerchberg-Papoulis method.
Working Seminar - a method for proactive learning in project based education
Nilsson, Fredrik
2012-01-01
This paper presents a method for increased individual and collective student learning called Working Seminar. The method is based on the assumption that groups with a common base of knowledge increase both the group results and the individual learning. The method has been developed and tested in three courses and the results of student projects and the individual comments from students during and after the courses have been used to evaluate its value. The result shows that individual le...
Ando, Yoshinobu; Eguchi, Yuya; Mizukawa, Makoto
In this research, we proposed and evaluated a management method of college mechatronics education. We applied the project management to college mechatronics education. We practiced our management method to the seminar “Microcomputer Seminar” for 3rd grade students who belong to Department of Electrical Engineering, Shibaura Institute of Technology. We succeeded in management of Microcomputer Seminar in 2006. We obtained the good evaluation for our management method by means of questionnaire.
Kun Ma
2014-10-01
Full Text Available Many universities are now offering software engineering an undergraduate level emphasizing knowledge point. However, some enterprise managers reflected that education ignore hands-on ability training, and claimed that there is the isolation between teaching and practice. This paper presents the design of a Software Engineering course (sixth semester in network engineering at University of Jinan for undergraduate Software Engineering students that uses virtualization technology to teach them project-driven learning-by-doing software development process. We present our motivation, challenges encountered, pedagogical goals and approaches, findings (both positive experiences and negative lessons. Our motivation was to teach project-driven Software Engineering using virtualization technology. The course also aims to develop entrepreneurial skills needed for software engineering graduates to better prepare them for the software industry. Billing models of virtualization help pupils and instructors find the cost of the experiment. In pay-as-you-go manner, two labs and three step-by-step projects (single project, pair project, and team project are designed to help the students to complete the assignment excitedly. We conduct some detailed surveys and present the results of student responses. The assessment process designed for this course is illustrated. The paper also shows that learning-by-doing method correlates with the characteristics of different projects, which has resulted in a successful experience as reported by students in an end of a semester survey.
Chun-Fu Li; Jue-Bang Yu
2008-01-01
In this three-part paper, an observer based projective synchronization method for a class of chaotic system is proposed. At the transmitter, a general observer is used to create the scalar signal for synchronizing. In this part, the structure of the projective synchronization method is presented. And the condition of projection synchronization is theoretically analyzed when the synchronization subsystem is linear.
Pyramid projection - validation of a new method of skin defect measurement.
Růzicka, J; Nový, P; Vávra, F; Bolek, L; Benes, J
2007-01-01
This paper presents a new method for the determination of the volume, surface area and depth of skin defects. The method is based on the description of a spatial defect using a pyramid (made, for example, from injection needles), which is placed over the defect. The projection of the pyramid on to the defect is photographed using a digital camera and subsequently compared with the projection of the same pyramid on to a sheet of grid paper. The defect is mathematically reconstructed on a computer, and an optimal body shape describing the defect is found, using a number of simplifications and assumptions. The method was then validated using a plaster mold of a real foot with 19 defects simulating real wounds. These plaster wounds were molded using alginate hydrocolloid, and the volume, surface area and depth were measured and compared with the results of the pyramid projection by means of regression analysis.This method correlates in all variables with correlation coefficients higher than 0.9. It can be concluded that the projection pyramid method correlates well with the reference mold method and can be used with good results for a whole range of variables.
Das, S.; Yadav, V. K.
2016-10-01
We study the chaos control and the function projective synchronization of a fractional-order T-system and Lorenz chaotic system using the backstepping method. Based on stability theory, we consider the condition for the local stability of nonlinear three-dimensional commensurate fractional-order system. Using the feedback control method, we control the chaos in the considered fractional-order T-system. We simulate the function projective synchronization between the fractional-order T-system and Lorenz system numerically using MATLAB and depict the results with plots.
Valentyn Chimshir
2014-06-01
Full Text Available This work demonstrates correlation between technical system efficiency criterion and complex system efficiency criterion in which the said technical system operates. Furthermore, the said correlation may be expressed by means of a set of separate particular criteria of a complex system. Methodology of choosing the technical system for project implementation within the framework of project-oriented organization of a complex sociotechnical system is also proposed. The offered method provides for a basis algorithm for calculations of situational efficiency criterion for technical system supposed to be applied within the project. The criterion in question indicates the extent to which the technical system is suitable for implementing its objective under specific conditions arising at various stages of the project implementation.
Project evaluation and selection using fuzzy Delphi method and zero - one goal programming
Alias, Suriana; Adna, Nofarziah; Arsad, Roslah; Soid, Siti Khuzaimah; Ali, Zaileha Md
2014-12-01
Project evaluation and selection is a factor affecting the impotence of board director in which is trying to maximize all the possible goals. Assessment of the problem occurred in organization plan is the first phase for decision making process. The company needs a group of expert to evaluate the problems. The Fuzzy Delphi Method (FDM) is a systematic procedure to evoke the group's opinion in order to get the best result to evaluate the project performance. This paper proposes an evaluation and selection of the best alternative project based on combination of FDM and Zero - One Goal Programming (ZOGP) formulation. ZOGP is used to solve the multi-criteria decision making for final decision part by using optimization software LINDO 6.1. An empirical example on an ongoing decision making project in Johor, Malaysia is implemented for case study.
Florin POPESCU
2017-12-01
Full Text Available Early warning system (EWS based on a reliable forecasting process has become a critical component of the management of large complex industrial projects in the globalized transnational environment. The purpose of this research is to critically analyze the forecasting methods from the point of view of early warning, choosing those useful for the construction of EWS. This research addresses complementary techniques, using Bayesian Networks, which addresses both uncertainties and causality in project planning and execution, with the goal of generating early warning signals for project managers. Even though Bayesian networks have been widely used in a range of decision-support applications, their application as early warning systems for project management is still new.
Time-Frequency Analysis and Hermite Projection Method Applied to Swallowing Accelerometry Signals
Ervin Sejdić
2010-01-01
Full Text Available Fast Hermite projections have been often used in image-processing procedures such as image database retrieval, projection filtering, and texture analysis. In this paper, we propose an innovative approach for the analysis of one-dimensional biomedical signals that combines the Hermite projection method with time-frequency analysis. In particular, we propose a two-step approach to characterize vibrations of various origins in swallowing accelerometry signals. First, by using time-frequency analysis we obtain the energy distribution of signal frequency content in time. Second, by using fast Hermite projections we characterize whether the analyzed time-frequency regions are associated with swallowing or other phenomena (vocalization, noise, bursts, etc.. The numerical analysis of the proposed scheme clearly shows that by using a few Hermite functions, vibrations of various origins are distinguishable. These results will be the basis for further analysis of swallowing accelerometry to detect swallowing difficulties.
柳华蔚; 郑树; 周怀春
2015-01-01
In order to improve the reconstruction performance for ill-posed emission tomographic problems with limited projec-tions, a generalized interpolation method is proposed in this paper, in which the virtual lines of projection are fabricated from, but not linearly dependent on, the measured projections. The method is called the virtual projection (VP) method. Also, an iterative correction method for the integral lengths is proposed to reduce the error brought about by the virtual lines of projection. The combination of the two methods is called the iterative virtual projection (IVP) method. Based on a scheme of equilateral triangle plane meshes and a six asymmetrically arranged detection system, numerical simulations and experimental verification are conducted. Simulation results obtained by using a non-negative linear least squares method, without any other constraints or regularization, demonstrate that the VP method can gradually reduce the reconstruction error and converges to the desired one by fabricating additional effective projections. When the mean square deviation of normal error superimposed on the simulated measured projections is smaller than 0.03, i.e., the signal-to-noise ratio (SNR) for the measured projections is higher than 30.4, the IVP method can further reduce the reconstruction error reached by the VP method apparently. In addition, as the regularization matrix in the Tikhonov regularization method is updated by an iterative correction process similar to the IVP method presented in this paper, or the Tikhonov regularization method is used in the IVP method, good improvement is achieved.
Yuxin Ren; Yuxi Jiang; Miao'er Liu; Hanxin Zhang
2005-01-01
In this paper, a fully third-order accurate projection method for solving the incompressible Navier-Stokes equations is proposed. To construct the scheme, a continuous projection procedure is firstly presented. We then derive a sufficient condition for the continuous projection equations to be temporally third-order accurate approximations of the original Navier-Stokes equations by means of the localtruncation-error-analysis technique. The continuous projection equations are discretized temporally and spatially to third-order accuracy on the staggered grids, resulting in a fully third-order discrete projection scheme. The possibility to design higher-order projection methods is thus demonstrated in the present paper. A heuristic stability analysis is performed on this projection method showing the probability of its being stable. The stability of the present scheme is further verified through numerical tests. The third-order accuracy of the present projection method is validated by several numerical test cases.
Level Set Projection Method for Incompressible Navier-Stokes on Arbitrary Boundaries
Williams-Rioux, Bertrand
2012-01-12
Second order level set projection method for incompressible Navier-Stokes equations is proposed to solve flow around arbitrary geometries. We used rectilinear grid with collocated cell centered velocity and pressure. An explicit Godunov procedure is used to address the nonlinear advection terms, and an implicit Crank-Nicholson method to update viscous effects. An approximate pressure projection is implemented at the end of the time stepping using multigrid as a conventional fast iterative method. The level set method developed by Osher and Sethian [17] is implemented to address real momentum and pressure boundary conditions by the advection of a distance function, as proposed by Aslam [3]. Numerical results for the Strouhal number and drag coefficients validated the model with good accuracy for flow over a cylinder in the parallel shedding regime (47 < Re < 180). Simulations for an array of cylinders and an oscillating cylinder were performed, with the latter demonstrating our methods ability to handle dynamic boundary conditions.
Jéfferson Jesus de Araujo
2016-06-01
Full Text Available The research is aimed at practical application of the ELECTRE I method for decision-making support in the selection of projects by a free software development company in the city of Juazeiro - BA. The methodology used in the company, the projects to be evaluated, the criteria chosen by the decision maker and their respective weights were used to model the problem, by building decision matrix and conducting ELECTRE I. The results proved effective, satisfying the proposal made in the research. Finally, the conclusions are presented, provoking a discussion of the current method and the proposed method, suggesting the application of the ELECTRE I method and other MCDA methods for other decision-making problems at the company.
CT metal artifact reduction method correcting for beam hardening and missing projections
Verburg, Joost M.; Seco, Joao
2012-05-01
We present and validate a computed tomography (CT) metal artifact reduction method that is effective for a wide spectrum of clinical implant materials. Projections through low-Z implants such as titanium were corrected using a novel physics correction algorithm that reduces beam hardening errors. In the case of high-Z implants (dental fillings, gold, platinum), projections through the implant were considered missing and regularized iterative reconstruction was performed. Both algorithms were combined if multiple implant materials were present. For comparison, a conventional projection interpolation method was implemented. In a blinded and randomized evaluation, ten radiation oncologists ranked the quality of patient scans on which the different methods were applied. For scans that included low-Z implants, the proposed method was ranked as the best method in 90% of the reviews. It was ranked superior to the original reconstruction (p = 0.0008), conventional projection interpolation (p implants, and better as compared to the original reconstruction (p combining algorithms tailored to specific types of implant materials.
Elhatisari, Serdar; Lee, Dean
2014-12-01
We present lattice Monte Carlo calculations of fermion-dimer scattering in the limit of zero-range interactions using the adiabatic projection method. The adiabatic projection method uses a set of initial cluster states and Euclidean time projection to give a systematically improvable description of the low-lying scattering cluster states in a finite volume. We use Lüscher's finite-volume relations to determine the s -wave, p -wave, and d -wave phase shifts. For comparison, we also compute exact lattice results using Lanczos iteration and continuum results using the Skorniakov-Ter-Martirosian equation. For our Monte Carlo calculations we use a new lattice algorithm called impurity lattice Monte Carlo. This algorithm can be viewed as a hybrid technique which incorporates elements of both worldline and auxiliary-field Monte Carlo simulations.
Wang, Tianren
2015-01-01
This paper presents a numerical study on a fast marching method based back projection reconstruction algorithm for photoacoustic tomography in heterogeneous media. Transcranial imaging is used here as a case study. To correct for the phase aberration from the heterogeneity (i.e., skull), the fast marching method is adopted to compute the phase delay based on the known speed of sound distribution, and the phase delay is taken into account by the back projection algorithm for more accurate reconstructions. It is shown that the proposed algorithm is more accurate than the conventional back projection algorithm, but slightly less accurate than the time reversal algorithm particularly in the area close to the skull. However, the image reconstruction time for the proposed algorithm can be as little as 124 ms when implemented by a GPU (512 sensors, 21323 pixels reconstructed), which is two orders of magnitude faster than the time reversal reconstruction. The proposed algorithm, therefore, not only corrects for the p...
Fermion-Dimer Scattering using Impurity Lattice Monte Carlo and the Adiabatic Projection Method
Elhatisari, Serdar
2014-01-01
We present lattice Monte Carlo calculations of fermion-dimer scattering in the limit of zero-range interactions using the adiabatic projection method. The adiabatic projection method uses a set of initial cluster states and Euclidean time projection to give a systematically improvable description of the low-lying scattering cluster states in a finite volume. We use L\\"uscher's finite-volume relations to determine the $s$-wave, $p$-wave, and $d$-wave phase shifts. For comparison, we also compute exact lattice results using Lanczos iteration and continuum results using the Skorniakov-Ter-Martirosian equation. For our Monte Carlo calculations we use a new lattice algorithm called impurity lattice Monte Carlo. This algorithm can be viewed as a hybrid technique which incorporates elements of both worldline and auxiliary-field Monte Carlo simulations.
An Aural Learning Project: Assimilating Jazz Education Methods for Traditional Applied Pedagogy
Gamso, Nancy M.
2011-01-01
The Aural Learning Project (ALP) was developed to incorporate jazz method components into the author's classical practice and her applied woodwind lesson curriculum. The primary objective was to place a more focused pedagogical emphasis on listening and hearing than is traditionally used in the classical applied curriculum. The components of the…
Bondar, Irina Alekseevna; Kulbakova, Renata Ivanovna; Svintorzhitskaja, Irina Andreevna; Pilat, Larisa Pavlovna; Zavrumov, Zaur Aslanovich
2016-01-01
The article explains how to use a project-based method as an effective means of interdisciplinary interaction when teaching a foreign language on the example of The Institute of service, tourism and design (branch) of the North Caucasus Federal University (Pyatigorsk, Stavropol Territory Russia). The article holds the main objectives of the…
Molecular biological methods for studying the gut microbiota : the EU human gut flora project
Blaut, M; Collins, MD; Welling, GW; Dore, J; van Loo, J; de Vos, W
2002-01-01
Seven European laboratories co-operated in a joint project (FAIR CT97-3035) to develop, refine and apply molecular methods towards facilitating elucidation of the complex composition of the human intestinal microflora and to devise robust methodologies for monitoring the gut flora in response to die
Accurate two-dimensional IMRT verification using a back-projection EPID dosimetry method.
Wendling, M.; Louwe, R.J.W.; McDermott, L.N.; Sonke, J.J.; Herk, M. van; Mijnheer, B.J.
2006-01-01
The use of electronic portal imaging devices (EPIDs) is a promising method for the dosimetric verification of external beam, megavoltage radiation therapy-both pretreatment and in vivo. In this study, a previously developed EPID back-projection algorithm was modified for IMRT techniques and applied
Lee, Ho; Lee, Jeongjin; Shin, Yeong Gil; Lee, Rena; Xing, Lei
2010-06-21
This paper presents a fast and accurate marker-based automatic registration technique for aligning uncalibrated projections taken from a transmission electron microscope (TEM) with different tilt angles and orientations. Most of the existing TEM image alignment methods estimate the similarity between images using the projection model with least-squares metric and guess alignment parameters by computationally expensive nonlinear optimization schemes. Approaches based on the least-squares metric which is sensitive to outliers may cause misalignment since automatic tracking methods, though reliable, can produce a few incorrect trajectories due to a large number of marker points. To decrease the influence of outliers, we propose a robust similarity measure using the projection model with a Gaussian weighting function. This function is very effective in suppressing outliers that are far from correct trajectories and thus provides a more robust metric. In addition, we suggest a fast search strategy based on the non-gradient Powell's multidimensional optimization scheme to speed up optimization as only meaningful parameters are considered during iterative projection model estimation. Experimental results show that our method brings more accurate alignment with less computational cost compared to conventional automatic alignment methods.
Boyle, Elizabeth; Van Rosmalen, Peter; MacArthur, Ewan; Connolly, Thomas; Hainey, Thomas
2012-01-01
Boyle, E., Van Rosmalen, P., MacArthur, E., Connolly, T., Hainey, T. & et al. (2012). Cognitive Task Analysis (CTA) in the Continuing/ Higher Education Methods Using Games (CHERMUG) Project. In P. Felicia (Ed.), Proceedings of the 6th European Conference on Games Based Learning (pp. 63-71). October,
Cross-Course Projects: Teaching Students on Changing Business Communication Methods
Flosi, Alicen; Fraccastoro, Kathy; Moss, Gisele J.
2010-01-01
The current business environment requires various communication skills to succeed. The skills include the use of a number of technologies that were not available 20 years ago. For this research, students were required to complete a project with students not in their own class using alternative communication methods. A questionnaire was…
Privatization and Other Post-Contract Reform Project Delivery Methods: What Works Best and Why
Person, J. C.
2003-02-27
This paper explores the successes and failures of privatization and other contract reform initiatives within the DOE Weapons Complex over the past seven years. The paper concludes that the successes and failures of these project delivery methods depend largely on the risks attendant with the project itself. For example, where the wastes to be remediated defy characterization and the technology is innovative, the Department ordinarily should bear most of the risk, and some specie of cost-reimbursable contracting should be employed. On the other hand, where the risks are readily quantifiable and the technology is proven, more of the risk and responsibility can and should be placed on the contractor. This form of risk transference runs the continuum from lump-sum contracting to design/build, to privatization, depending on the circumstances. The preferred contracting form, however, is not dictated solely by project-related risk. Onto this risk must be overlain a set of risks that derive from the project management capabilities and the institutional biases of the oversight M&O or M&I contractor. Foremost among this additional set of risks is the ability of the oversight contractor to employ a level of contractual interface that is commensurate and proportionate with the selected project delivery method.
REAL OPTIONS ANALYSIS – ASSESSMENT METHOD OF INVESTMENT PROJECTS IN GREEN ENERGY
MAFTEI DANIEL
2014-10-01
Full Text Available This article highlights the importance of real options as a evaluation method of investment in green energy. Article consider several theoretical and practical approaches, the analysis based on real options by many authors who have theorized and used this method. Each approach provides a operationalisation through a steps series of specific evaluation. This paper highlights the different views: academics, financiers, managers and facilitates the access to an accurate evaluation decisions of projects.
Research and development of fringe projection-based methods in 3D shape reconstruction
WU Lu-shen; PENG Qing-jin
2006-01-01
This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system improves the method of phase unwrapping to gain accurate 3D shapes of objects. The method uses a region-growing algorithm for the path prediction guided by the quality map to increase the recovering accuracy and provides a fast and simple tool for 3D shape recovery. The shape measurement and data recovery are integrated to offer a new method of 3D modelling. Examples are presented to verify the feasibility of the proposed method.
Marko Mladineo
2016-12-01
Full Text Available In the last 20 years, priority setting in mine actions, i.e. in humanitarian demining, has become an increasingly important topic. Given that mine action projects require management and decision-making based on a multi -criteria approach, multi-criteria decision-making methods like PROMETHEE and AHP have been used worldwide for priority setting. However, from the aspect of mine action, where stakeholders in the decision-making process for priority setting are project managers, local politicians, leaders of different humanitarian organizations, or similar, applying these methods can be difficult. Therefore, a specialized web-based decision support system (Web DSS for priority setting, developed as part of the FP7 project TIRAMISU, has been extended using a module for developing custom priority setting scenarios in line with an exceptionally easy, user-friendly approach. The idea behind this research is to simplify the multi-criteria analysis based on the PROMETHEE method. Therefore, a simplified PROMETHEE method based on statistical analysis for automated suggestions of parameters such as preference function thresholds, interactive selection of criteria weights, and easy input of criteria evaluations is presented in this paper. The result is web-based DSS that can be applied worldwide for priority setting in mine action. Additionally, the management of mine action projects is supported using modules for providing spatial data based on the geographic information system (GIS. In this paper, the benefits and limitations of a simplified PROMETHEE method are presented using a case study involving mine action projects, and subsequently, certain proposals are given for the further research.
Evaluation and selection of decision-making methods to assess landfill mining projects.
