Continuously variable transmission: Assessment of applicability to advance electric vehicles
NASA Technical Reports Server (NTRS)
Loewenthal, S. H.; Parker, R. J.
1981-01-01
A brief historical account of the evolution of continuously variable transmissions (CVT) for automotive use is given. The CVT concepts which are potentially suitable for application with electric and hybrid vehicles are discussed. The arrangement and function of several CVT concepts are cited along with their current developmental status. The results of preliminary design studies conducted on four CVT concepts for use in advanced electric vehicles are discussed.
Advanced continuously variable transmissions for electric and hybrid vehicles
NASA Technical Reports Server (NTRS)
Loewenthal, S. H.
1980-01-01
A brief survey of past and present continuously variable transmissions (CVT) which are potentially suitable for application with electric and hybrid vehicles is presented. Discussion of general transmission requirements and benefits attainable with a CVT for electric vehicle use is given. The arrangement and function of several specific CVT concepts are cited along with their current development status. Lastly, the results of preliminary design studies conducted under a NASA contract for DOE on four CVT concepts for use in advanced electric vehicles are reviewed.
Entanglement in continuous-variable systems: recent advances and current perspectives
NASA Astrophysics Data System (ADS)
Adesso, Gerardo; Illuminati, Fabrizio
2007-07-01
We review the theory of continuous-variable entanglement with special emphasis on foundational aspects, conceptual structures and mathematical methods. Much attention is devoted to the discussion of separability criteria and entanglement properties of Gaussian states, for their great practical relevance in applications to quantum optics and quantum information, as well as for the very clean framework that they allow for the study of the structure of nonlocal correlations. We give a self-contained introduction to phase-space and symplectic methods in the study of Gaussian states of infinite-dimensional bosonic systems. We review the most important results on the separability and distillability of Gaussian states and discuss the main properties of bipartite entanglement. These include the extremal entanglement, minimal and maximal, of two-mode mixed Gaussian states, the ordering of two-mode Gaussian states according to different measures of entanglement, the unitary (reversible) localization and the scaling of bipartite entanglement in multimode Gaussian states. We then discuss recent advances in the understanding of entanglement sharing in multimode Gaussian states, including the proof of the monogamy inequality of distributed entanglement for all Gaussian states. Multipartite entanglement of Gaussian states is reviewed by discussing its qualification by different classes of separability, and the main consequences of the monogamy inequality, such as the quantification of genuine tripartite entanglement in three-mode Gaussian states, the promiscuous nature of entanglement sharing in symmetric Gaussian states and the possible coexistence of unlimited bipartite and multipartite entanglement. We finally review recent advances and discuss possible perspectives on the qualification and quantification of entanglement in non-Gaussian states, a field of research that is to a large extent yet to be explored.
Advancements for continuous miners
Fiscor, S.
2007-06-15
Design changes and new technology make the modern continuous miner more user friendly. Two of the major manufacturers, Joy Mining Machinery and DBT, both based near Pittsburgh, PA, USA, have recently acquired other OEMs to offer a greater product line. Joy's biggest development in terms of improving cutting time is the FACEBOSS Control System which has an operator assistance element and Joy Surface Reporting Software (JSRP). Joy's WetHead continuous miners have excellent performance. DBT is researching ways to make the machines more reliable with new drive systems. It has also been experimenting with water sprays to improve dust suppression. 4 photos.
Continuously variable focal length lens
Adams, Bernhard W; Chollet, Matthieu C
2013-12-17
A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.
Continuous-variable entanglement on a chip
NASA Astrophysics Data System (ADS)
Masada, Genta; Miyata, Kazunori; Politi, Alberto; Hashimoto, Toshikazu; O'Brien, Jeremy L.; Furusawa, Akira
2015-05-01
Encoding quantum information in continuous variables, as the quadrature of electromagnetic fields, is a powerful approach to quantum information science and technology. Continuous-variable entanglement (light beams in Einstein-Podolsky-Rosen, or EPR, states) is a key resource for quantum information protocols and enables hybridization between continuous-variable and single-photon discrete-variable qubit systems. However, continuous-variable systems are currently limited by their implementation in free-space optical networks, and the demand for increased complexity, low loss, high-precision alignment and stability, as well as hybridization, require an alternative approach. Here we present an integrated photonic implementation of the key capabilities for continuous-variable quantum technologies—the generation and characterization of EPR beams in a photonic chip. When combined with integrated squeezing and non-Gaussian operations, these results will open the way to universal quantum information processing with light.
Continuous-variable private quantum channel
Bradler, Kamil
2005-10-15
In this paper we introduce the concept of quantum private channel within the continuous variables framework (CVPQC) and investigate its properties. In terms of CVPQC we naturally define a 'maximally' mixed state in phase space together with its explicit construction and show that for increasing number of encryption operations (which sets the length of a shared key between Alice and Bob) the encrypted state is arbitrarily close to the maximally mixed state in the sense of the Hilbert-Schmidt distance. We bring the exact solution for the distance dependence and give also a rough estimate of the necessary number of bits of the shared secret key (i.e., how much classical resources are needed for an approximate encryption of a generally unknown continuous-variable state). The definition of the CVPQC is analyzed from the Holevo bound point of view which determines an upper bound of information about an incoming state an eavesdropper is able to get from his optimal measurement.
Continuous-Variable Blind Quantum Computation
NASA Astrophysics Data System (ADS)
Morimae, Tomoyuki
2012-12-01
Blind quantum computation is a secure delegated quantum computing protocol where Alice, who does not have sufficient quantum technology at her disposal, delegates her computation to Bob, who has a fully fledged quantum computer, in such a way that Bob cannot learn anything about Alice’s input, output, and algorithm. Protocols of blind quantum computation have been proposed for several qudit measurement-based computation models, such as the graph state model, the Affleck-Kennedy-Lieb-Tasaki model, and the Raussendorf-Harrington-Goyal topological model. Here, we consider blind quantum computation for the continuous-variable measurement-based model. We show that blind quantum computation is possible for the infinite squeezing case. We also show that the finite squeezing causes no additional problem in the blind setup apart from the one inherent to the continuous-variable measurement-based quantum computation.
Disentanglement in bipartite continuous-variable systems
Barbosa, F. A. S.; Coelho, A. S.; Nussenzveig, P.; Martinelli, M.; Faria, A. J. de; Cassemiro, K. N.; Villar, A. S.
2011-11-15
Entanglement in bipartite continuous-variable systems is investigated in the presence of partial losses such as those introduced by a realistic quantum communication channel, e.g., by propagation in an optical fiber. We find that entanglement can vanish completely for partial losses, in a situation reminiscent of so-called entanglement sudden death. Even states with extreme squeezing may become separable after propagation in lossy channels. Having in mind the potential applications of such entangled light beams to optical communications, we investigate the conditions under which entanglement can survive for all partial losses. Different loss scenarios are examined, and we derive criteria to test the robustness of entangled states. These criteria are necessary and sufficient for Gaussian states. Our study provides a framework to investigate the robustness of continuous-variable entanglement in more complex multipartite systems.
Coherent communication with continuous quantum variables
Wilde, Mark M.; Krovi, Hari; Brun, Todd A.
2007-06-15
The coherent bit (cobit) channel is a resource intermediate between classical and quantum communication. It produces coherent versions of teleportation and superdense coding. We extend the cobit channel to continuous variables by providing a definition of the coherent nat (conat) channel. We construct several coherent protocols that use both a position-quadrature and a momentum-quadrature conat channel with finite squeezing. Finally, we show that the quality of squeezing diminishes through successive compositions of coherent teleportation and superdense coding.
Quantum Information with Continuous Variable systems
NASA Astrophysics Data System (ADS)
Rodó, Carles
2010-05-01
This thesis deals with the study of quantum communication protocols with Continuous Variable (CV) systems. Continuous Variable systems are those described by canonical conjugated coordinates x and p endowed with infinite dimensional Hilbert spaces, thus involving a complex mathematical structure. A special class of CV states, are the so-called Gaussian states. With them, it has been possible to implement certain quantum tasks as quantum teleportation, quantum cryptography and quantum computation with fantastic experimental success. The importance of Gaussian states is two-fold; firstly, its structural mathematical description makes them much more amenable than any other CV system. Secondly, its production, manipulation and detection with current optical technology can be done with a very high degree of accuracy and control. Nevertheless, it is known that in spite of their exceptional role within the space of all Continuous Variable states, in fact, Gaussian states are not always the best candidates to perform quantum information tasks. Thus non-Gaussian states emerge as potentially good candidates for communication and computation purposes.
Variability in continuous traffic monitoring data
Wright, T.; Hu, P.S.; Young, J.
1996-07-01
Each state in the United States can be viewed as a universe of road segments. For each road segment in each state, it is desired to know various traffic characteristics based on count data, classification count data, and weigh-in-motion data. These data are absolutely essential for highway design, maintenance, safety, and planning. Given no cost constraints, each road segment would be continuously monitored every day of the year. However, in practice, a few road segments are monitored continuously every day of the year to produce annual characteristics of traffic flow. The remaining road segments are monitored for one or two days each year, and this resulting data are `adjusted` (using factors based on data collected from the continuously monitored road segments) to produce estimates of annual characteristics. With this general approach, each state strives to provide estimates of annual characteristics for each road segment within its jurisdiction. In 1985, the Federal Highway Administration (FHWA) published the Traffic Monitoring Guide to assist states in achieving this end. As with almost any data collection effort, the monitoring data suffers from errors from many sources. In this paper, we report some empirical findings in a research project sponsored by the FHWA. This research project studied the variability in the traffic data from the continuously monitored road segments from state(s) and, the extent to which this variability is transferred to and affects the precision of the data produced from the road segments which are monitored only one or two days each year. The ultimate hope is that states will eventually be able to not only publish an estimate of a characteristic such as Average Annual Daily Traffic (AADT) for each road segment, but also that each estimate will be accompanied by a statement expressing how good the estimate is in terms of its estimated variability or precision, which will likely be expressed as a coefficient of variation.
Continuously-variable series-elastic actuator.
Mooney, Luke; Herr, Hugh
2013-06-01
Actuator efficiency is an important factor in the design of powered leg prostheses, orthoses, exoskeletons, and legged robots. A continuously-variable series-elastic actuator (CV-SEA) is presented as an efficient actuator for legged locomotion. The CV-SEA implements a continuously-variable transmission (CVT) between a motor and series elastic element. The CVT reduces the torque seen at the motor and allows the motor to operate in speed regimes of higher efficiency, while the series-elastic element efficiently stores and releases mechanical energy, reducing motor work requirements for actuator applications where an elastic response is sought. An energy efficient control strategy for the CV-SEA was developed using a Monte-Carlo minimization method that randomly generates transmission profiles and converges on those that minimize the electrical energy consumption of the motor. The CV-SEA is compared to a standard SEA and an infinitely variable series elastic actuator (IV-SEA). Simulations suggest that a CV-SEA will require less energy that an SEA or IV-SEA when used in a knee prosthesis during level-ground walking. PMID:24187221
Entanglement Swapping between Discrete and Continuous Variables
NASA Astrophysics Data System (ADS)
Takeda, Shuntaro; Fuwa, Maria; van Loock, Peter; Furusawa, Akira
2015-03-01
We experimentally realize "hybrid" entanglement swapping between discrete-variable (DV) and continuous-variable (CV) optical systems. DV two-mode entanglement as obtainable from a single photon split at a beam splitter is robustly transferred by means of efficient CV entanglement and operations, using sources of squeezed light and homodyne detections. The DV entanglement after the swapping is verified without postselection by the logarithmic negativity of up to 0.28 ±0.01 . Furthermore, our analysis shows that the optimally transferred state can be postselected into a highly entangled state that violates a Clauser-Horne-Shimony-Holt inequality by more than 4 standard deviations, and thus it may serve as a resource for quantum teleportation and quantum cryptography.
Entanglement swapping between discrete and continuous variables.
Takeda, Shuntaro; Fuwa, Maria; van Loock, Peter; Furusawa, Akira
2015-03-13
We experimentally realize "hybrid" entanglement swapping between discrete-variable (DV) and continuous-variable (CV) optical systems. DV two-mode entanglement as obtainable from a single photon split at a beam splitter is robustly transferred by means of efficient CV entanglement and operations, using sources of squeezed light and homodyne detections. The DV entanglement after the swapping is verified without postselection by the logarithmic negativity of up to 0.28±0.01. Furthermore, our analysis shows that the optimally transferred state can be postselected into a highly entangled state that violates a Clauser-Horne-Shimony-Holt inequality by more than 4 standard deviations, and thus it may serve as a resource for quantum teleportation and quantum cryptography. PMID:25815914
Interesting examples of supervised continuous variable systems
NASA Technical Reports Server (NTRS)
Chase, Christopher; Serrano, Joe; Ramadge, Peter
1990-01-01
The authors analyze two simple deterministic flow models for multiple buffer servers which are examples of the supervision of continuous variable systems by a discrete controller. These systems exhibit what may be regarded as the two extremes of complexity of the closed loop behavior: one is eventually periodic, the other is chaotic. The first example exhibits chaotic behavior that could be characterized statistically. The dual system, the switched server system, exhibits very predictable behavior, which is modeled by a finite state automaton. This research has application to multimodal discrete time systems where the controller can choose from a set of transition maps to implement.
Nondestructive verification of continuous-variable entanglement
NASA Astrophysics Data System (ADS)
de Faria, Alencar J.
2016-07-01
An optical procedure in the context of continuous variables to verify bipartite entanglement without destroying both systems and their entanglement is proposed. To perform the nondestructive verification of entanglement, the method relies on beam-splitter and quantum nondemolition (QND) interactions of the signal modes with two ancillary probe modes. The probe modes are measured by homodyne detections, and the obtained information is used to feed forward modulation of signal modes, concluding the procedure. Characterizing the method by figures of merit used in QND processes, we can establish the conditions for an effectively quantum scheme. Based on such conditions, it is shown that the classical information acquired from the homodyne detections of probe modes is sufficient to verify the entanglement of the output signal modes. The processing impact due to added noise on the output entanglement is assessed in the case of Gaussian modes.
Unidimensional continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Usenko, Vladyslav C.; Grosshans, Frédéric
2015-12-01
We propose the continuous-variable quantum key distribution protocol based on the Gaussian modulation of a single quadrature of the coherent states of light, which is aimed to provide simplified implementation compared to the symmetrically modulated Gaussian coherent-state protocols. The protocol waives the necessity in one of the quadrature modulations and the corresponding channel transmittance estimation. The security of the protocol against collective attacks in a generally phase-sensitive Gaussian channel is analyzed and is shown achievable upon certain conditions. Robustness of the protocol to channel imperfections is compared to that of the symmetrical coherent-state protocol. The simplified unidimensional protocol is shown possible at a reasonable quantitative cost in terms of key rate and of tolerable channel excess noise.
Atmospheric continuous-variable quantum communication
NASA Astrophysics Data System (ADS)
Heim, B.; Peuntinger, C.; Killoran, N.; Khan, I.; Wittmann, C.; Marquardt, Ch; Leuchs, G.
2014-11-01
We present a quantum communication experiment conducted over a point-to-point free-space link of 1.6 km in urban conditions. We study atmospheric influences on the capability of the link to act as a continuous-variable (CV) quantum channel. Continuous polarization states (that contain the signal encoding as well as a local oscillator (LO) in the same spatial mode) are prepared and sent over the link in a polarization multiplexed setting. Both signal and LO undergo the same atmospheric fluctuations. These are intrinsically auto-compensated which removes detrimental influences on the interferometric visibility. At the receiver, we measure the Q-function and interpret the data using the framework of effective entanglement (EE). We compare different state amplitudes and alphabets (two-state and four-state) and determine their optimal working points with respect to the distributed EE. Based on the high entanglement transmission rates achieved, our system indicates the high potential of atmospheric links in the field of CV quantum key distribution.
Variable cycle engines for advanced supersonic transports
NASA Technical Reports Server (NTRS)
Howlett, R. A.; Kozlowski, H.
1975-01-01
Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.
Control system for a continuously variable transmission
Sakai, Y.
1987-11-03
This patent describes a control system for a continuously variable belt-drive transmission having a selector device including a drive range position, a drive pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc, a driven pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc, and a belt engaged with both the pulleys, an hydraulic control circuit for supplying oil to the servo chambers and for draining the servo chambers, the hydraulic control circuit being provided with a pressure regulator valve for providing a line pressure and a transmission ratio control valve for applying the line pressure to the servo chamber of the drive pulley. The improvement comprises: a first drain passage from the pressure regulator valve; a second drain passage from the transmission ratio control valve; a first check valve provided in the first drain passage and a second check valve provided in the second drain passage for building up supplementary low pressure in both drain passages at upstream of both the check valves; a supplementary oil passage communicating both the first and second drain passages at upstream of the check valves for supplying a part of drain oil to the servo chamber of the drive pulley.
Control system for a continuously variable transmission
Vahabzadeh, H.
1986-08-26
A hydraulic control is described for a continuously variable transmission having hydraulically adjustable axially movable pulley members and a gearing arrangement for the transmitting of torque between an input shaft and a output shaft. The control consists of: a source of fluid pressure; first valve means connected with the source and being operable to supply control fluid to one of the first valve means to impose a force thereon; feedback means for imposing a force proportional to the axial position of the one adjustable pulley member on the first valve means in addition to the control fluid imposed force; torque sensing means operatively connected with the gearing arrangement for transmitting a force proportional to the torque transmitted by the gearing arrangement; servo motor means operatively connected with the torque sensing means; second valve means connected with the torque sensing means and being operable on a change of torque transmission to distribute a pressure signal from the source to the servo motor means and the servo motor means being responsive to the pressure fluid to balance the force on the torque to balance the force on the torque sensing means and discontinue fluid distribution thereto; and means for directing the pressure signal from the second valve means to the first valve means.
Advanced continuous cultivation methods for systems microbiology.
Adamberg, Kaarel; Valgepea, Kaspar; Vilu, Raivo
2015-09-01
Increasing the throughput of systems biology-based experimental characterization of in silico-designed strains has great potential for accelerating the development of cell factories. For this, analysis of metabolism in the steady state is essential as only this enables the unequivocal definition of the physiological state of cells, which is needed for the complete description and in silico reconstruction of their phenotypes. In this review, we show that for a systems microbiology approach, high-resolution characterization of metabolism in the steady state--growth space analysis (GSA)--can be achieved by using advanced continuous cultivation methods termed changestats. In changestats, an environmental parameter is continuously changed at a constant rate within one experiment whilst maintaining cells in the physiological steady state similar to chemostats. This increases the resolution and throughput of GSA compared with chemostats, and, moreover, enables following of the dynamics of metabolism and detection of metabolic switch-points and optimal growth conditions. We also describe the concept, challenge and necessary criteria of the systematic analysis of steady-state metabolism. Finally, we propose that such systematic characterization of the steady-state growth space of cells using changestats has value not only for fundamental studies of metabolism, but also for systems biology-based metabolic engineering of cell factories. PMID:26220303
Heralded processes on continuous-variable spaces as quantum maps
Ferreyrol, Franck; Spagnolo, Nicolò; Blandino, Rémi; Barbieri, Marco; Tualle-Brouri, Rosa
2014-12-04
Heralding processes, which only work when a measurement on a part of the system give the good result, are particularly interesting for continuous-variables. They permit non-Gaussian transformations that are necessary for several continuous-variable quantum information tasks. However if maps and quantum process tomography are commonly used to describe quantum transformations in discrete-variable space, they are much rarer in the continuous-variable domain. Also, no convenient tool for representing maps in a way more adapted to the particularities of continuous variables have yet been explored. In this paper we try to fill this gap by presenting such a tool.
Multiple factor analysis with continuous and dichotomous variables
NASA Astrophysics Data System (ADS)
Thanoon, Thanoon Y.; Adnan, Robiah; Saffari, Seyed Ehsan
2014-12-01
In this paper, continuous and dichotomous variables are used in multiple factor analysis method. When all variables within the same group are continuous, we use principal component analysis method in factor analysis, if all variables within the same group are dichotomous we use multiple correspondence analysis method in factor analysis. Statistical analyses, which involve Eigen roots, Eigen vectors, multiple factor loadings, correlation coefficient RV, contribution table, are discussed. The proposed procedure is illustrated by a lung cancer data consists of four groups "group of personal variables", "group of therapeutic variables", "group of nutritional variables", "group of genetic variables". Analysis are done by using XLSTAT program.
Quantum Encryption Protocol Based on Continuous Variable EPR Correlations
NASA Astrophysics Data System (ADS)
He, Guang-Qiang; Zeng, Gui-Hua
2006-07-01
A quantum encryption protocol based on Gaussian-modulated continuous variable EPR correlations is proposed. The security is guaranteed by continuous variable EPR entanglement correlations produced by nondegenerate optical parametric amplifier (NOPA). For general beam splitter eavesdropping strategy, the mutual information I(α,epsilon) between Alice and Eve is calculated by employing Shannon information theory. Finally the security analysis is presented.
Stronger steerability criterion for more uncertain continuous-variable systems
NASA Astrophysics Data System (ADS)
Chowdhury, Priyanka; Pramanik, Tanumoy; Majumdar, A. S.
2015-10-01
We derive a fine-grained uncertainty relation for the measurement of two incompatible observables on a single quantum system of continuous variables, and show that continuous-variable systems are more uncertain than discrete-variable systems. Using the derived fine-grained uncertainty relation, we formulate a stronger steering criterion that is able to reveal the steerability of NOON states that has hitherto not been possible using other criteria. We further obtain a monogamy relation for our steering inequality which leads to an, in principle, improved lower bound on the secret key rate of a one-sided device independent quantum key distribution protocol for continuous variables.
Continuously-Variable Positive-Mesh Power Transmission
NASA Technical Reports Server (NTRS)
Johnson, J. L.
1982-01-01
Proposed transmission with continuously-variable speed ratio couples two mechanical trigonometric-function generators. Transmission is expected to handle higher loads than conventional variable-pulley drives; and, unlike variable pulley, positive traction through entire drive train with no reliance on friction to transmit power. Able to vary speed continuously through zero and into reverse. Possible applications in instrumentation where drive-train slippage cannot be tolerated.
NASA Astrophysics Data System (ADS)
Adesso, Gerardo; Illuminati, Fabrizio
2006-01-01
For continuous-variable (CV) systems, we introduce a measure of entanglement, the CV tangle (contangle), with the purpose of quantifying the distributed (shared) entanglement in multimode, multipartite Gaussian states. This is achieved by a proper convex-roof extension of the squared logarithmic negativity. We prove that the contangle satisfies the Coffman Kundu Wootters monogamy inequality in all three-mode Gaussian states, and in all fully symmetric N-mode Gaussian states, for arbitrary N. For three-mode pure states, we prove that the residual entanglement is a genuine tripartite entanglement monotone under Gaussian local operations and classical communication. We show that pure, symmetric three-mode Gaussian states allow a promiscuous entanglement sharing, having both maximum tripartite residual entanglement and maximum couplewise entanglement between any pair of modes. These states are thus simultaneous CV analogues of both the GHZ and the W states of three qubits: in CV systems monogamy does not prevent promiscuity, and the inequivalence between different classes of maximally entangled states, holding for systems of three or more qubits, is removed.
A random number generator for continuous random variables
NASA Technical Reports Server (NTRS)
Guerra, V. M.; Tapia, R. A.; Thompson, J. R.
1972-01-01
A FORTRAN 4 routine is given which may be used to generate random observations of a continuous real valued random variable. Normal distribution of F(x), X, E(akimas), and E(linear) is presented in tabular form.
Development of Variable Camber Continuous Trailing Edge Flap System
NASA Technical Reports Server (NTRS)
Urnes, Jim, Sr.; Nguyen, Nhan T.; Dykman, John
2012-01-01
This presentation describes the current status of the joint NASA/Boeing collaboration on the development of a variable camber continuous trailing edge flap system for use in wing shaping control for cruise drag reduction.
Efficient entanglement criteria for discrete, continuous, and hybrid variables
NASA Astrophysics Data System (ADS)
Gessner, Manuel; Pezzè, Luca; Smerzi, Augusto
2016-08-01
We develop a method to construct entanglement criteria for arbitrary multipartite systems of discrete or continuous variables and hybrid combinations of both. While any set of local operators generates a sufficient condition for entanglement of arbitrary quantum states, a suitable set leads to a necessary and sufficient criterion for pure states. The criteria are readily implementable with existing technology and reveal entanglement that remains undetected by the respective state-of-the-art methods for discrete and continuous variables.
Path entanglement of continuous-variable quantum microwaves.
Menzel, E P; Di Candia, R; Deppe, F; Eder, P; Zhong, L; Ihmig, M; Haeberlein, M; Baust, A; Hoffmann, E; Ballester, D; Inomata, K; Yamamoto, T; Nakamura, Y; Solano, E; Marx, A; Gross, R
2012-12-21
Path entanglement constitutes an essential resource in quantum information and communication protocols. Here, we demonstrate frequency-degenerate entanglement between continuous-variable quantum microwaves propagating along two spatially separated paths. We combine a squeezed and a vacuum state using a microwave beam splitter. Via correlation measurements, we detect and quantify the path entanglement contained in the beam splitter output state. Our experiments open the avenue to quantum teleportation, quantum communication, or quantum radar with continuous variables at microwave frequencies. PMID:23368439
Advanced Adiabatic Demagnetization Refrigerators for Continuous Cooling
NASA Technical Reports Server (NTRS)
Chu, Paul C. W.
2004-01-01
The research at Houston was focused on optimizing the design of superconducting magnets for advanced adiabatic demagnetization refrigerators (ADRs), assessing the feasibility of using high temperature superconducting (HTS) magnets in ADRs in the future, and developing techniques to deposit HTS thin and thick films on high strength, low thermal conductivity substrates for HTS magnet leads. Several approaches have been tested for the suggested superconducting magnets.
Hybrid discrete- and continuous-variable quantum information
NASA Astrophysics Data System (ADS)
Andersen, Ulrik L.; Neergaard-Nielsen, Jonas S.; van Loock, Peter; Furusawa, Akira
2015-09-01
Research in quantum information processing has followed two different directions: the use of discrete variables (qubits) and that of high-dimensional, continuous-variable Gaussian states (coherent and squeezed states). Recently, these two approaches have been converging in potentially more powerful hybrid protocols.
Detecting entanglement of continuous variables with three mutually unbiased bases
NASA Astrophysics Data System (ADS)
Paul, E. C.; Tasca, D. S.; Rudnicki, Łukasz; Walborn, S. P.
2016-07-01
An uncertainty relation is introduced for a symmetric arrangement of three mutually unbiased bases in continuous-variable phase space, and then used to derive a bipartite entanglement criterion based on the variance of global operators composed of these three phase-space variables. We test this criterion using spatial variables of photon pairs and show that the entangled photons are correlated in three pairs of bases.
Device-independent quantum cryptography for continuous variables
NASA Astrophysics Data System (ADS)
Marshall, Kevin; Weedbrook, Christian
2014-10-01
We present a device-independent quantum cryptography protocol for continuous variables. Our scheme is based on the Gottesman-Kitaev-Preskill encoding scheme whereby a qubit is embedded in the infinite-dimensional space of a quantum harmonic oscillator. The application of discrete-variable device-independent quantum key distribution to this encoding enables a continuous-variable analog. Since the security of this protocol is based on discrete variables we inherit by default security against collective attacks and, under certain memoryless assumptions, coherent attacks. We find that our protocol is valid over the same distances as its discrete-variable counterpart, except that we are able to take advantage of high efficiency commercially available detectors where, for the most part, only homodyne detection is required. This offers the prospect of closing the loopholes associated with Bell inequalities.
Discrete-continuous variable structural synthesis using dual methods
NASA Technical Reports Server (NTRS)
Schmit, L. A.; Fleury, C.
1980-01-01
Approximation concepts and dual methods are extended to solve structural synthesis problems involving a mix of discrete and continuous sizing type of design variables. Pure discrete and pure continuous variable problems can be handled as special cases. The basic mathematical programming statement of the structural synthesis problem is converted into a sequence of explicit approximate primal problems of separable form. These problems are solved by constructing continuous explicit dual functions, which are maximized subject to simple nonnegativity constraints on the dual variables. A newly devised gradient projection type of algorithm called DUAL 1, which includes special features for handling dual function gradient discontinuities that arise from the discrete primal variables, is used to find the solution of each dual problem. Computational implementation is accomplished by incorporating the DUAL 1 algorithm into the ACCESS 3 program as a new optimizer option. The power of the method set forth is demonstrated by presenting numerical results for several example problems, including a pure discrete variable treatment of a metallic swept wing and a mixed discrete-continuous variable solution for a thin delta wing with fiber composite skins.
Quantum simulation of quantum field theory using continuous variables
Marshall, Kevin; Pooser, Raphael C.; Siopsis, George; Weedbrook, Christian
2015-12-14
Much progress has been made in the field of quantum computing using continuous variables over the last couple of years. This includes the generation of extremely large entangled cluster states (10,000 modes, in fact) as well as a fault tolerant architecture. This has lead to the point that continuous-variable quantum computing can indeed be thought of as a viable alternative for universal quantum computing. With that in mind, we present a new algorithm for continuous-variable quantum computers which gives an exponential speedup over the best known classical methods. Specifically, this relates to efficiently calculating the scattering amplitudes in scalar bosonic quantum field theory, a problem that is known to be hard using a classical computer. Thus, we give an experimental implementation based on cluster states that is feasible with today's technology.
Testing quantum contextuality of continuous-variable states
McKeown, Gerard; Paternostro, Mauro; Paris, Matteo G. A.
2011-06-15
We investigate the violation of noncontextuality by a class of continuous-variable states, including variations of entangled coherent states and a two-mode continuous superposition of coherent states. We generalize the Kochen-Specker (KS) inequality discussed by Cabello [A. Cabello, Phys. Rev. Lett. 101, 210401 (2008)] by using effective bidimensional observables implemented through physical operations acting on continuous-variable states, in a way similar to an approach to the falsification of Bell-Clauser-Horne-Shimony-Holt inequalities put forward recently. We test for state-independent violation of KS inequalities under variable degrees of state entanglement and mixedness. We then demonstrate theoretically the violation of a KS inequality for any two-mode state by using pseudospin observables and a generalized quasiprobability function.
Quantum simulation of quantum field theory using continuous variables
Marshall, Kevin; Pooser, Raphael C.; Siopsis, George; Weedbrook, Christian
2015-12-14
Much progress has been made in the field of quantum computing using continuous variables over the last couple of years. This includes the generation of extremely large entangled cluster states (10,000 modes, in fact) as well as a fault tolerant architecture. This has lead to the point that continuous-variable quantum computing can indeed be thought of as a viable alternative for universal quantum computing. With that in mind, we present a new algorithm for continuous-variable quantum computers which gives an exponential speedup over the best known classical methods. Specifically, this relates to efficiently calculating the scattering amplitudes in scalar bosonicmore » quantum field theory, a problem that is known to be hard using a classical computer. Thus, we give an experimental implementation based on cluster states that is feasible with today's technology.« less
Continuous-variable measurement-device-independent multipartite quantum communication
NASA Astrophysics Data System (ADS)
Wu, Yadong; Zhou, Jian; Gong, Xinbao; Guo, Ying; Zhang, Zhi-Ming; He, Guangqiang
2016-02-01
A continuous-variable measurement-device-independent multiparty quantum communication protocol is investigated in this paper. Utilizing the distributed continuous-variable Greenberger-Horne-Zeilinger state, this protocol can implement both quantum cryptographic conference and quantum secret sharing. We analyze the security of the protocol against both the entangling cloner attack and the coherent attack. The entangling cloner attack is a practical individual attack, and the coherent attack is the optimal attack Eve can implement. Simulation results show that the coherent attack can greatly reduce the secret key rate. Different kinds of entangled attacks are compared and we finally discuss the optimal coherent attacks.
Discriminant Analysis Using Mixed Continuous, Dichotomous, and Ordered Categorical Variables
ERIC Educational Resources Information Center
Lee, Sik-Yum; Song, Xin-Yuan; Lu, Bin
2007-01-01
This article proposes an intuitive approach for predictive discriminant analysis with mixed continuous, dichotomous, and ordered categorical variables that are defined via an underlying multivariate normal distribution with a threshold specification. The classification rule is based on the comparison of the observed data logarithm probability…
Determination of continuous variable entanglement by purity measurements.
Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio
2004-02-27
We classify the entanglement of two-mode Gaussian states according to their degree of total and partial mixedness. We derive exact bounds that determine maximally and minimally entangled states for fixed global and marginal purities. This characterization allows for an experimentally reliable estimate of continuous variable entanglement based on measurements of purity. PMID:14995815
The generation of Continuous-Variable Entanglement Frequency Comb
Yu, Youbin; Cheng, Xiaomin; Wang, Huaijun; Shi, Zhongtao; Zhao, Junwei; Ji, Fengmin; Yin, Zhi; Wang, Yajuan
2015-01-01
Continuous-variable (CV) entanglement frequency comb can be produced by enhanced Raman scattering in an above-threshold optical oscillator cavity in which a hexagonally-poled LiTaO3 crystal resides as a Raman gain medium. The Stokes and anti-Stokes Raman signals are enhanced by a coupled quasi-phase-matching optical parametric process and the entanglement natures among these Raman signals and pump are demonstrated by applying a sufficient inseparability criterion for CV entanglement. Such entanglement frequency comb source with different frequencies and continuously tunable frequency interval may be very significant for the applications in quantum communication and networks. PMID:25600617
The generation of continuous-variable entanglement frequency comb.
Yu, Youbin; Cheng, Xiaomin; Wang, Huaijun; Shi, Zhongtao; Zhao, Junwei; Ji, Fengmin; Yin, Zhi; Wang, Yajuan
2015-01-01
Continuous-variable (CV) entanglement frequency comb can be produced by enhanced Raman scattering in an above-threshold optical oscillator cavity in which a hexagonally-poled LiTaO3 crystal resides as a Raman gain medium. The Stokes and anti-Stokes Raman signals are enhanced by a coupled quasi-phase-matching optical parametric process and the entanglement natures among these Raman signals and pump are demonstrated by applying a sufficient inseparability criterion for CV entanglement. Such entanglement frequency comb source with different frequencies and continuously tunable frequency interval may be very significant for the applications in quantum communication and networks. PMID:25600617
The generation of Continuous-Variable Entanglement Frequency Comb
NASA Astrophysics Data System (ADS)
Yu, Youbin; Cheng, Xiaomin; Wang, Huaijun; Shi, Zhongtao; Zhao, Junwei; Ji, Fengmin; Yin, Zhi; Wang, Yajuan
2015-01-01
Continuous-variable (CV) entanglement frequency comb can be produced by enhanced Raman scattering in an above-threshold optical oscillator cavity in which a hexagonally-poled LiTaO3 crystal resides as a Raman gain medium. The Stokes and anti-Stokes Raman signals are enhanced by a coupled quasi-phase-matching optical parametric process and the entanglement natures among these Raman signals and pump are demonstrated by applying a sufficient inseparability criterion for CV entanglement. Such entanglement frequency comb source with different frequencies and continuously tunable frequency interval may be very significant for the applications in quantum communication and networks.
Phase-space approach to continuous variable quantum teleportation
Ban, Masashi
2004-05-01
The phase-space method is applied for considering continuous variable quantum teleportation. It is found that the continuous variable quantum teleportation transforms the s-parametrized phase-space function of an input state into the (s+{delta})-parametrized phase-space function, where the parameter {delta} is determined by the shared quantum entanglement. It is shown from this result that the Wigner function of the teleported state is always non-negative for F{sub c}{<=}2/3 and the Glauber-Sudarshan P function non-negative for F{sub c}{<=}1/2, where F{sub c} is the fidelity of the coherent-state teleportation. Furthermore the fidelity between input and output states is calculated when Gaussian states are teleported.
Continuous-variable quantum teleportation with non-Gaussian resources
Dell'Anno, F.; De Siena, S.; Albano, L.; Illuminati, F.
2007-08-15
We investigate continuous variable quantum teleportation using non-Gaussian states of the radiation field as entangled resources. We compare the performance of different classes of degaussified resources, including two-mode photon-added and two-mode photon-subtracted squeezed states. We then introduce a class of two-mode squeezed Bell-like states with one-parameter dependence for optimization. These states interpolate between and include as subcases different classes of degaussified resources. We show that optimized squeezed Bell-like resources yield a remarkable improvement in the fidelity of teleportation both for coherent and nonclassical input states. The investigation reveals that the optimal non-Gaussian resources for continuous variable teleportation are those that most closely realize the simultaneous maximization of the content of entanglement, the degree of affinity with the two-mode squeezed vacuum, and the, suitably measured, amount of non-Gaussianity.
Path Entanglement of Continuous-Variable Quantum Microwaves
NASA Astrophysics Data System (ADS)
Menzel, E. P.; Deppe, F.; Eder, P.; Zhong, L.; Haeberlein, M.; Baust, A.; Hoffmann, E.; Marx, A.; Gross, R.; di Candia, R.; Solano, E.; Ballester, D.; Ihmig, M.; Inomata, K.; Yamamoto, T.; Nakamura, Y.
2013-03-01
Entanglement is a quantum mechanical phenomenon playing a key role in quantum communication and information processing protocols. Here, we report on frequency-degenerate entanglement between continuous-variable quantum microwaves propagating along two separated paths. In our experiment, we combine a squeezed and a vacuum state via a beam splitter. Overcoming the challenges imposed by the low photon energies in the microwave regime, we reconstruct the squeezed state and, independently from this, detect and quantify the produced entanglement via correlation measurements (E. P. Menzel et al., arXiv:1210.4413). Our work paves the way towards quantum communication and teleportation with continuous variables in the microwave regime. This work is supported by SFB 631, German Excellence Initiative via NIM, EU projects SOLID, CCQED and PROMISCE, MEXT Kakenhi ``Quantum Cybernetics'', JSPS FIRST Program, the NICT Commissioned Research, EPSRC EP/H050434/1, Basque Government IT472-10, and Spanish MICINN FIS2009-12773-C02-01.
Quantum simulation of quantum field theory using continuous variables
NASA Astrophysics Data System (ADS)
Marshall, Kevin; Pooser, Raphael; Siopsis, George; Weedbrook, Christian
2015-12-01
The year 1982 is often credited as the year that theoretical quantum computing was started with a keynote speech by Richard Feynman, who proposed a universal quantum simulator, the idea being that if you had such a machine you could in principle "imitate any quantum system, including the physical world." With that in mind, we present an algorithm for a continuous-variable quantum computing architecture which gives an exponential speedup over the best-known classical methods. Specifically, this relates to efficiently calculating the scattering amplitudes in scalar bosonic quantum field theory, a problem that is believed to be hard using a classical computer. Building on this, we give an experimental implementation based on continuous-variable states that is feasible with today's technology.
Gate sequence for continuous variable one-way quantum computation
Su, Xiaolong; Hao, Shuhong; Deng, Xiaowei; Ma, Lingyu; Wang, Meihong; Jia, Xiaojun; Xie, Changde; Peng, Kunchi
2013-01-01
Measurement-based one-way quantum computation using cluster states as resources provides an efficient model to perform computation and information processing of quantum codes. Arbitrary Gaussian quantum computation can be implemented sufficiently by long single-mode and two-mode gate sequences. However, continuous variable gate sequences have not been realized so far due to an absence of cluster states larger than four submodes. Here we present the first continuous variable gate sequence consisting of a single-mode squeezing gate and a two-mode controlled-phase gate based on a six-mode cluster state. The quantum property of this gate sequence is confirmed by the fidelities and the quantum entanglement of two output modes, which depend on both the squeezing and controlled-phase gates. The experiment demonstrates the feasibility of implementing Gaussian quantum computation by means of accessible gate sequences.