Hermann, Robert; Baumgartner, Rupert J; Vorbach, Stefan; Ragossnig, Arne; Pomberger, Roland
2015-09-01
For the first time in Austria, fundamental technological and economic studies on recovering secondary raw materials from large landfills have been carried out, based on the 'LAMIS - Landfill Mining Austria' pilot project. A main focus of the research - and the subject of this article - was to develop an assessment or decision-making procedure that allows landfill owners to thoroughly examine the feasibility of a landfill mining project in advance. Currently there are no standard procedures that would sufficiently cover all the multiple-criteria requirements. The basic structure of the multiple attribute decision making process was used to narrow down on selection, conceptual design and assessment of suitable procedures. Along with a breakdown into preliminary and main assessment, the entire foundation required was created, such as definitions of requirements to an assessment method, selection and accurate description of the various assessment criteria and classification of the target system for the present 'landfill mining' vs. 'retaining the landfill in after-care' decision-making problem. Based on these studies, cost-utility analysis and the analytical-hierarchy process were selected from the range of multiple attribute decision-making procedures and examined in detail. Overall, both methods have their pros and cons with regard to their use for assessing landfill mining projects. Merging these methods or connecting them with single-criteria decision-making methods (like the net present value method) may turn out to be reasonable and constitute an appropriate assessment method.
An Appraisal of Project Procurement Methods in the Nigerian Construction Industry
Ujaddughe I.C.
2010-01-01
Full Text Available The aim of every client at the beginning of any project is to have at the end of the day a quality structure delivered on time and within budget. However, researches have shown that in most cases this aim is not met. The aim of the study that formed the basis for this paper was to identify and assess procurement methods in use in the Nigerian construction industry and identify the factors that affect the choice of the variants under the traditional and the non-conventional procurement methods. Data were collected using well-structured questionnaires administered to professionals in Lagos metropolis. Data collected were analyzed using descriptive and inferential statistics. The study reveals that the variants of traditional method of contract procurement are the most adopted in project execution in Nigeria. In making choice of procurement method, the study reveals that project completion at estimated time ranks as the highest factor considered for traditional method, while quality assurance ranks highest with non-conventional method.
A Refined Method for Estimating the Annual Extreme Wave Heights at A Project Site
徐德伦; 范海梅; 张军
2003-01-01
This paper presents a refined method for estimating the annual extreme wave heights at a coastal or offshore project site on the basis of the data acquired at some nearby routine hydrographic stations. This method is based on the orthogonality principle in linear mean square estimation of stochastic processes. The error of the method is analyzed and compared with that of the conventional method. It is found that the method is able to effectively reduce the error so long as some feasible measures are adopted. A simulated test of the method has been conducted in a large-scale wind-wave flume. The test results are in good agreement with those given by theoretical error analysis. A scheme to implement the method is proposed on the basis of error analysis. The scheme is so designed as to reduce the estimation error as far as possible. This method is also suitable to utilizing satellite wave data for the estimation.
Wang, Qi; Wang, Huaxiang; Zhang, Ronghua; Wang, Jinhai; Zheng, Yu; Cui, Ziqiang; Yang, Chengyi
2012-10-01
Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at the boundary of a subject and measuring the resulting changes in voltage. Image reconstruction in EIT is a nonlinear and ill-posed inverse problem. The Tikhonov method with L(2) regularization is always used to solve the EIT problem. However, the L(2) method always smoothes the sharp changes or discontinue areas of the reconstruction. Image reconstruction using the L(1) regularization allows addressing this difficulty. In this paper, a sum of absolute values is substituted for the sum of squares used in the L(2) regularization to form the L(1) regularization, the solution is obtained by the barrier method. However, the L(1) method often involves repeatedly solving large-dimensional matrix equations, which are computationally expensive. In this paper, the projection method is combined with the L(1) regularization method to reduce the computational cost. The L(1) problem is mainly solved in the coarse subspace. This paper also discusses the strategies of choosing parameters. Both simulation and experimental results of the L(1) regularization method were compared with the L(2) regularization method, indicating that the L(1) regularization method can improve the quality of image reconstruction and tolerate a relatively high level of noise in the measured voltages. Furthermore, the projected L(1) method can also effectively reduce the computational time without affecting the quality of reconstructed images.
The Impact of Project Work and the Writing Process Method on Writing Production
Marcela Díaz Ramírez
2014-10-01
Full Text Available This article presents the outcomes of an investigation whose main goal was to implement the methodology of project work and a process approach in order to improve writing production in an English class of Colombian university students since their diagnostic tests showed that their written production had the lowest score. Based on data collected, four factors were developed in the process of learning to write when project work and the writing process method are implemented: accuracy, fluency, integrative language skills, and a positive perception towards writing.
Jian Guo
2013-01-01
Full Text Available Information system (IS project selection is of critical importance to every organization in dynamic competing environment. The aim of this paper is to develop a hybrid multicriteria group decision making approach based on intuitionistic fuzzy theory for IS project selection. The decision makers’ assessment information can be expressed in the form of real numbers, interval-valued numbers, linguistic variables, and intuitionistic fuzzy numbers (IFNs. All these evaluation pieces of information can be transformed to the form of IFNs. Intuitionistic fuzzy weighted averaging (IFWA operator is utilized to aggregate individual opinions of decision makers into a group opinion. Intuitionistic fuzzy entropy is used to obtain the entropy weights of the criteria. TOPSIS method combined with intuitionistic fuzzy set is proposed to select appropriate IS project in group decision making environment. Finally, a numerical example for information system projects selection is given to illustrate application of hybrid multi-criteria group decision making (MCGDM method based on intuitionistic fuzzy theory and TOPSIS method.
Binding energy and dephasing of biexcitons in In0.18Ga0.82As/GaAs single quantum wells
Borri, Paola; Langbein, Wolfgang Werner; Hvam, Jørn Märcher
1999-01-01
Biexciton binding energies and biexciton dephasing in In0.18Ga0.82As/GaAs single quantum wells have been measured by time-integrated and spectrally resolved four-wave mixing. The biexciton binding energy increases from 1.5 to 2.6 meV for well widths increasing from 1 to 4 nm. The ratio between ex...
The Projection Method for Reaching Consensus and the Regularized Power Limit of a Stochastic Matrix
Agaev, R P
2011-01-01
In the coordination/consensus problem for multi-agent systems, a well-known condition of achieving consensus is the presence of a spanning arborescence in the communication digraph. The paper deals with the discrete consensus problem in the case where this condition is not satisfied. A characterization of the subspace $T_P$ of initial opinions (where $P$ is the influence matrix) that \\emph{ensure} consensus in the DeGroot model is given. We propose a method of coordination that consists of: (1) the transformation of the vector of initial opinions into a vector belonging to $T_P$ by orthogonal projection and (2) subsequent iterations of the transformation $P.$ The properties of this method are studied. It is shown that for any non-periodic stochastic matrix $P,$ the resulting matrix of the orthogonal projection method can be treated as a regularized power limit of $P.$
Puckett, Elbridge Gerry; Almgren, Ann S.; Bell, John B.; Marcus, Daniel L.; Rider, William J.
1997-01-01
We present a numerical method for computing solutions of the incompressible Euler or Navier-Stokes equations when a principal feature of the flow is the presence of an interface between two fluids with different fluid properties. The method is based on a second-order projection method for variable density flows using an "approximate projection" formulation. The boundary between the fluids is tracked with a second-order, volume-of-fluid interface tracking algorithm. We present results for viscious Rayleigh-Taylor problems at early time with equal and unequal viscosities to demonstrate the convergence of the algorithm. We also present computational results for the Rayleigh-Taylor instability in air-helium and for bubbles and drops in an air-water system without surface tension to demonstrate the behavior of the algorithm on problems with large density and viscosity contrasts.
Reduced projection augmented Lagrange bi-conjugate gradient method for contact and impact problems
无
2007-01-01
Based on the numerical governing formulation and non-linear complementary conditions of contact and impact problems, a reduced projection augmented Lagrange biconjugate gradient method is proposed for contact and impact problems by translating non-linear complementary conditions into equivalent formulation of non-linear programming. For contact-impact problems, a larger time-step can be adopted arriving at numerical convergence compared with penalty method. By establishment of the impact-contact formulations which are equivalent with original non-linear complementary conditions, a reduced projection augmented Lagrange bi-conjugate gradient method is deduced to improve precision and efficiency of numerical solutions. A numerical example shows that the algorithm we suggested is valid and exact.
Shung Han Cho; Yuntai Kyong; Sangjin Hong; We-Duke Cho
2009-01-01
This paper presents a novel self localization method using parallel projection model for mobile sensor in navigation applications. The algorithm estimates the coordinate and the orientation of mobile sensor using projected on visual image. The proposed method considers the lens non-linearity of the camera and compensates the distortion by using a calibration table. The method determines the coordinates and orientations with iterative process, which is very accurate with low computational demand. We identify various sources of error on the coordinate and orientation estimations, and present both static sensitivity analysis of the algorithm and dynamic behavior of the mobile sensor. The algorithm can be utilized in mobile robot navigation as well as positioning application where accurate self localization is necessary.
Capital Finance Decisions for project managers - A reflection on current methods
C. Scheepers
2003-12-01
Full Text Available This paper evaluates some of current financial investment selection methodologies for capital projects. The proc ess (and criteria of capital investment decisions is reviewed. The capital budget for most organisations is prepared annually by a committee of senior managers who then present it for approval by the board of directors. Investment proposals are usually subjected to two financial tests, "payback" and "internal rate of return (IRR". The management committee usually decides on the tests and acceptance criteria vary according to the type of project. Some shortcomings of these most frequently used current tests (Payback & IRR are identified and it is recommended that the Net Present Value (NPV should be used as the primary method for analysing, comparing and selecting capital projects.
A moment projection method for population balance dynamics with a shrinkage term
Wu, Shaohua; Yapp, Edward K. Y.; Akroyd, Jethro; Mosbach, Sebastian; Xu, Rong; Yang, Wenming; Kraft, Markus
2017-02-01
A new method of moments for solving the population balance equation is developed and presented. The moment projection method (MPM) is numerically simple and easy to implement and attempts to address the challenge of particle shrinkage due to processes such as oxidation, evaporation or dissolution. It directly solves the moment transport equation for the moments and tracks the number of the smallest particles using the algorithm by Blumstein and Wheeler (1973) [41]. The performance of the new method is measured against the method of moments (MOM) and the hybrid method of moments (HMOM). The results suggest that MPM performs much better than MOM and HMOM where shrinkage is dominant. The new method predicts mean quantities which are almost as accurate as a high-precision stochastic method calculated using the established direct simulation algorithm (DSA).
A moment projection method for population balance dynamics with a shrinkage term
Wu, Shaohua [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Yapp, Edward K.Y.; Akroyd, Jethro; Mosbach, Sebastian [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore); Yang, Wenming [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)
2017-02-01
A new method of moments for solving the population balance equation is developed and presented. The moment projection method (MPM) is numerically simple and easy to implement and attempts to address the challenge of particle shrinkage due to processes such as oxidation, evaporation or dissolution. It directly solves the moment transport equation for the moments and tracks the number of the smallest particles using the algorithm by Blumstein and Wheeler (1973) . The performance of the new method is measured against the method of moments (MOM) and the hybrid method of moments (HMOM). The results suggest that MPM performs much better than MOM and HMOM where shrinkage is dominant. The new method predicts mean quantities which are almost as accurate as a high-precision stochastic method calculated using the established direct simulation algorithm (DSA).
Video Frames Reconstruction Based on Time-Frequency Analysis and Hermite Projection Method
Krylov Andrey
2010-01-01
Full Text Available A method for temporal analysis and reconstruction of video sequences based on the time-frequency analysis and Hermite projection method is proposed. The S-method-based time-frequency distribution is used to characterize stationarity within the sequence. Namely, a sequence of DCT coefficients along the time axes is used to create a frequency-modulated signal. The reconstruction of nonstationary sequences is done using the Hermite expansion coefficients. Here, a small number of Hermite coefficients can be used, which may provide significant savings for some video-based applications. The results are illustrated with video examples.
An iterative regularization method for nonlinear problems based on Bregman projections
Maaß, Peter; Strehlow, Robin
2016-11-01
In this paper, we present an iterative method for the regularization of ill-posed, nonlinear problems. The approach is based on the Bregman projection onto stripes the width of which is controlled by both the noise level and the structure of the operator. In our investigations, we follow (Lorenz et al 2014 SIAM J. Imaging Sci. 7 1237-62) and extend the respective method to the setting of nonlinear operators. Furthermore, we present a proof for the regularizing properties of the method.
A Projected Non-linear Conjugate Gradient Method for Interactive Inverse Kinematics
Engell-Nørregård, Morten; Erleben, Kenny
2009-01-01
Inverse kinematics is the problem of posing an articulated figure to obtain a wanted goal, without regarding inertia and forces. Joint limits are modeled as bounds on individual degrees of freedom, leading to a box-constrained optimization problem. We present A projected Non-linear Conjugate...... Gradient optimization method suitable for box-constrained optimization problems for inverse kinematics. We show application on inverse kinematics positioning of a human figure. Performance is measured and compared to a traditional Jacobian Transpose method. Visual quality of the developed method...
The Financial Impact of Risk Factors Affecting Project Cost Contingency: Evidential Reasoning Method
Emmanuel Abeere-Inga
2013-07-01
Full Text Available The process of cost modeling using risk analysis for construction projects is very crucial for the achievement of project success. The purpose of this paper is to present an analysis of the financial impact of risk factors affecting key construction work sections; using a systematic risk methodology based on empirical judgment. The failure mode effect analysis (FMEA and the evidential reasoning methods are presented as qualitative and quantitative risk tools respectively. Data analysis from structured questionnaires revealed that four work sections are prone to high scope changes contemporaneous with seven risk factors. Contrary to the usual 10% contingency estimate allowed for construction projects in Ghana, an approximate overall physical contingency range of between 13.36% and 17.88% was determined using evidential reasoning methods. The likely impact of the integrated work sections and risk factors provide a clue to estimators on how to estimate and account for project cost contingency. The research concludes by recommending a framework for improving the estimation process of cost contingency through the integration of efficient risk management strategies, cost estimation and design management process.
Demographic Models for Projecting Population and Migration: Methods for African Historical Analysis
Patrick Manning
2015-08-01
Full Text Available This study presents methods for projecting population and migration over time in cases were empirical data are missing or undependable. The methods are useful for cases in which the researcher has details of population size and structure for a limited period of time (most obviously, the end point, with scattered evidence on other times. It enables estimation of population size, including its structure in age, sex, and status, either forward or backward in time. The program keeps track of all the details. The calculated data can be reported or sampled and compared to empirical findings at various times and places to expected values based on other procedures of estimation. The application of these general methods that is developed here is the projection of African populations backwards in time from 1950, since 1950 is the first date for which consistently strong demographic estimates are available for national-level populations all over the African continent. The models give particular attention to migration through enslavement, which was highly important in Africa from 1650 to 1900. Details include a sensitivity analysis showing relative significance of input variables and techniques for calibrating various dimensions of the projection with each other. These same methods may be applicable to quite different historical situations, as long as the data conform in structure to those considered here.
Nikazad, T.; Davidi, R.; Herman, G. T.
2012-03-01
We study the convergence of a class of accelerated perturbation-resilient block-iterative projection methods for solving systems of linear equations. We prove convergence to a fixed point of an operator even in the presence of summable perturbations of the iterates, irrespective of the consistency of the linear system. For a consistent system, the limit point is a solution of the system. In the inconsistent case, the symmetric version of our method converges to a weighted least-squares solution. Perturbation resilience is utilized to approximate the minimum of a convex functional subject to the equations. A main contribution, as compared to previously published approaches to achieving similar aims, is a more than an order of magnitude speed-up, as demonstrated by applying the methods to problems of image reconstruction from projections. In addition, the accelerated algorithms are illustrated to be better, in a strict sense provided by the method of statistical hypothesis testing, than their unaccelerated versions for the task of detecting small tumors in the brain from x-ray CT projection data.
Trace projection transformation: a new method for measurement of debris flow surface velocity fields
Yan, Yan; Cui, Peng; Guo, Xiaojun; Ge, Yonggang
2016-12-01
Spatiotemporal variation of velocity is important for debris flow dynamics. This paper presents a new method, the trace projection transformation, for accurate, non-contact measurement of a debris-flow surface velocity field based on a combination of dense optical flow and perspective projection transformation. The algorithm for interpreting and processing is implemented in C ++ and realized in Visual Studio 2012. The method allows quantitative analysis of flow motion through videos from various angles (camera positioned at the opposite direction of fluid motion). It yields the spatiotemporal distribution of surface velocity field at pixel level and thus provides a quantitative description of the surface processes. The trace projection transformation is superior to conventional measurement methods in that it obtains the full surface velocity field by computing the optical flow of all pixels. The result achieves a 90% accuracy of when comparing with the observed values. As a case study, the method is applied to the quantitative analysis of surface velocity field of a specific debris flow.
Pedro Brandão
2015-06-01
• In the development of design practice and studio teaching methods We shall see in this paper how interdisciplinary approaches correspond to new and complex urban transformations, focusing on the importance of actors’ interaction processes, combining professional and non-professional knowledge and theory-practice relations. Therefore, we aim at a deepening in public space area of knowledge under the growing complexity of urban life. We see it as a base for further development of collaborative projects and their implications on community empowerment and urban governance at local level. Motivations of this line of work are persistent in several ongoing research projects, aiming to: - Understand public space as a cohesion factor both in urban life and urban form - Manage processes and strategies as elements of urban transformation, - Stimulate the understanding of actors’ roles in urban design practices. - Favoring the questioning of emerging aspects of urban space production… The paper presents and analyses processes, methods and results from civic participation projects developed in the neighbourhood of Barò de Viver (Barcelona and in the District of Marvila (Lisbon. In the first case, a long process initiated in 2004 and partially completed in 2011, neighbours developed the projects "Memory Wall" and Ciutat d'Asuncion Promenade as part of identity construction in public space, in collaboration with a team of facilitators from CrPolis group. In the second case, different participatory processes dated from 2001 and 2003 have resulted in the implementation of a specific identity urban brand and communication system with an ongoing project of "maps" construction according to the neighbours perception and representation systems. We may conclude that processes of urban governance require more active participation of citizens in projects regarding the improvement of quality of life. At the same time, the implementation of these processes requires a clear
Glazoff, Michael V.; Gering, Kevin L.; Garnier, John E.; Rashkeev, Sergey N.; Pyt'ev, Yuri Petrovich
2016-05-17
Embodiments discussed herein in the form of methods, systems, and computer-readable media deal with the application of advanced "projectional" morphological algorithms for solving a broad range of problems. In a method of performing projectional morphological analysis, an N-dimensional input signal is supplied. At least one N-dimensional form indicative of at least one feature in the N-dimensional input signal is identified. The N-dimensional input signal is filtered relative to the at least one N-dimensional form and an N-dimensional output signal is generated indicating results of the filtering at least as differences in the N-dimensional input signal relative to the at least one N-dimensional form.
Comparison of parabolic filtration methods for 3D filtered back projection in pulsed EPR imaging.
Qiao, Zhiwei; Redler, Gage; Epel, Boris; Halpern, Howard J
2014-11-01
Pulse electron paramagnetic resonance imaging (Pulse EPRI) is a robust method for noninvasively measuring local oxygen concentrations in vivo. For 3D tomographic EPRI, the most commonly used reconstruction algorithm is filtered back projection (FBP), in which the parabolic filtration process strongly influences image quality. In this work, we designed and compared 7 parabolic filtration methods to reconstruct both simulated and real phantoms. To evaluate these methods, we designed 3 error criteria and 1 spatial resolution criterion. It was determined that the 2 point derivative filtration method and the two-ramp-filter method have unavoidable negative effects resulting in diminished spatial resolution and increased artifacts respectively. For the noiseless phantom the rectangular-window parabolic filtration method and sinc-window parabolic filtration method were found to be optimal, providing high spatial resolution and small errors. In the presence of noise, the 3 point derivative method and Hamming-window parabolic filtration method resulted in the best compromise between low image noise and high spatial resolution. The 3 point derivative method is faster than Hamming-window parabolic filtration method, so we conclude that the 3 point derivative method is optimal for 3D FBP. Copyright © 2014. Published by Elsevier Inc.
A. O. Baklanov
2011-01-01
Full Text Available The following principles are discussed as methodical bases of the choice of innovative project and enterprise management organizational structures: hierarchism, bureaucratization, adhocratie, tent organization, lean business engineering, rational organization, amorphous organization, teaching organization. Conditions that complicate industrial and technological processes influence enterprise management process dynamics. The variety of existing types of organizational structures is determined by industrial, economic, psychological and social conditions.
无
2008-01-01
Based on a differentiable merit function proposed by Taji,et al in "Mathematical Programming,1993,58: 369-383",a projected gradient trust region method for the monotone variational inequality problem with convex constraints is presented.Theoretical analysis is given which proves that the proposed algorithm is globally convergent and has a local quadratic convergence rate under some reasonable conditions.The results of numerical experiments are reported to show the effectiveness of the proposed algorithm.
Simple Radiowave-Based Method For Measuring Peripheral Blood Flow Project
Oliva-Buisson, Yvette J.
2014-01-01
Project objective is to design small radio frequency based flow probes for the measurement of blood flow velocity in peripheral arteries such as the femoral artery and middle cerebral artery. The result will be the technological capability to measure peripheral blood flow rates and flow changes during various environmental stressors such as microgravity without contact to the individual being monitored. This technology may also lead to an easier method of detecting venous gas emboli during extravehicular activities.
Huybrechts, Inge; Sioen, Isabelle; Boon, Polly E; Ruprich, Jiri; Lafay, Lionel; Turrini, Aida; Amiano, Pilar; Hirvonen, Tero; Neve, Melissa; Arcella, Davide; Moschandreas, Joanna; Westerlund, Anna; Ribas-Barba, Lourdes; Hilbig, Annett; Papoutsou, Stalo
2011-01-01
Background/purpose The number of dietary exposure assessment studies focussing on children is very limited. Children are however a vulnerable group due to their higher food consumption level per kg body weight. Therefore, the EXPOCHI project aims [1] to create a relational network of individual food consumption databases in children, covering different geographical areas within Europe, and [2] to use these data to assess the usual intake of lead, chromium, selenium and food colours. Methods E...
APhoRISM FP7 project: the A Priori information for Earthquake damage mapping method
Bignami, Christian; Stramondo, Salvatore; Pierdicca, Nazzareno
2014-05-01
The APhoRISM - Advanced PRocedure for volcanIc and Seismic Monitoring - project is an FP7 funded project, which aims at developing and testing two new methods to combine Earth Observation satellite data from different sensors, and ground data for seismic and volcanic risk management. The objective is to demonstrate that this two types of data, appropriately managed and integrated, can provide new improved products useful for seismic and volcanic crisis management. One of the two methods deals with earthquakes, and it concerns the generation of maps to address the detection and estimate of damage caused by a seism. The method is named APE - A Priori information for Earthquake damage mapping. The use of satellite data to investigate earthquake damages is not an innovative issue. Indeed, a wide literature and projects have addressed and focused such issue, but usually the proposed approaches are only based on change detection techniques and/or classifications algorithms. The novelty of APhoRISM-APE relies on the exploitation of a priori information derived by: - InSAR time series to measure surface movements - shakemaps obtained from seismological data - vulnerability information. This a priori information is then integrated with change detection map from earth observation satellite sensors (either Optical or Synthetic Aperture Radar) to improve accuracy and to limit false alarms.
Anna Maria Misiak
2016-06-01
Full Text Available The global Business Intelligence (BI market grew by 10% in 2013 according to the Gartner Report. Today organizations require better use of data and analytics to support their business decisions. Internet power and business trend changes have provided a broad term for data analytics – Big Data. To be able to handle it and leverage a value of having access to Big Data, organizations have no other choice than to get proper systems implemented and working. However traditional methods are not efficient for changing business needs. The long time between project start and go-live causes a gap between initial solution blueprint and actual user requirements in the end of the project. This article presents the latest market trends in BI systems implementation by comparing Agile with traditional methods. It presents a case study provided in a large telecommunications company (20K employees and the results of a pilot research provided in the three large companies: telecommunications, digital, and insurance. Both studies prove that Agile methods might be more effective in BI projects from an end-user perspective and give first results and added value in a much shorter time compared to a traditional approach.
Real-time Obstacle Avoidance of a Two-wheeled Mobile Robot via Minimum Projection Method
Fukui, Yoshiro; Nakamura, Hisakazu; Nishitani, Hirokazu
This paper considers a real-time obstacle avoidance control problem of a two-wheeled nonholonomic mobile robot. In this research, we propose a discontinuous asymptotic stabilizing state feedback control law for the problem via the minimum projection method. The proposed method does not need path planning. Hence, the computational cost is reduced. Moreover, the method theoretically guarantees the asymptotic stability of the system. Owing to these advantages, we can redesign the control law in real-time depending on the location and the size of the obstacle. Therefore, the method can be used as a control law for searching unknown space. The effectiveness of the method is confirmed by experiments using a two-wheeled mobile robot, Khepera 2.
ALTERNATING PROJECTION BASED PREDICTION-CORRECTION METHODS FOR STRUCTURED VARIATIONAL INEQUALITIES
Bing-sheng He; Li-zhi Liao; Mai-jian Qian
2006-01-01
The monotone variational inequalities Ⅵ(Ω, F) have vast applications, including optimal controls and convex programming. In this paper we focus on the Ⅵ problems that have a particular splitting structure and in which the mapping F does not have an explicit form, therefore only its function values can be employed in the numerical methods for solving such problems. We study a set of numerical methods that are easily implementable.Each iteration of the proposed methods consists of two procedures. The first (prediction) procedure utilizes alternating projections to produce a predictor. The second (correction) procedure generates the new iterate via some minor computations. Convergence of the proposed methods is proved under mild conditions. Preliminary numerical experiments for some traffic equilibrium problems illustrate the effectiveness of the proposed methods.
1986-09-01
20% of minor 66 V construction, maintenance, and repair projects using CPrI is so small that no generalizations can be made. However, of the six...respondents in these categories, five indicate that CPrI would be effective on base-level projects. Summary of Responses to Research Objective #G. Exactly
RISK ASSESSMENT IN PROJECT PLANNING USING FMEA AND CRITICAL PATH METHOD
Sandra Milena CHOLES ARVILLA
2014-10-01
Full Text Available This paper is based upon the research undertaken for the development of the doctoral thesis “Management of software projects based on object-oriented technology”. The study examines the existing risk management practices commonly used for classic software development. The goal is to integrate the elements of the traditional risk management methodologies to create a new agile risk management methodology. The thesis focuses on techniques that can be easily implemented in extreme programming (XP and SCRUM. This study is motivated by the following research questions: What are the elements of existing quality assurance tools that could meet the principles of agile development? And is it possible to use risk estimation for improving quality in agile projects? The thesis presents a synthesis of the most common risk management techniques, as well as an introduction to agile methods XP and SCRUM. The proposal integrates the concepts of Failure Mode and Effect Analysis into the iterative life cycle of an agile software project. The thesis presents a metamodel which integrates the concepts of agile development methodologies: SCRUM and XP with the FMEA concepts for risk quantification. The model was partly implemented into a real development project. Partial results show the improvement in early identification of failures and allowed to reconsider the Sprint plan.
Sunyer Pinya, Maria Antonia; Hundecha, Y.; Lawrence, D.;
2015-01-01
Information on extreme precipitation for future climate is needed to assess the changes in the frequency and intensity of flooding. The primary source of information in climate change impact studies is climate model projections. However, due to the coarse resolution and biases of these models...... be drawn regarding the differences between CFs and BC methods. The performance of the BC methods during the control period also depends on the catchment, but in most cases they represent an improvement compared to RCM outputs. Analysis of the variance in the ensemble of RCMs and SDMs indicates...
Abdel-Salam, Emad A-B; Hassan, Gmal F
2015-01-01
In this paper, the fractional projective Riccati expansion method is proposed to solve fractional differential equations. To illustrate the effectiveness of the method, we discuss the space-time fractional Burgers equation, the space-time fractional mKdV equation and time fractional biological population model. The solutions are expressed in terms of fractional hyperbolic functions. These solutions are useful to understand the mechanisms of the complicated nonlinear physical phenomena and fractional differential equations. Among these solutions, some are found for the first time. The fractal index for the obtained results is equal to one. Counter examples to compute the fractal index are introduced in appendix.
YUAN Si; HE Xue-feng
2006-01-01
Based on the newly-developed element energy projection (EEP) method for computation of super-convergent results in one-dimensional finite element method (FEM),the task of self-adaptive FEM analysis was converted into the task of adaptive piecewise polynomial interpolation. As a result, a satisfactory FEM mesh can be obtained, and further FEM analysis on this mesh would immediately produce an FEM solution which usually satisfies the user specified error tolerance. Even though the error tolerance was not completely satisfied, one or two steps of further local refinements would be sufficient.This strategy was found to be very simple, rapid, cheap and efficient. Taking the elliptical ordinary differential equation of second order as the model problem, the fundamental idea,implementation strategy and detailed algorithm are described. Representative numerical examples are given to show the effectiveness and reliability of the proposed approach.
Sparse Pseudo Spectral Projection Methods with Directional Adaptation for Uncertainty Quantification
Winokur, J.
2015-12-19
We investigate two methods to build a polynomial approximation of a model output depending on some parameters. The two approaches are based on pseudo-spectral projection (PSP) methods on adaptively constructed sparse grids, and aim at providing a finer control of the resolution along two distinct subsets of model parameters. The control of the error along different subsets of parameters may be needed for instance in the case of a model depending on uncertain parameters and deterministic design variables. We first consider a nested approach where an independent adaptive sparse grid PSP is performed along the first set of directions only, and at each point a sparse grid is constructed adaptively in the second set of directions. We then consider the application of aPSP in the space of all parameters, and introduce directional refinement criteria to provide a tighter control of the projection error along individual dimensions. Specifically, we use a Sobol decomposition of the projection surpluses to tune the sparse grid adaptation. The behavior and performance of the two approaches are compared for a simple two-dimensional test problem and for a shock-tube ignition model involving 22 uncertain parameters and 3 design parameters. The numerical experiments indicate that whereas both methods provide effective means for tuning the quality of the representation along distinct subsets of parameters, PSP in the global parameter space generally requires fewer model evaluations than the nested approach to achieve similar projection error. In addition, the global approach is better suited for generalization to more than two subsets of directions.
Tolstooukhov, D.A. [Research and Development Institute of Power Engineering, RDIPE, Minatom RF, Moscow (Russian Federation); Karkhov, A.N. [Nuclear Safety Institute, IBRAE, Russian Academy of Sciences, Moscow (Russian Federation)
2001-07-01
At present time, a transition is made to market mechanisms of economy functioning based on equilibrium price formation for products of enterprises and their self-financing. Based on long-term forecasts of economic development, electric power industry should not only ensure preservation of the accumulated potential but should also provide for modernization, reconstruction, service life extension of operating power facilities and construction of new ones. Under market conditions, nuclear power installations will have to prove their right to exist and develop in competition with other power technologies. In these conditions, the responsibility is growing for the correctness of investment decisions taken in the power industry and methods on which they are based. This paper analyzes currently used calculation methods for economic efficiency of investment projects. It emphasizes the limitations and drawbacks of the existing methodical approaches, and their inconsistency with market economy and scientific and technological progress (STP). The said drawbacks lead to serious mistakes in evaluating the prospects for the development of nuclear power. The paper describes a methodical approach based on equilibrium price formation that does not have the said drawbacks and may be used as the basis for further work on creation of improved calculation methods for the economic efficiency of investment projects in nuclear power. (authors)
Almgren, Ann S.; Bell, John B.; Colella, Phillip; Howell, Louis H.; Welcome, Michael L.
1998-05-01
In this paper we present a method for solving the equations governing time-dependent, variable density incompressible flow in two or three dimensions on an adaptive hierarchy of grids. The method is based on a projection formulation in which we first solve advection-diffusion equations to predict intermediate velocities, and then project these velocities onto a space of approximately divergence-free vector fields. Our treatment of the first step uses a specialized second-order upwind method for differencing the nonlinear convection terms that provides a robust treatment of these terms suitable for inviscid and high Reynolds number flow. Density and other scalars are advected in such a way as to maintain conservation, if appropriate, and free-stream preservation. Our approach to adaptive refinement uses a nested hierarchy of logically-rectangular girds with simultaneous refinement of the girds in both space and time. The integration algorithm on the grid hierarchy is a recursive procedure in which coarse grids are advanced in time, fine grids are advanced multiple steps to reach the same time as the coarse grids and the data at different levels are then synchronized. The single grid algorithm is described briefly, but the emphasis here is on the time-stepping procedure for the adaptive hierarchy. Numerical examples are presented to demonstrate the algorithms's accuracy and convergence properties, and illustrate the behavior of the method. An additional example demonstrates the performance of the method on a more realistic problem, namely, a three-dimensional variable density shear layer.
Hybridizable discontinuous Galerkin projection methods for Navier-Stokes and Boussinesq equations
Ueckermann, M. P.; Lermusiaux, P. F. J.
2016-02-01
Schemes for the incompressible Navier-Stokes and Boussinesq equations are formulated and derived combining the novel Hybridizable Discontinuous Galerkin (HDG) method, a projection method, and Implicit-Explicit Runge-Kutta (IMEX-RK) time-integration schemes. We employ an incremental pressure correction and develop the corresponding HDG finite element discretization including consistent edge-space fluxes for the velocity predictor and pressure correction. We then derive the proper forms of the element-local and HDG edge-space final corrections for both velocity and pressure, including the HDG rotational correction. We also find and explain a consistency relation between the HDG stability parameters of the pressure correction and velocity predictor. We discuss and illustrate the effects of the time-splitting error. We then detail how to incorporate the HDG projection method time-split within standard IMEX-RK time-stepping schemes. Our high-order HDG projection schemes are implemented for arbitrary, mixed-element unstructured grids, with both straight-sided and curved meshes. In particular, we provide a quadrature-free integration method for a nodal basis that is consistent with the HDG method. To prevent numerical oscillations, we develop a selective nodal limiting approach. Its applications show that it can stabilize high-order schemes while retaining high-order accuracy in regions where the solution is sufficiently smooth. We perform spatial and temporal convergence studies to evaluate the properties of our integration and selective limiting schemes and to verify that our solvers are properly formulated and implemented. To complete these studies and to illustrate a range of properties for our new schemes, we employ an unsteady tracer advection benchmark, a manufactured solution for the steady diffusion and Stokes equations, and a standard lock-exchange Boussinesq problem.
Giuseppe Maria Carpaneto
2017-08-01
Full Text Available The Life Project “Monitoring of insects with public participation” (LIFE11 NAT/IT/000252 had as the main objective to develop and test methods for the monitoring of five beetle species listed in the Annexes of the Habitats Directive (92/43/EEC: Osmoderma eremita (hermit beetle, Scarabaeidae, Lucanus cervus (European stag beetle, Lucanidae, Cerambyx cerdo (great capricorn beetle, Cerambycidae, Rosalia alpina (rosalia longicorn, Cerambycidae and Morimus asper/funereus (morimus longicorn, Cerambycidae. The data gathered represent an important contribution to the monitoring of these target species in Italy. The methods developed for monitoring of the target species are intended for use by the local management authorities and staff of protected areas. These developed methods are the result of extensive fieldwork and ensure scientific validity, ease of execution and limited labour costs. The detailed description of methods and the results for each species are published in separate articles of this special issue of Nature Conservation. A second objective of the project was to gather faunistic data with a Citizen Science approach, using the web and a mobile application software (app specifically built for mobile devices. The validation of the records collected by the citizens was carried out by experts, based on photographs, which were obligatory for all records. Dissemination activities represented the principal way to contact and engage citizens for the data collection and also offered the possibility of providing information on topics such as Natura 2000, the Habitats Directive, the role of monitoring in nature conservation, the importance of forest ecosystems and the ecological role of the saproxylic insects. An innovative method tested during the project was the training of a dog for searching and monitoring the elusive hermit beetle; the trained dog also added a “curiosity” factor to attract public attention towards this rare insect and
Operation safety risk analysis method of hydropower project considering time-dependent effect
Zhang Sherong; Yan Lei
2012-01-01
In order to consider the time-dependent characteristic of risk factors of hydropower project, the method of stochastic process simulating structure resistance and load effect is adopted. On the basis of analyzing the structure characteristics and mode of operation, the operation safety risk rate assessment model of hydropower project is established on the comprehensive application of the improved analytic hierarchy process, the time-dependent reliability theory and the risk rate threshold. A scheme to demonstrate the time-dependent risk rate assessment method for an example of the earth-rock dam is particularly implemented by the proposed approach. The example shows that operation safety risk rate is closely related to both the service period and design standard ; considering the effect of time-dependent, the risk rate increases with time and the intersection of them reflects the technical service life of structures. It could provide scientific basis for the operation safety and risk decision of the hydropower project by predicting the trend of risk rate via this model.
Investigate Methods to Decrease Compilation Time-AX-Program Code Group Computer Science R& D Project
Cottom, T
2003-06-11
Large simulation codes can take on the order of hours to compile from scratch. In Kull, which uses generic programming techniques, a significant portion of the time is spent generating and compiling template instantiations. I would like to investigate methods that would decrease the overall compilation time for large codes. These would be methods which could then be applied, hopefully, as standard practice to any large code. Success is measured by the overall decrease in wall clock time a developer spends waiting for an executable. Analyzing the make system of a slow to build project can benefit all developers on the project. Taking the time to analyze the number of processors used over the life of the build and restructuring the system to maximize the parallelization can significantly reduce build times. Distributing the build across multiple machines with the same configuration can increase the number of available processors for building and can help evenly balance the load. Becoming familiar with compiler options can have its benefits as well. The time improvements of the sum can be significant. Initial compilation time for Kull on OSF1 was {approx} 3 hours. Final time on OSF1 after completion is 16 minutes. Initial compilation time for Kull on AIX was {approx} 2 hours. Final time on AIX after completion is 25 minutes. Developers now spend 3 hours less waiting for a Kull executable on OSF1, and 2 hours less on AIX platforms. In the eyes of many Kull code developers, the project was a huge success.
A project to develop restoration methods for buildings and facilities after a terrorist attack
Fingas, M.F. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Div]|[Environment Canada, Ottawa, ON (Canada). River Road Environmental Technology Centre; Volchek, K.; Hornof, M.; Boudreau, L.; Punt, M. [SAIC Canada, Ottawa, ON (Canada); Payette, P.; Best, M. [Health Canada, Ottawa, ON (Canada); Garbutt, M.; Krishnan, J.; Wagener, S.; Bernard, K. [Health Canada, Winnipeg, MB (Canada); Cousins, T.; Haslip, D. [Defence Research and Development Canada, Ottawa, ON (Canada)
2004-07-01
A multi-agent project was initiated to review site restoration after a terrorist attack. The objective was to acquire and compile information on all known restoration procedures for buildings, exteriors of buildings, their interior contents, and adjacent areas such as parking lots, lawns and vehicles. All procedures were then tested and validated. Restoration procedures included pickup, neutralization, decontamination, removal and final destruction/deposition of the contaminant, cleaning material and contaminated debris resulting from the terrorist act. This research and development project considered chemical, biological and nuclear contamination with the intent to develop methods to decontaminate and restore buildings after a chemical, biological and radiological (CBR) attack. Ideas were collected from work conducted around the world. The efficacy of best candidates was tested along with all selected chemical target items. The project also involved the preparation of procedures for decontamination and restoration. Ultimately, a tradeoff decision basis will be developed to provide information on abandonment and quarantine versus cleanup. The study revealed that there are several technologies that can be used for the decontamination of structures and equipment after acts of terrorism, however, no one technique will work for all contaminants on all surfaces. The selection of a decontamination method depends on the contaminant, the surface being decontaminated and economic, social and health factors. The amount of waste generated by decontamination is a major feasibility factor. 25 refs., 6 tabs.
Efficient methods for solving discrete topology design problems in the PLATO-N project
Canh, Nam Nguyen; Stolpe, Mathias
This paper considers the general multiple load structural topology design problems in the framework of the PLATO-N project. The problems involve a large number of discrete design variables and were modeled as a non-convex mixed 0–1 program. For the class of problems considered, a global...... optimization method based on the branch-and-cut concept was developed and implemented. In the method a large number of continuous relaxations were solved. We also present an algorithm for generating cuts to strengthen the quality of the relaxations. Several heuristics were also investigated to obtain efficient...... algorithms. The branch and cut method is used to solve benchmark examples which can be used to validate other methods and heuristics....
Rationale and methods of the European Food Consumption Validation (EFCOVAL) Project
de Boer, E. J.; Slimani, N.; van 't Veer, P.
2011-01-01
Background/Objectives: The overall objective of the European Food Consumption Validation (EFCOVAL) Project was to further develop and validate a trans-European food consumption method to be used for the evaluation of the intake of foods, nutrients and potentially hazardous chemicals within...... the EPIC-Soft databases were adapted. Finally, the EFCOVAL Consortium developed a statistical tool (Multiple Source Method) for estimating the usual intake and distribution, which has been tested using real food consumption data and compared with three other statistical methods through a simulation study......, the repeated 24-HDR method using EPIC-Soft and a food propensity questionnaire was evaluated against biomarkers in 24-h urine collections and in blood samples among adults from Belgium, the Czech Republic, (the South of) France, the Netherlands and Norway. As a result from an expert workshop on a proposed...
Jun Zhou
2015-05-01
Full Text Available Purpose: As one of the most important overhead capital of urban economics and social development, the sustainable development of urban infrastructure is becoming a key issue of prosperous society growing. The purpose of this paper is to establish a basic model to analysis certain infrastructure project’s sustainable construction and operation. Design/methodology/approach: System dynamics is an effective stimulation method and tool to deal with such complex, dynamics, nonlinear systems, which could be used in analyzing and evaluating all aspects of infrastructure sustainability internally and externally. In this paper, the system is divided into four subsystems and 12 main impact indicators. Through setting the boundary and other basic hypothesis, this paper designs the basic causal loop diagrams and stock & flow diagrams to describe the relationship between variables and establish a quantifiable structure for the system. Findings: Adopting a sewerage treatment in China as a case to test our model, we could conclude that the model of internal sustainable subsystem is reasonable. However, this model is a basic model, and it need to be specific designed for the certain project due to the diversity of infrastructure types and the unique conditions of each projects. Originality/value: System Dynamics (SD is widely used in the study of sustainable development and has plentiful research achievements from macro perspective but few studies in the microcosmic project systems. This paper focuses on the unique characteristics of urban infrastructure in China and selects infrastructure project which is based on micro-system discussion. The model we designed has certain practical significance in policy setting, operation monitoring and adjustment of the urban projects with high rationality and accuracy.