Continuous-variable quantum identity authentication based on quantum teleportation
NASA Astrophysics Data System (ADS)
Ma, Hongxin; Huang, Peng; Bao, Wansu; Zeng, Guihua
2016-03-01
A continuous-variable quantum identity authentication protocol, which is based on quantum teleportation, is presented by employing two-mode squeezed vacuum state and coherent state. The proposed protocol can verify user's identity efficiently with a new defined fidelity parameter. Update of authentication key can also be implemented in our protocol. Moreover, the analysis shows its feasibility and security under the general Gaussian-cloner attack on authentication key, which is guaranteed by quantum entanglement, insertion of decoy state and random displacement.
Quantification and scaling of multipartite entanglement in continuous variable systems.
Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio
2004-11-26
We present a theoretical method to determine the multipartite entanglement between different partitions of multimode, fully or partially symmetric Gaussian states of continuous variable systems. For such states, we determine the exact expression of the logarithmic negativity and show that it coincides with that of equivalent two-mode Gaussian states. Exploiting this reduction, we demonstrate the scaling of the multipartite entanglement with the number of modes and its reliable experimental estimate by direct measurements of the global and local purities. PMID:15601075
Breaking Gaussian incompatibility on continuous variable quantum systems
Heinosaari, Teiko; Kiukas, Jukka; Schultz, Jussi
2015-08-15
We characterise Gaussian quantum channels that are Gaussian incompatibility breaking, that is, transform every set of Gaussian measurements into a set obtainable from a joint Gaussian observable via Gaussian postprocessing. Such channels represent local noise which renders measurements useless for Gaussian EPR-steering, providing the appropriate generalisation of entanglement breaking channels for this scenario. Understanding the structure of Gaussian incompatibility breaking channels contributes to the resource theory of noisy continuous variable quantum information protocols.
Continuous-variable quantum key distribution with Gaussian source noise
Shen Yujie; Peng Xiang; Yang Jian; Guo Hong
2011-05-15
Source noise affects the security of continuous-variable quantum key distribution (CV QKD) and is difficult to analyze. We propose a model to characterize Gaussian source noise through introducing a neutral party (Fred) who induces the noise with a general unitary transformation. Without knowing Fred's exact state, we derive the security bounds for both reverse and direct reconciliations and show that the bound for reverse reconciliation is tight.
Continuous-variable quantum identity authentication based on quantum teleportation
NASA Astrophysics Data System (ADS)
Ma, Hongxin; Huang, Peng; Bao, Wansu; Zeng, Guihua
2016-06-01
A continuous-variable quantum identity authentication protocol, which is based on quantum teleportation, is presented by employing two-mode squeezed vacuum state and coherent state. The proposed protocol can verify user's identity efficiently with a new defined fidelity parameter. Update of authentication key can also be implemented in our protocol. Moreover, the analysis shows its feasibility and security under the general Gaussian-cloner attack on authentication key, which is guaranteed by quantum entanglement, insertion of decoy state and random displacement.
Extremal entanglement and mixedness in continuous variable systems
Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio
2004-08-01
We investigate the relationship between mixedness and entanglement for Gaussian states of continuous variable systems. We introduce generalized entropies based on Schatten p norms to quantify the mixedness of a state and derive their explicit expressions in terms of symplectic spectra. We compare the hierarchies of mixedness provided by such measures with the one provided by the purity (defined as tr {rho}{sup 2} for the state {rho}) for generic n-mode states. We then review the analysis proving the existence of both maximally and minimally entangled states at given global and marginal purities, with the entanglement quantified by the logarithmic negativity. Based on these results, we extend such an analysis to generalized entropies, introducing and fully characterizing maximally and minimally entangled states for given global and local generalized entropies. We compare the different roles played by the purity and by the generalized p entropies in quantifying the entanglement and the mixedness of continuous variable systems. We introduce the concept of average logarithmic negativity, showing that it allows a reliable quantitative estimate of continuous variable entanglement by direct measurements of global and marginal generalized p entropies.
Quantum secret sharing with continuous-variable cluster states
NASA Astrophysics Data System (ADS)
Lau, Hoi-Kwan; Weedbrook, Christian
2013-10-01
We extend the formalism of cluster-state quantum secret sharing, as presented by Markham and Sanders [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.78.042309 78, 042309 (2008)] and Keet [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.82.062315 82, 062315 (2010)], to the continuous-variable regime. We show that both classical and quantum information can be shared by distributing continuous-variable cluster states through either public or private channels. We find that the adversary structure is completely denied from the secret if the cluster state is infinitely squeezed, but some secret information would be leaked if a realistic finitely squeezed state is employed. We suggest benchmarks to evaluate the security in the finitely squeezed cases. For the sharing of classical secrets, we borrow techniques from the continuous-variable quantum key distribution to compute the secret-sharing rate. For the sharing of quantum states, we estimate the amount of entanglement distilled for teleportation from each cluster state.
Statistical Quadrature Evolution for Continuous-Variable Quantum Key Distribution
NASA Astrophysics Data System (ADS)
Gyongyosi, Laszlo; Imre, Sandor
2016-05-01
We propose a statistical quadrature evolution (SQE) method for multicarrier continuous-variable quantum key distribution (CVQKD). A multicarrier CVQKD protocol utilizes Gaussian subcarrier quantum continuous variables (CV) for information transmission. The SQE framework provides a minimal error estimate of the quadratures of the CV quantum states from the discrete, measured noisy subcarrier variables. We define a method for the statistical modeling and processing of noisy Gaussian subcarrier quadratures. We introduce the terms statistical secret key rate and statistical private classical information, which quantities are derived purely by the statistical functions of our method. We prove the secret key rate formulas for a multiple access multicarrier CVQKD. The framework can be established in an arbitrary CVQKD protocol and measurement setting, and are implementable by standard low-complexity statistical functions, which is particularly convenient for an experimental CVQKD scenario. This work was partially supported by the GOP-1.1.1-11-2012-0092 project sponsored by the EU and European Structural Fund, by the Hungarian Scientific Research Fund - OTKA K-112125, and by the COST Action MP1006.
Gaussian quadrature inference for continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Gyongyosi, L.; Imre, S.
2016-05-01
We propose the Gaussian quadrature inference (GQI) method for multicarrier continuous-variable quantum key distribution (CVQKD). A multicarrier CVQKD protocol utilizes Gaussian subcarrier quantum continuous variables (CV) for information transmission. The GQI framework provides a minimal error estimate of the quadratures of the CV quantum states from the discrete, measured noisy subcarrier variables. GQI utilizes the fundamentals of regularization theory and statistical information processing. We characterize GQI for multicarrier CVQKD, and define a method for the statistical modeling and processing of noisy Gaussian subcarrier quadratures. We demonstrate the results through the adaptive multicarrier quadrature division (AMQD) scheme. We introduce the terms statistical secret key rate and statistical private classical information, which quantities are derived purely by the statistical functions of GQI. We prove the secret key rate formulas for a multiple access multicarrier CVQKD via the AMQD-MQA (multiuser quadrature allocation) scheme. The framework can be established in an arbitrary CVQKD protocol and measurement setting, and are implementable by standard low-complexity statistical functions, which is particularly convenient for an experimental CVQKD scenario.
Flexible quantum circuits using scalable continuous-variable cluster states
NASA Astrophysics Data System (ADS)
Alexander, Rafael N.; Menicucci, Nicolas C.
2016-06-01
We show that measurement-based quantum computation on scalable continuous-variable (CV) cluster states admits more quantum-circuit flexibility and compactness than similar protocols for standard square-lattice CV cluster states. This advantage is a direct result of the macronode structure of these states—that is, a lattice structure in which each graph node actually consists of several physical modes. These extra modes provide additional measurement degrees of freedom at each graph location, which can be used to manipulate the flow and processing of quantum information more robustly and with additional flexibility that is not available on an ordinary lattice.
Continuous-variable quantum teleportation in bosonic structured environments
He Guangqiang; Zhang Jingtao; Zhu Jun; Zeng Guihua
2011-09-15
The effects of dynamics of continuous-variable entanglement under the various kinds of environments on quantum teleportation are quantitatively investigated. Only under assumption of the weak system-reservoir interaction, the evolution of teleportation fidelity is analytically derived and is numerically plotted in terms of environment parameters including reservoir temperature and its spectral density, without Markovian and rotating wave approximations. We find that the fidelity of teleportation is a monotonically decreasing function for Markovian interaction in Ohmic-like environments, while it oscillates for non-Markovian ones. According to the dynamical laws of teleportation, teleportation with better performances can be implemented by selecting the appropriate time.
Secure Continuous Variable Teleportation and Einstein-Podolsky-Rosen Steering
NASA Astrophysics Data System (ADS)
He, Qiongyi; Rosales-Zárate, Laura; Adesso, Gerardo; Reid, Margaret D.
2015-10-01
We investigate the resources needed for secure teleportation of coherent states. We extend continuous variable teleportation to include quantum teleamplification protocols that allow nonunity classical gains and a preamplification or postattenuation of the coherent state. We show that, for arbitrary Gaussian protocols and a significant class of Gaussian resources, two-way steering is required to achieve a teleportation fidelity beyond the no-cloning threshold. This provides an operational connection between Gaussian steerability and secure teleportation. We present practical recipes suggesting that heralded noiseless preamplification may enable high-fidelity heralded teleportation, using minimally entangled yet steerable resources.
Continuous variable (2, 3) threshold quantum secret sharing schemes
NASA Astrophysics Data System (ADS)
Lance, Andrew M.; Symul, Thomas; Bowen, Warwick P.; Tyc, Tomás; Sanders, Barry C.; Lam, Ping Koy
2003-01-01
We present two schemes to perform continuous variable (2, 3) threshold quantum secret sharing (QSS) on the quadrature amplitudes of bright light beams. Both schemes require a pair of entangled light beams. The first scheme utilizes two phase sensitive optical amplifiers, whilst the second uses an electro-optic feedforward loop for the reconstruction of the secret. We examine the efficacy of QSS in terms of fidelity, as well as the signal transfer coefficients and the conditional variances of the reconstructed output state. We show that both schemes in the ideal case yield perfect secret reconstruction.
Universal Continuous-Variable State Orthogonalizer and Qubit Generator
NASA Astrophysics Data System (ADS)
Coelho, Antonio S.; Costanzo, Luca S.; Zavatta, Alessandro; Hughes, Catherine; Kim, M. S.; Bellini, Marco
2016-03-01
We experimentally demonstrate a universal strategy for producing a quantum state that is orthogonal to an arbitrary, infinite-dimensional, pure input one, even if only a limited amount of information about the latter is available. Arbitrary coherent superpositions of the two mutually orthogonal states are then produced by a simple change in the experimental parameters. We use input coherent states of light to illustrate two variations of the method. However, we show that the scheme works equally well for arbitrary input fields and constitutes a universal procedure, which may thus prove a useful building block for quantum state engineering and quantum information processing with continuous-variable qubits.
Measures of Quantum Synchronization in Continuous Variable Systems
NASA Astrophysics Data System (ADS)
Mari, A.; Farace, A.; Didier, N.; Giovannetti, V.; Fazio, R.
2013-09-01
We introduce and characterize two different measures which quantify the level of synchronization of coupled continuous variable quantum systems. The two measures allow us to extend to the quantum domain the notions of complete and phase synchronization. The Heisenberg principle sets a universal bound to complete synchronization. The measure of phase synchronization is, in principle, unbounded; however, in the absence of quantum resources (e.g., squeezing) the synchronization level is bounded below a certain threshold. We elucidate some interesting connections between entanglement and synchronization and, finally, discuss an application based on quantum optomechanical systems.
Measures of quantum synchronization in continuous variable systems.
Mari, A; Farace, A; Didier, N; Giovannetti, V; Fazio, R
2013-09-01
We introduce and characterize two different measures which quantify the level of synchronization of coupled continuous variable quantum systems. The two measures allow us to extend to the quantum domain the notions of complete and phase synchronization. The Heisenberg principle sets a universal bound to complete synchronization. The measure of phase synchronization is, in principle, unbounded; however, in the absence of quantum resources (e.g., squeezing) the synchronization level is bounded below a certain threshold. We elucidate some interesting connections between entanglement and synchronization and, finally, discuss an application based on quantum optomechanical systems. PMID:25166668
Secure Continuous Variable Teleportation and Einstein-Podolsky-Rosen Steering.
He, Qiongyi; Rosales-Zárate, Laura; Adesso, Gerardo; Reid, Margaret D
2015-10-30
We investigate the resources needed for secure teleportation of coherent states. We extend continuous variable teleportation to include quantum teleamplification protocols that allow nonunity classical gains and a preamplification or postattenuation of the coherent state. We show that, for arbitrary Gaussian protocols and a significant class of Gaussian resources, two-way steering is required to achieve a teleportation fidelity beyond the no-cloning threshold. This provides an operational connection between Gaussian steerability and secure teleportation. We present practical recipes suggesting that heralded noiseless preamplification may enable high-fidelity heralded teleportation, using minimally entangled yet steerable resources. PMID:26565449
Advances in Understanding Decadal Climate Variability
NASA Technical Reports Server (NTRS)
Busalacchi, Antonio J.
1999-01-01
Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL-FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few ship-tracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.
Advances in Understanding Decadal Climate Variability
NASA Technical Reports Server (NTRS)
Busalaacchi, Antonio J.
1998-01-01
Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL- FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few shiptracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.
Continuous-variable teleportation of a negative Wigner function
Mista, Ladislav Jr.; Filip, Radim; Furusawa, Akira
2010-07-15
Teleportation is a basic primitive for quantum communication and quantum computing. We address the problem of continuous-variable (unconditional and conditional) teleportation of a pure single-photon state and a mixed attenuated single-photon state generally in a nonunity-gain regime. Our figure of merit is the maximum negativity of the Wigner function, which demonstrates a highly nonclassical feature of the teleported state. We find that the negativity of the Wigner function of the single-photon state can be unconditionally teleported for an arbitrarily weak squeezed state used to create the entangled state shared in teleportation. In contrast, for the attenuated single-photon state there is a strict threshold squeezing one has to surpass to successfully teleport the negativity of its Wigner function. The conditional teleportation allows one to approach perfect transmission of the single photon for an arbitrarily low squeezing at a cost of decrease of the success rate. In contrast, for the attenuated single photon state, conditional teleportation cannot overcome the squeezing threshold of the unconditional teleportation and it approaches negativity of the input state only if the squeezing increases simultaneously. However, as soon as the threshold squeezing is surpassed, conditional teleportation still pronouncedly outperforms the unconditional one. The main consequences for quantum communication and quantum computing with continuous variables are discussed.
Eigenchannel decomposition for continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Gyongyosi, L.; Imre, S.
2015-03-01
We develop a singular layer transmission model for continuous-variable quantum key distribution (CVQKD). In CVQKD, the transmit information is carried by continuous-variable (CV) quantum states, particularly by Gaussian random distributed position and momentum quadratures. The reliable transmission of the quadrature components over a noisy link is a cornerstone of CVQKD protocols. The proposed singular layer uses the singular value decomposition of the Gaussian quantum channel, which yields an additional degree of freedom for the phase space transmission. This additional degree of freedom can further be exploited in a multiple-access scenario. The singular layer defines the eigenchannels of the Gaussian physical link, which can be used for the simultaneous reliable transmission of multiple user data streams. We demonstrate the results through the adaptive multicarrier quadrature division-multiuser quadrature allocation (AMQD-MQA) CVQKD multiple-access scheme. We define the singular model of AMQD-MQA and characterize the properties of the eigenchannel interference. The singular layer transmission provides improved simultaneous transmission rates for the users with unconditional security in a multiple-access scenario, particularly in crucial low signal-to-noise ratio regimes.
Continuous-variable teleportation of a negative Wigner function
NASA Astrophysics Data System (ADS)
Mišta, Ladislav, Jr.; Filip, Radim; Furusawa, Akira
2010-07-01
Teleportation is a basic primitive for quantum communication and quantum computing. We address the problem of continuous-variable (unconditional and conditional) teleportation of a pure single-photon state and a mixed attenuated single-photon state generally in a nonunity-gain regime. Our figure of merit is the maximum negativity of the Wigner function, which demonstrates a highly nonclassical feature of the teleported state. We find that the negativity of the Wigner function of the single-photon state can be unconditionally teleported for an arbitrarily weak squeezed state used to create the entangled state shared in teleportation. In contrast, for the attenuated single-photon state there is a strict threshold squeezing one has to surpass to successfully teleport the negativity of its Wigner function. The conditional teleportation allows one to approach perfect transmission of the single photon for an arbitrarily low squeezing at a cost of decrease of the success rate. In contrast, for the attenuated single photon state, conditional teleportation cannot overcome the squeezing threshold of the unconditional teleportation and it approaches negativity of the input state only if the squeezing increases simultaneously. However, as soon as the threshold squeezing is surpassed, conditional teleportation still pronouncedly outperforms the unconditional one. The main consequences for quantum communication and quantum computing with continuous variables are discussed.
LQR Controller for Toroidal Continuously Variable Transmission in Reverse Motion
NASA Astrophysics Data System (ADS)
Mensler, Michel; Kawabe, Taketoshi; Joe, Shinichiro
The system considered in this paper is a Toroidal Continuously Variable Transmission (TCVT) system for cars. This system is unstable in reverse motion as some mechanical parts have been removed from the original one for cost reduction, and the gear ratio has to be regulated around its nominal value for car reverse motion. The control theory used here is the Linear Quadratic Regulator (LQR) associated to a gain-scheduling technique, as the TCVT system is nonlinear according to the car speed. Moreover, as the LQR method requires the entire TCVT state vector and as the only available signal is the gear ratio, a full-order observer is designed. In order to take the other nonlinearities of the system into account, the observer is nonlinear: a diffeomorphism is then used for converting the variables provided by the nonlinear observer into the needed variables. In order to verify the effectiveness and the robustness of the controller against the car speed and the torque shift disturbance phenomenon, several experiments with a test-bed and with an actual vehicle have been performed and showed the efficiency of the proposed controller.
Continuous-Variable Quantum Computation of Oracle Decision Problems
NASA Astrophysics Data System (ADS)
Adcock, Mark R. A.
Quantum information processing is appealing due its ability to solve certain problems quantitatively faster than classical information processing. Most quantum algorithms have been studied in discretely parameterized systems, but many quantum systems are continuously parameterized. The field of quantum optics in particular has sophisticated techniques for manipulating continuously parameterized quantum states of light, but the lack of a code-state formalism has hindered the study of quantum algorithms in these systems. To address this situation, a code-state formalism for the solution of oracle decision problems in continuously-parameterized quantum systems is developed. Quantum information processing is appealing due its ability to solve certain problems quantitatively faster than classical information processing. Most quantum algorithms have been studied in discretely parameterized systems, but many quantum systems are continuously parameterized. The field of quantum optics in particular has sophisticated techniques for manipulating continuously parameterized quantum states of light, but the lack of a code-state formalism has hindered the study of quantum algorithms in these systems. To address this situation, a code-state formalism for the solution of oracle decision problems in continuously-parameterized quantum systems is developed. In the infinite-dimensional case, we study continuous-variable quantum algorithms for the solution of the Deutsch--Jozsa oracle decision problem implemented within a single harmonic-oscillator. Orthogonal states are used as the computational bases, and we show that, contrary to a previous claim in the literature, this implementation of quantum information processing has limitations due to a position-momentum trade-off of the Fourier transform. We further demonstrate that orthogonal encoding bases are not unique, and using the coherent states of the harmonic oscillator as the computational bases, our formalism enables quantifying
Schmidt-number benchmarks for continuous-variable quantum devices
NASA Astrophysics Data System (ADS)
Namiki, Ryo
2016-05-01
We present quantum fidelity benchmarks for continuous-variable (CV) quantum devices to outperform quantum channels which can transmit at most k -dimensional coherences for positive integers k . We determine an upper bound of an average fidelity over Gaussian distributed coherent states for quantum channels whose Schmidt class is k . This settles fundamental fidelity steps where the known classical limit and quantum limit correspond to the two end points of k =1 and k =∞ , respectively. It turns out that the average fidelity is useful to verify to what extent an experimental CV gate can transmit a high-dimensional coherence. The result is further extended to be applicable to general quantum operations or stochastic quantum channels. Although the fidelity is often associated with heterodyne measurements in quantum optics, we can also obtain similar criteria based on quadrature deviations determined via homodyne measurements.
Quantum frequency up-conversion of continuous variable entangled states
Liu, Wenyuan; Wang, Ning; Li, Zongyang; Li, Yongmin
2015-12-07
We demonstrate experimentally quantum frequency up-conversion of a continuous variable entangled optical field via sum-frequency-generation process. The two-color entangled state initially entangled at 806 and 1518 nm with an amplitude quadrature difference squeezing of 3.2 dB and phase quadrature sum squeezing of 3.1 dB is converted to a new entangled state at 530 and 1518 nm with the amplitude quadrature difference squeezing of 1.7 dB and phase quadrature sum squeezing of 1.8 dB. Our implementation enables the observation of entanglement between two light fields spanning approximately 1.5 octaves in optical frequency. The presented scheme is robust to the excess amplitude and phase noises of the pump field, making it a practical building block for quantum information processing and communication networks.
Design studies of continuously variable transmissions for electric vehicles
NASA Technical Reports Server (NTRS)
Parker, R. J.; Loewenthal, S. H.; Fischer, G. K.
1981-01-01
Preliminary design studies were performed on four continuously variable transmission (CVT) concepts for use with a flywheel equipped electric vehicle of 1700 kg gross weight. Requirements of the CVT's were a maximum torque of 450 N-m (330 lb-ft), a maximum output power of 75 kW (100 hp), and a flywheel speed range of 28,000 to 14,000 rpm. Efficiency, size, weight, cost, reliability, maintainability, and controls were evaluated for each of the four concepts which included a steel V-belt type, a flat rubber belt type, a toroidal traction type, and a cone roller traction type. All CVT's exhibited relatively high calculated efficiencies (68 percent to 97 percent) over a broad range of vehicle operating conditions. Estimated weight and size of these transmissions were comparable to or less than equivalent automatic transmission. The design of each concept was carried through the design layout stage.
Continuous-variable teleportation in the characteristic-function description
Marian, Paulina; Marian, Tudor A.
2006-10-15
We give a description of the continuous-variable teleportation protocol in terms of the characteristic functions of the quantum states involved. The Braunstein-Kimble protocol is written for an unbalanced homodyne measurement and arbitrary input and resource states. We show that the output of the protocol is a superposition between the input one-mode field and a classical one induced by measurement and classical communication. We choose to describe the input state distortion through teleportation by the average photon number of the measurement-induced field. Only in the case of symmetric Gaussian resource states we find a relation between the optimal added noise and the minimal EPR correlations used to define inseparability.
Investigation of continuously variable slope delta modulator/demodulator compatibility
NASA Astrophysics Data System (ADS)
Lersch, J. A.
1980-12-01
A computer model of the continuously variable slope delta voice encoding system specified in the draft STANAG on "Analogue/Digital Conversion of Speech Signals for Tactical, Digital Area Communication Systems", dated June 1978, is developed and implemented in FORTRAN IV. The model's performance is then characterized in terms of idle channel noise, total harmonic distortion, intermodulation distortion, signal-to-noise ratio, and frequency response. For each of these attributes, the system's performance is presented graphically and compared to the criteria established in the draft standard. The model is then exercised by varying the system parameters to the limits imposed by the standard and the resulting performance compared to the previously determined ideal system performance. The results show that the performance characteristics measured are most sensitive to the primary integrator response and output filter response when the system parameters are restricted to the range allowed by the draft NATO standard.
Continuous eclogite melting and variable refertilisation in upwelling heterogeneous mantle
Rosenthal, Anja; Yaxley, Gregory M.; Green, David H.; Hermann, Joerg; Kovács, István; Spandler, Carl
2014-01-01
Large-scale tectonic processes introduce a range of crustal lithologies into the Earth's mantle. These lithologies have been implicated as sources of compositional heterogeneity in mantle-derived magmas. The model being explored here assumes the presence of widely dispersed fragments of residual eclogite (derived from recycled oceanic crust), stretched and stirred by convection in the mantle. Here we show with an experimental study that these residual eclogites continuously melt during upwelling of such heterogeneous mantle and we characterize the melting reactions and compositional changes in the residue minerals. The chemical exchange between these partial melts and more refractory peridotite leads to a variably metasomatised mantle. Re-melting of these metasomatised peridotite lithologies at given pressures and temperatures results in diverse melt compositions, which may contribute to the observed heterogeneity of oceanic basalt suites. We also show that heterogeneous upwelling mantle is subject to diverse local freezing, hybridization and carbonate-carbon-silicate redox reactions along a mantle adiabat. PMID:25130275
A continuous-variable quantum key distribution using correlated photons
NASA Astrophysics Data System (ADS)
Donkor, Eric; Erdmann, Reinhard; Kumavor, Patrick D.
2015-05-01
We propose a quantum key distribution system based on the generation and transmission of random continuous variables in time, energy (frequency), phase, and photon number. The bounds for quantum measurement in our scheme are determined by the uncertainty principle, rather than single quadrature measurements of entangled states, or the no-cloning of (unknown) single quantum states. Correlated measurements are performed in the energy-time, and momentum-displacement frames. As a result the QKD protocols for generation of raw-keys, sifted-keys and privacy amplifications offer a higher level of security against individual or multi-attacks. The network architecture is in a plug-and-play configuration; the QKD protocol; determination of quantum bit error rate, and estimation of system performance in the presence of eavesdropping are presented.
Continuous-variable entanglement distillation and noncommutative central limit theorems
NASA Astrophysics Data System (ADS)
Campbell, Earl T.; Genoni, Marco G.; Eisert, Jens
2013-04-01
Entanglement distillation transforms weakly entangled noisy states into highly entangled states, a primitive to be used in quantum repeater schemes and other protocols designed for quantum communication and key distribution. In this work, we present a comprehensive framework for continuous-variable entanglement distillation schemes that convert noisy non-Gaussian states into Gaussian ones in many iterations of the protocol. Instances of these protocols include (a) the recursive-Gaussifier protocol, (b) the temporally reordered recursive-Gaussifier protocol, and (c) the pumping-Gaussifier protocol. The flexibility of these protocols gives rise to several beneficial trade-offs related to success probabilities or memory requirements, which can be adjusted to reflect experimental demands. Despite these protocols involving measurements, we relate the convergence in this protocol to new instances of noncommutative central limit theorems, in a formalism that we lay out in great detail. Implications of the findings for quantum repeater schemes are discussed.
Optimal continuous variable quantum teleportation protocol for realistic settings
NASA Astrophysics Data System (ADS)
Luiz, F. S.; Rigolin, Gustavo
2015-03-01
We show the optimal setup that allows Alice to teleport coherent states | α > to Bob giving the greatest fidelity (efficiency) when one takes into account two realistic assumptions. The first one is the fact that in any actual implementation of the continuous variable teleportation protocol (CVTP) Alice and Bob necessarily share non-maximally entangled states (two-mode finitely squeezed states). The second one assumes that Alice's pool of possible coherent states to be teleported to Bob does not cover the whole complex plane (| α | < ∞). The optimal strategy is achieved by tuning three parameters in the original CVTP, namely, Alice's beam splitter transmittance and Bob's displacements in position and momentum implemented on the teleported state. These slight changes in the protocol are currently easy to be implemented and, as we show, give considerable gain in performance for a variety of possible pool of input states with Alice.
Continuous-variable-entanglement dynamics in structured reservoirs
Vasile, Ruggero; Maniscalco, Sabrina; Olivares, Stefano; Paris, Matteo G. A.
2009-12-15
We address the evolution of entanglement in bimodal continuous variable quantum systems interacting with two independent structured reservoirs. We derive an analytic expression for the entanglement of formation without performing the Markov and the secular approximations and study in details the entanglement dynamics for various types of structured reservoirs and for different reservoir temperatures, assuming the two modes initially excited in a twin-beam state. Our analytic solution allows us to identify three dynamical regimes characterized by different behaviors of the entanglement: the entanglement sudden death, the non-Markovian revival and the non-secular revival regimes. Remarkably, we find that, contrarily to the Markovian case, the short-time system-reservoir correlations in some cases destroy quickly the initial entanglement even at zero temperature.
Experimental analysis of decoherence in continuous-variable bipartite systems
NASA Astrophysics Data System (ADS)
Buono, D.; Nocerino, G.; Porzio, A.; Solimeno, S.
2012-10-01
Quantum properties are soon subject to decoherence once the quantum system interacts with the classical environment. In this paper we experimentally test how propagation losses, in a Gaussian channel, affect the bipartite Gaussian entangled state generated by a subthreshold type-II optical parametric oscillator. Experimental results are discussed in terms of different quantum markers, as teleportation fidelity, quantum discord, and mutual information, and continuous-variable (CV) entanglement criteria. To analyze state properties we have retrieved the composite system covariance matrix by a single homodyne detector. We experimentally found that, even in the presence of a strong decoherence, the generated state never disentangles and keeps breaking the quantum limit for the discord. This result proves that the class of CV entangled states discussed in this paper would allow, in principle, to realize quantum teleportation over an infinitely long Gaussian channel.
Continuous eclogite melting and variable refertilisation in upwelling heterogeneous mantle.
Rosenthal, Anja; Yaxley, Gregory M; Green, David H; Hermann, Joerg; Kovács, István; Spandler, Carl
2014-01-01
Large-scale tectonic processes introduce a range of crustal lithologies into the Earth's mantle. These lithologies have been implicated as sources of compositional heterogeneity in mantle-derived magmas. The model being explored here assumes the presence of widely dispersed fragments of residual eclogite (derived from recycled oceanic crust), stretched and stirred by convection in the mantle. Here we show with an experimental study that these residual eclogites continuously melt during upwelling of such heterogeneous mantle and we characterize the melting reactions and compositional changes in the residue minerals. The chemical exchange between these partial melts and more refractory peridotite leads to a variably metasomatised mantle. Re-melting of these metasomatised peridotite lithologies at given pressures and temperatures results in diverse melt compositions, which may contribute to the observed heterogeneity of oceanic basalt suites. We also show that heterogeneous upwelling mantle is subject to diverse local freezing, hybridization and carbonate-carbon-silicate redox reactions along a mantle adiabat. PMID:25130275
Quantum frequency up-conversion of continuous variable entangled states
NASA Astrophysics Data System (ADS)
Liu, Wenyuan; Wang, Ning; Li, Zongyang; Li, Yongmin
2015-12-01
We demonstrate experimentally quantum frequency up-conversion of a continuous variable entangled optical field via sum-frequency-generation process. The two-color entangled state initially entangled at 806 and 1518 nm with an amplitude quadrature difference squeezing of 3.2 dB and phase quadrature sum squeezing of 3.1 dB is converted to a new entangled state at 530 and 1518 nm with the amplitude quadrature difference squeezing of 1.7 dB and phase quadrature sum squeezing of 1.8 dB. Our implementation enables the observation of entanglement between two light fields spanning approximately 1.5 octaves in optical frequency. The presented scheme is robust to the excess amplitude and phase noises of the pump field, making it a practical building block for quantum information processing and communication networks.
Continuous-variable telecloning with phase-conjugate inputs
Zhang Jing; Xie Changde; Peng Kunchi; Loock, Peter van
2008-02-15
We propose a scheme for continuous-variable telecloning with phase-conjugate inputs (PCI). Two cases of PCI telecloning are considered. The first case is where PCI telecloning produces M clones nonlocally and M anticlones locally, or vice versa. This kind of PCI telecloning requires only one Einstein-Podolsky-Rosen (EPR) entangled, two-mode squeezed state as a resource for building the appropriate multimode, multipartite entangled state via linear optics. The other case is a PCI telecloning protocol in which both clones and anticlones are created nonlocally. Such a scheme requires two EPR entangled states for the generation of a suitable multipartite entangled state. As our schemes are reversible, optimal cloning fidelities are achieved in the limit of infinite squeezing.
Quantum anonymous voting with unweighted continuous-variable graph states
NASA Astrophysics Data System (ADS)
Guo, Ying; Feng, Yanyan; Zeng, Guihua
2016-08-01
Motivated by the revealing topological structures of continuous-variable graph state (CVGS), we investigate the design of quantum voting scheme, which has serious advantages over the conventional ones in terms of efficiency and graphicness. Three phases are included, i.e., the preparing phase, the voting phase and the counting phase, together with three parties, i.e., the voters, the tallyman and the ballot agency. Two major voting operations are performed on the yielded CVGS in the voting process, namely the local rotation transformation and the displacement operation. The voting information is carried by the CVGS established before hand, whose persistent entanglement is deployed to keep the privacy of votes and the anonymity of legal voters. For practical applications, two CVGS-based quantum ballots, i.e., comparative ballot and anonymous survey, are specially designed, followed by the extended ballot schemes for the binary-valued and multi-valued ballots under some constraints for the voting design. Security is ensured by entanglement of the CVGS, the voting operations and the laws of quantum mechanics. The proposed schemes can be implemented using the standard off-the-shelf components when compared to discrete-variable quantum voting schemes attributing to the characteristics of the CV-based quantum cryptography.
Quantum anonymous voting with unweighted continuous-variable graph states
NASA Astrophysics Data System (ADS)
Guo, Ying; Feng, Yanyan; Zeng, Guihua
2016-05-01
Motivated by the revealing topological structures of continuous-variable graph state (CVGS), we investigate the design of quantum voting scheme, which has serious advantages over the conventional ones in terms of efficiency and graphicness. Three phases are included, i.e., the preparing phase, the voting phase and the counting phase, together with three parties, i.e., the voters, the tallyman and the ballot agency. Two major voting operations are performed on the yielded CVGS in the voting process, namely the local rotation transformation and the displacement operation. The voting information is carried by the CVGS established before hand, whose persistent entanglement is deployed to keep the privacy of votes and the anonymity of legal voters. For practical applications, two CVGS-based quantum ballots, i.e., comparative ballot and anonymous survey, are specially designed, followed by the extended ballot schemes for the binary-valued and multi-valued ballots under some constraints for the voting design. Security is ensured by entanglement of the CVGS, the voting operations and the laws of quantum mechanics. The proposed schemes can be implemented using the standard off-the-shelf components when compared to discrete-variable quantum voting schemes attributing to the characteristics of the CV-based quantum cryptography.
Arbitrated Quantum Signature Scheme with Continuous-Variable Coherent States
NASA Astrophysics Data System (ADS)
Guo, Ying; Feng, Yanyan; Huang, Dazu; Shi, Jinjing
2016-04-01
Motivated by the revealing features of the continuous-variable (CV) quantum cryptography, we suggest an arbitrated quantum signature (AQS) protocol with CV coherent states. It involves three participants, i.e., the signer Alice, the verifier Bob and the arbitrator Charlie who is trustworthy by Alice and Bob. Three phases initializing phase, signing phase and verifying phase are included in our protocol. The security of the signature scheme is guaranteed by the generation of the shared keys via the CV-based quantum key distribution (CV-QKD) and the implementation process of the CV-based quantum teleportation as well. Security analysis demonstrates that the signature can be neither forged by anyone nor disavowed by the receiver and signer. Moreover, the authenticity and integrality of the transmitted messages can be ensured. The paper shows that a potential high-speed quantum signature scheme with high detection efficiency and repetition rate can be realized when compared to the discrete-variable (DV) quantum signature scheme attributing to the well characteristics of CV-QKD.
Improving teleportation of continuous variables by local operations
Mista, Ladislav Jr.; Filip, Radim
2005-03-01
We study a continuous-variable (CV) teleportation protocol based on a shared entangled state produced by the quantum-nondemolition (QND) interaction of two vacuum states. The scheme utilizes the QND interaction or an unbalanced beam splitter in the Bell measurement. It is shown that in the nonunity gain regime the signal transfer coefficient can be enhanced while the conditional variance product remains preserved by applying appropriate local squeezing operation on sender's part of the shared entangled state. In the unity gain regime, it is demonstrated that the fidelity of teleportation can be increased with the help of the local squeezing operations on parts of the shared entangled state that effectively convert our scheme to the standard CV teleportation scheme. Further, it is proved analytically that such a choice of the local symplectic operations minimizes the noise by which the mean number of photons in the input state is increased during the teleportation. Finally, our analysis reveals that the local symplectic operation on sender's side can be integrated into the Bell measurement if the interaction constant of the interaction in the Bell measurement can be adjusted properly.
Coexistence of continuous variable QKD with intense DWDM classical channels
NASA Astrophysics Data System (ADS)
Kumar, Rupesh; Qin, Hao; Alléaume, Romain
2015-04-01
We demonstrate experimentally the feasibility of continuous variable quantum key distribution (CV-QKD) in dense-wavelength-division multiplexing networks (DWDM), where QKD will typically have to coexist with several co-propagating (forward or backward) C-band classical channels whose launch power is around 0 dBm. We have conducted experimental tests of the coexistence of CV-QKD multiplexed with an intense classical channel, for different input powers and different DWDM wavelengths. Over a 25 km fiber, a CV-QKD operated over the 1530.12 nm channel can tolerate the noise arising from up to 11.5 dBm classical channel at 1550.12 nm in the forward direction (9.7 dBm in backward). A positive key rate (0.49 kbits s-1) can be obtained at 75 km with classical channel power of respectively -3 and -9 dBm in forward and backward. Based on these measurements, we have also simulated the excess noise and optimized channel allocation for the integration of CV-QKD in some access networks. We have, for example, shown that CV-QKD could coexist with five pairs of channels (with nominal input powers: 2 dBm forward and 1 dBm backward) over a 25 km WDM-PON network. The obtained results demonstrate the outstanding capacity of CV-QKD to coexist with classical signals of realistic intensity in optical networks.
Self-Referenced Continuous-Variable Quantum Key Distribution Protocol
NASA Astrophysics Data System (ADS)
Soh, Daniel B. S.; Brif, Constantin; Coles, Patrick J.; Lütkenhaus, Norbert; Camacho, Ryan M.; Urayama, Junji; Sarovar, Mohan
2015-10-01
We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice's and Bob's measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.
Self-referenced continuous-variable quantum key distribution protocol
Soh, Daniel B. S.; Brif, Constantin; Coles, Patrick J.; Lutkenhaus, Norbert; Camacho, Ryan M.; Urayama, Junji; Sarovar, Mohan
2015-10-21
Here, we introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration ofmore » the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.« less
Self-referenced continuous-variable quantum key distribution protocol
Soh, Daniel B. S.; Brif, Constantin; Coles, Patrick J.; Lutkenhaus, Norbert; Camacho, Ryan M.; Urayama, Junji; Sarovar, Mohan
2015-10-21
Here, we introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.
Teleportation of continuous variable multimode Greeberger Horne Zeilinger entangled states
NASA Astrophysics Data System (ADS)
He, Guangqiang; Zhang, Jingtao; Zeng, Guihua
2008-11-01
Quantum teleportation protocols of continuous variable (CV) Greeberger-Horne-Zeilinger (GHZ) and Einstein-Podolsky-Rosen (EPR) entangled states are proposed, and are generalized to teleportation of arbitrary multimode GHZ entangled states described by Van Loock and Braunstein (2000 Phys. Rev. Lett. 84 3482). Each mode of a multimode entangled state is teleported using a CV EPR entangled pair and classical communication. The analytical expression of fidelity for the multimode Gaussian states which evaluates the teleportation quality is presented. The analytical results show that the fidelity is a function of both the squeezing parameter r, which characterizes the multimode entangled state to be teleported, and the channel parameter p, which characterizes the EPR pairs shared by Alice and Bob. The fidelity increases with increasing p, but decreases with increasing r, i.e., it is more difficult to teleport the more perfect multimode entangled states. The entanglement degree of the teleported multimode entangled states increases with increasing both r and p. In addition, the fact is proved that our teleportation protocol of EPR entangled states using parallel EPR pairs as quantum channels is the best case of the protocol using four-mode entangled states (Adhikari et al 2008 Phys. Rev. A 77 012337).