LAMINATION METHOD OF FLOOD WADIS AND PROJECTION OF THE LAMINATED FLOOD HYDROGRAPH
M. Ladjel
2016-01-01
Full Text Available The catastrophic floods in semi-arid areas are often caused by floods storm that occur at any time during the year, including the hot season. The prevention of these floods could be done by the construction of small dam hills. This requires the control of theoretical concepts hydrological sizing, especially the hydrological structure to evacuate floods. We suggest a method to calculate the optimal regulation flow of the flood and also the development of a direct calculation formula of a laminated maximum flow. The analysis of the hydro graph’s analogy at the input and the output of the dam, allow searching the dependencies between their characteristics. knowing the characteristics of the hydrograph flood of the project and the reserved capacity for the amortization of the flood, we can directly determine the laminated maximum flow and project the hydrograph of the laminated flood.
Methods of determining the optimal project of reconstruction of The Petrovsky Dock in Kronstadt
Romanovich Marina
2016-01-01
Full Text Available Today in Russia there are many historical monuments, which are in a derelict and not the operational state. So, this is actual question about their reconstruction with preservation of historical significance, with current technology, and innovation. One of these abandoned objects is The Petrovsky Dock in Kronstadt. Priority idea of its reconstruction it is museum. The Russian and foreign experience in development of the modern sea museums is analysed. In article the existing options of reconstruction of Dock are considered. The method of calculation of total optimality project coefficient of reconstruction is offered. Survey of experts showing what functions are most interesting to the museum is conducted. As a result, we determine the optimal reconstruction project of Dock with unique functionality.
Projecting rates of urbanisation in England, 1991-2016: method, policy application and results.
Bibby, P; Shepherd, J
1997-01-01
"The rate of conversion of land from rural to urban uses has been a central concern of the British planning system. Despite this interest, however, the factual basis of the debate on the pace of urban growth, its form and distribution has been extremely weak. The reason for this is lack of appropriate data. This paper reports research on two new data sources on land use--a digital database of the boundaries of tracts of urban land in 1981 and 1991 and the Land Use Change Statistics--to analyse recent urban growth in England and, in conjunction with current household projections, to estimate the likely extent of urbanisation in 2016. In addition to assessing the geographical distribution of this growth, the paper draws out some implications for policy analysis of the method of projecting the extent of land in urban use." excerpt
Disturbance rejection control based on acceleration projection method for walking robots
Xu-yang WANG; Zhao-hong XU; Tian-sheng LU
2008-01-01
This paper presents a disturbance rejection scheme for walking robots under unknown external forces and moments.The disturbance rejection strategy,which combines the inverse dynamics control with the acceleration projection onto the ZMP (zero moment point)-plane,can ensure the overall dynamic stability of the robot during tracking the pre-computed trajectories.Under normal conditions,I.e.,the system is dynamically balanced,a primary inverse dynamics control is utilized.In the case that the system becomes unbalanced due to external disturbances,the acceleration projection control(APC)loop,will be activated to keep the dynamic stability of the walking robot through modifying the input torques.The preliminary experimental results on a robot leg demonstrate that the proposed method can actually make the robot keep a stable motion under unknown external per-turbations.
Clevenson, Rhonda Suzanne
This research examined the responses of families to bilingual communication methods, text versus video, designed to facilitate school to home communication to increase parent involvement and seventh grade student achievement in the science fair project. Using an experimental design, 161 families were randomly selected to receive either a two part informational text or video series during the science fair unit taught at a culturally diverse urban middle school. The bilingual informational materials were created and produced by the staff at the research site. Measures were taken to make sure all families could access the informational materials and innovations such as a special travel envelope and reminding procedures aided data collection. Surveys measuring variables on a Likert scale with spaces for comments were collected from the parents and students. An interrater reliability study was completed to measure the agreement of the two teachers who used a grading checklist to score science fair project achievement. Quantitative methods including ANOVA and MLR were used to examine the data in terms of student achievement and the communication method (text or video), audience (students and parents), and the anticipated outcome (parent help). Nonparametric and qualitative data analyses were used to explore how families used and responded to the informational materials. Significant results were that the video communication method was positively associated with student achievement on the science fair project. Significant main effects were observed for the student characteristics, educational services (general and special education, and English as a Second Language), and previous achievement in science, and the parent characteristics, previous experience with science fair projects, primary viewing language (English or Spanish), and expectations for student achievement. Student achievement was not significantly related to the amount or usefulness of parent help. The amount
Nonlinear projection trick in kernel methods: an alternative to the kernel trick.
Kwak, Nojun
2013-12-01
In kernel methods such as kernel principal component analysis (PCA) and support vector machines, the so called kernel trick is used to avoid direct calculations in a high (virtually infinite) dimensional kernel space. In this brief, based on the fact that the effective dimensionality of a kernel space is less than the number of training samples, we propose an alternative to the kernel trick that explicitly maps the input data into a reduced dimensional kernel space. This is easily obtained by the eigenvalue decomposition of the kernel matrix. The proposed method is named as the nonlinear projection trick in contrast to the kernel trick. With this technique, the applicability of the kernel methods is widened to arbitrary algorithms that do not use the dot product. The equivalence between the kernel trick and the nonlinear projection trick is shown for several conventional kernel methods. In addition, we extend PCA-L1, which uses L1-norm instead of L2-norm (or dot product), into a kernel version and show the effectiveness of the proposed approach.
Woodruff, D.P. [Physics Department, University of Warwick, Coventry (United Kingdom); Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany); Baumgaertel, P.; Hoeft, J.T.; Kittel, M.; Polcik, M. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany)
2001-11-26
As part of a programme of full quantitative adsorbate structure determinations on surfaces using scanned-energy-mode photoelectron diffraction (PhD) combined with multiple-scattering simulations, direct data-inversion methods based on Fourier transforms and the so-called projection method have been tested on experimental data from more than 30 adsorbate/substrate systems. The results highlight both strengths and weaknesses, many of which are likely to be generic in the use of direct methods. The most obvious feature is the reduced value of the methods for systems involving low emitter site symmetry or multiple-site occupation, but some specific problems attributed to the elastic scattering cross-section 'signatures' of different elemental species and cases in which multiple scattering proves to be especially important are also discussed. A combination of these problems in a particular system can lead to complete failure, although even in these cases the results are unlikely to be actively misleading as regards the correct structure. (author)
Sunyer, M. A.; Hundecha, Y.; Lawrence, D.; Madsen, H.; Willems, P.; Martinkova, M.; Vormoor, K.; Bürger, G.; Hanel, M.; Kriaučiūnienė, J.; Loukas, A.; Osuch, M.; Yücel, I.
2015-04-01
Information on extreme precipitation for future climate is needed to assess the changes in the frequency and intensity of flooding. The primary source of information in climate change impact studies is climate model projections. However, due to the coarse resolution and biases of these models, they cannot be directly used in hydrological models. Hence, statistical downscaling is necessary to address climate change impacts at the catchment scale. This study compares eight statistical downscaling methods (SDMs) often used in climate change impact studies. Four methods are based on change factors (CFs), three are bias correction (BC) methods, and one is a perfect prognosis method. The eight methods are used to downscale precipitation output from 15 regional climate models (RCMs) from the ENSEMBLES project for 11 catchments in Europe. The overall results point to an increase in extreme precipitation in most catchments in both winter and summer. For individual catchments, the downscaled time series tend to agree on the direction of the change but differ in the magnitude. Differences between the SDMs vary between the catchments and depend on the season analysed. Similarly, general conclusions cannot be drawn regarding the differences between CFs and BC methods. The performance of the BC methods during the control period also depends on the catchment, but in most cases they represent an improvement compared to RCM outputs. Analysis of the variance in the ensemble of RCMs and SDMs indicates that at least 30% and up to approximately half of the total variance is derived from the SDMs. This study illustrates the large variability in the expected changes in extreme precipitation and highlights the need for considering an ensemble of both SDMs and climate models. Recommendations are provided for the selection of the most suitable SDMs to include in the analysis.
Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.; Weiss, Elisabeth; Williamson, Jeffrey F. [Department of Radiation Oncology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)
2011-01-15
Purpose: To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. Methods: The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. Results: In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 deg., respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78{+-}0.57) mm or less. The {theta} and {phi} angle errors were found to be (5.7{+-}4.9) deg. and (6.0{+-}4.1) deg., respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 deg. compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. Conclusions: This work describes a novel, accurate, and completely automatic method for reconstructing
Online monitoring of gas-solid two-phase flow using projected CG method in ECT image reconstruction
Qi wang; Chengyi Yang; Huaxiang Wang; Ziqiang Cui; Zhentao Gao
2013-01-01
Electrical capacitance tomography (ECT) is a promising technique for multi-phase flow measurement due to its high speed,low cost and non-intrusive sensing.Image reconstruction for ECT is an inverse problem of finding the permittivity distribution of an object by measuring the electrical capacitances between sets of electrodes placed around its periphery.The conjugate gradient (CG) method is a popular image reconstruction method for ECT,in spite of its low convergence rate.In this paper,an advanced version of the CG method,the projected CG method,is used for image reconstruction of an ECT system.The solution space is projected into the Krylov subspace and the inverse problem is solved by the CG method in a low-dimensional specific subspace.Both static and dynamic experiments were carried out for gas-solid two-phase flows.The flow regimes are identified using the reconstructed images obtained with the projected CG method.The results obtained indicate that the projected CG method improves the quality of reconstructed images and dramatically reduces computation time,as compared to the traditional sensitivity,Landweber,and CG methods.Furthermore,the projected CG method was also used to estimate the important parameters of the pneumatic conveying process,such as the volume concentration,flow velocity and mass flow rate of the solid phase.Therefore,the projected CG method is considered suitable for online gas-solid two-phase flow measurement.
Is social projection based on simulation or theory? Why new methods are needed for differentiating.
Bazinger, Claudia; Kühberger, Anton
2012-12-01
The literature on social cognition reports many instances of a phenomenon titled 'social projection' or 'egocentric bias'. These terms indicate egocentric predictions, i.e., an over-reliance on the self when predicting the cognition, emotion, or behavior of other people. The classic method to diagnose egocentric prediction is to establish high correlations between our own and other people's cognition, emotion, or behavior. We argue that this method is incorrect because there is a different way to come to a correlation between own and predicted states, namely, through the use of theoretical knowledge. Thus, the use of correlational measures is not sufficient to identify the source of social predictions. Based on the distinction between simulation theory and theory theory, we propose the following alternative methods for inferring prediction strategies: independent vs. juxtaposed predictions, the use of 'hot' mental processes, and the use of participants' self-reports.
Derivation of second-order nonlinear optical conductivity by the projection-diagram method
Nam Lyong Kang
2012-03-01
Full Text Available A projection-diagram method is introduced for optical conductivity with lineshape functions, which takes into account the population criterion that the electron and phonon distribution functions are multiplicatively combined along with the energy conservation factors for proper interpretation of emission and absorption of phonons and photons in all the processes of electron transitions. It is further shown that the second order nonlinear optical conductivity of the system of electrons interacting with phonons, obtained using this method, is identical with that derived by using the state dependent projectors and the KC reduction identities [J. Phys. A: Math. Theor. 43, 165203 (2010]. We expect that this method can reduce the amount of many-body calculation and can be of help in providing physical intuition into solid state quantum dynamics and representing perturbation expressions for such systems.
Hakala, Kirsti; Addor, Nans; Seibert, Jan
2017-04-01
Streamflow stemming from Switzerland's mountainous landscape will be influenced by climate change, which will pose significant challenges to the water management and policy sector. In climate change impact research, the determination of future streamflow is impeded by different sources of uncertainty, which propagate through the model chain. In this research, we explicitly considered the following sources of uncertainty: (1) climate models, (2) downscaling of the climate projections to the catchment scale, (3) bias correction method and (4) parameterization of the hydrological model. We utilize climate projections at the 0.11 degree 12.5 km resolution from the EURO-CORDEX project, which are the most recent climate projections for the European domain. EURO-CORDEX is comprised of regional climate model (RCM) simulations, which have been downscaled from global climate models (GCMs) from the CMIP5 archive, using both dynamical and statistical techniques. Uncertainties are explored by applying a modeling chain involving 14 GCM-RCMs to ten Swiss catchments. We utilize the rainfall-runoff model HBV Light, which has been widely used in operational hydrological forecasting. The Lindström measure, a combination of model efficiency and volume error, was used as an objective function to calibrate HBV Light. Ten best sets of parameters are then achieved by calibrating using the genetic algorithm and Powell optimization (GAP) method. The GAP optimization method is based on the evolution of parameter sets, which works by selecting and recombining high performing parameter sets with each other. Once HBV is calibrated, we then perform a quantitative comparison of the influence of biases inherited from climate model simulations to the biases stemming from the hydrological model. The evaluation is conducted over two time periods: i) 1980-2009 to characterize the simulation realism under the current climate and ii) 2070-2099 to identify the magnitude of the projected change of
Garavaglia, F.; Paquet, E.; Lang, M.; Renard, B.; Arnaud, P.; Aubert, Y.; Carre, J.
2013-12-01
In flood risk assessment the methods can be divided in two families: deterministic methods and probabilistic methods. In the French hydrologic community the probabilistic methods are historically preferred to the deterministic ones. Presently a French research project named EXTRAFLO (RiskNat Program of the French National Research Agency, https://extraflo.cemagref.fr) deals with the design values for extreme rainfall and floods. The object of this project is to carry out a comparison of the main methods used in France for estimating extreme values of rainfall and floods, to obtain a better grasp of their respective fields of application. In this framework we present the results of Task 7 of EXTRAFLO project. Focusing on French watersheds, we compare the main extreme flood estimation methods used in French background: (i) standard flood frequency analysis (Gumbel and GEV distribution), (ii) regional flood frequency analysis (regional Gumbel and GEV distribution), (iii) local and regional flood frequency analysis improved by historical information (Naulet et al., 2005), (iv) simplify probabilistic method based on rainfall information (i.e. Gradex method (CFGB, 1994), Agregee method (Margoum, 1992) and Speed method (Cayla, 1995)), (v) flood frequency analysis by continuous simulation approach and based on rainfall information (i.e. Schadex method (Paquet et al., 2013, Garavaglia et al., 2010), Shyreg method (Lavabre et al., 2003)) and (vi) multifractal approach. The main result of this comparative study is that probabilistic methods based on additional information (i.e. regional, historical and rainfall information) provide better estimations than the standard flood frequency analysis. Another interesting result is that, the differences between the various extreme flood quantile estimations of compared methods increase with return period, staying relatively moderate up to 100-years return levels. Results and discussions are here illustrated throughout with the example
LU Bin; ZHANG Hong-Qing
2008-01-01
In this paper, extended projective Riccati equation method is presented for constructing more new exact solutions of nonlinear differential equations in mathematical physics, which is direct and more powerful than projective Riecati equation method. In order to illustrate the effect of the method, Broer-Kaup Kupershmidt system is employed and Jacobi doubly periodic solutions are obtained. This algorithm can also be applied to other nonlinear differential equations.
Practical implications of procedures developed in IDEA project--comparison with traditional methods.
Andrasi, A; Bouvier, C; Brandl, A; de Carlan, L; Fischer, H; Franck, D; Höllriegl, V; Li, W B; Oeh, U; Ritt, J; Roth, P; Schlagbauer, M; Schmitzer, Ch; Wahl, W; Zombori, P
2007-01-01
The idea of the IDEA project aimed to improve assessment of incorporated radionuclides through developments of more reliable and possibly faster in vivo and bioassay monitoring techniques and making use of such enhancements for improvements in routine monitoring. In direct in vivo monitoring technique the optimum choice of the detectors to be applied for different monitoring tasks has been investigated in terms of material, size and background in order to improve conditions namely to increase counting efficiency and reduce background. Detailed studies have been performed to investigate the manifold advantageous applications and capabilities of numerical simulation method for the calibration and optimisation of in vivo counting systems. This calibration method can be advantageously applied especially in the measurement of low-energy photon emitting radionuclides, where individual variability is a significant source of uncertainty. In bioassay measurements the use of inductively coupled plasma mass spectrometry (ICP-MS) can improve considerably both the measurement speed and the lower limit of detection currently achievable with alpha spectrometry for long-lived radionuclides. The work carried out in this project provided detailed guidelines for optimum performance of the technique of ICP-MS applied mainly for the determination of uranium and thorium nuclides in the urine including sampling procedure, operational parameters of the instruments and interpretation of the measured data. The paper demonstrates the main advantages of investigated techniques in comparison with the performances of methods commonly applied in routine monitoring practice.
Analysis and design of wedge projection display system based on ray retracing method.
Lee, Chang-Kun; Lee, Taewon; Sung, Hyunsik; Min, Sung-Wook
2013-06-10
A design method for the wedge projection display system based on the ray retracing method is proposed. To analyze the principle of image formation on the inclined surface of the wedge-shaped waveguide, the bundle of rays is retraced from an imaging point on the inclined surface to the aperture of the waveguide. In consequence of ray retracing, we obtain the incident conditions of the ray, such as the position and the angle at the aperture, which provide clues for image formation. To illuminate the image formation, the concept of the equivalent imaging point is proposed, which is the intersection where the incident rays are extended over the space regardless of the refraction and reflection in the waveguide. Since the initial value of the rays arriving at the equivalent imaging point corresponds to that of the rays converging into the imaging point on the inclined surface, the image formation can be visualized by calculating the equivalent imaging point over the entire inclined surface. Then, we can find image characteristics, such as their size and position, and their degree of blur--by analyzing the distribution of the equivalent imaging point--and design the optimized wedge projection system by attaching the prism structure at the aperture. The simulation results show the feasibility of the ray retracing analysis and characterize the numerical relation between the waveguide parameters and the aperture structure for on-axis configuration. The experimental results verify the designed system based on the proposed method.
New teaching methods for practical training in nursing within the project Tempus IV – CCNURCA
Gabriela Kuriplachová
2015-12-01
Full Text Available The aim of this article is to present new teaching methods for practical training in nursing within the project Tempus IV – CCNURCA (Competency based Curriculum Reform in Nursing and Healthcare in Western Balkan Universities No. 544169-TEMPUS-1-2013-1-BE-TEMPUS-JPCR. Implementation of new practical teaching methods, such as learning with simulator mannequins, practical workshop, nursing process, mind mapping, case studies and problem-based learning (PBL in practical training could help to improve the quality of the educational process in nursing at Universities of Western Balkan countries that have been involved in this project. The realistic conditions in simulation laboratories are reflecting real hospital and patient´s care, communication with patient and hospital staff, discussion and analysis of all student´s activities. The methods of next nursing generation in practical training that can help nurses to get used to the recognition and management of patients by using of simulated real life situations.
Design method of dichroic filter using color appearance model in LCD projection systems
Kim, Jee-Hong
1998-11-01
A new design method using a color appearance model is proposed for the dichroic filters in LCD projection systems. The dichroic filters used for color separation/composition play a dominant role in the performance of color reproduction so that its spectral transmittance should be designed to have optimized color performance. In the proposed method, a reproducible color gamut in the 3D color space is used as a performance index, and we find the optimal half-power wavelengths of dichroic filters, which are applicable to the development of LCD projection TV systems. Considering diverse viewing conditions with moderate ambient light, the design parameters are optimized by maximizing the volume of the color gamut in an apparent color space for each condition. Here, the RLAB color space developed by Fairchild is used as a color appearance model and the white balancing method is applied to restore the designate color temperature of peak white. The optimal wavelengths are compared with the design based on the CIELAB color space without considering nonstandard viewing conditions, and both results do not show as much difference as expected due to the white balance.
Coe, Ryan L; Seibel, Eric J
2012-12-01
We present a method for modeling image formation in optical projection tomographic microscopy (OPTM) using high numerical aperture (NA) condensers and objectives. Similar to techniques used in computed tomography, OPTM produces three-dimensional, reconstructed images of single cells from two-dimensional projections. The model is capable of simulating axial scanning of a microscope objective to produce projections, which are reconstructed using filtered backprojection. Simulation of optical scattering in transmission optical microscopy is designed to analyze all aspects of OPTM image formation, such as degree of specimen staining, refractive-index matching, and objective scanning. In this preliminary work, a set of simulations is performed to examine the effect of changing the condenser NA, objective scan range, and complex refractive index on the final reconstruction of a microshell with an outer radius of 1.5 μm and an inner radius of 0.9 μm. The model lays the groundwork for optimizing OPTM imaging parameters and triaging efforts to further improve the overall system design. As the model is expanded in the future, it will be used to simulate a more realistic cell, which could lead to even greater impact.