Technical Advances in the Continuous Melting of Phosphate Laser Glass
Suratwala, T; Thorsness, C; Campbell, J; Takeuchi, K; Suzuki, K; Yamamoto, K; Cimino, J; Thorne, A; Hayden, J
2001-09-05
Continuous melting of phosphate laser glass is now being used for the first time to prepare meter-scale amplifier optics for megajoule lasers. The scale-up to continuous melting from the previous one-at-a-time ''discontinuous'' batch process has allowed for the production of glass at rates more than 20 times faster, 5 times cheaper, and with 2-3 times better optical quality. Almost 8000 slabs of laser glass will be used in high-energy, high-peak-power laser systems that are being designed and built for fusion energy research. The success of this new continuous melting process, which is a result of a six year joint R&D program between government and industry, stems from numerous technical advances which include (1) dehydroxylating the glass to concentrations less than {approx}100 ppm OH; (2) minimizing damage-causing Pt-inclusions; (3) preventing glass fracture; (4) minimizing impurities such as Cu and Fe to <20 ppm; (5) improving forming methods to get high optical homogeneity glass; and (6) developing large aperture quality assurance tools to verify properties of the glass.
ERIC Educational Resources Information Center
Wall, Melanie M.; Guo, Jia; Amemiya, Yasuo
2012-01-01
Mixture factor analysis is examined as a means of flexibly estimating nonnormally distributed continuous latent factors in the presence of both continuous and dichotomous observed variables. A simulation study compares mixture factor analysis with normal maximum likelihood (ML) latent factor modeling. Different results emerge for continuous versus…
Continued Development of the Advanced Stirling Convertor (ASC)
NASA Technical Reports Server (NTRS)
Wong, Wayne A.; Wood, J. Gary; Wilson, Kyle; Buffalino, Andrew; Frye, Patrick; Matejczyk, Dan; Penswick, L.B.
2008-01-01
The Advanced Stirling Convertor (ASC) is being developed under contract with the NASA Glenn Research Center (GRC) and is supported by NASA s Science Mission Directorate for potential use in future radioisotope power systems having significantly increased efficiency and higher specific power compared to the current thermoelectric systems. An ASC with a lower temperature (approx.650 C) Inconel heater head is currently being substituted into the DOE/Lockheed Martin Advanced Stirling Radioisotope Generator (ASRG) program with a predicted convertor efficiency of 34 percent (AC electrical out to heat input ) at a temperature ratio of 2.7 and is expected to deliver approximately 75 W(sub ac). Continued development of the higher temperature (approx.850 C) version using existing materials and fabrication techniques in the hot portions is reported on here. The higher temperature ASC is expected to have 38 percent efficiency (AC electrical out to heat input) at a temperature ratio of 3.1 and is expected to deliver approximately 88 W(sub ac). The high temperature ASC also has approximately 30 C higher rejection temperature, which allows for further reduced system mass because of the reduced radiator size. Six higher temperature and hermetically sealed convertors are being built under this effort for extended life testing at GRC.
Variable Patterns of Continuous Morphine Infusions at End of Life
Lin, Katrina J.; Ching, Andrea; Edmonds, Kyle P.; Roeland, Eric J.; Revta, Carolyn; Ma, Joseph D.
2015-01-01
Abstract Background: Continuous morphine infusions (CMIs) treat pain and dyspnea at the end of life (EOL). CMIs may be initiated at an empiric rate and/or are rapidly escalated without proper titration. Objective: The study objective was to evaluate CMI patterns at the EOL. Methods: This single-center, retrospective chart review evaluated adult patients who died while receiving CMI at EOL. Patient demographics and opioid dosing information were extracted from an electronic medical record. Twenty-four hour IV morphine equivalent was calculated prior to CMI initiation and at the time of death. Results: Of the 190 patient charts, 63.2% (n=120) received no bolus doses prior to CMI initiation. Mean 24-hour IV morphine equivalent prior to CMI initiation was 49.3 mg (range: 0–1200 mg, SD 384.9) and at time of death was 267.1 mg (12.0–5193.2 mg, SD 442.2), representing an increase of +442%. Mean CMI starting rate was 3.3 mg/hour (0.4–30.0 mg/hour, SD 3.6) with titration at time of death to a mean of 7.7 mg/hour (0.4–70.0 mg/hour, SD 9.4), representing an increase of +130%. Mean number of CMI rate adjustments was 2.5 (0–5, SD 3.3); and number of bolus doses administered between titrations was 4.2 (0–27, SD 4.8). Mean time from CMI initiation to death was 15.5 hours (0.05–126.9 hours, SD 21.7). There was a negative association between rate of infusion increase per hour and total number of hours on CMI (r=−0.2, p=0.0062). Conclusions: Hospitalized patients at EOL had a much higher 24-hour IV morphine equivalents and CMI rates at time of death compared to CMI initiation. Variability was observed in the number of CMI rate adjustments and the number of bolus doses administered. PMID:26107143
The Danger of Dichotomizing Continuous Variables: A Visualization
ERIC Educational Resources Information Center
Kuss, Oliver
2013-01-01
Four rather different scatterplots of two variables X and Y are given, which, after dichotomizing X and Y, result in identical fourfold-tables misleadingly showing no association. (Contains 1 table and 1 figure.)
Atomic filtering for hybrid continuous-variable/discrete-variable quantum optics.
Zielińska, Joanna A; Beduini, Federica A; Lucivero, Vito Giovanni; Mitchell, Morgan W
2014-10-20
We demonstrate atomic filtering of frequency-degenerate photon pairs from a sub-threshold optical parametric oscillator (OPO). The filter, a modified Faraday anomalous dispersion optical filter (FADOF), achieves 70% peak transmission simultaneous with 57 dB out-of-band rejection and a 445 MHz transmission bandwidth. When applied to the OPO output, only the degenerate mode, containing one-mode squeezed vacuum, falls in the filter pass-band; all other modes are strongly suppressed. The high transmission preserves non-classical continuous-variable features, e.g. squeezing or non-gaussianity, while the high spectral purity allows reliable discrete-variable detection and heralding. Correlation and atomic absorption measurements indicate a spectral purity of 96% for the individual photons, and 98% for the photon pairs. These capabilities will enable generation of atom-resonant hybrid states, e.g. "Schrödinger kittens" obtained by photon subtraction from squeezed vacuum, making these exotic states available for quantum networking and atomic quantum metrology applications. PMID:25401564
Generalization of continuous-variable quantum cloning with linear optics
NASA Astrophysics Data System (ADS)
Zhai, Zehui; Guo, Juan; Gao, Jiangrui
2006-05-01
We propose an asymmetric quantum cloning scheme. Based on the proposal and experiment by Andersen [Phys. Rev. Lett. 94, 240503 (2005)], we generalize it to two asymmetric cases: quantum cloning with asymmetry between output clones and between quadrature variables. These optical implementations also employ linear elements and homodyne detection only. Finally, we also compare the utility of symmetric and asymmetric cloning in an analysis of a squeezed-state quantum key distribution protocol and find that the asymmetric one is more advantageous.
Interactions of Task and Subject Variables among Continuous Performance Tests
ERIC Educational Resources Information Center
Denney, Colin B.; Rapport, Mark D.; Chung, Kyong-Mee
2005-01-01
Background: Contemporary models of working memory suggest that target paradigm (TP) and target density (TD) should interact as influences on error rates derived from continuous performance tests (CPTs). The present study evaluated this hypothesis empirically in a typically developing, ethnically diverse sample of children. The extent to which…
High-fidelity continuous-variable quantum teleportation toward multistep quantum operations
Yukawa, Mitsuyoshi; Furusawa, Akira; Benichi, Hugo
2008-02-15
The progress in quantum operations of continuous-variable (CV) schemes can be reduced to that in CV quantum teleportation. The fidelity of quantum teleportation of an optical setup is limited by the finite degree of quantum correlation that can be prepared with a pair of finitely squeezed states. Reports of improvement of squeezing level have appeared recently, and we adopted the improved methods in our experimental system of quantum teleportation. As a result, we teleported a coherent state with a fidelity F=0.83{+-}0.01, which is better than any other figures reported to date, to our knowledge. In this paper, we introduce a measure n{sub s}, the number of teleportations expected to be carried out sequentially. Our result corresponds to n{sub s}=5.0{+-}0.4. It suggests that our improvement would enable us to proceed toward more advanced quantum operations involving multiple steps.
Generalization of continuous-variable quantum cloning with linear optics
Zhai Zehui; Guo Juan; Gao Jiangrui
2006-05-15
We propose an asymmetric quantum cloning scheme. Based on the proposal and experiment by Andersen et al. [Phys. Rev. Lett. 94, 240503 (2005)], we generalize it to two asymmetric cases: quantum cloning with asymmetry between output clones and between quadrature variables. These optical implementations also employ linear elements and homodyne detection only. Finally, we also compare the utility of symmetric and asymmetric cloning in an analysis of a squeezed-state quantum key distribution protocol and find that the asymmetric one is more advantageous.
Intervention Research in Social Work: Recent Advances and Continuing Challenges
ERIC Educational Resources Information Center
Fraser, Mark W.
2004-01-01
The purpose of this article is to review substantive and methodological advances in interventive research. Three substantive advances are discussed: (a) the growing use of a risk factor perspective, (b) the emergence of practice-relevant micro social theories, and (c) the increased acceptance of structured treatment protocols and manual. In…
Evidence against continuous variables driving numerical discrimination in infancy
Starr, Ariel; Brannon, Elizabeth M.
2015-01-01
Over the past decades, abundant evidence has amassed that demonstrates infants’ sensitivity to changes in number. Nonetheless, a prevalent view is that infants are more sensitive to continuous properties of stimulus arrays such as surface area and contour length than they are to numerosity. Very little research, however, has directly addressed infants’ sensitivity to contour. Here we used a change detection paradigm to assess infants’ acuity for the cumulative contour length of an array when the array’s surface area and number were held constant. Seven-month-old infants detected a threefold change in contour length but failed to detect a twofold change. These results, in conjunction with previously published data on numerosity discrimination using the same experimental paradigm, suggest that infants are not more sensitive to changes in contour length compared to changes in numerosity. Consequently, these findings undermine the claim that attention toward contour length is a primary driver of numerical discrimination in infancy. PMID:26191028
Violation of Bell's inequality with continuous spatial variables
Abouraddy, Ayman F.; Yarnall, Timothy; Saleh, Bahaa E. A.; Teich, Malvin C.
2007-05-15
The Einstein-Podolsky-Rosen (EPR) argument revealed the paradoxical properties of a two-particle system entangled continuously in the spatial parameter. Yet a direct test of quantum nonlocality exhibited by this state, via a violation of Bell's inequality, has not been forthcoming. In this paper, we identify and construct experimental arrangements comprising simple optical components, without nonlinearities or moving parts, that implement operators in the spatial-parity space of single-photon fields that correspond to the familiar Pauli spin operators. We achieve this by first establishing an isomorphism between the single-mode multiphoton electromagnetic-field space spanned by a Fock-state basis and the single-photon multimode electromagnetic-field space spanned by a spatial-eigenmode basis. We then proceed to construct a Hilbert space with a two-dimensional basis of spatial even-odd parity modes. In particular, we describe an arrangement that implements a rotation in the parity space of each photon of an entangled-photon pair, allowing for a straightforward experimental test of Bell's inequality using the EPR state. Finally, the violation of a Bell inequality is quantified in terms of the physical parameters of the two-photon source.
Jin Chen
2009-12-07
Efficient and robust Variable Relaxation Solver, based on pseudo-transient continuation, is developed to solve nonlinear anisotropic thermal conduction arising from fusion plasma simulations. By adding first and/or second order artificial time derivatives to the system, this type of method advances the resulting time-dependent nonlinear PDEs to steady state, which is the solution to be sought. In this process, only the stiffness matrix itself is involved so that the numerical complexity and errors can be greatly reduced. In fact, this work is an extension of integrating efficient linear elliptic solvers for fusion simulation on Cray XIE. Two schemes are derived in this work, first and second order Variable Relaxations. Four factors are observed to be critical for efficiency and preservation of solution's symmetric structure arising from periodic boundary condition: refining meshes in different coordinate directions, initializing nonlinear process, varying time steps in both temporal and spatial directions, and accurately generating nonlinear stiffness matrix. First finer mesh scale should be taken in strong transport direction; Next the system is carefully initialized by the solution with linear conductivity; Third, time step and relaxation factor are vertex-based varied and optimized at each time step; Finally, the nonlinear stiffness matrix is updated by just scaling corresponding linear one with the vector generated from nonlinear thermal conductivity.
NASA Astrophysics Data System (ADS)
Wasko, Conrad; Pui, Alexander; Sharma, Ashish; Mehrotra, Rajeshwar; Jeremiah, Erwin
2015-12-01
Low-frequency variability, in the form of the El Niño-Southern Oscillation, plays a key role in shaping local weather systems. However, current continuous stochastic rainfall models do not account for this variability in their simulations. Here a modified Random Pulse Bartlett Lewis stochastic generation model is presented for continuous rainfall simulation exhibiting low-frequency variability. Termed the Hierarchical Random Bartlett Lewis Model (HRBLM), the model features a hierarchical structure to represent a range of rainfall characteristics associated with the El Niño-Southern Oscillation with parameters conditioned to vary as functions of relevant climatic states. Long observational records of near-continuous rainfall at various locations in Australia are used to formulate and evaluate the model. The results indicate clear benefits of using the hierarchical climate-dependent structure proposed. In addition to accurately representing the wet spells characteristics and observed low-frequency variability, the model replicates the interannual variability of the antecedent rainfall preceding the extremes, which is known to be of considerable importance in design flood estimation applications.
Recent Advances on Solar Global Magnetism and Variability
NASA Astrophysics Data System (ADS)
Brun, A. S.; Browning, M. K.; Dikpati, M.; Hotta, H.; Strugarek, A.
2015-12-01
We discuss recent observational, theoretical and numerical progress made in understanding the solar global magnetism and its short and long term variability. We discuss the physical process thought to be at the origin of the solar magnetic field and its 22-yr cycle, namely dynamo action, and the nonlinear interplay between convection, rotation, radiation and magnetic field, yielding modulations of the solar constant or of the large scale flows such as the torsional oscillations. We also discuss the role of the field parity and dynamo families in explaining the complex multipolar structure of the solar global magnetic field. We then present some key MHD processes acting in the deep radiative interior and discuss the probable topology of a primordial field there. Finally we summarize how helioseismology has contributed to these recent advances and how it could contribute to resolving current unsolved problems in solar global dynamics and magnetism.
Efficient Three-Party Quantum Dialogue Protocol Based on the Continuous Variable GHZ States
NASA Astrophysics Data System (ADS)
Yu, Zhen-Bo; Gong, Li-Hua; Zhu, Qi-Biao; Cheng, Shan; Zhou, Nan-Run
2016-07-01
Based on the continuous variable GHZ entangled states, an efficient three-party quantum dialogue protocol is devised, where each legitimate communication party could simultaneously deduce the secret information of the other two parties with perfect efficiency. The security is guaranteed by the correlation of the continuous variable GHZ entangled states and the randomly selected decoy states. Furthermore, the three-party quantum dialogue protocol is directly generalized to an N-party quantum dialogue protocol by using the n-tuple continuous variable GHZ entangled states.
Efficient Three-Party Quantum Dialogue Protocol Based on the Continuous Variable GHZ States
NASA Astrophysics Data System (ADS)
Yu, Zhen-Bo; Gong, Li-Hua; Zhu, Qi-Biao; Cheng, Shan; Zhou, Nan-Run
2016-02-01
Based on the continuous variable GHZ entangled states, an efficient three-party quantum dialogue protocol is devised, where each legitimate communication party could simultaneously deduce the secret information of the other two parties with perfect efficiency. The security is guaranteed by the correlation of the continuous variable GHZ entangled states and the randomly selected decoy states. Furthermore, the three-party quantum dialogue protocol is directly generalized to an N-party quantum dialogue protocol by using the n-tuple continuous variable GHZ entangled states.
Vázquez, Pablo; Hristovski, Robert; Balagué, Natàlia
2016-01-01
The aim of this study was to detect qualitative changes in the structure of coordinative variable (elbow angle) fluctuations during a quasi-isometric exercise performed until exhaustion. Seven physical education students performed a quasi-isometric arm-curl exercise holding an Olympic bar (weight: 80% 1RM) with an initial elbow flexion of 90° three times over a period of 4 weeks. They were encouraged to persist, even if the elbow angle was lost, until the fatigue-induced spontaneous termination point (FISTP). Changes in both elbow angles were registered during the task through an electrogoniometer. Detrended Fluctuation Analysis (DFA) was conducted on the initial and final 1024 data points of the series and the associated Hurst exponents were obtained. Multi-way RM ANOVA analyses revealed a significant main effect of the Time on task on the Hurst exponent values but also revealed a significant Trial × Time on task interaction. In the initial (non-fatigue) condition participants tended to produce anti-persistent fBm fluctuations. In the final part before exhaustion a tendency toward persistent fBm was dominant. The trial to trial differences in time-variability structure points to an existence of a long-term variability in control strategies during exercise. The changes in the temporal structure of the elbow angle variability as effort accumulated reflected an increase in low-frequency fluctuations signifying a change in psychobiological mechanisms used to negotiate the task demands. The variability properties of the coordinative variable during exercise may provide information about the dynamic mechanisms that lead to exhaustion. PMID:26913006
Vázquez, Pablo; Hristovski, Robert; Balagué, Natàlia
2016-01-01
The aim of this study was to detect qualitative changes in the structure of coordinative variable (elbow angle) fluctuations during a quasi-isometric exercise performed until exhaustion. Seven physical education students performed a quasi-isometric arm-curl exercise holding an Olympic bar (weight: 80% 1RM) with an initial elbow flexion of 90° three times over a period of 4 weeks. They were encouraged to persist, even if the elbow angle was lost, until the fatigue-induced spontaneous termination point (FISTP). Changes in both elbow angles were registered during the task through an electrogoniometer. Detrended Fluctuation Analysis (DFA) was conducted on the initial and final 1024 data points of the series and the associated Hurst exponents were obtained. Multi-way RM ANOVA analyses revealed a significant main effect of the Time on task on the Hurst exponent values but also revealed a significant Trial × Time on task interaction. In the initial (non-fatigue) condition participants tended to produce anti-persistent fBm fluctuations. In the final part before exhaustion a tendency toward persistent fBm was dominant. The trial to trial differences in time-variability structure points to an existence of a long-term variability in control strategies during exercise. The changes in the temporal structure of the elbow angle variability as effort accumulated reflected an increase in low-frequency fluctuations signifying a change in psychobiological mechanisms used to negotiate the task demands. The variability properties of the coordinative variable during exercise may provide information about the dynamic mechanisms that lead to exhaustion. PMID:26913006
NASA Technical Reports Server (NTRS)
Dunn, H. J.
1981-01-01
A computer program for performing frequency analysis of time history data is presented. The program uses circular convolution and the fast Fourier transform to calculate power density spectrum (PDS) of time history data. The program interfaces with the advanced continuous simulation language (ACSL) so that a frequency analysis may be performed on ACSL generated simulation variables. An example of the calculation of the PDS of a Van de Pol oscillator is presented.
Advancing Public Health through Continuing Education of Health Care Professionals
ERIC Educational Resources Information Center
Hudmon, Karen Suchanek; Addleton, Robert L.; Vitale, Frank M.; Christiansen, Bruce A.; Mejicano, George C.