Walter, Alexander I; Helgenberger, Sebastian; Wiek, Arnim; Scholz, Roland W
2007-11-01
Most Transdisciplinary Research (TdR) projects combine scientific research with the building of decision making capacity for the involved stakeholders. These projects usually deal with complex, societally relevant, real-world problems. This paper focuses on TdR projects, which integrate the knowledge of researchers and stakeholders in a collaborative transdisciplinary process through structured methods of mutual learning. Previous research on the evaluation of TdR has insufficiently explored the intended effects of transdisciplinary processes on the real world (societal effects). We developed an evaluation framework for assessing the societal effects of transdisciplinary processes. Outputs (measured as procedural and product-related involvement of the stakeholders), impacts (intermediate effects connecting outputs and outcomes) and outcomes (enhanced decision making capacity) are distinguished as three types of societal effects. Our model links outputs and outcomes of transdisciplinary processes via the impacts using a mediating variables approach. We applied this model in an ex post evaluation of a transdisciplinary process. 84 out of 188 agents participated in a survey. The results show significant mediation effects of the two impacts "network building" and "transformation knowledge". These results indicate an influence of a transdisciplinary process on the decision making capacity of stakeholders, especially through social network building and the generation of knowledge relevant for action.
Use of the Contingent Valuation Method in the assessment of a landfill mining project.
Marella, Giuliano; Raga, Roberto
2014-07-01
A comprehensive approach for the evaluation of the economic feasibility of landfill mining (LFM) should take into account not only the direct costs and revenues for the private investor, but also the social benefits or costs (generally called externalities), in such a way that projects generating major social benefits (and no significant private revenues) are not overlooked. With a view to contributing to the development of a common framework for the evaluation of LFM projects, this paper presents the results of a case study where the issue of the assessment of social benefits from a LFM project is addressed. In particular, the Contingent Valuation Method is applied for the monetary assessment of the community-perceived benefits from the remediation of an old uncontrolled waste deposit by means of LFM and the conversion of the area into a park. Based on the results of a survey carried out on a random sample of people living near the old landfill, the economic values of the individual willingness to pay (WTP) for LFM and the subsequent creation of a public park were calculated and the correlations with the relevant variables (distance from the landfill site, age, income, sex, education level) assessed. The results were then suitably extended and the monetary value of the welfare increase of the whole population resident in the area and potentially affected both by LFM and the creation of the park was calculated. Copyright © 2014 Elsevier Ltd. All rights reserved.
Project JADE. Description of the MLH-method; Projekt JADE. Beskrivning av MLH-metoden
Sandstedt, H.; Munier, R. [Scandiaconsult, Stockholm (Sweden); Wichmann, C. [Nitro Consult AB, Stockholm (Sweden); Isaksson, Therese [Royal Inst. of Tech., Stockholm (Sweden). Div. of Soil and Rock Mechanics
2001-08-01
This report constitutes a part of a series of reports within project JADE, comparison of deposition methods. A comparison of the deposition methods MLH (Medium Long Holes with approximately 25 copper canisters emplaced in a horizontal deposition hole about 200 metres in length bored between central and side tunnels) and KBS-3 (copper canisters are emplaced in vertical deposition holes bored in the floors of horizontal tunnels) has earlier been performed and KBS-3 was judged to be more advantageous than MLH. However, the prerequisites for the comparison have changed with time and an updated evaluation of MLH was therefore required. In this report, the current knowledge of MLH is summarized with focus on geological prerequisites, methods for boring long, horizontal deposition holes, reinforcement and sealing, deposition and cost. Comparisons with KBS-3 are performed sequentially. An MLH-repository is judged to be more sensitive to ingress of water to the deposition holes during the deposition process. This implies that a MLH repository based on today's knowledge is basically recommended for bedrock with fairly low water baring capacity. It has been demonstrated that MLH has considerable economic potential compared to KBS-3. However, the method is judged to be more technically immature than KBS-3. Particularly, methods and equipment for deposition of canisters need to be developed further. Methods and equipment for deposition can be developed, which fulfill the demands on function and safety, in the near future. MLH cannot therefore be rejected as deposition method.
The ACTwatch project: methods to describe anti-malarial markets in seven countries
Chapman Steven
2011-10-01
Full Text Available Abstract Background Policy makers, governments and donors are faced with an information gap when considering ways to improve access to artemisinin-based combination therapy (ACT and malaria diagnostics including rapid diagnostic tests (RDTs. To help address some of these gaps, a five-year multi-country research project called ACTwatch was launched. The project is designed to provide a comprehensive picture of the anti-malarial market to inform national and international anti-malarial drug policy decision-making. Methods The project is being conducted in seven malaria-endemic countries: Benin, Cambodia, the Democratic Republic of Congo, Madagascar, Nigeria, Uganda and Zambia from 2008 to 2012. ACTwatch measures which anti-malarials are available, where they are available and at what price and who they are used by. These indicators are measured over time and across countries through three study components: outlet surveys, supply chain studies and household surveys. Nationally representative outlet surveys examine the market share of different anti-malarials passing through public facilities and private retail outlets. Supply chain research provides a picture of the supply chain serving drug outlets, and measures mark-ups at each supply chain level. On the demand side, nationally representative household surveys capture treatment seeking patterns and use of anti-malarial drugs, as well as respondent knowledge of anti-malarials. Discussion The research project provides findings on both the demand and supply side determinants of anti-malarial access. There are four key features of ACTwatch. First is the overlap of the three study components where nationally representative data are collected over similar periods, using a common sampling approach. A second feature is the number and diversity of countries that are studied which allows for cross-country comparisons. Another distinguishing feature is its ability to measure trends over time. Finally, the
Optimal Selection Method for Investment Project Investicinių projektų optimalios atrankos metodas
Vytautas Jonas Žilinskas
2011-02-01
Full Text Available
Under the modern world market conditions the investment activity of enterprises is increasing. Therefore, one of the main aspects of the investment activity guarantee is a selection and apprehension of the main principles of the investment control and possi-bilities of different uses of the investment instruments. For the optimum selection of the investment projects it is suggested to use a formalistic experimental author’s modified method of priority allocation and selection, which gives an opportunity to evaluate the investment project according to different partial criteria and their meaning of importance. Working out this way a complex evaluation of each chosen investment project is obtai-ned. Using the suggested MPSP (modified method of priority allocation and selection the investment projects are evaluated with qualitative and quantitative criteria. So this method can be used when qualitative criteria of evaluation are predominated. Formalis-tic methods of analysis cannot be used to establish quantitative criteria and those small projects when it is relatively too expensive to apply other usual methods of the financial economic analysis. Method MPSP selection is universal and ordinary so it can be used to establish the efficiency of different projects, to classify projects, to model the strategy of the state economy. If you like to control the realization of the chosen investment project more effectively and rationally it is suggested to use PERT (Program Evaluation and Review Technique.The main control elements of the investment project are reviewed in the article using PERT which is useful to draw up an optimistic reticular schedule of the investment work implementation.
Community Air Sensor Network (CAIRSENSE) Project: Lower Cost, Continuous Ambient Monitoring Methods
CAIRSENSE Project presentation was given at the 108th Annual Meeting of the Air & Waste Management Associate in June 2015. The presentation provides an overview of the CAIRSENSE Project and general info about the sensors used in the CAIRSENSE Project.
In-medium QCD sum rules for D mesons: A projection method for higher order contributions
Buchheim, Thomas; Kampfer, Burkhard
2014-01-01
D mesons serve as excellent probes of hot and/or dense strongly interacting matter. They can provide insight into the restoration of chiral symmetry. The chiral condensate as well as other chirally odd condensates, such as certain four-quark condensates, are linked to order parameters of spontaneous chiral symmetry breaking. Thus, the evaluation of these higher order condensate contributions in the framework of QCD sum rules is of high interest. We present a general method for projecting Lorentz indices of ground state expectation values providing a crucial step towards a comprehensive calculation of higher order corrections to the operator product expansion of hadrons, especially D mesons, in a strongly interacting medium.
Low Speed Motion Optimization of Space Manipulator Based on Gradient Projection Method
Peng Junjie
2015-01-01
Full Text Available Low-speed crawling phenomenon may occur when space manipulators run at a low speed, which may bring big problem for manipulation work. A kind of low-speed optimization algorithm based on gradient projection method is pro-posed in this paper. The designing of continuous balanced proportional factor can effectively reduce the quantitative differences between the homogeneous solution and the special solution, avoiding the joint velocities oscillations. The low-speed crawling problem can be effectively improved by appropriate increase of joint velocities. And the effectiveness and correctness of the optimization algorithm are confirmed by the simulation.
KUSDHIANTO SETIAWAN
Full Text Available This paper discusses the application of real options analysis for a project that is in the process of construction and was affected by a natural disaster. The use of the analytical method has become a way of thinking in making decisions that should be taught to business school students. The case in this paper is based on an MBA thesis at the University of Gadjah Mada that was intended as a showcase for application of real options to address real business problems. It shows one of the strategies in mainstreaming disaster risk management in the business school that also answers the needs of businesses in the disaster-prone country.
Yue, Yang-Yang; Lu, Rong-er; Yang, Bo; Huang, Huang; Hong, Xu-Hao; Zhang, Chao; Qin, Yi-Qiang; Zhu, Yong-Yuan
2016-10-01
We take a theoretical investigation on the reciprocal property of a class of 2D nonlinear photonic quasicrystal proposed by Lifshitz et al. in PRL 95, 133901 (2005). Using the rectangular projection method, the analytical expression for the Fourier spectrum of the quasicrystal structure is obtained explicitly. It is interesting to find that the result has a similar form to the corresponding expression of the well-known 1D Fibonacci lattice. In addition, we predict a further extension of the result to higher dimensions. This work is of practical importance for the photonic device design in nonlinear optical conversion progresses.
Prediction and optimization methods for electric vehicle charging schedules in the EDISON project
Aabrandt, Andreas; Andersen, Peter Bach; Pedersen, Anders Bro;
2012-01-01
project has been launched to investigate various areas relevant to electric vehicle integration. As part of EDISON an electric vehicle aggregator has been developed to demonstrate smart charging of electric vehicles. The emphasis of this paper is the mathematical methods on which the EDISON aggregator......Smart charging, where the charging of an electric vehicle battery is delayed or advanced in time based on energy costs, grid capacity or renewable contents, has a great potential for increasing the value of the electric vehicle to the owner, the grid and society as a whole. The Danish EDISON...
Robson, Paula J.; Solbak, Nathan M.; Haig, Tiffany R.; Whelan, Heather K.; Vena, Jennifer E.; Akawung, Alianu K.; Rosner, William K.; Brenner, Darren R.; Cook, Linda S.; Csizmadi, Ilona; Kopciuk, Karen A.; McGregor, S. Elizabeth; Friedenreich, Christine M.
2016-01-01
Background: Prospective cohorts have the potential to support multifactorial, health-related research, particularly if they are drawn from the general population, incorporate active and passive follow-up and permission is obtained to allow access by researchers to data repositories. This paper describes Phase I of the Alberta's Tomorrow Project cohort, a broad-based research platform designed to support investigations into factors that influence cancer and chronic disease risk. Methods: Adults aged 35-69 years living in Alberta, Canada, with no previous cancer diagnosis other than nonmelanoma skin cancer were recruited to the project by telephone-based random digit dialling. Participants were enrolled if they returned a Health and Lifestyle Questionnaire. Past year diet and physical activity questionnaires were mailed 3 months after enrolment. Consent was sought for active follow-up and linkage with administrative databases. Depending on enrolment date, participants were invited to complete up to 2 follow-up questionnaires (2004 and 2008). Results: Between 2001 and 2009, 31 072 (39% men) participants (mean age 50.2 [± 9.2] yr) were enrolled and 99% consented to linkage with administrative databases. Participants reported a wide range of educational attainment and household income. Compared with provincial surveillance data from the Canadian Community Health Survey, Alberta's Tomorrow Project participants had higher body mass index, lower prevalence of smoking and similar distribution of chronic health conditions. Follow-up questionnaires were completed by 83% and 72% of participants in 2004 and 2008, respectively. Robust quality control measures resulted in low frequencies of missing data. Interpretation: Alberta's Tomorrow Project provides a robust platform, based on a prospective cohort design, to support research into risk factors for cancer and chronic disease. PMID:27730115
Alla O. Shcheglova
2016-07-01
Full Text Available Project-based method in teaching English is explored in the article. Its role for students' communicative competence development is defined. The study analyzes the factors affecting speaking skills. The article presents the detailed analysis of blended learning system, and project-based method with multimedia technology usage as a means of communication skills improving for students of non-linguistic specialties at the National University of Food Technologies. It has been proved that efficiency of speaking skills directly depends on students' engagement in the tasks, that is fully covered by project method, which is optimum in blended learning system.
Patrick Gonzalez; Antonio Lara; Jorge Gayoso; Eduardo Neira; Patricio Romero; Leonardo Sotomayor
2005-07-14
Deforestation of temperate rainforests in Chile has decreased the provision of ecosystem services, including watershed protection, biodiversity conservation, and carbon sequestration. Forest conservation can restore those ecosystem services. Greenhouse gas policies that offer financing for the carbon emissions avoided by preventing deforestation require a projection of future baseline carbon emissions for an area if no forest conservation occurs. For a proposed 570 km{sup 2} conservation area in temperate rainforest around the rural community of Curinanco, Chile, we compared three methods to project future baseline carbon emissions: extrapolation from Landsat observations, Geomod, and Forest Restoration Carbon Analysis (FRCA). Analyses of forest inventory and Landsat remote sensing data show 1986-1999 net deforestation of 1900 ha in the analysis area, proceeding at a rate of 0.0003 y{sup -1}. The gross rate of loss of closed natural forest was 0.042 y{sup -1}. In the period 1986-1999, closed natural forest decreased from 20,000 ha to 11,000 ha, with timber companies clearing natural forest to establish plantations of non-native species. Analyses of previous field measurements of species-specific forest biomass, tree allometry, and the carbon content of vegetation show that the dominant native forest type, broadleaf evergreen (bosque siempreverde), contains 370 {+-} 170 t ha{sup -1} carbon, compared to the carbon density of non-native Pinus radiata plantations of 240 {+-} 60 t ha{sup -1}. The 1986-1999 conversion of closed broadleaf evergreen forest to open broadleaf evergreen forest, Pinus radiata plantations, shrublands, grasslands, urban areas, and bare ground decreased the carbon density from 370 {+-} 170 t ha{sup -1} carbon to an average of 100 t ha{sup -1} (maximum 160 t ha{sup -1}, minimum 50 t ha{sup -1}). Consequently, the conversion released 1.1 million t carbon. These analyses of forest inventory and Landsat remote sensing data provided the data to
Evaluation and improvement of methods to quantify the exploration risk of geothermal projects
Ganz, Britta; Schellschmidt, Rüdiger; Schulz, Rüdiger; Thomas, Rüdiger
2015-04-01
The quantification of exploration risks is of major importance for geothermal project planning. The exploration risk is defined as the risk of not successfully achieving a geothermal reservoir with minimum levels of thermal water production and reservoir temperatures (UNEP 2004). A simple method to quantify the probability of success (POS) for geothermal wells is to determine the single risks for temperature and flow rate and calculate the overall probability by multiplying the individual probabilities (SCHULZ et al. 2010). Since 2002, over 50 expert studies to evaluate the exploration risk of geothermal projects in Germany were carried out based on this method. The studies are requested as a basis for insurance contracts covering the risk of not achieving the necessary parameters. The estimated probabilities for temperature and flow rate in the expert reports were now compared with the parameters actually reached in meanwhile realised projects. The results are used for an improvement of the method. The probability of success for a given temperature was calculated using local temperature information in the vicinity of the planned well location. The greater significance of nearby temperature data was considered by inverse distance weighting. In highly productive deep aquifers, which are of major interest for geothermal projects, temperature gradients often strongly decrease due to an intense vertical mixing of the thermal water. Thus, the top of the considered aquifer was used as the reference point of the temperature assessment. As still some positive gradient can be expected within the aquifer, this is a conservative estimation. The evaluation of the reports should therefore especially answer the question, whether this approach has led to a systematic underestimation of the temperature. To calculate the probability of success for hydraulic parameters, the theoretical drawdown at a given flow rate was calculated for existing wells from hydraulic test data. The
Ashis De
2014-01-01
Full Text Available In this paper a detailed comparison between the estimation results of unknown inputs of a linear time invariant system using projection operator approach and using the method of generalized matrix inverse have been discussed. The full order observer constructed using projection operator approach has been extended and implemented for this purpose.
ESP v2.0: Improved method for projecting U.S. GHG and air pollution emissions through 2055
This product includes both a presentation and an extended abstract. We describe the Emission Scenario Projection (ESP) method, version 2.0. ESP is used to develop multi-decadal projections of U.S. greenhouse gas (GHG) and criteria pollutant emissions. The resulting future-year em...
ESP 2.0: Improved method for projecting U.S. GHG and air pollution emissions through 2055
The Emission Scenario Projection (ESP) method is used to develop multi-decadal projections of U.S. Greenhouse Gas (GHG) and criteria pollutant emissions. The resulting future-year emissions can then translated into an emissions inventory and applied in climate and air quality mod...
French Rebecca S
2009-10-01
Full Text Available Abstract Background Since May 2004, ten Central and Eastern European (CEE countries have joined the European Union, leading to a large influx of CEE migrants to the United Kingdom (UK. The SALLEE project (sexual attitudes and lifestyles of London's Eastern Europeans set out to establish an understanding of the sexual lifestyles and reproductive health risks of CEE migrants. CEE nationals make up a small minority of the population resident in the UK with no sampling frame from which to select a probability sample. There is also difficulty estimating the socio-demographic and geographical distribution of the population. In addition, measuring self-reported sexual behaviour which is generally found to be problematic, may be compounded among people from a range of different cultural and linguistic backgrounds. This paper will describe the methods adopted by the SALLEE project to address these challenges. Methods The research was undertaken using quantitative and qualitative methods: a cross-sectional survey of CEE migrants based on three convenience samples (recruited from community venues, sexual health clinics and from the Internet and semi-structured in-depth interviews with a purposively selected sample of CEE migrants. A detailed social mapping exercise of the CEE community was conducted prior to commencement of the survey to identify places where CEE migrants could be recruited. A total of 3,005 respondents took part in the cross-sectional survey, including 2,276 respondents in the community sample, 357 in the clinic sample and 372 in the Internet sample. 40 in-depth qualitative interviews were undertaken with a range of individuals, as determined by the interview quota matrix. Discussion The SALLEE project has benefited from using quantitative research to provide generalisable data on a range of variables and qualitative research to add in-depth understanding and interpretation. The social mapping exercise successfully located a large number
Ibrahim Karahan
2016-04-01
Full Text Available Let C be a nonempty closed convex subset of a real Hilbert space H. Let {T_{n}}:C›H be a sequence of nearly nonexpansive mappings such that F:=?_{i=1}^{?}F(T_{i}?Ø. Let V:C›H be a ?-Lipschitzian mapping and F:C›H be a L-Lipschitzian and ?-strongly monotone operator. This paper deals with a modified iterative projection method for approximating a solution of the hierarchical fixed point problem. It is shown that under certain approximate assumptions on the operators and parameters, the modified iterative sequence {x_{n}} converges strongly to x^{*}?F which is also the unique solution of the following variational inequality: ?0, ?x?F. As a special case, this projection method can be used to find the minimum norm solution of above variational inequality; namely, the unique solution x^{*} to the quadratic minimization problem: x^{*}=argmin_{x?F}?x?². The results here improve and extend some recent corresponding results of other authors.
Directed electromagnetic wave propagation in 1D metamaterial: Projecting operators method
Ampilogov, Dmitrii, E-mail: DVAmpilogov@kantiana.ru; Leble, Sergey, E-mail: sleble@kantiana.ru
2016-07-01
We consider a boundary problem for 1D electrodynamics modeling of a pulse propagation in a metamaterial medium. We build and apply projecting operators to a Maxwell system in time domain that allows to split the linear propagation problem to directed waves for a material relations with general dispersion. Matrix elements of the projectors act as convolution integral operators. For a weak nonlinearity we generalize the linear results still for arbitrary dispersion and derive the system of interacting right/left waves with combined (hybrid) amplitudes. The result is specified for the popular metamaterial model with Drude formula for both permittivity and permeability coefficients. We also discuss and investigate stationary solutions of the system related to some boundary regimes. - Highlights: • The problem of boundary regime propagation is solved by a systematic dynamic projecting method. • By this method a hybrid amplitude is introduced and used for derivation of nonlinear equation of opposite directed waves. • The equations are specified for Drude metamaterial dispersion and Kerr nonlinearity. • It is shown that one of unidirection waves in the metamaterial is specified as Shafer–Wayn integrable equation. • A stationary wave solution is approximately expressed in terms of elliptic functions.
Ageskog, L. [SWECO VBB VIAK AB, Stockholm (Sweden)
2001-08-01
Within the SKB Deep Repository Project, a study called JADE (Comparison of Deposition Methods) has been performed with the purpose of systematically evaluating different deposition methods The study has encompassed the areas of technology, long term performance and safety, and costs. The alternative methods studied are all within the frame of the so-called KBS-3 concept. The present report deals with the comparison regarding costs. The following deposition methods have been studied and compared: deposition in vertical holes (KBS-3 V), single canister deposition in horizontal holes (KBS-3 H) and serial canister deposition in medium long holes (MLH). KBS-3 V constitutes the reference concept for current development and planing activities within SKB. The cost calculations have been performed according to a method called 'the Successive Principle'. The same method is currently used by SKB in the cost analyses reported to the authorities on a yearly basis (the so-called PLAN analyses). The method covers uncertainties of various kinds and presents data in a statistical manner, providing means for a result interpretation in terms of probabilities. Beside the methodology, also technical and cost data have been derived from the PLAN works, mostly from the report PLAN 97, which was forwarded to the authorities in June 1997. Hence, all cost data in the present study refer to price level January 1997. The findings of the present study are compared with the reference method KBS 3 V. (The report also includes comparisons between alternatives within each one of the three principal methods.)
Lyudmila Sinitsyna
2015-04-01
Full Text Available Projection of design objects is the main type of professional activity of designers, the creative almost un-predictable process. The skills of a designer are demanded by the society, when a certain designer at any time and without effort in a short period of time can develop a design object, which can easily be imple-mented in production, which will be in demand by a consumer for a long time and almost without special modifications. Each teacher of design thinks about the ways and methods of teaching the design stages. The author offers a way to get the skills of design based on the simultaneous execution of two tasks with different goals, objectives and method of images.
Dmitriy Y. Anistratov; Adrian Constantinescu; Loren Roberts; William Wieselquist
2007-04-30
This is a project in the field of fundamental research on numerical methods for solving the particle transport equation. Numerous practical problems require to use unstructured meshes, for example, detailed nuclear reactor assembly-level calculations, large-scale reactor core calculations, radiative hydrodynamics problems, where the mesh is determined by hydrodynamic processes, and well-logging problems in which the media structure has very complicated geometry. Currently this is an area of very active research in numerical transport theory. main issues in developing numerical methods for solving the transport equation are the accuracy of the numerical solution and effectiveness of iteration procedure. The problem in case of unstructured grids is that it is very difficult to derive an iteration algorithm that will be unconditionally stable.
Communication: An efficient analytic gradient theory for approximate spin projection methods
Hratchian, Hrant P.
2013-03-01
Spin polarized and broken symmetry density functional theory are popular approaches for treating the electronic structure of open shell systems. However, spin contamination can significantly affect the quality of predicted geometries and properties. One scheme for addressing this concern in studies involving broken-symmetry states is the approximate projection method developed by Yamaguchi and co-workers. Critical to the exploration of potential energy surfaces and the study of properties using this method will be an efficient analytic gradient theory. This communication introduces such a theory formulated, for the first time, within the framework of general post-self consistent field (SCF) derivative theory. Importantly, the approach taken here avoids the need to explicitly solve for molecular orbital derivatives of each nuclear displacement perturbation, as has been used in a recent implementation. Instead, the well-known z-vector scheme is employed and only one SCF response equation is required.
Reconstruction from Uniformly Attenuated SPECT Projection Data Using the DBH Method
Huang, Qiu; You, Jiangsheng; Zeng, Gengsheng L.; Gullberg, Grant T.
2008-03-20
An algorithm was developed for the two-dimensional (2D) reconstruction of truncated and non-truncated uniformly attenuated data acquired from single photon emission computed tomography (SPECT). The algorithm is able to reconstruct data from half-scan (180o) and short-scan (180?+fan angle) acquisitions for parallel- and fan-beam geometries, respectively, as well as data from full-scan (360o) acquisitions. The algorithm is a derivative, backprojection, and Hilbert transform (DBH) method, which involves the backprojection of differentiated projection data followed by an inversion of the finite weighted Hilbert transform. The kernel of the inverse weighted Hilbert transform is solved numerically using matrix inversion. Numerical simulations confirm that the DBH method provides accurate reconstructions from half-scan and short-scan data, even when there is truncation. However, as the attenuation increases, finer data sampling is required.
Gradient methods for variational optimization of projected entangled-pair states
Vanderstraeten, Laurens; Haegeman, Jutho; Corboz, Philippe; Verstraete, Frank
2016-10-01
We present a conjugate-gradient method for the ground-state optimization of projected entangled-pair states (PEPS) in the thermodynamic limit, as a direct implementation of the variational principle within the PEPS manifold. Our optimization is based on an efficient and accurate evaluation of the gradient of the global energy functional by using effective corner environments, and is robust with respect to the initial starting points. It has the additional advantage that physical and virtual symmetries can be straightforwardly implemented. We provide the tools to compute static structure factors directly in momentum space, as well as the variance of the Hamiltonian. We benchmark our method on Ising and Heisenberg models, and show a significant improvement on the energies and order parameters as compared to algorithms based on imaginary-time evolution.
2011-01-01
When an atom in vacuum is near a surface of a dielectric the energy of a fluctuating electromagnetic field depends on a distance between them resulting, as known, in the force called van der Waals one. Besides this fluctuation phenomenon there is one associated with formation of a mean electric field which is equivalent to an order parameter. In this case atomic electrons are localized within atomic distances close to the atom and the total ground state energy is larger, compared to the bare ...
A Simple Sampling Method for Estimating the Accuracy of Large Scale Record Linkage Projects.
Boyd, James H; Guiver, Tenniel; Randall, Sean M; Ferrante, Anna M; Semmens, James B; Anderson, Phil; Dickinson, Teresa
2016-05-17
Record linkage techniques allow different data collections to be brought together to provide a wider picture of the health status of individuals. Ensuring high linkage quality is important to guarantee the quality and integrity of research. Current methods for measuring linkage quality typically focus on precision (the proportion of incorrect links), given the difficulty of measuring the proportion of false negatives. The aim of this work is to introduce and evaluate a sampling based method to estimate both precision and recall following record linkage. In the sampling based method, record-pairs from each threshold (including those below the identified cut-off for acceptance) are sampled and clerically reviewed. These results are then applied to the entire set of record-pairs, providing estimates of false positives and false negatives. This method was evaluated on a synthetically generated dataset, where the true match status (which records belonged to the same person) was known. The sampled estimates of linkage quality were relatively close to actual linkage quality metrics calculated for the whole synthetic dataset. The precision and recall measures for seven reviewers were very consistent with little variation in the clerical assessment results (overall agreement using the Fleiss Kappa statistics was 0.601). This method presents as a possible means of accurately estimating matching quality and refining linkages in population level linkage studies. The sampling approach is especially important for large project linkages where the number of record pairs produced may be very large often running into millions.
Dachyar, M.; Rhezza Pratama, Novandra
2014-04-01
Decision-making in a project is a complex undertaking. A project is a temporary organization that is surrounded by inherent uncertainties. Uncertainties that may occur in the project, among others, are the uncertainty of the time, cost, and quality. To overcome this complexity, we need a project performance evaluation. At one of the services the oil and gas in Indonesia, the performance evaluation has been done, but it is done separately and only few criteria are evaluated, so that the overall project performance is still not visible. Therefore it is necessary to evaluate the performance of the company's project with the MCDA (Multi Criteria Decision Analysis) approach using MACBETH (Measuring Attractiveness by a Categorical Based Evaluation Technique) method that can model the elements of the project into a supervisory level group to facilitate decision making by the project manager. These measurements will produce levels of monitoring classification of project element groups, i.e. absolute vigilance, strong attention, close surveillance, and normal monitoring of the project elements. This research finds that the criteria of Effectiveness, Efficiency, Time, Cost, and Complete Reports & Field Tickets require absolute vigilance so that the performance criteria can be increased.
Silvério, Adriano Augusto
2015-07-01
Full Text Available Choosing from several alternative investment projects in hydropower to build a portfolio of projects is a complex matter. The most commonly used selection model for building the portfolio is the financial method, however it constraints options investments to the economic and financial parameters, which are limiting in nature. Alternatively, this paper proposes the use of multicriterial method Analytic Hierarchy Process – AHP, which incorporates measures to evaluate both quantitative and qualitative data. This method is based on criteria or parameters of operational processes that hinder or facilitate the execution of projects. In order to get the definition of the set of criteria, the Delphi technique was applied to a group of seven experts in managing hydropower projects. Main results show that essential criteria for selection of project investment portfolio, are not limited to financial aspects, but it involves criteria of bureaucratic, organizational, and political environment and technological characters. The conclusion is that the financial potential of hydropower projects are not the only determinants for investments on hydropower projects and, at large, these project are conditioned to other criteria such as, those of bureaucratic and technological nature.
Solving the Poisson partial differential equation using vector space projection methods
Marendic, Boris
This research presents a new approach at solving the Poisson partial differential equation using Vector Space Projection (VSP) methods. The work attacks the Poisson equation as encountered in two-dimensional phase unwrapping problems, and in two-dimensional electrostatic problems. Algorithms are developed by first considering simple one-dimensional cases, and then extending them to two-dimensional problems. In the context of phase unwrapping of two-dimensional phase functions, we explore an approach to the unwrapping using a robust extrapolation-projection algorithm. The unwrapping is done iteratively by modification of the Gerchberg-Papoulis (GP) extrapolation algorithm, and the solution is refined by projecting onto the available global data. An important contribution to the extrapolation algorithm is the formulation of the algorithm with the relaxed bandwidth constraint, and the proof that such modified GP extrapolation algorithm still converges. It is also shown that the unwrapping problem is ill-posed in the VSP setting, and that the modified GP algorithm is the missing link to pushing the iterative algorithm out of the trap solution under certain conditions. Robustness of the algorithm is demonstrated through its performance in a noisy environment. Performance is demonstrated by applying it to phantom phase functions, as well as to the real phase functions. Results are compared to well known algorithms in literature. Unlike many existing unwrapping methods which perform unwrapping locally, this work approaches the unwrapping problem from a globally, and eliminates the need for guiding instruments, like quality maps. VSP algorithm also very effectively battles problems of shadowing and holes, where data is not available or is heavily corrupted. In solving the classical Poisson problems in electrostatics, we demonstrate the effectiveness and ease of implementation of the VSP methodology to solving the equation, as well as imposing of the boundary conditions
Makarenkov, A. M.; Seregina, E. V.; Stepovich, M. A.
2017-05-01
Using the diffusion equation as an example, results of applying the projection Galerkin method for solving time-independent heat and mass transfer equations in a semi-infinite domain are presented. The convergence of the residual corresponding to the approximate solution of the timeindependent diffusion equation obtained by the projection method using the modified Laguerre functions is proved. Computational results for a two-dimensional toy problem are presented.
Jörg Rekittke
2011-10-01
Full Text Available The research project “Grassroots GIS” focuses on the development of low-cost mapping and publishing methods for slums and slum-upgrading projects in Manila. In this project smartphones, collaborative mapping and 3D visualization applications are systematically employed to support landscape architectural analysis and design work in the context of urban poverty and urban informal settlements. In this paper we focus on the description of the developed methods and present preliminary results of this work-in-progress.
Pyka, Martin; Klatt, Sebastian; Cheng, Sen
2014-01-01
Computational models of neural networks can be based on a variety of different parameters. These parameters include, for example, the 3d shape of neuron layers, the neurons' spatial projection patterns, spiking dynamics and neurotransmitter systems. While many well-developed approaches are available to model, for example, the spiking dynamics, there is a lack of approaches for modeling the anatomical layout of neurons and their projections. We present a new method, called Parametric Anatomical Modeling (PAM), to fill this gap. PAM can be used to derive network connectivities and conduction delays from anatomical data, such as the position and shape of the neuronal layers and the dendritic and axonal projection patterns. Within the PAM framework, several mapping techniques between layers can account for a large variety of connection properties between pre- and post-synaptic neuron layers. PAM is implemented as a Python tool and integrated in the 3d modeling software Blender. We demonstrate on a 3d model of the hippocampal formation how PAM can help reveal complex properties of the synaptic connectivity and conduction delays, properties that might be relevant to uncover the function of the hippocampus. Based on these analyses, two experimentally testable predictions arose: (i) the number of neurons and the spread of connections is heterogeneously distributed across the main anatomical axes, (ii) the distribution of connection lengths in CA3-CA1 differ qualitatively from those between DG-CA3 and CA3-CA3. Models created by PAM can also serve as an educational tool to visualize the 3d connectivity of brain regions. The low-dimensional, but yet biologically plausible, parameter space renders PAM suitable to analyse allometric and evolutionary factors in networks and to model the complexity of real networks with comparatively little effort.
Ni, Ming-Jiu
2009-10-01
Two consistent projection methods of second-order temporal and spatial accuracy have been developed on a rectangular collocated mesh for variable density Navier-Stokes equations with a continuous surface force. Instead of the original projection methods (denoted as algorithms I and II in this paper), in which the updated cell center velocity from the intermediate velocity and the pressure gradient is not guaranteed solenoidal, the consistent projection methods (denoted as algorithms III and IV) obtain the cell center velocity based on an interpolation from a conservative fluxes with velocity unit on surrounding cell faces. Dependent on treatment of the continuous surface force, the pressure gradient in algorithm III or the sum of the pressure gradient and the surface force in algorithm IV at a cell center is then conducted from the difference between the updated velocity and the intermediate velocity in a consistent projection method. A non-viscous 3D static drop with serials of density ratios is numerically simulated. Using the consistent projection methods, the spurious currents can be greatly reduced and the pressure jump across the interface can be accurately captured without oscillations. The developed consistent projection method are also applied for simulation of interface evolution of an initial ellipse driven by the surface tension and of an initial sphere bubble driven by the buoyancy with good accuracy and good resolution.
Ahmad Norang
2016-01-01
Full Text Available Nowadays, the increase in competition has increased the relative importance of innovation for most firms and many managers believe a good innovation must be knowledge oriented. This paper has tried to determine different methods for creating knowledge in project oriented organizations. The study designs a questionnaire in Likert scale and distributes it among 32 experts who were well informed about different methods of knowledge creation and lessons learned. Cronbach alphas for all components of the survey were well above the desirable level. The study has detected 11 methods for knowledge creation and lessons learned. In terms of preliminary assessment, business transactions has received the highest impact while knowledge team has received the highest effect in terms of necessary assessment. The results of this survey have indicated that although there are several methods for detecting knowledge within organizations, in most cases, it is not easy to gain value added knowledge within an organization, quickly. The people who participated in our survey have indicated that organizational commitment, brainstorming, Delphi and storytelling also have played important role for creation of knowledge. The results have also shown that brainstorming, knowledge brokers, map knowledge and work experience were easier to use for knowledge creation and lessons learned compared with other forms of knowledge creation.
Walker, Rebecca L; Morrissey, Clair
2014-11-01
While bioethics as a field has concerned itself with methodological issues since the early years, there has been no systematic examination of how ethics is incorporated into research on the Ethical, Legal and Social Implications (ELSI) of the Human Genome Project. Yet ELSI research may bear a particular burden of investigating and substantiating its methods given public funding, an explicitly cross-disciplinary approach, and the perceived significance of adequate responsiveness to advances in genomics. We undertook a qualitative content analysis of a sample of ELSI publications appearing between 2003 and 2008 with the aim of better understanding the methods, aims, and approaches to ethics that ELSI researchers employ. We found that the aims of ethics within ELSI are largely prescriptive and address multiple groups. We also found that the bioethics methods used in the ELSI literature are both diverse between publications and multiple within publications, but are usually not themselves discussed or employed as suggested by bioethics method proponents. Ethics in ELSI is also sometimes undistinguished from related inquiries (such as social, legal, or political investigations).
GUYanfeng; ZHANGYe; QUANTaifan
2003-01-01
A challenging problem in using hyper-spectral data is to eliminate redundancy and preserve useful spectral information for applications. In this pa-per, a kernel-based nonlinear subspace projection (KNSP)method is proposed for feature extraction and dimension-ality reduction in hyperspectral images. The proposed method includes three key steps: subspace partition of hyperspectral data, feature extraction using kernel-based principal component analysis (KPCA) and feature selec-tion based on class separability in the subspaces. Accord-ing to the strong correlation between neighboring bands,the whole data space is partitioned to requested subspaces.In each subspace, the KPCA method is used to effectively extract spectral feature and eliminate redundancies. A criterion function based on class discrimination and sepa-rability is used for the transformed feature selection. For the purpose of testifying its effectiveness, the proposed new method is compared with the classical principal component analysis (PCA) and segmented principal component trans-formation (SPCT). A hyperspectral image classification is performed on AVIRIS data. which have 224 svectral bands.Experimental results show that KNSP is very effective for feature extraction and dimensionality reduction of hyper-spectral data and provides significant improvement over classical PCA and current SPCT technique.
Strongly Coupled Fluid-Body Dynamics in the Immersed Boundary Projection Method
Wang, Chengjie; Eldredge, Jeff D.
2014-11-01
A computational algorithm is developed to simulate dynamically coupled interaction between fluid and rigid bodies. The basic computational framework is built upon a multi-domain immersed boundary method library, whirl, developed in previous work. In this library, the Navier-Stokes equations for incompressible flow are solved on a uniform Cartesian grid by the vorticity-based immersed boundary projection method of Colonius and Taira. A solver for the dynamics of rigid-body systems is also included. The fluid and rigid-body solvers are strongly coupled with an iterative approach based on the block Gauss-Seidel method. Interfacial force, with its intimate connection with the Lagrange multipliers used in the fluid solver, is used as the primary iteration variable. Relaxation, developed from a stability analysis of the iterative scheme, is used to achieve convergence in only 2-4 iterations per time step. Several two- and three-dimensional numerical tests are conducted to validate and demonstrate the method, including flapping of flexible wings, self-excited oscillations of a system of linked plates and three-dimensional propulsion of flexible fluked tail. This work has been supported by AFOSR, under Award FA9550-11-1-0098.
A method of generalized projections (MGP) ghost correction algorithm for interleaved EPI.
Lee, K J; Papadakis, N G; Barber, D C; Wilkinson, I D; Griffiths, P D; Paley, M N J
2004-07-01
Investigations into the method of generalized projections (MGP) as a ghost correction method for interleaved EPI are described. The technique is image-based and does not require additional reference scans. The algorithm was found to be more effective if a priori knowledge was incorporated to reduce the degrees of freedom, by modeling the ghosting as arising from a small number of phase offsets. In simulations with phase variation between consecutive shots for n-interleaved echo planar imaging (EPI), ghost reduction was achieved for n = 2 only. With no phase variation between shots, ghost reduction was obtained with n up to 16. Incorporating a relaxation parameter was found to improve convergence. Dependence of convergence on the region of support was also investigated. A fully automatic version of the method was developed, using results from the simulations. When tested on in vivo 2-, 16-, and 32-interleaved spin-echo EPI data, the method achieved deghosting and image restoration close to that obtained by both reference scan and odd/even filter correction, although some residual artifacts remained.
A novel background field removal method for MRI using projection onto dipole fields (PDF).
Liu, Tian; Khalidov, Ildar; de Rochefort, Ludovic; Spincemaille, Pascal; Liu, Jing; Tsiouris, A John; Wang, Yi
2011-11-01
For optimal image quality in susceptibility-weighted imaging and accurate quantification of susceptibility, it is necessary to isolate the local field generated by local magnetic sources (such as iron) from the background field that arises from imperfect shimming and variations in magnetic susceptibility of surrounding tissues (including air). Previous background removal techniques have limited effectiveness depending on the accuracy of model assumptions or information input. In this article, we report an observation that the magnetic field for a dipole outside a given region of interest (ROI) is approximately orthogonal to the magnetic field of a dipole inside the ROI. Accordingly, we propose a nonparametric background field removal technique based on projection onto dipole fields (PDF). In this PDF technique, the background field inside an ROI is decomposed into a field originating from dipoles outside the ROI using the projection theorem in Hilbert space. This novel PDF background removal technique was validated on a numerical simulation and a phantom experiment and was applied in human brain imaging, demonstrating substantial improvement in background field removal compared with the commonly used high-pass filtering method. Copyright © 2011 John Wiley & Sons, Ltd.
MATTHIAS ZIEGLER
2007-12-01
Full Text Available Different means can be applied to assess noncognitive personality aspects: projective, semi-projective, self-report, and objective. However, so far little attention has been paid towards the different fakability of these methods. The present study investigated this question with different achievement motivation instruments. The instruments were randomly administered to three student groups: fake bad (n = 41, fake good (n = 37, and control group (n = 41. The faking groups were given specific faking instructions while the control group only received the standard instructions. All instruments were applied computer-assisted. The results show that all tests are fakeable with the exception of the objective measure which could not be faked good as was expected. The effect sizes (d ranged from .10 to 2.36. Cut-off scores for the detection of faking were computed based on sensitivity as well as specificity. Moreover, they were tested within a second student sample (n = 123. Sensitivity and specificity values are reported. The practical implications for test authors and practitioners are discussed.
Experience in Use of Project Method During Technology Lessons in Secondary Schools of the USA
Sheludko Inna
2015-08-01
Full Text Available The article examines the opportunities and prospects for the use of experience of project method during “technology lessons” in US secondary schools, since the value of project technology implementation experience into the educational process in the USA for ensuring holistic development of children, preparing them for adult life, in which they will be able to realize themselves and benefit society, seems undeniable to improve the quality of Ukrainian education. Its structure and content accorded with national traditions and European standards have made possible the success of educational components of American secondary school. This encourages national scientists and teachers to identify and scientifically justify the ways how to use scientific achievements of American educational system. Given the above, we have defined the following objectives: to summarize progressive trends and innovative approaches to the quality training of students in national secondary schools; to formulate guidelines that will improve the efficiency of training Ukrainian students during technology lessons and as a result, will provide the successful integration of the national education system into the European educational space.