2011-01-01
This article describes how the CS2day (Cease Smoking Today) initiative positioned continuing education (CE) in the intersection between medicine and public health. The authors suggest that most CE activities address the medical challenges that clinicians confront, often to the neglect of the public health issues that are key risk factors for the…
Quantum secure communication using continuous variable Einstein-Podolsky-Rosen correlations
He Guangqiang; Zhu Jun; Zeng Guihua
2006-01-15
A quantum secure communication protocol using correlations of continuous variable Einstein-Podolsky-Rosen (EPR) pairs is proposed. The proposed protocol may implement both quantum key distribution and quantum message encryption by using a nondegenerate optical parametric amplifier (NOPA). The general Gaussian-cloner attack strategy is investigated in detail by employing Shannon information theory. Results show that the proposed scheme is secure, which is guaranteed physically by the correlations of the continuous variable EPR entanglement pairs generated by the NOPA.
Wilkes, Donald F.; Purvis, James W.; Miller, A. Keith
1997-01-01
An infinitely variable transmission is capable of operating between a maximum speed in one direction and a minimum speed in an opposite direction, including a zero output angular velocity, while being supplied with energy at a constant angular velocity. Input energy is divided between a first power path carrying an orbital set of elements and a second path that includes a variable speed adjustment mechanism. The second power path also connects with the orbital set of elements in such a way as to vary the rate of angular rotation thereof. The combined effects of power from the first and second power paths are combined and delivered to an output element by the orbital element set. The transmission can be designed to operate over a preselected ratio of forward to reverse output speeds.
NASA Astrophysics Data System (ADS)
Mikhalev, A. S.; Rouban, A. I.
2016-04-01
The algorithms of global non-differentiable minimization of functions on set of the mixed variables: continuous and discrete with unordered specific possible values are constructed. The method of optimization is based on selective averaging of required variables, on adaptive reorganization of the sizes of admissible domain of trial movements and on use of relative values for minimised functions. Existence of discrete variables leads to solution of a sequence of global minimization problems of the functions in space of only continuous variables at the presence: 1) of their inequality restrictions for each problem; 2) of the general inequality restrictions for all problems (i.e. at the absence of dependence of functions fore inequality restrictions from discrete variables). In the first case, presence of discrete variables with unordered non-numeric possible values leads to solution of sequence of problems of global minimization of multiextreme functions on set only of continuous variables at the presence of their inequality restrictions. As a result, among the received optimum solutions the best is selected. In the second variant all minimized functions is convoluted in each sampling point in one multiextreme function and this function is minimised on continuous variables.
Long-distance continuous-variable quantum key distribution by controlling excess noise
Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua
2016-01-01
Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network. PMID:26758727
Long-distance continuous-variable quantum key distribution by controlling excess noise
NASA Astrophysics Data System (ADS)
Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua
2016-01-01
Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network.
Long-distance continuous-variable quantum key distribution by controlling excess noise.
Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua
2016-01-01
Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network. PMID:26758727
Crawford, John T; Loken, Luke C; Casson, Nora J; Smith, Colin; Stone, Amanda G; Winslow, Luke A
2015-01-01
Advanced sensor technology is widely used in aquatic monitoring and research. Most applications focus on temporal variability, whereas spatial variability has been challenging to document. We assess the capability of water chemistry sensors embedded in a high-speed water intake system to document spatial variability. This new sensor platform continuously samples surface water at a range of speeds (0 to >45 km h(-1)) resulting in high-density, mesoscale spatial data. These novel observations reveal previously unknown variability in physical, chemical, and biological factors in streams, rivers, and lakes. By combining multiple sensors into one platform, we were able to detect terrestrial-aquatic hydrologic connections in a small dystrophic lake, to infer the role of main-channel vs backwater nutrient processing in a large river and to detect sharp chemical changes across aquatic ecosystem boundaries in a stream/lake complex. Spatial sensor data were verified in our examples by comparing with standard lab-based measurements of selected variables. Spatial fDOM data showed strong correlation with wet chemistry measurements of DOC, and optical NO3 concentrations were highly correlated with lab-based measurements. High-frequency spatial data similar to our examples could be used to further understand aquatic biogeochemical fluxes, ecological patterns, and ecosystem processes, and will both inform and benefit from fixed-site data. PMID:25406073
Continued advancement of laser damage resistant optically functional microstructures
NASA Astrophysics Data System (ADS)
Hobbs, Douglas S.; MacLeod, Bruce D.; Sabatino, Ernest
2012-11-01
Micro- and nano-structured optically functional surface textures continue to exhibit higher performance and longer term survivability than thin-film coatings for an increasing number of materials used within high energy laser (HEL) systems. Anti-reflection (AR) microstructures (ARMs) produce a graded refractive index yielding high transmission over wide spectral ranges along with a chemical, mechanical and laser damage resistance inherited from the bulk optic material. In this study, ARMs were fabricated in the relevant HEL materials sapphire, neodymium-doped YAG, fused silica, BK7 glass, and the magnesium aluminate known as SPINEL. Standardized pulsed laser induced damage threshold (LiDT) measurements were made using commercial testing services to directly compare the damage resistance of ARMs-treated optics to uncoated and thin-film-AR-coated (TFARC) optics at wavelengths of 532nm, 694nm, 800nm, 1064nm, and 1538nm. As found with prior work, the LiDT of ARMs etched in fused silica was typically in the range of 35 J/cm2 at a wavelength of 1064nm and a pulse width of 10ns, a level that is comparable to uncoated samples and 3.5 times greater than the level specified by six prominent TFARC providers. The Army Research Laboratory measured the pulsed LiDT at 532nm (10ns) of ARMs in fused silica to be up to 5 times the level of the ion beam sputtered TFARC previously employed in their HEL system, and 2 times higher than a low performance single layer MgF2 TFARC. This result was repeated and expanded using a commercial LiDT testing service for ARMs in two types of fused silica and for Schott N-BK7 glass. An average damage threshold of 26.5 J/cm2 was recorded for the ARMs-treated glass materials, a level 4 times higher than the commercial IBS TFARCs tested.
Kozlowski, Szymon; Kochanek, Christopher S.; Udalski, A.; Wyrzykowski, L.; Soszynski, I.; Szymanski, M. K.; Kubiak, M.; Pietrzynski, G.; Szewczyk, O.; Ulaczyk, K.; Poleski, R. E-mail: ckochanek@astronomy.ohio-state.ed
2010-01-10
Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae, microlensing events), there is no equivalent for non-periodic continuously varying sources (quasars, aperiodic stellar variability). In this paper, we present a fast method for modeling and classifying such sources. We demonstrate the method using approx86, 000 variable sources from the OGLE-II survey of the LMC and approx2700 mid-IR-selected quasar candidates from the OGLE-III survey of the LMC and SMC. We discuss the location of common variability classes in the parameter space of the model. In particular, we show that quasars occupy a distinct region of variability space, providing a simple quantitative approach to the variability selection of quasars.
NASA Astrophysics Data System (ADS)
Yu, Zhen-Bo; Gong, Li-Hua; Wen, Ru-Hong
2016-03-01
A novel multiparty controlled bidirectional quantum secure direct communication protocol combining continuous-variable states with qubit block transmission is proposed. Two legitimate communication parties encode their own secret information into entangled optical modes with translation operations, and the secret information of each counterpart can only be recovered under the permission of all controllers. Due to continuous-variable states and block transmission strategy, the proposed protocol is easy to realize with perfect qubit efficiency. Security analyses show that the proposed protocol is free from common attacks, including the man-in-the-middle attack.
Equivalence between entanglement and the optimal fidelity of continuous variable teleportation.
Adesso, Gerardo; Illuminati, Fabrizio
2005-10-01
We devise the optimal form of Gaussian resource states enabling continuous-variable teleportation with maximal fidelity. We show that a nonclassical optimal fidelity of N-user teleportation networks is necessary and sufficient for N-party entangled Gaussian resources, yielding an estimator of multipartite entanglement. The entanglement of teleportation is equivalent to the entanglement of formation in a two-user protocol, and to the localizable entanglement in a multiuser one. Finally, we show that the continuous-variable tangle, quantifying entanglement sharing in three-mode Gaussian states, is defined operationally in terms of the optimal fidelity of a tripartite teleportation network. PMID:16241708
High-fidelity teleportation of continuous-variable quantum states using delocalized single photons.
Andersen, Ulrik L; Ralph, Timothy C
2013-08-01
Traditional continuous-variable teleportation can only approach unit fidelity in the limit of an infinite (and unphysical) amount of squeezing. We describe a new method for continuous-variable teleportation that approaches unit fidelity with finite resources. The protocol is not based on squeezed states as in traditional teleportation but on an ensemble of single photon entangled states. We characterize the teleportation scheme with coherent states, mesoscopic superposition states, and two-mode squeezed states and we find several situations in which near-unity teleportation fidelity can be obtained with modest resources. PMID:23952378
Sherwood, David E; Fosler, Jessica
2013-04-01
The main goal of the study was to test a prediction of schema theory: a wider range of variable practice would result in better transfer performance compared to a narrower range of variable practice in less-studied, continuous aiming movements. Constant and variable amplitude continuous aiming movements were investigated in the preferred hand of participants of college age (N = 32; 8 men, 24 women). Participants made continuous rapid reversal movements with a lever in the horizontal plane. Groups attempted to reach a short (20 degrees) target and a long target (either 45 degrees or 70 degrees) in separate constant-practice conditions, but alternated between the two targets in a variable practice condition. On the transfer test, participants alternated between unpracticed 10 degrees and 80 degrees targets. Four blocks of practice trials were provided in each condition, with 20 movements made in each. Movements were more accurate and consistent during constant practice compared to variable practice, with the 20 degrees-70 degrees group having greater spatial errors compared to the 20 degrees-45 degrees group. Both groups performed equally well on the novel transfer test suggesting that adequate practice variability had been provided during acquisition. PMID:24032334
GY SAMPLING THEORY AND GEOSTATISTICS: ALTERNATE MODELS OF VARIABILITY IN CONTINUOUS MEDIA
In the sampling theory developed by Pierre Gy, sample variability is modeled as the sum of a set of seven discrete error components. The variogram used in geostatisties provides an alternate model in which several of Gy's error components are combined in a continuous mode...
Continuous-variable Einstein-Podolsky-Rosen paradox with traveling-wave second-harmonic generation
Olsen, M.K.
2004-09-01
The Einstein-Podolsky-Rosen paradox and quantum entanglement are at the heart of quantum mechanics. Here we show that single-pass traveling-wave second-harmonic generation can be used to demonstrate both entanglement and the paradox with continuous variables that are analogous to the position and momentum of the original proposal.
Quantum error correction of continuous-variable states against Gaussian noise
Ralph, T. C.
2011-08-15
We describe a continuous-variable error correction protocol that can correct the Gaussian noise induced by linear loss on Gaussian states. The protocol can be implemented using linear optics and photon counting. We explore the theoretical bounds of the protocol as well as the expected performance given current knowledge and technology.
Design study of a continuously variable roller cone traction CVT for electric vehicles
NASA Technical Reports Server (NTRS)
Mccoin, D. K.; Walker, R. D.
1980-01-01
Continuously variable ratio transmissions (CVT) featuring cone and roller traction elements and computerized controls are studied. The CVT meets or exceeds all requirements set forth in the design criteria. Further, a scalability analysis indicates the basic concept is applicable to lower and higher power units, with upward scaling for increased power being more readily accomplished.
Assessing the Potential of a Mechanical Continuously Variable Transmission for Wind Turbines
Cotrell, J.
2005-08-01
This paper provides an update to a previous report that summarizes the results of a cooperative research and development agreement (CRADA) between the National Renewable Energy Laboratory (NREL) and Fallbrook Technologies, Inc. (Fallbrook). The purpose of the CRADA is to assess the usefulness of a continuously variable transmission (CVT) for wind turbine applications.
Atomic homodyne detection of continuous-variable entangled twin-atom states.
Gross, C; Strobel, H; Nicklas, E; Zibold, T; Bar-Gill, N; Kurizki, G; Oberthaler, M K
2011-12-01
Historically, the completeness of quantum theory has been questioned using the concept of bipartite continuous-variable entanglement. The non-classical correlations (entanglement) between the two subsystems imply that the observables of one subsystem are determined by the measurement choice on the other, regardless of the distance between the subsystems. Nowadays, continuous-variable entanglement is regarded as an essential resource, allowing for quantum enhanced measurement resolution, the realization of quantum teleportation and quantum memories, or the demonstration of the Einstein-Podolsky-Rosen paradox. These applications rely on techniques to manipulate and detect coherences of quantum fields, the quadratures. Whereas in optics coherent homodyne detection of quadratures is a standard technique, for massive particles a corresponding method was missing. Here we report the realization of an atomic analogue to homodyne detection for the measurement of matter-wave quadratures. The application of this technique to a quantum state produced by spin-changing collisions in a Bose-Einstein condensate reveals continuous-variable entanglement, as well as the twin-atom character of the state. Our results provide a rare example of continuous-variable entanglement of massive particles. The direct detection of atomic quadratures has applications not only in experimental quantum atom optics, but also for the measurement of fields in many-body systems of massive particles. PMID:22139418
ERIC Educational Resources Information Center
Markon, Kristian E.; Krueger, Robert F.
2006-01-01
Distinguishing between discrete and continuous latent variable distributions has become increasingly important in numerous domains of behavioral science. Here, the authors explore an information-theoretic approach to latent distribution modeling, in which the ability of latent distribution models to represent statistical information in observed…
NASA Astrophysics Data System (ADS)
Ma, Xiang-Chun; Sun, Shi-Hai; Jiang, Mu-Sheng; Liang, Lin-Mei
2013-05-01
We present the wavelength attack on a practical continuous-variable quantum-key-distribution system with a heterodyne protocol, in which the transmittance of beam splitters at Bob's station is wavelength dependent. Our strategy is proposed independent of but analogous to that of Huang [arXiv:1206.6550v1 [quant-ph
SamACO: variable sampling ant colony optimization algorithm for continuous optimization.
Hu, Xiao-Min; Zhang, Jun; Chung, Henry Shu-Hung; Li, Yun; Liu, Ou
2010-12-01
An ant colony optimization (ACO) algorithm offers algorithmic techniques for optimization by simulating the foraging behavior of a group of ants to perform incremental solution constructions and to realize a pheromone laying-and-following mechanism. Although ACO is first designed for solving discrete (combinatorial) optimization problems, the ACO procedure is also applicable to continuous optimization. This paper presents a new way of extending ACO to solving continuous optimization problems by focusing on continuous variable sampling as a key to transforming ACO from discrete optimization to continuous optimization. The proposed SamACO algorithm consists of three major steps, i.e., the generation of candidate variable values for selection, the ants' solution construction, and the pheromone update process. The distinct characteristics of SamACO are the cooperation of a novel sampling method for discretizing the continuous search space and an efficient incremental solution construction method based on the sampled values. The performance of SamACO is tested using continuous numerical functions with unimodal and multimodal features. Compared with some state-of-the-art algorithms, including traditional ant-based algorithms and representative computational intelligence algorithms for continuous optimization, the performance of SamACO is seen competitive and promising. PMID:20371409
NASA Technical Reports Server (NTRS)
Burghart, J. H.; Donoghue, J. F.
1980-01-01
The design and evaluation of a control system for a sedan with a heat engine and a continuously variable transmission, is considered in a effort to minimize fuel consumption and achieve satisfactory dynamic response of vehicle variables as the vehicle is driven over a standard driving cycle. Even though the vehicle system was highly nonlinear, attention was restricted to linear control algorithms which could be easily understood and implemented demonstrated by simulation. Simulation results also revealed that the vehicle could exhibit unexpected dynamic behavior which must be taken into account in any control system design.
A 24 km fiber-based discretely signaled continuous variable quantum key distribution system.
Dinh Xuan, Quyen; Zhang, Zheshen; Voss, Paul L
2009-12-21
We report a continuous variable key distribution system that achieves a final secure key rate of 3.45 kilobits/s over a distance of 24.2 km of optical fiber. The protocol uses discrete signaling and post-selection to improve reconciliation speed and quantifies security by means of quantum state tomography. Polarization multiplexing and a frequency translation scheme permit transmission of a continuous wave local oscillator and suppression of noise from guided acoustic wave Brillouin scattering by more than 27 dB. PMID:20052135
NASA Technical Reports Server (NTRS)
Kaul, Upender K.; Nguyen, Nhan T.
2015-01-01
Results of a computational study carried out to explore the effects of various elastomer configurations joining spanwise contiguous Variable Camber Continuous Trailing Edge Flap (VCCTEF) segments are reported here. This research is carried out as a proof-of-concept study that will seek to push the flight envelope in cruise with drag optimization as the objective. The cruise conditions can be well off design such as caused by environmental conditions, maneuvering, etc. To handle these off-design conditions, flap deflection is used so when the flap is deflected in a given direction, the aircraft angle of attack changes accordingly to maintain a given lift. The angle of attack is also a design parameter along with the flap deflection. In a previous 2D study,1 the effect of camber was investigated and the results revealed some insight into the relative merit of various camber settings of the VCCTEF. The present state of the art has not advanced sufficiently to do a full 3-D viscous analysis of the whole NASA Generic Transport Model (GTM) wing with VCCTEF deployed with elastomers. Therefore, this study seeks to explore the local effects of three contiguous flap segments on lift and drag of a model devised here to determine possible trades among various flap deflections to achieve desired lift and drag results. Although this approach is an approximation, it provides new insights into the "local" effects of the relative deflections of the contiguous spanwise flap systems and various elastomer segment configurations. The present study is a natural extension of the 2-D study to assess these local 3-D effects. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and a mean aerodynamic chord (MAC) based Reynolds number of 30.734x10(exp 6) is simulated for an angle of attack (AoA) range of 0 to 6 deg. In the previous 2-D study, the calculations revealed that the parabolic arc camber (1x2x3) and circular arc camber (VCCTEF222) offered the best L
Composable Security Proof for Continuous-Variable Quantum Key Distribution with Coherent States
NASA Astrophysics Data System (ADS)
Leverrier, Anthony
2015-02-01
We give the first composable security proof for continuous-variable quantum key distribution with coherent states against collective attacks. Crucially, in the limit of large blocks the secret key rate converges to the usual value computed from the Holevo bound. Combining our proof with either the de Finetti theorem or the postselection technique then shows the security of the protocol against general attacks, thereby confirming the long-standing conjecture that Gaussian attacks are optimal asymptotically in the composable security framework. We expect that our parameter estimation procedure, which does not rely on any assumption about the quantum state being measured, will find applications elsewhere, for instance, for the reliable quantification of continuous-variable entanglement in finite-size settings.
Quantum hacking of a continuous-variable quantum-key-distribution system using a wavelength attack
NASA Astrophysics Data System (ADS)
Huang, Jing-Zheng; Weedbrook, Christian; Yin, Zhen-Qiang; Wang, Shuang; Li, Hong-Wei; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu
2013-06-01
The security proofs of continuous-variable quantum key distribution are based on the assumptions that the eavesdropper can neither act on the local oscillator nor control Bob's beam splitter. These assumptions may be invalid in practice due to potential imperfections in the implementations of such protocols. In this paper, we consider the problem of transmitting the local oscillator in a public channel and propose a wavelength attack which allows the eavesdropper to control the intensity transmission of Bob's beam splitter by switching the wavelength of the input light. Specifically we target continuous-variable quantum key distribution systems that use the heterodyne detection protocol using either direct or reverse reconciliation. Our attack is proved to be feasible and renders all of the final keys shared between the legitimate parties insecure, even if they have monitored the intensity of the local oscillator. To prevent our attack on commercial systems, a simple wavelength filter should be randomly added before performing monitoring detection.
NASA Astrophysics Data System (ADS)
Zhang, Yichen; Yu, Song; Guo, Hong
2015-11-01
We propose a modified no-switching continuous-variable quantum key distribution protocol by employing a practical noiseless linear amplifier at the receiver to increase the maximal transmission distance and tolerable excess noise. A security analysis is presented to derive the secure bound of the protocol in presence of a Gaussian noisy lossy channel. Simulation results show that the modified protocol can not only transmit longer distance and tolerate more channel excess noise than the original protocol, but also distribute more secure keys in the enhanced region where we define a critical point to separate the enhanced and degenerative region. This critical point presents the condition of using a practical noiseless linear amplifier in the no-switching continuous-variable quantum cryptography, which is meaningful and instructive to implement a practical experiment.