Thermal resonating Hartree-Bogoliubov theory based on the projection method
Nishiyama, Seiya; Ohnishi, Hiromasa
2013-01-01
We propose a rigorous thermal resonating mean-field theory (Res-MFT). A state is approximated by superposition of multiple MF wavefunctions (WFs) composed of non-orthogonal Hartree-Bogoliubov (HB) WFs. We adopt a Res-HB subspace spanned by Res-HB ground and excited states. A partition function (PF) in a SO(2N) coherent state representation |g> (N:Number of single-particle states) is expressed as Tr(e^{-\\beta H})=2^{N-1} \\int dg (\\beta=1/k_BT). Introducing a projection operator P to the Res-HB subspace, the PF in the Res-HB subspace is given as Tr(Pe^{-\\beta H}), which is calculated within the Res-HB subspace by using the Laplace transform of e^{-\\beta H} and the projection method. The variation of the Res-HB free energy is made, which leads to a thermal HB density matrix W_{Res}^{thermal} expressed in terms of a thermal Res-FB operator F_{Res}^{thermal} as W_{Res}^{thermal}={1_{2N}+exp(\\beta F_{Res}^{thermal})}^{-1}. A calculation of the PF by an infinite matrix continued fraction is cumbersome and a procedur...
Kawamoto, Shigeru; Ikeda, Yuichi; Fukui, Chihiro; Tateshita, Fumihiko
Private finance initiative is a business scheme that materializes social infrastructure and public services by utilizing private-sector resources. In this paper we propose a new method to optimize capital structure, which is the ratio of capital to debt, and senior-sub structure, which is the ratio of senior loan to subordinated loan, for private finance initiative. We make the quantitative analysis of a private finance initiative's project using the proposed method. We analyze trade-off structure between risk and return in the project, and optimize capital structure and senior-sub structure. The method we propose helps to improve financial stability of the project, and to make a fund raising plan that is expected to be reasonable for project sponsor and moneylender.
Zwinderman Aeilko H
2004-06-01
Full Text Available Abstract Background Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a 'not applicable' category to items included in the AMC Linear Disability Score (ALDS project item bank. Methods The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. Results The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. The estimates obtained using the cold deck imputation method were substantially different. Conclusions The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used.
Holman, Rebecca; Glas, Cees AW; Lindeboom, Robert; Zwinderman, Aeilko H; de Haan, Rob J
2004-01-01
Background Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a 'not applicable' category to items included in the AMC Linear Disability Score (ALDS) project item bank. Methods The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. Results The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. The estimates obtained using the cold deck imputation method were substantially different. Conclusions The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used. PMID:15200681
Fernandez Casani, Alvaro; The ATLAS collaboration
2016-01-01
One of the key and challenging tasks of the ATLAS EventIndex project is to index and catalog all the produced events not only at CERN but also at hundreds of worldwide grid sites, and convey the data in real time to a central Hadoop instance at CERN. While this distributed data collection is currently operating correctly in production, there are some issues that might impose performance bottlenecks in the future, with an expected rise in the event production and reprocessing rates. In this work, we first describe the current approach based on a messaging system, which conveys the data from the sources to the central catalog, and we identify some weaknesses of this system. Then, we study a promising alternative transport method based on an object store, presenting a performance comparison with the current approach, and the architectural design changes needed to adapt the system to the next run of the ATLAS experiment at CERN.
National data analysis of general radiography projection method in medical imaging
Kim, Jung Su; Seo, Deok Nam; Choi, In Seok [Dept. of Bio-Convergence Engineering, Korea University Graduate School, Seoul (Korea, Republic of); and others
2014-09-15
According to database of medical institutions of health insurance review and assessment service in 2013, 1,118 hospitals and clinics have department of radiology in Korea. And there are CT, fluoroscopic and general radiographic equipment in those hospitals. Above all, general radiographic equipment is the most commonly used in the radiology department. And most of the general radiographic equipment are changing the digital radiography system from the film-screen types of the radiography system nowadays. However, most of the digital radiography department are used the film-screen types of the radiography system. Therefore, in this study, we confirmed present conditions of technical items for general radiography used in hospital and research on general radiographic techniques in domestic medical institutions. We analyzed 26 radiography projection method including chest, skull, spine and pelvis which are generally used in the radiography department.
Project - based teaching and other methods to make learning more attractive
Švecová, Libuše; Vlková, Iva
2017-01-01
This contribution presents the results of a research carried out at secondary schools in the Moravian-Silesian Region. This research involved a total of 120 pupils and focused on project teaching with the emphasis on pupil inquiry activity and the connection of their knowledge in the fields of physics and biology. To verify pupil inquiry activity, the tasks on the worksheets have been designed specifically to measure physical quantities on the human body by computer-aided measuring processes. To support pupil inquiry activity, group work was selected as the organization method of teaching. Audio recording and pedagogical observations were used as the research tools for assessment and a consequent evaluation of acquired data.
Local Projection-Based Stabilized Mixed Finite Element Methods for Kirchhoff Plate Bending Problems
Xuehai Huang
2013-01-01
Full Text Available Based on stress-deflection variational formulation, we propose a family of local projection-based stabilized mixed finite element methods for Kirchhoff plate bending problems. According to the error equations, we obtain the error estimates of the approximation to stress tensor in energy norm. And by duality argument, error estimates of the approximation to deflection in H1-norm are achieved. Then we design an a posteriori error estimator which is closely related to the equilibrium equation, constitutive equation, and nonconformity of the finite element spaces. With the help of Zienkiewicz-Guzmán-Neilan element spaces, we prove the reliability of the a posteriori error estimator. And the efficiency of the a posteriori error estimator is proved by standard bubble function argument.
When the project becomes method: New perspectives for network-based socio-educational research
José Antonio Caride Gómez
2015-05-01
Full Text Available This paper centers its arguments in the epistemological shift that the so-called mixed methods have provided the Social and Educational Sciences with. It is not just as a way for widening the expectations they generate in socio-educational action and reflection but also in the change processes and social transformation. Based on these assumptions it is introduced the Network of Research Groups OcioGune and the coordinated project “From Educational to Social Times: the Daily Building of the Young Condition into a Network Society” (RESORTES. A practical realization of the potentialities inherent to collaborative work and the multidisciplinary approach provided by shared knowledge: a way, among others, to extend the frontiers of knowledge and its transfer to society by using mixed research methodologies.
Torrelles, X.; Rius, J.; Boscherini, F.; Heun, S.; Mueller, B. H.; Ferrer, S.; Alvarez, J.; Miravitlles, C.
1998-02-01
The projections of surface reconstructions are normally solved from the interatomic vectors found in two-dimensional Patterson maps computed with the intensities of the in-plane superstructure reflections. Since for difficult reconstructions this procedure is not trivial, an alternative automated one based on the ``direct methods'' sum function [Rius, Miravitlles, and Allmann, Acta Crystallogr. A52, 634 (1996)] is shown. It has been applied successfully to the known c(4×2) reconstruction of Ge(001) and to the so-far unresolved In0.04Ga0.96As (001) p(4×2) surface reconstruction. For this last system we propose a modification of one of the models previously proposed for GaAs(001) whose characteristic feature is the presence of dimers along the fourfold direction.
Application of the Sketch Match method in Sulina coastal study area within PEGASO project
Marin, Eugenia; Nichersu, Iuliana; Mierla, Marian; Trifanov, Cristian; Nichersu, Iulian
2013-04-01
The Sketch Match approach for Sulina pilot case was carried out in the frame of the project "People for Ecosystem Based Governance in Assessing Sustainable Development of Ocean and Coast" - PEGASO, funded by the Seventh Framework Programme. The PEGASO project has been designed to identify common threats and solutions in relation to the long-term sustainable development and environmental protection of coastal zones bordering the Mediterranean and Black Seas in ways relevant to the implementation of the Integrated Coastal Zone Management Protocol (ICZM) for the Mediterranean. PEGASO will use the model of the existing ICZM Protocol for the Mediterranean and adjust it to the needs of the Black Sea through innovative actions, one of them being Refine and develop efficient and easy to use tools for making sustainability assessments in the coastal zone tested through a number of relevant pilot sites. Thus, for the Romania case study, the Sketch Match approach was selected, being an interactive public participation planning method, developed by the Dutch Government, and applied for Sulina area in order to stimulate support and involvement from stakeholders regarding Integrated Coastal Zone Management Protocol by consulting and involving these people in the planning process and making use of a coherent package of interactive methods. Participants were representatives of a wide range of stakeholders, varying from local fisherman to representatives of the Local and County council and Danube Delta Biosphere Reserve Authority. They participated in a two-day design session, focused on problems and potentials of the area, with the aim to work out possible solutions for an integrated coastal spatial planning, focusing on the parallel enhance of the various local functions in the spatial design (coastal area protection next to industry, tourism, nature, recreation, and other activities).
San, Omer
2013-01-01
This paper puts forth a coarse grid projection (CGP) multiscale method to accelerate computations of quasigeostrophic (QG) models for large scale ocean circulation. These models require solving an elliptic sub-problem at each time step, which takes the bulk of the computational time. The method we propose here is a modular approach that facilitates data transfer with simple interpolations and uses black-box solvers for solving the elliptic sub-problem and potential vorticity equations in the QG flow solvers. After solving the elliptic sub-problem on a coarsened grid, an interpolation scheme is used to obtain the fine data for subsequent time stepping on the full grid. The potential vorticity field is then updated on the fine grid with savings in computational time due to the reduced number of grid points for the elliptic solver. The method is applied to both single layer barotropic and two-layer stratified QG ocean models for mid-latitude oceanic basins in the beta plane, which are standard prototypes of more...
Denton, William T.; Murray, Wayne R.
This paper describes six existing evaluator-auditor working formats and the conditions which foster credibility of evaluation findings. Evaluators were classified as: (1) member of project developmental team, accountable to project director; (2) independent internal evaluator, accountable to system in general but not to project directors, and (3)…
Blumenstock, Gunnar; Fischer, Imma; de Cruppé, Werner; Geraedts, Max; Selbmann, Hans-Konrad
2011-01-01
A survey among 232 German health care organisations addressed benchmarking projects in patient care. 53 projects were reported and analysed using a benchmarking development scheme and a list of criteria. None of the projects satisfied all the criteria. Rather, examples of best practice for single aspects have been identified.
Ortíz, Miguel A; Felizzola, Heriberto A; Nieto Isaza, Santiago
2015-01-01
The project selection process is a crucial step for healthcare organizations at the moment of implementing six sigma programs in both administrative and caring processes. However, six-sigma project selection is often defined as a decision making process with interaction and feedback between criteria; so that it is necessary to explore different methods to help healthcare companies to determine the Six-sigma projects that provide the maximum benefits. This paper describes the application of both ANP (Analytic Network process) and DEMATEL (Decision Making trial and evaluation laboratory)-ANP in a public medical centre to establish the most suitable six sigma project and finally, these methods were compared to evaluate their performance in the decision making process. ANP and DEMATEL-ANP were used to evaluate 6 six sigma project alternatives under an evaluation model composed by 3 strategies, 4 criteria and 15 sub-criteria. Judgement matrixes were completed by the six sigma team whose participants worked in different departments of the medical centre. The improving of care opportunity in obstetric outpatients was elected as the most suitable six sigma project with a score of 0,117 as contribution to the organization goals. DEMATEL-ANP performed better at decision making process since it reduced the error probability due to interactions and feedback. ANP and DEMATEL-ANP effectively supported six sigma project selection processes, helping to create a complete framework that guarantees the prioritization of projects that provide maximum benefits to healthcare organizations. As DEMATEL- ANP performed better, it should be used by practitioners involved in decisions related to the implementation of six sigma programs in healthcare sector accompanied by the adequate identification of the evaluation criteria that support the decision making model. Thus, this comparative study contributes to choosing more effective approaches in this field. Suggestions of further work are also
Medicinal Chemistry Projects Requiring Imaginative Structure-Based Drug Design Methods.
Moitessier, Nicolas; Pottel, Joshua; Therrien, Eric; Englebienne, Pablo; Liu, Zhaomin; Tomberg, Anna; Corbeil, Christopher R
2016-09-20
Computational methods for docking small molecules to proteins are prominent in drug discovery. There are hundreds, if not thousands, of documented examples-and several pertinent cases within our research program. Fifteen years ago, our first docking-guided drug design project yielded nanomolar metalloproteinase inhibitors and illustrated the potential of structure-based drug design. Subsequent applications of docking programs to the design of integrin antagonists, BACE-1 inhibitors, and aminoglycosides binding to bacterial RNA demonstrated that available docking programs needed significant improvement. At that time, docking programs primarily considered flexible ligands and rigid proteins. We demonstrated that accounting for protein flexibility, employing displaceable water molecules, and using ligand-based pharmacophores improved the docking accuracy of existing methods-enabling the design of bioactive molecules. The success prompted the development of our own program, Fitted, implementing all of these aspects. The primary motivation has always been to respond to the needs of drug design studies; the majority of the concepts behind the evolution of Fitted are rooted in medicinal chemistry projects and collaborations. Several examples follow: (1) Searching for HDAC inhibitors led us to develop methods considering drug-zinc coordination and its effect on the pKa of surrounding residues. (2) Targeting covalent prolyl oligopeptidase (POP) inhibitors prompted an update to Fitted to identify reactive groups and form bonds with a given residue (e.g., a catalytic residue) when the geometry allows it. Fitted-the first fully automated covalent docking program-was successfully applied to the discovery of four new classes of covalent POP inhibitors. As a result, efficient stereoselective syntheses of a few screening hits were prioritized rather than synthesizing large chemical libraries-yielding nanomolar inhibitors. (3) In order to study the metabolism of POP inhibitors by
Kelly, C. L.; Lawrence, J. F.
2014-12-01
During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and
孙英杰; 曹其新; 洪炳熔
2004-01-01
We present an omnidirectional vision system we have implemented to provide our mobile robot with a fast tracking and robust localization capability. An algorithm is proposed to do reconstruction of the environmentfrom the omnidirectional image and global localization of the robot in the context of the Middle Size League RoboCup field. This is accomplished by learning a set of visual landmarks such as the goals and the corner posts. Due to the dynamic changing environment and the partially observable landmarks, four localization cases are discussed in order to get robust localization performance. Localization is performed using a method that matches the observed landmarks, i.e. color blobs, which are extracted from the environment. The advantages of the cylindrical projection are discussed giving special consideration to the characteristics of the visual landmark and the meaning of the blob extraction. The analysis is established based on real time experiments with our omnidirectional vision system and the actual mobile robot. The comparative studies are presented and the feasibility of the method is shown.
Study of reconstruction methods for a time projection chamber with GEM gas amplification system
Diener, R.
2006-12-15
A new e{sup +}e{sup -} linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)
ChavarrIas, C; Vaquero, J J; Sisniega, A; RodrIguez-Ruano, A; Soto-Montenegro, M L; GarcIa-Barreno, P; Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital General Universitario Gregorio Maranon, Anexo PsiquiatrIa, 1 Planta. C/Ibiza, 43. Madrid 28007 (Spain)
2008-09-07
We propose a retrospective respiratory gating algorithm to generate dynamic CT studies. To this end, we compared three different methods of extracting the respiratory signal from the projections of small-animal cone-beam computed tomography (CBCT) scanners. Given a set of frames acquired from a certain axial angle, subtraction of their average image from each individual frame produces a set of difference images. Pixels in these images have positive or negative values (according to the respiratory phase) in those areas where there is lung movement. The respiratory signals were extracted by analysing the shape of the histogram of these difference images: we calculated the first four central and non-central moments. However, only odd-order moments produced the desired breathing signal, as the even-order moments lacked information about the phase. Each of these curves was compared to a reference signal recorded by means of a pneumatic pillow. Given the similar correlation coefficients yielded by all of them, we selected the mean to implement our retrospective protocol. Respiratory phase bins were separated, reconstructed independently and included in a dynamic sequence, suitable for cine playback. We validated our method in five adult rat studies by comparing profiles drawn across the diaphragm dome, with and without retrospective respiratory gating. Results showed a sharper transition in the gated reconstruction, with an average slope improvement of 60.7%.
Aslan Efe, Hulya; Yucel, Sait; Baran, Medine; Oner Sunkur, Meral
2012-01-01
The present study conducted to establish effective environmental education investigated the influence of the project-based environmental education method supported with computer animations and of the traditional environmental education method on students' environmental literacy and on their self-efficacy beliefs in giving environmental education.…
Aslan Efe, Hulya; Yucel, Sait; Baran, Medine; Oner Sunkur, Meral
2012-01-01
The present study conducted to establish effective environmental education investigated the influence of the project-based environmental education method supported with computer animations and of the traditional environmental education method on students' environmental literacy and on their self-efficacy beliefs in giving environmental education.…
Natalia S. MAYKOVA
2015-01-01
Full Text Available Teachers turn to design the method to solve different didactic problems. The method projects the expected notion of "project", its focus on results, which can be obtained by the solution of this or that practically or theoretically significant problem. The result of the project activity should be such that it could be seen, comprehended, applied in practice. To achieve this result, it is necessary to teach pupils or students to think independently, to find and solve problems, involving for this purpose of interdisciplinary knowledge, ability to predict results and possible consequences of different solutions, the ability to establish a causal link. Method of projects is always focused on independent activity of students individual, pair, group, which students will complete within a certain period of time. This method is organically combined with group (collaborative or cooperative learning methods. The teacher can suggest sources of information, and can simply send a thought of the disciples in the right direction for independent research. But students must independently and in a collaborative effort to solve the problem by applying the necessary knowledge, sometimes from different areas, get real and tangible results. All work on the problem, thus, becomes the footprints of project activities.
José Mateo
2017-01-01
Full Text Available Numerous contemporary problems that project managers face today can be considered as unstructured decision problems characterized by multiple actors and perspectives, incommensurable and/or conflicting objectives, and important intangibles. This work environment demands that project managers possess not only hard skills but also soft skills with the ability to take a management perspective and, above all, develop real leadership capabilities. In this paper, a family of problem structured methods for decision support aimed at assisting project managers in tackling complex problems are presented. Problem structured methods are a family of soft operations research methods for decision support that assist groups of diverse composition to agree a problem focus and make commitments to consequential action. Project management programs are challenged to implement these methodologies in such a way that it is organized around the key competences that a project manager needs in order to be more effective, work efficiently as members of interdisciplinary teams and successfully execute even a small project.
Perception-Based Evaluation of Projection Methods for Multidimensional Data Visualization.
Etemadpour, Ronak; Motta, Robson; de Souza Paiva, Jose Gustavo; Minghim, Rosane; Ferreira de Oliveira, Maria Cristina; Linsen, Lars
2015-01-01
Similarity-based layouts generated by multidimensional projections or other dimension reduction techniques are commonly used to visualize high-dimensional data. Many projection techniques have been recently proposed addressing different objectives and application domains. Nonetheless, very little is known about the effectiveness of the generated layouts from a user's perspective, how distinct layouts from the same data compare regarding the typical visualization tasks they support, or how domain-specific issues affect the outcome of the techniques. Learning more about projection usage is an important step towards both consolidating their role in high-dimensional data analysis and taking informed decisions when choosing techniques. This work provides a contribution towards this goal. We describe the results of an investigation on the performance of layouts generated by projection techniques as perceived by their users. We conducted a controlled user study to test against the following hypotheses: (1) projection performance is task-dependent; (2) certain projections perform better on certain types of tasks; (3) projection performance depends on the nature of the data; and (4) subjects prefer projections with good segregation capability. We generated layouts of high-dimensional data with five techniques representative of different projection approaches. As application domains we investigated image and document data. We identified eight typical tasks, three of them related to segregation capability of the projection, three related to projection precision, and two related to incurred visual cluttering. Answers to questions were compared for correctness against `ground truth' computed directly from the data. We also looked at subject confidence and task completion times. Statistical analysis of the collected data resulted in Hypotheses 1 and 3 being confirmed, Hypothesis 2 being confirmed partially and Hypotheses 4 could not be confirmed. We discuss our findings in
Mohammad Mehdi Mozaffari
2012-09-01
Full Text Available Complexity is one of the most important issues influencing success of any construction project and there are literally different studies devoted to detect important factors increasing complexity of projects. During the past few years, there have been growing interests in developing mass construction projects in Iran. The proposed study of this paper uses Delphi technique to find out about important factors as barriers of construction projects in Iran. The results show that among 47 project complexity factors, 19 factors are more important than others are. The study groups different factors into seven categories including environmental, organizational, objectives, tasks, stakeholders, technological, information systems and determines the relative importance of each. In each group, many other sub group activities are determined and they are carefully investigated. The study provides some detailed suggestions on each category to reduce the complexity of construction project.