Finite-size analysis of a continuous-variable quantum key distribution
Leverrier, Anthony; Grangier, Philippe
2010-06-15
The goal of this paper is to extend the framework of finite-size analysis recently developed for quantum key distribution to continuous-variable protocols. We do not solve this problem completely here, and we mainly consider the finite-size effects on the parameter estimation procedure. Despite the fact that some questions are left open, we are able to give an estimation of the secret key rate for protocols which do not contain a postselection procedure. As expected, these results are significantly more pessimistic than those obtained in the asymptotic regime. However, we show that recent continuous-variable protocols are able to provide fully secure secret keys in the finite-size scenario, over distances larger than 50 km.
Unifying parameter estimation and the Deutsch-Jozsa algorithm for continuous variables
Zwierz, Marcin; Perez-Delgado, Carlos A.; Kok, Pieter
2010-10-15
We reveal a close relationship between quantum metrology and the Deutsch-Jozsa algorithm on continuous-variable quantum systems. We develop a general procedure, characterized by two parameters, that unifies parameter estimation and the Deutsch-Jozsa algorithm. Depending on which parameter we keep constant, the procedure implements either the parameter-estimation protocol or the Deutsch-Jozsa algorithm. The parameter-estimation part of the procedure attains the Heisenberg limit and is therefore optimal. Due to the use of approximate normalizable continuous-variable eigenstates, the Deutsch-Jozsa algorithm is probabilistic. The procedure estimates a value of an unknown parameter and solves the Deutsch-Jozsa problem without the use of any entanglement.
A New Integrated Weighted Model in SNOW-V10: Verification of Continuous Variables
NASA Astrophysics Data System (ADS)
Huang, Laura X.; Isaac, George A.; Sheng, Grant
2014-01-01
This paper presents the verification results of nowcasts of four continuous variables generated from an integrated weighted model and underlying Numerical Weather Prediction (NWP) models. Real-time monitoring of fast changing weather conditions and the provision of short term forecasts, or nowcasts, in complex terrain within coastal regions is challenging to do with sufficient accuracy. A recently developed weighting, evaluation, bias correction and integration system was used in the Science of Nowcasting Olympic Weather for Vancouver 2010 project to generate integrated weighted forecasts (INTW) out to 6 h. INTW forecasts were generated with in situ observation data and background gridded forecasting data from Canadian high-resolution deterministic NWP system with three nested grids at 15-, 2.5- and 1-km horizontal grid-spacing configurations. In this paper, the four variables of temperature, relative humidity, wind speed and wind gust are treated as continuous variables for verifying the INTW forecasts. Fifteen sites were selected for the comparison of the model performances. The results of the study show that integrating surface observation data with the NWP forecasts produce better statistical scores than using either the NWP forecasts or an objective analysis of observed data alone. Overall, integrated observation and NWP forecasts improved forecast accuracy for the four continuous variables. The mean absolute errors from the INTW forecasts for the entire test period (12 February to 21 March 2010) are smaller than those from NWP forecasts with three configurations. The INTW is the best and most consistent performer among all models regardless of location and variable analyzed.
Simple proof of the quantum benchmark fidelity for continuous-variable quantum devices
Namiki, Ryo
2011-04-15
An experimental success criterion for continuous-variable quantum teleportation and memory is to surpass the limit of the average fidelity achieved by classical measure-and-prepare schemes with respect to a Gaussian-distributed set of coherent states. We present an alternative proof of the classical limit based on the familiar notions of state-channel duality and partial transposition. The present method enables us to produce a quantum-domain criterion associated with a given set of measured fidelities.
NASA Astrophysics Data System (ADS)
Wang, Tianyi; Yu, Song; Gu, Wanyi
2016-03-01
In continuous-variable quantum key distribution, detectors are necessarily coarse grained and of finite range. We analyze the impact of both features and demonstrate that while coarse graining adds a fixed error to the estimated excess noise, finite range degrades the estimation accuracy of both transmission and excess noise. Moreover, the inaccurate estimation due to finite range may results in secret key rate underestimation, even misjudgment of security. To compensate these consequences, tuning the modulation variance is a possible way.
Takei, Nobuyuki; Yonezawa, Hidehiro; Aoki, Takao; Furusawa, Akira
2005-06-10
We experimentally demonstrate continuous-variable quantum teleportation beyond the no-cloning limit. We teleport a coherent state and achieve the fidelity of 0.70 +/- 0.02 that surpasses the no-cloning limit of 2/3. Surpassing the limit is necessary to transfer the nonclassicality of an input quantum state. By using our high-fidelity teleporter, we demonstrate entanglement swapping, namely, teleportation of quantum entanglement, as an example of transfer of nonclassicality. PMID:16090375
Graphical rule of transforming continuous-variable graph states by local homodyne detection
Zhang Jing
2010-09-15
Graphical rule, describing that any single-mode homodyne detection turns a given continuous-variable (CV) graph state into a new one, is presented. Employing two simple graphical rules--local complement operation and vertex deletion (single quadrature-amplitude x measurement)--the graphical rule for any single-mode quadrature component measurement can be obtained. The shape of CV weighted graph state may be designed and constructed easily from a given larger graph state by applying this graphical rule.
Gaussian interferometric power as a measure of continuous-variable non-Markovianity
NASA Astrophysics Data System (ADS)
Souza, Leonardo A. M.; Dhar, Himadri Shekhar; Bera, Manabendra Nath; Liuzzo-Scorpo, Pietro; Adesso, Gerardo
2015-11-01
We investigate the non-Markovianity of continuous-variable Gaussian quantum channels through the evolution of an operational metrological quantifier, namely, the Gaussian interferometric power, which captures the minimal precision that can be achieved using bipartite Gaussian probes in a black-box phase estimation setup, where the phase shift generator is a priori unknown. We observe that the monotonicity of the Gaussian interferometric power under the action of local Gaussian quantum channels on the ancillary arm of the bipartite probes is a natural indicator of Markovian dynamics; consequently, its breakdown for specific maps can be used to construct a witness and an effective quantifier of non-Markovianity. In our work, we consider two paradigmatic Gaussian models, the damping master equation and the quantum Brownian motion, and identify analytically and numerically the parameter regimes that give rise to non-Markovian dynamics. We then quantify the degree of non-Markovianity of the channels in terms of Gaussian interferometric power, showing, in particular, that even nonentangled probes can be useful to witness non-Markovianity. This establishes an interesting link between the dynamics of bipartite continuous-variable open systems and their potential for optical interferometry. The results are an important supplement to the recent research on characterization of non-Markovianity in continuous-variable systems.
ERIC Educational Resources Information Center
Boletin del Centro Nacional de Documentacion e Informacion Educativa, 1970
1970-01-01
This document describes the teacher education reform implemented in Argentina beginning in 1968. Details of the changes are provided for: types of schools and degrees, new programs, admission criteria, career training opportunities, special fields, advanced and continuing education, and opportunities for educational research and experiments. (VM)
Continued advancement of the programming language HAL to an operational status
NASA Technical Reports Server (NTRS)
1971-01-01
The continued advancement of the programming language HAL to operational status is reported. It is demonstrated that the compiler itself can be written in HAL. A HAL-in-HAL experiment proves conclusively that HAL can be used successfully as a compiler implementation tool.
Correction of walk-off induced wavefront distortion for continuous-variable applications
NASA Astrophysics Data System (ADS)
Zou, Hongxin; Shen, Yong; Guo, Hong
2016-05-01
We theoretically and experimentally investigate wave front distortion in critically phase matched continuous-wave (CW) second harmonic generation (SHG). Due to the walk-off effect in the nonlinear crystal, the generated second harmonic is extremely elliptical and quite non-Gaussian, which causes a very low matching and coupling efficiency in experiment. Cylindrical lenses and walk-off compensating crystals are adopted to correct distorted wave fronts, and obtain a good TEM00 mode efficiency. Theoretically we simulate the correction effect of 266nm laser generated with SHG. The experiment results accord well with theoretical simulation and above 80 percent TEM00 component is obtained for 266nm continuous wave laser with 4.8 degree walk-off angle in BBO crystal. After that, an optical mode cleaner is used to obtain an ideal Gaussian mode. With these treatments, the generated second harmonic can be utilized in continuous-variable regime, where almost perfect mode matching is demanded.
Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control
NASA Technical Reports Server (NTRS)
Nguyen, Nhan T. (Inventor)
2016-01-01
An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.
Use of generalised additive models to categorise continuous variables in clinical prediction
2013-01-01
Background In medical practice many, essentially continuous, clinical parameters tend to be categorised by physicians for ease of decision-making. Indeed, categorisation is a common practice both in medical research and in the development of clinical prediction rules, particularly where the ensuing models are to be applied in daily clinical practice to support clinicians in the decision-making process. Since the number of categories into which a continuous predictor must be categorised depends partly on the relationship between the predictor and the outcome, the need for more than two categories must be borne in mind. Methods We propose a categorisation methodology for clinical-prediction models, using Generalised Additive Models (GAMs) with P-spline smoothers to determine the relationship between the continuous predictor and the outcome. The proposed method consists of creating at least one average-risk category along with high- and low-risk categories based on the GAM smooth function. We applied this methodology to a prospective cohort of patients with exacerbated chronic obstructive pulmonary disease. The predictors selected were respiratory rate and partial pressure of carbon dioxide in the blood (PCO2), and the response variable was poor evolution. An additive logistic regression model was used to show the relationship between the covariates and the dichotomous response variable. The proposed categorisation was compared to the continuous predictor as the best option, using the AIC and AUC evaluation parameters. The sample was divided into a derivation (60%) and validation (40%) samples. The first was used to obtain the cut points while the second was used to validate the proposed methodology. Results The three-category proposal for the respiratory rate was ≤ 20;(20,24];> 24, for which the following values were obtained: AIC=314.5 and AUC=0.638. The respective values for the continuous predictor were AIC=317.1 and AUC=0.634, with no statistically
Continuous twin screw granulation: influence of process variables on granule and tablet quality.
Vercruysse, J; Córdoba Díaz, D; Peeters, E; Fonteyne, M; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C
2012-09-01
The aim of the current study was to screen theophylline (125 mg) tablets manufactured via twin screw granulation in order to improve process understanding and knowledge of process variables that determine granule and tablet quality. A premix of theophylline anhydrate, α-lactose monohydrate and PVP (ratio: 30/67.5/2.5,w/w) was granulated with demineralized water. Experiments were done using the high-shear wet granulation module (based on twin screw granulation) of the ConsiGma™-25 unit (a continuous tablet manufacturing system) for particle size enlargement. After drying, granules were compressed using a MODUL™ P tablet press (compression force: 10 kN, tablet diameter: 12 mm). Using a D-optimal experimental design, the effect of several process variables (throughput (10-25 kg/h), screw speed (600-950 rpm), screw configuration (number (2, 4, 6 and 12) and angle (30°, 60° and 90°) of kneading elements), barrel temperature (25-40°C) and method of binder addition (dry versus wet)) on the granulation process (torque and temperature increase in barrel wall), granule (particle size distribution, friability and flowability) and tablet (tensile strength, porosity, friability, disintegration time and dissolution) quality was evaluated. The results showed that the quality of granules and tablets can be optimized by adjusting specific process variables (number of kneading elements, barrel temperature and binder addition method) during a granulation process using a continuous twin screw granulator. PMID:22687571
Yukawa, Mitsuyoshi; Miyata, Kazunori; Mizuta, Takahiro; Yonezawa, Hidehiro; Marek, Petr; Filip, Radim; Furusawa, Akira
2013-03-11
We develop an experimental scheme based on a continuous-wave (cw) laser for generating arbitrary superpositions of photon number states. In this experiment, we successfully generate superposition states of zero to three photons, namely advanced versions of superpositions of two and three coherent states. They are fully compatible with developed quantum teleportation and measurement-based quantum operations with cw lasers. Due to achieved high detection efficiency, we observe, without any loss correction, multiple areas of negativity of Wigner function, which confirm strongly nonclassical nature of the generated states. PMID:23482124
Continuous-variable quantum computation with spatial degrees of freedom of photons
Tasca, D. S.; Gomes, R. M.; Toscano, F.; Souto Ribeiro, P. H.; Walborn, S. P.
2011-05-15
We discuss the use of the transverse spatial degrees of freedom of photons propagating in the paraxial approximation for continuous-variable information processing. Given the wide variety of linear optical devices available, a diverse range of operations can be performed on the spatial degrees of freedom of single photons. Here we show how to implement a set of continuous quantum logic gates which allow for universal quantum computation. In contrast with the usual quadratures of the electromagnetic field, the entire set of single-photon gates for spatial degrees of freedom does not require optical nonlinearity and, in principle, can be performed with a single device: the spatial light modulator. Nevertheless, nonlinear optical processes, such as four-wave mixing, are needed in the implementation of two-photon gates. The efficiency of these gates is at present very low; however, small-scale investigations of continuous-variable quantum computation are within the reach of current technology. In this regard, we show how novel cluster states for one-way quantum computing can be produced using spontaneous parametric down-conversion.
NASA Astrophysics Data System (ADS)
Opanchuk, B.; Arnaud, L.; Reid, M. D.
2014-06-01
We demonstrate the principle of one-sided device-independent continuous-variable (CV) quantum information. In situations of no trust, we show by enactment how the use of standard CV entanglement criteria can mislead Charlie into thinking that Alice and Bob share entanglement, when the data are actually generated classically using a local-hidden-variable theory based on the Wigner function. We distinguish between criteria that demonstrate CV entanglement, and criteria that demonstrate the CV Einstein-Podolsky-Rosen (EPR) steering paradox. We show that the latter, but not the former, are necessarily one-sided device-independent entanglement witnesses, and can be used by Charlie to signify genuine EPR entanglement, if he trusts only Alice. A monogamy result for the EPR steering paradox confirms the security of the shared amplitude values in that case.
Variable-Rate Ring Convolutional Coded Continuous Phase Modulation Using Puncturing
NASA Astrophysics Data System (ADS)
Zhang, Lei; Wu, Jun; Zhu, Aiming
2013-01-01
In this paper, puncturing technique is used to establish variable-rate ring convolutional coded continuous phase modulation (CPM) systems. Maximum likelihood sequence detectors over both AWGN channels and Rayleigh flat-fading channels are considered. The suggested system provides us with different rates and performance when simple adjustment is taken to the puncturing matrix. Since the performance of the first error event of this system is represented by normalized minimum squared Euclidean distance (NMSED), some typical codes with maximum NMSED are searched and given. The performance of symbol error rate for the suggested system is simulated using computer software, and the results show that this system provides good performance of symbol error rate with variable-rate capabilities in time varying channels. Furthermore, simulation results also prove that the transmission efficiency increases when code rate is decreasing.
Development of a new adaptive ordinal approach to continuous-variable probabilistic optimization.
Romero, Vicente JosÔe; Chen, Chun-Hung (George Mason University, Fairfax, VA)
2006-11-01
A very general and robust approach to solving continuous-variable optimization problems involving uncertainty in the objective function is through the use of ordinal optimization. At each step in the optimization problem, improvement is based only on a relative ranking of the uncertainty effects on local design alternatives, rather than on precise quantification of the effects. One simply asks ''Is that alternative better or worse than this one?'' -not ''HOW MUCH better or worse is that alternative to this one?'' The answer to the latter question requires precise characterization of the uncertainty--with the corresponding sampling/integration expense for precise resolution. However, in this report we demonstrate correct decision-making in a continuous-variable probabilistic optimization problem despite extreme vagueness in the statistical characterization of the design options. We present a new adaptive ordinal method for probabilistic optimization in which the trade-off between computational expense and vagueness in the uncertainty characterization can be conveniently managed in various phases of the optimization problem to make cost-effective stepping decisions in the design space. Spatial correlation of uncertainty in the continuous-variable design space is exploited to dramatically increase method efficiency. Under many circumstances the method appears to have favorable robustness and cost-scaling properties relative to other probabilistic optimization methods, and uniquely has mechanisms for quantifying and controlling error likelihood in design-space stepping decisions. The method is asymptotically convergent to the true probabilistic optimum, so could be useful as a reference standard against which the efficiency and robustness of other methods can be compared--analogous to the role that Monte Carlo simulation plays in uncertainty propagation.
Security of two-way continuous-variable quantum key distribution with source noise
NASA Astrophysics Data System (ADS)
Wang, Tianyi; Yu, Song; Zhang, Yi-Chen; Gu, Wanyi; Guo, Hong
2014-11-01
We investigate the security of reverse reconciliation two-way continuous-variable quantum key distribution with source noise at both legitimate sides. Because the source noise originates from imperfect devices, we ascribe it to the legitimate sides rather than the eavesdropper. The trusted model consists of a thermal noise injected into a beam splitter. The expressions of secret key rate are derived against collective entangling cloner attacks for homodyne and heterodyne detections. Simulation results show that by applying the trusted model, the security bound of the reverse reconciliation two-way protocols can be tightened, while the advantage over one-way protocols still maintains.
Robust shot-noise measurement for continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Kunz-Jacques, Sébastien; Jouguet, Paul
2015-02-01
We study a practical method to measure the shot noise in real time in continuous-variable quantum key distribution systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity since it affects in particular the computation of the excess noise (i.e., noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks relying on faking the estimated value of the shot noise to hide an intercept and resend strategy were proposed. Here, we provide experimental evidence that our method can defeat the saturation attack and the wavelength attack.
Family of continuous-variable entanglement criteria using general entropy functions
Saboia, A.; Toscano, F.; Walborn, S. P.
2011-03-15
We derive a family of entanglement criteria for continuous-variable systems based on the Renyi entropy of complementary distributions. We show that these entanglement witnesses can be more sensitive than those based on second-order moments, as well as previous tests involving the Shannon entropy [Phys. Rev. Lett. 103, 160505 (2009)]. We extend our results to include the case of discrete sampling. We provide several numerical results which show that our criteria can be used to identify entanglement in a number of experimentally relevant quantum states.
Family of continuous-variable entanglement criteria using general entropy functions
NASA Astrophysics Data System (ADS)
Saboia, A.; Toscano, F.; Walborn, S. P.
2011-03-01
We derive a family of entanglement criteria for continuous-variable systems based on the Rényi entropy of complementary distributions. We show that these entanglement witnesses can be more sensitive than those based on second-order moments, as well as previous tests involving the Shannon entropy [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.103.160505 103, 160505 (2009)]. We extend our results to include the case of discrete sampling. We provide several numerical results which show that our criteria can be used to identify entanglement in a number of experimentally relevant quantum states.
Blandino, Rémi; Etesse, Jean; Grangier, Philippe; Leverrier, Anthony; Barbieri, Marco; Tualle-Brouri, Rosa
2014-12-04
We show that the maximum transmission distance of continuous-variable quantum key distribution in presence of a Gaussian noisy lossy channel can be arbitrarily increased using a heralded noiseless linear amplifier. We explicitly consider a protocol using amplitude and phase modulated coherent states with reverse reconciliation. Assuming that the secret key rate drops to zero for a line transmittance T{sub lim}, we find that a noiseless amplifier with amplitude gain g can improve this value to T{sub lim}/g{sup 2}, corresponding to an increase in distance proportional to log g. We also show that the tolerance against noise is increased.
Frank, A.A.
1984-07-10
A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine. 4 figs.
Implementation of a long range, distributed-volume, continuously variable turbulence generator.