Intensive survey methods in the framework of a regional project: the Serena Region study case
Mayoral Herrera, Victorino
2009-06-01
Full Text Available The aim of this paper is to show the survey methods developed in the framework of a research project carried out in the Serena region (Badajoz Province, Spain. We start from a critical use of the notion of archaeological site and an assessment of the meaning of intensive surface collection in the context of the study of the structure of preindustrial agrarian landscapes. We offer a detailed exposition of the survey planning, data capture and spatial analysis. In a first stage we make a global estimate of density of surface finds, locating possible areas of interest. In a second phase detected dispersions are qualified by systematic sampling. Its main purpose is to dismiss selective procedures leading to remarkable biases in surface record. We emphasize the balance achieved between data resolution and effort invested. This method has shown its effectiveness to characterize archaeological entities often not considered in Peninsular regional projects. Other factors affecting the recognition of sherd scatters are discussed, like the so-called “background noise”.
El propósito de este trabajo es mostrar la metodología de prospección de superficie empleada en el marco de un proyecto regional sobre la evolución del paisaje en la comarca de La Serena (Badajoz. Se parte de una utilización crítica del concepto de sitio arqueológico y de una valoración del significado de estrategias intensivas de prospección de superficie en el contexto del estudio de la estructuración de los paisajes agrarios preindustriales. Se exponen los planteamientos, diseño y ejecución de los últimos trabajos efectuados. En una primera etapa se realiza una estimación global de la densidad de ítems y se determinan los posibles puntos de interés. Posteriormente se caracterizan cualitativamente las dispersiones detectadas mediante un muestreo aleatorio estratificado. Se pretende de este modo desterrar procedimientos selectivos y poco sistemáticos en la
NERI PROJECT 99-119. TASK 1. ADVANCED CONTROL TOOLS AND METHODS. FINAL REPORT
March-Leuba, J.A.
2002-09-09
Nuclear plants of the 21st century will employ higher levels of automation and fault tolerance to increase availability, reduce accident risk, and lower operating costs. Key developments in control algorithms, fault diagnostics, fault tolerance, and communication in a distributed system are needed to implement the fully automated plant. Equally challenging will be integrating developments in separate information and control fields into a cohesive system, which collectively achieves the overall goals of improved performance, safety, reliability, maintainability, and cost-effectiveness. Under the Nuclear Energy Research Initiative (NERI), the U. S. Department of Energy is sponsoring a project to address some of the technical issues involved in meeting the long-range goal of 21st century reactor control systems. This project, ''A New Paradigm for Automated Development Of Highly Reliable Control Architectures For Future Nuclear Plants,'' involves researchers from Oak Ridge National Laboratory, University of Tennessee, and North Carolina State University. This paper documents a research effort to develop methods for automated generation of control systems that can be traced directly to the design requirements. Our final goal is to allow the designer to specify only high-level requirements and stress factors that the control system must survive (e.g. a list of transients, or a requirement to withstand a single failure.) To this end, the ''control engine'' automatically selects and validates control algorithms and parameters that are optimized to the current state of the plant, and that have been tested under the prescribed stress factors. The control engine then automatically generates the control software from validated algorithms. Examples of stress factors that the control system must ''survive'' are: transient events (e.g., set-point changes, or expected occurrences such a load rejection,) and postulated
Sexual health of ethnic minority MSM in Britain (MESH project: design and methods
Low Nicola
2010-07-01
Full Text Available Abstract Background Men who have sex with men (MSM remain the group most at risk of acquiring HIV infection in Britain. HIV prevalence appears to vary widely between MSM from different ethnic minority groups in this country for reasons that are not fully understood. The aim of the MESH project was to examine in detail the sexual health of ethnic minority MSM living in Britain. Methods/Design The main objectives of the MESH project were to explore among ethnic minority MSM living in Britain: (i sexual risk behaviour and HIV prevalence; (ii their experience of stigma and discrimination; (iii disclosure of sexuality; (iv use of, and satisfaction with sexual health services; (v the extent to which sexual health services (for treatment and prevention are aware of the needs of ethnic minority MSM. The research was conducted between 2006 and 2008 in four national samples: (i ethnic minority MSM living in Britain; (ii a comparison group of white British MSM living in Britain; (iii NHS sexual health clinic staff in 15 British towns and cities with significant ethnic minority communities and; (iv sexual health promotion/HIV prevention service providers. We also recruited men from two "key migrant" groups living in Britain: MSM born in Central or Eastern Europe and MSM born in Central or South America. Internet-based quantitative and qualitative research methods were used. Ethnic minority MSM were recruited through advertisements on websites, in community venues, via informal networks and in sexual health clinics. White and "key migrant" MSM were recruited mostly through Gaydar, one of the most popular dating sites used by gay men in Britain. MSM who agreed to take part completed a questionnaire online. Ethnic minority MSM who completed the online questionnaire were asked if they would be willing to take part in an online qualitative interview using email. Service providers were identified through the British Association of Sexual Health and HIV (BASHH and
The economics of project analysis: Optimal investment criteria and methods of study
Scriven, M. C.
1979-01-01
Insight is provided toward the development of an optimal program for investment analysis of project proposals offering commercial potential and its components. This involves a critique of economic investment criteria viewed in relation to requirements of engineering economy analysis. An outline for a systems approach to project analysis is given Application of the Leontief input-output methodology to analysis of projects involving multiple processes and products is investigated. Effective application of elements of neoclassical economic theory to investment analysis of project components is demonstrated. Patterns of both static and dynamic activity levels are incorporated.
Model and controller reduction of large-scale structures based on projection methods
Gildin, Eduardo
The design of low-order controllers for high-order plants is a challenging problem theoretically as well as from a computational point of view. Frequently, robust controller design techniques result in high-order controllers. It is then interesting to achieve reduced-order models and controllers while maintaining robustness properties. Controller designed for large structures based on models obtained by finite element techniques yield large state-space dimensions. In this case, problems related to storage, accuracy and computational speed may arise. Thus, model reduction methods capable of addressing controller reduction problems are of primary importance to allow the practical applicability of advanced controller design methods for high-order systems. A challenging large-scale control problem that has emerged recently is the protection of civil structures, such as high-rise buildings and long-span bridges, from dynamic loadings such as earthquakes, high wind, heavy traffic, and deliberate attacks. Even though significant effort has been spent in the application of control theory to the design of civil structures in order increase their safety and reliability, several challenging issues are open problems for real-time implementation. This dissertation addresses with the development of methodologies for controller reduction for real-time implementation in seismic protection of civil structures using projection methods. Three classes of schemes are analyzed for model and controller reduction: nodal truncation, singular value decomposition methods and Krylov-based methods. A family of benchmark problems for structural control are used as a framework for a comparative study of model and controller reduction techniques. It is shown that classical model and controller reduction techniques, such as balanced truncation, modal truncation and moment matching by Krylov techniques, yield reduced-order controllers that do not guarantee stability of the closed-loop system, that
The AgMIP Coordinated Climate-Crop Modeling Project (C3MP): Methods and Protocols
Shukla, Sonali P.; Ruane, Alexander Clark
2014-01-01
Climate change is expected to alter a multitude of factors important to agricultural systems, including pests, diseases, weeds, extreme climate events, water resources, soil degradation, and socio-economic pressures. Changes to carbon dioxide concentration ([CO2]), temperature, and water (CTW) will be the primary drivers of change in crop growth and agricultural systems. Therefore, establishing the CTW-change sensitivity of crop yields is an urgent research need and warrants diverse methods of investigation. Crop models provide a biophysical, process-based tool to investigate crop responses across varying environmental conditions and farm management techniques, and have been applied in climate impact assessment by using a variety of methods (White et al., 2011, and references therein). However, there is a significant amount of divergence between various crop models' responses to CTW changes (Rotter et al., 2011). While the application of a site-based crop model is relatively simple, the coordination of such agricultural impact assessments on larger scales requires consistent and timely contributions from a large number of crop modelers, each time a new global climate model (GCM) scenario or downscaling technique is created. A coordinated, global effort to rapidly examine CTW sensitivity across multiple crops, crop models, and sites is needed to aid model development and enhance the assessment of climate impacts (Deser et al., 2012). To fulfill this need, the Coordinated Climate-Crop Modeling Project (C3MP) (Ruane et al., 2014) was initiated within the Agricultural Model Intercomparison and Improvement Project (AgMIP; Rosenzweig et al., 2013). The submitted results from C3MP Phase 1 (February 15, 2013-December 31, 2013) are currently being analyzed. This chapter serves to present and update the C3MP protocols, discuss the initial participation and general findings, comment on needed adjustments, and describe continued and future development. AgMIP aims to improve
Knoll, Michael
1988-01-01
Describes the origin of the project method and questions the educational and political intentions Calvin M. Woodward had when he introduced manual training and the project idea. Examines the project method's history and rise to significance when, around 1900, it became the sole means of manual education. (GEA)
Rasmussen, T.M.; Thorning, L.
2012-09-15
Project ALTKUL was commissioned by DONG E and P A/S and Nordsoefonden; the Danish Energy Agency followed the project closely. The starting point of the study was the need in Danish onshore areas for more knowledge on alternative methods that could be used for hydrocarbon exploration, as an alternative to seismic investigations. DONG E and P A/S and Nordsoefonden approached GEUS, suggesting a study of seven different methods. The Danish Energy Agency was interested in the subject and requested that an actual test of a method be carried out as a part of the project. The seven methods considered and reviewed are: 1: Surface geochemistry; 2: Gravimetric modelling; 3: Magnetotellurics (MT, AMT and ZTEM); 4: High-Moment Electromagnetics (HMEM); 5: High-Powered Spectral Induced Polarization (HPSIP); 6: Electron Para-magnetic Resonance (EPR); 7: Airborne Transient Pulse Surveys. Getting a test of one of the methods based on electromagnetic theory organised caused some difficulties. An experiment with a galvanic controlled source was considered to be the optimum choice. However, based on various contacts and failed attempts to organise a test, a contract was entered with Uppsala University for some initial tests of the MT method. The test is to be carried out in August 2012 and will be reported in a separate report (ALTKUL Project Report Part 2). (LN)
Moschini, Elena
Academics are beginning to explore the educational potential of Second LifeTM (SL) by setting up inworld educational activities and projects. Given the relative novelty of the use of virtual world environments in higher education many such projects are still at pilot stage. However the initial pilot and experimentation stage will have to be followed by a rigorous evaluation process as for more traditional teaching projects. The chapter addresses issues about SL research tools and research methods. It introduces a "researcher toolkit" that includes: the various stages in the evaluation of SL educational projects and the theoretical framework that can inform such projects; an outline of the inworld tools that can be utilised or customised for academic research purposes; a review of methods for collecting feedback from participants and of the main ethical issues involved in researching virtual world environments; a discussion on the technical skills required to operate a research project in SL. The chapter also offers an indication of the inworld opportunities for the dissemination of SL research findings.
Szymszal J.
2014-08-01
Full Text Available A comparative analysis involving the evaluation of the effectiveness of investment projects can be based on various rules indicating selection of the most favorable decisions. The dynamic methods for assessment of investment projects discussed in this article, which consider the possibility of modifying the predetermined investment options, are quite complex and difficult to implement. They are used both in the construction phase of the new company, as well as in its subsequent modernization. The assessments should be characterized by a high coefficient of the economic efficiency. The, observed in practice, high dynamic variability of both the external and internal conditions under which the company operates is the reason why in the process of calculating the economic efficiency of investment projects, there is a significant number of random parameters affected by high uncertainty and risk. Investments in the metallurgical industry are characterized by a relatively long cycle of implementation and operation. These are capital-intensive projects and often mistakenly taken investment decisions end in failure of the investment project and, consequently, in the collapse of the company. In addition, the applied methods of risk assessment of investment projects, especially the dynamic ones, should be fully understood by managerial staff and constitute an easy to use, yet accurate tool for improving the efficiency of the company.
A Novel Method Based on Oblique Projection Technology for Mixed Sources Estimation
Weijian Si
2014-01-01
Full Text Available Reducing the computational complexity of the near-field sources and far-field sources localization algorithms has been considered as a serious problem in the field of array signal processing. A novel algorithm caring for mixed sources location estimation based on oblique projection is proposed in this paper. The sources are estimated at two different stages and the sensor noise power is estimated and eliminated from the covariance which improve the accuracy of the estimation of mixed sources. Using the idea of compress, the range information of near-field sources is obtained by searching the partial area instead of the whole Fresnel area which can reduce the processing time. Compared with the traditional algorithms, the proposed algorithm has the lower computation complexity and has the ability to solve the two closed-spaced sources with high resolution and accuracy. The duplication of range estimation is also avoided. Finally, simulation results are provided to demonstrate the performance of the proposed method.
Applying Formal Methods to NASA Projects: Transition from Research to Practice
Othon, Bill
2009-01-01
NASA project managers attempt to manage risk by relying on mature, well-understood process and technology when designing spacecraft. In the case of crewed systems, the margin for error is even tighter and leads to risk aversion. But as we look to future missions to the Moon and Mars, the complexity of the systems will increase as the spacecraft and crew work together with less reliance on Earth-based support. NASA will be forced to look for new ways to do business. Formal methods technologies can help NASA develop complex but cost effective spacecraft in many domains, including requirements and design, software development and inspection, and verification and validation of vehicle subsystems. To realize these gains, the technologies must be matured and field-tested so that they are proven when needed. During this discussion, current activities used to evaluate FM technologies for Orion spacecraft design will be reviewed. Also, suggestions will be made to demonstrate value to current designers, and mature the technology for eventual use in safety-critical NASA missions.
A New Iris Segmentation Method Based on Improved Snake Model and Angular Integral Projection
Ann A. Jarjes
2011-06-01
Full Text Available Segmenting iris region is fundamental for iris-based biometric systems. The overall performance of an iris recognition system is highly dependent on accurate iris segmentation. In this paper, a new algorithm for iris segmentation is proposed towards more accurate and efficient segmentation, it detects the precise pupil contour and localizes the limbic boundary. An improved snake model is presented, wherein a new external energy function is designed. This external energy is computed based on the Angular Integral Projection Function (AIPF. First, the AIPF is combined with the improved snake to detect the pupil boundary. For that, pupil boundary points are detected by using the AIPF, and circle fitting is followed to localize the circular pupil boundary giving the initial snake contour. Then, the precise pupil contour is detected by deploying the improved snake. Second, as another contribution of this work, the limbic boundary is localized by combining the AIPF with a technique to extract outlier boundary points based on Mahalanobis distance. Experimental results on CASIA V3.0 iris image database show that the improved snake model is comparable with conventional snake model, and the whole segmentation performance of the proposed algorithm outperforms those of other wellknown existing methods in both terms of accuracy and processing time.
Parmagnani, Federica; Ranzi, Andrea; Ancona, Carla; Angelini, Paola; Chiusolo, Monica; Cadum, Ennio; Lauriola, Paolo; Forastiere, Francesco
2014-01-01
The Project Epidemiological Surveillance of Health Status of Resident Population Around the Waste Treatment Plants (SESPIR) included five Italian regions (Emilia-Romagna, Piedmont, Lazio, Campania, and Sicily) and the National Institute of Health in the period 2010-2013. SESPIR was funded by the Ministry of Health as part of the National centre for diseases prevention and control (CCM) programme of 2010 with the general objective to provide methods and operational tools for the implementation of surveillance systems for waste and health, aimed at assessing the impact of the municipal solid waste (MSW) treatment cycle on the health of the population. The specific objective was to assess health impacts resulting from the presence of disposal facilities related to different regional scenarios of waste management. Suitable tools for analysis of integrated assessment of environmental and health impact were developed and applied, using current demographic, environmental and health data. In this article, the methodology used for the quantitative estimation of the impact on the health of populations living nearby incinerators, landfills and mechanical biological treatment plants is showed, as well as the analysis of three different temporal scenarios: the first related to the existing plants in the period 2008-2009 (baseline), the second based on regional plans, the latter referring to MSW virtuous policy management based on reduction of produced waste and an intense recovery policy.
La Cour, Brian R.; Ostrove, Corey I.
2017-01-01
This paper describes a novel approach to solving unstructured search problems using a classical, signal-based emulation of a quantum computer. The classical nature of the representation allows one to perform subspace projections in addition to the usual unitary gate operations. Although bandwidth requirements will limit the scale of problems that can be solved by this method, it can nevertheless provide a significant computational advantage for problems of limited size. In particular, we find that, for the same number of noisy oracle calls, the proposed subspace projection method provides a higher probability of success for finding a solution than does an single application of Grover's algorithm on the same device.
Scaldaferri, M M; Freitas, J S; Vieira, J G P; Gonçalves, Z S; Souza, A M; Cerqueira-Silva, C B M
2014-07-25
We investigated 10 similarity (and disimilarity) coefficients in a set of 40 wild genotypes of Croton linearifolius subjected to analyses using hierarchical grouping methods, grouping methods by optimization and data projection in two-dimensional space. Genotypes were characterized by analyzing DNA polymorphism with the use of 15 ISSR and 12 RAPD markers. The distance measurements were compared by the Spearman correlation test, projection in two-dimensional space and grouping efficiency evaluation. The Spearman correlation coefficients between the 10 coefficients evaluated were significant (P Croton.
Prell, Daniel; Kyriakou, Yiannis; Beister, Marcel; Kalender, Willi A
2009-11-07
Metallic implants generate streak-like artifacts in flat-detector computed tomography (FD-CT) reconstructed volumetric images. This study presents a novel method for reducing these disturbing artifacts by inserting discarded information into the original rawdata using a three-step correction procedure and working directly with each detector element. Computation times are minimized by completely implementing the correction process on graphics processing units (GPUs). First, the original volume is corrected using a three-dimensional interpolation scheme in the rawdata domain, followed by a second reconstruction. This metal artifact-reduced volume is then segmented into three materials, i.e. air, soft-tissue and bone, using a threshold-based algorithm. Subsequently, a forward projection of the obtained tissue-class model substitutes the missing or corrupted attenuation values directly for each flat detector element that contains attenuation values corresponding to metal parts, followed by a final reconstruction. Experiments using tissue-equivalent phantoms showed a significant reduction of metal artifacts (deviations of CT values after correction compared to measurements without metallic inserts reduced typically to below 20 HU, differences in image noise to below 5 HU) caused by the implants and no significant resolution losses even in areas close to the inserts. To cover a variety of different cases, cadaver measurements and clinical images in the knee, head and spine region were used to investigate the effectiveness and applicability of our method. A comparison to a three-dimensional interpolation correction showed that the new approach outperformed interpolation schemes. Correction times are minimized, and initial and corrected images are made available at almost the same time (12.7 s for the initial reconstruction, 46.2 s for the final corrected image compared to 114.1 s and 355.1 s on central processing units (CPUs)).
Prell, Daniel; Kyriakou, Yiannis; Beister, Marcel; Kalender, Willi A.
2009-11-01
Metallic implants generate streak-like artifacts in flat-detector computed tomography (FD-CT) reconstructed volumetric images. This study presents a novel method for reducing these disturbing artifacts by inserting discarded information into the original rawdata using a three-step correction procedure and working directly with each detector element. Computation times are minimized by completely implementing the correction process on graphics processing units (GPUs). First, the original volume is corrected using a three-dimensional interpolation scheme in the rawdata domain, followed by a second reconstruction. This metal artifact-reduced volume is then segmented into three materials, i.e. air, soft-tissue and bone, using a threshold-based algorithm. Subsequently, a forward projection of the obtained tissue-class model substitutes the missing or corrupted attenuation values directly for each flat detector element that contains attenuation values corresponding to metal parts, followed by a final reconstruction. Experiments using tissue-equivalent phantoms showed a significant reduction of metal artifacts (deviations of CT values after correction compared to measurements without metallic inserts reduced typically to below 20 HU, differences in image noise to below 5 HU) caused by the implants and no significant resolution losses even in areas close to the inserts. To cover a variety of different cases, cadaver measurements and clinical images in the knee, head and spine region were used to investigate the effectiveness and applicability of our method. A comparison to a three-dimensional interpolation correction showed that the new approach outperformed interpolation schemes. Correction times are minimized, and initial and corrected images are made available at almost the same time (12.7 s for the initial reconstruction, 46.2 s for the final corrected image compared to 114.1 s and 355.1 s on central processing units (CPUs)).
Bove, Liliana L.; Davies, W. Martin
2009-01-01
This case study outlines the use of client-sponsored research projects in a quantitative postgraduate marketing research subject conducted in a 12-week semester in a research-intensive Australian university. The case study attempts to address the dearth of recent literature on client-sponsored research projects in the discipline of marketing.…
Project 8: Determining neutrino mass from tritium beta decay using a frequency-based method
Doe, Peter J.; Kofron, Jared N.; MCBride, Lisa; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Doelman, S.; Rogers, Alan E.; Formaggio, Joseph; Furse, Daniel; Oblath, Noah S.; LaRoque, Benjamin; Leber, Michelle; Monreal, Ben; Bahr, Matthew; Asner, David M.; Jones, Anthony M.; Fernandes, Justin L.; VanDevender, Brent A.; Patterson, Ryan B.; Bradley, Rich; Thummler, Thomas
2013-10-04
A general description is given of Project 8, a new approach to measuring the neutrino mass scale via the beta decay of tritium. In Project 8, the energy of electrons emitted in beta decay is determined from the frequency of cyclotron radiation emitted as the electrons spiral in a uniform magnetic field