DiComo, Gregory; Helle, Michael; Peñano, Joe; Ting, Antonio; Schmitt-Sody, Andreas; Elle, Jennifer
2016-07-01
We have constructed a 180-m-long distributed, continuously variable atmospheric turbulence generator to study high-power laser beam propagation. This turbulence generator operates on the principle of free convection from a heated surface placed below the entire propagation path of the beam, similar to the situation in long-distance horizontal propagation for laser communications, power beaming, or directed energy applications. The turbulence produced by this generator has been characterized through constant-temperature anemometry, as well as by the scintillation of a low-power laser beam. PMID:27409209
Controlling Continuous-Variable Quantum Key Distribution with Tuned Linear Optics Cloning Machines
NASA Astrophysics Data System (ADS)
Guo, Ying; Qiu, Deli; Huang, Peng; Zeng, Guihua
2015-09-01
We show that the tolerable excess noise can be elegantly controlled while inserting a tunable linear optics cloning machine (LOCM) for continuous-variable key distribution (CVQKD). The LOCM-tuned noise can be stabilized to an optimal value by the reference partner of reconciliation to guarantee the high secret key rate. Simulation results show that there is a considerable improvement of the performance for the LOCM-based CVQKD protocol in terms of the secret rate while making a fine balance between the secret key rate and the transmission distance with the dynamically tuned parameters in suitable ranges.
NASA Astrophysics Data System (ADS)
Ray, Megan R.; van Enk, S. J.
2013-10-01
In continuous-variable quantum information processing, detectors are necessarily coarse grained and of finite range. We discuss how, especially, the latter feature is a bug and may easily lead to overoptimistic estimates of entanglement and of security when missed data outside the detector range are ignored. We demonstrate that a straightforward worst-case analysis is sufficient to avoid false positive statements about entanglement. We show that, for our worst-case analysis, entropic separability or security criteria are much superior to variance-based criteria.
Frank, Andrew A.
1984-01-01
A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.
Long-distance continuous-variable quantum key distribution with efficient channel estimation
NASA Astrophysics Data System (ADS)
Ruppert, László; Usenko, Vladyslav C.; Filip, Radim
2014-12-01
We investigate the main limitations which prevent the continuous-variable quantum key distribution protocols from achieving long distances in the finite-size setting. We propose a double-modulation protocol which allows using each state for both channel estimation and key distribution. As opposed to the standard method, we optimize the parameters of the protocol and consider squeezed as well as coherent states as a signal. By optimally combining the resources the key rate can approach the theoretical limit for long distances, and one can obtain about ten times higher key rate using ten times shorter block size than in the current state-of-the-art implementation.
NASA Astrophysics Data System (ADS)
Cheung, Wai Ming; Liao, Wei-Hsin
2013-04-01
The use of magnetorheological (MR) fluids in vehicles has been gaining popular recently due to its controllable nature, which gives automotive designers more dimensions of freedom in functional designs. However, not much attention has been paid to apply it to bicycles. This paper is aimed to study the feasibility of applying MR fluids in different dynamic parts of a bicycle such as the transmission and braking systems. MR continuous variable transmission (CVT) and power generator assisted in braking systems were designed and analyzed. Both prototypes were fabricated and tested to evaluate their performances. Experimental results showed that the proposed designs are promising to be used in bicycles.
Continuous-variable quantum-key-distribution protocols with a non-Gaussian modulation
Leverrier, Anthony; Grangier, Philippe
2011-04-15
In this paper, we consider continuous-variable quantum-key-distribution (QKD) protocols which use non-Gaussian modulations. These specific modulation schemes are compatible with very efficient error-correction procedures, hence allowing the protocols to outperform previous protocols in terms of achievable range. In their simplest implementation, these protocols are secure for any linear quantum channels (hence against Gaussian attacks). We also show how the use of decoy states makes the protocols secure against arbitrary collective attacks, which implies their unconditional security in the asymptotic limit.
Channel purification via continuous-variable quantum teleportation with Gaussian postselection
NASA Astrophysics Data System (ADS)
Blandino, Rémi; Walk, Nathan; Lund, Austin P.; Ralph, Timothy C.
2016-01-01
We present a protocol based on continuous-variable quantum teleportation and Gaussian postselection that can be used to correct errors introduced by a lossy channel. We first show that the global transformation enacted by the protocol is equivalent to an effective system composed of a noiseless amplification (or attenuation), and an effective quantum channel, which can in theory have no loss and an amount of thermal noise arbitrarily small, hence tending to an identity channel. An application of our protocol is the probabilistic purification of quantum non-Gaussian states using only Gaussian operations.
Continuous-variable quantum cryptography is secure against non-Gaussian attacks.
Grosshans, Frédéric; Cerf, Nicolas J
2004-01-30
A general study of arbitrary finite-size coherent attacks against continuous-variable quantum cryptographic schemes is presented. It is shown that, if the size of the blocks that can be coherently attacked by an eavesdropper is fixed and much smaller than the key size, then the optimal attack for a given signal-to-noise ratio in the transmission line is an individual Gaussian attack. Consequently, non-Gaussian coherent attacks do not need to be considered in the security analysis of such quantum cryptosystems. PMID:14995411
Continuous Multi-Parameter Heart Rate Variability Analysis Heralds Onset of Sepsis in Adults
Ahmad, Saif; Ramsay, Tim; Huebsch, Lothar; Flanagan, Sarah; McDiarmid, Sheryl; Batkin, Izmail; McIntyre, Lauralyn; Sundaresan, Sudhir R.; Maziak, Donna E.; Shamji, Farid M.; Hebert, Paul; Fergusson, Dean; Tinmouth, Alan; Seely, Andrew J. E.
2009-01-01
Background Early diagnosis of sepsis enables timely resuscitation and antibiotics and prevents subsequent morbidity and mortality. Clinical approaches relying on point-in-time analysis of vital signs or lab values are often insensitive, non-specific and late diagnostic markers of sepsis. Exploring otherwise hidden information within intervals-in-time, heart rate variability (HRV) has been documented to be both altered in the presence of sepsis, and correlated with its severity. We hypothesized that by continuously tracking individual patient HRV over time in patients as they develop sepsis, we would demonstrate reduced HRV in association with the onset of sepsis. Methodology/Principal Findings We monitored heart rate continuously in adult bone marrow transplant (BMT) patients (n = 21) beginning a day before their BMT and continuing until recovery or withdrawal (12±4 days). We characterized HRV continuously over time with a panel of time, frequency, complexity, and scale-invariant domain techniques. We defined baseline HRV as mean variability for the first 24 h of monitoring and studied individual and population average percentage change (from baseline) over time in diverse HRV metrics, in comparison with the time of clinical diagnosis and treatment of sepsis (defined as systemic inflammatory response syndrome along with clinically suspected infection requiring treatment). Of the 21 patients enrolled, 4 patients withdrew, leaving 17 patients who completed the study. Fourteen patients developed sepsis requiring antibiotic therapy, whereas 3 did not. On average, for 12 out of 14 infected patients, a significant (25%) reduction prior to the clinical diagnosis and treatment of sepsis was observed in standard deviation, root mean square successive difference, sample and multiscale entropy, fast Fourier transform, detrended fluctuation analysis, and wavelet variability metrics. For infected patients (n = 14), wavelet HRV demonstrated a 25% drop from baseline 35 h
Zhou, Jian; Li, Hong; Ran, Xingwu; Yang, Wenying; Li, Qiang; Peng, Yongde; Li, Yanbing; Gao, Xin; Luan, Xiaojun; Wang, Weiqing; Jia, Weiping
2011-01-01
Summary Background Glycemic variability is increasingly recognized as an important issue in diabetes management. However, the lack of normative values may limit its applicability in the clinical setting. The objective of this study was to establish preliminary normal reference ranges for glycemic variability by analyzing continuous glucose monitoring (CGM) data obtained from healthy Chinese adults. Material/Methods Three-day CGM data were obtained from 434 healthy adults at 10 academic hospitals throughout China. Glycemic variability was calculated as the 24-hour mean amplitude of glycemic excursions (MAGE) and standard deviations (SD) of blood glucose readings. Results 434 healthy subjects (male 213, female 221; age 43±14, 20–69 years old; BMI 21.8±1.7 kg/m2, 18.5–24.9 kg/m2) completed the study. MAGE and SD values for the 434 healthy subjects were 1.73 (1.08) mmol/L and 0.75 (0.42) mmol/L [median (interquartile range)], respectively. In both men and women, MAGE and SD tended to increase with age. Neither MAGE nor SD showed a significant difference between men and women. Values for both parameters were non-normally distributed within the population. The 95th percentiles of MAGE and SD were 3.86 and 1.40 mmol/L, respectively. These values were adopted as the upper limits of normal. Conclusions MAGE <3.9 mmol/L and SD <1.4 mmol/L are recommended as the normal reference ranges for glycemic variability in Chinese adults. The values established in this study may facilitate the adoption of glycemic variability as a metric of overall glycemic control in diabetes. PMID:21169911
Continuous-variable entanglement distillation of non-Gaussian mixed states
Dong Ruifang; Lassen, Mikael; Heersink, Joel; Marquardt, Christoph; Leuchs, Gerd; Andersen, Ulrik L.
2010-07-15
Many different quantum-information communication protocols such as teleportation, dense coding, and entanglement-based quantum key distribution are based on the faithful transmission of entanglement between distant location in an optical network. The distribution of entanglement in such a network is, however, hampered by loss and noise that is inherent in all practical quantum channels. Thus, to enable faithful transmission one must resort to the protocol of entanglement distillation. In this paper we present a detailed theoretical analysis and an experimental realization of continuous variable entanglement distillation in a channel that is inflicted by different kinds of non-Gaussian noise. The continuous variable entangled states are generated by exploiting the third order nonlinearity in optical fibers, and the states are sent through a free-space laboratory channel in which the losses are altered to simulate a free-space atmospheric channel with varying losses. We use linear optical components, homodyne measurements, and classical communication to distill the entanglement, and we find that by using this method the entanglement can be probabilistically increased for some specific non-Gaussian noise channels.
Kipnis, Victor; Freedman, Laurence S.; Carroll, Raymond J.; Midthune, Douglas
2015-01-01
SUMMARY Semicontinuous data in the form of a mixture of a large portion of zero values and continuously distributed positive values frequently arise in many areas of biostatistics. This study is motivated by the analysis of relationships between disease outcomes and intakes of episodically consumed dietary components. An important aspect of studies in nutritional epidemiology is that true diet is unobservable and commonly evaluated by food frequency questionnaires with substantial measurement error. Following the regression calibration approach for measurement error correction, unknown individual intakes in the risk model are replaced by their conditional expectations given mismeasured intakes and other model covariates. Those regression calibration predictors are estimated using short-term unbiased reference measurements in a calibration substudy. Since dietary intakes are often “energy-adjusted”, e.g., by using ratios of the intake of interest to total energy intake, the correct estimation of the regression calibration predictor for each energy-adjusted episodically consumed dietary component requires modeling short-term reference measurements of the component (a semicontinuous variable) and energy (a continuous variable) simultaneously in a bivariate model. In this paper, we develop such a bivariate model, together with its application to regression calibration. We illustrate the new methodology using data from the NIH-AARP Diet and Health Study (Schatzkin et al., 2001, American Journal of Epidemiology 154, 1119–1125), and also evaluate its performance in a simulation study. PMID:26332011
Wang, Chen-Pin; Jo, Booil; Brown, C. Hendricks
2014-01-01
We propose a principal stratification approach to assess causal effects in non-randomized longitudinal comparative effectiveness studies with a binary endpoint outcome and repeated measures of a continuous intermediate variable. Our method is an extension of the principal stratification approach by Lin et al. [10,11], originally proposed for a longitudinal randomized study to assess the treatment effect of a continuous outcome adjusting for the heterogeneity of a repeatedly measured binary intermediate variable. Our motivation for this work comes from a comparison of the effect of two glucose-lowering medications on a clinical cohort of patients with type 2 diabetes. Here we consider a causal inference problem assessing how well the two medications work relative to one another on two binary endpoint outcomes: cardiovascular disease related hospitalization and all-cause mortality. Clinically, these glucose-lowering medications can have differential effects on the intermediate outcome, glucose level over time. Ultimately we want to compare medication effects on the endpoint outcomes among individuals in the same glucose trajectory stratum while accounting for the heterogeneity in baseline covariates (i.e., to obtain “principal effects” on the endpoint outcomes). The proposed method involves a 3-step model estimation procedure. Step 1 identifies principal strata associated with the intermediate variable using hybrid growth mixture modeling analyses [13]. Step 2 obtains the stratum membership using the pseudoclass technique [17,18], and derives propensity scores for treatment assignment. Step 3 obtains the stratum-specific treatment effect on the endpoint outcome weighted by inverse propensity probabilities derived from Step 2. PMID:24577715
Royston, Patrick; Sauerbrei, Willi
2014-11-30
In a large simulation study reported in a companion paper, we investigated the significance levels of 21 methods for investigating interactions between binary treatment and a continuous covariate in a randomised controlled trial. Several of the methods were shown to have inflated type 1 errors. In the present paper, we report the second part of the simulation study in which we investigated the power of the interaction procedures for two sample sizes and with two distributions of the covariate (well and badly behaved). We studied several methods involving categorisation and others in which the covariate was kept continuous, including fractional polynomials and splines. We believe that the results provide sufficient evidence to recommend the multivariable fractional polynomial interaction procedure as a suitable approach to investigate interactions of treatment with a continuous variable. If subject-matter knowledge gives good arguments for a non-monotone treatment effect function, we propose to use a second-degree fractional polynomial approach, but otherwise a first-degree fractional polynomial (FP1) function with added flexibility (FLEX3) is the method of choice. The FP1 class includes the linear function, and the selected functions are simple, understandable, and transferable. Furthermore, software is available. We caution that investigation of interactions in one dataset can only be interpreted in a hypothesis-generating sense and needs validation in new data. PMID:25244679
Advanced supersonic propulsion study, phases 3 and 4. [variable cycle engines
NASA Technical Reports Server (NTRS)
Allan, R. D.; Joy, W.
1977-01-01
An evaluation of various advanced propulsion concepts for supersonic cruise aircraft resulted in the identification of the double-bypass variable cycle engine as the most promising concept. This engine design utilizes special variable geometry components and an annular exhaust nozzle to provide high take-off thrust and low jet noise. The engine also provides good performance at both supersonic cruise and subsonic cruise. Emission characteristics are excellent. The advanced technology double-bypass variable cycle engine offers an improvement in aircraft range performance relative to earlier supersonic jet engine designs and yet at a lower level of engine noise. Research and technology programs required in certain design areas for this engine concept to realize its potential benefits include refined parametric analysis of selected variable cycle engines, screening of additional unconventional concepts, and engine preliminary design studies. Required critical technology programs are summarized.
NASA Astrophysics Data System (ADS)
Williams, Thomas R.; Saladyga, Michael
2011-05-01
Preface; Part I. Pioneers in Variable Star Astronomy Prior to 1909: 1. The emergence of variable star astronomy - a need for observations; 2. A need for observers; Part II. The Founding of the AAVSO - The William Tyler Olcott Era: 3. The amateur's amateur; 4. Amateurs in the service of science; Part III. The Leon Campbell Era: 5. Leon Campbell to the rescue; 6. Formalizing relationships; 7. The Pickering Memorial Endowment; 8. Fading of the Old Guard; 9. Growing pains and distractions; Part IV. The Service Bureau - The Margaret Mayall Era: 10. Learning about independence; 11. Eviction from Harvard College Observatory; 12. Actions and reactions; 13. In search of a home; 14. Survival on Brattle Street; 15. AAVSO achievements; 16. Breathing room on Concord Avenue; Part V. Analysis and Science: The Janet Mattei Era: 17. The growth of a director; 18. Learning the ropes the hard way; 19. Managing with renewed confidence; 20. Expanding the scientific charter; Part VI. Accelerating Observational Science - The Arne Henden Era: 21. Bridging the gap; 22. Accelerating the science - the Henden era begins; Epilogue; Appendices; Index.
Estimation of output-channel noise for continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Thearle, Oliver; Assad, Syed M.; Symul, Thomas
2016-04-01
Estimation of channel parameters is important for extending the range and increasing the key rate of continuous-variable quantum key distribution protocols. We propose an estimator for the channel noise parameter based on the method-of-moments. The method-of-moments finds an estimator from the moments of the output distribution of the protocol. This estimator has the advantage of being able to use all of the states shared between Alice and Bob. Other estimators are limited to a smaller publicly revealed subset of the states. The proposed estimator has a lower variance for the high-loss channel than what has previously been proposed. We show that the method-of-moments estimator increases the key rate by up to an order of magnitude at the maximum transmission of the protocol.
NASA Astrophysics Data System (ADS)
Lv, Geli; Huang, Dazu; Guo, Ying
2016-05-01
The intensities of signal and local oscillator (LO) can be elegantly manipulated for the noise-based quantum system while manipulating the wavelength-dependent modulation in source to increase the performance of the continuous-variable key distribution in terms of the secret key rate and maximal transmission distance. The source-based additional noises can be tuned and stabilized to the suitable values to eliminate the effect of the LO fluctuations and defeat the potential attacks in imperfect quantum channels. It is firmly proved that the secret key rate can be manipulated in source over imperfect channels by the intensities of signal and LO with different wavelengths, which have an effect on the optimal signal-to-noise ratio of the heterodyne detectors resulting from the detection efficiency and the additional electronic noise as well. Simulation results show that there is a nice balance between the secret key rate and the maximum transmission distance.
NASA Astrophysics Data System (ADS)
Li, Zhengyu; Zhang, Yichen; Wang, Xiangyu; Xu, Bingjie; Peng, Xiang; Guo, Hong
2016-01-01
Photon subtraction can enhance the performance of continuous-variable quantum key distribution (CV QKD). However, the enhancement effect will be reduced by the imperfections of practical devices, especially the limited efficiency of a single-photon detector. In this paper, we propose a non-Gaussian postselection method to emulate the photon substraction used in coherent-state CV QKD protocols. The virtual photon subtraction not only can avoid the complexity and imperfections of a practical photon-subtraction operation, which extends the secure transmission distance as the ideal case does, but also can be adjusted flexibly according to the channel parameters to optimize the performance. Furthermore, our preliminary tests on the information reconciliation suggest that in the low signal-to-noise ratio regime, the performance of reconciliating the postselected non-Gaussian data is better than that of the Gaussian data, which implies the feasibility of implementing this method practically.
NASA Astrophysics Data System (ADS)
Wang, Chao; Huang, Peng; Huang, Duan; Lin, Dakai; Zeng, Guihua
2016-02-01
Practical security of the continuous-variable quantum key distribution (CVQKD) system with finite sampling bandwidth of analog-to-digital converter (ADC) at the receiver's side is investigated. We find that the finite sampling bandwidth effects may decrease the lower bound of secret key rate without awareness of the legitimate communicators. This leaves security loopholes for Eve to attack the system. In addition, this effect may restrains the linear relationship of secret key bit rate with repetition rate of the system; subsequently, there is a saturation value for the secret key bit rate with the repetition rate. To resist such kind of effects, we propose a dual sampling detection approach in which two ADCs are employed so that the finite sampling bandwidth effects are removed.
Field demonstration of a continuous-variable quantum key distribution network.
Huang, Duan; Huang, Peng; Li, Huasheng; Wang, Tao; Zhou, Yingming; Zeng, Guihua
2016-08-01
We report on what we believe is the first field implementation of a continuous-variable quantum key distribution (CV-QKD) network with point-to-point configuration. Four QKD nodes are deployed on standard communication infrastructures connected with commercial telecom optical fiber. Reliable key exchange is achieved in the wavelength-division-multiplexing CV-QKD network. The impact of a complex and volatile field environment on the excess noise is investigated, since excess noise controlling and reduction is arguably the major issue pertaining to distance and the secure key rate. We confirm the applicability and verify the maturity of the CV-QKD network in a metropolitan area, thus paving the way for a next-generation global secure communication network. PMID:27472606
Quantifying non-Markovianity of continuous-variable Gaussian dynamical maps
Vasile, Ruggero; Maniscalco, Sabrina; Paris, Matteo G. A.; Breuer, Heinz-Peter; Piilo, Jyrki
2011-11-15
We introduce a non-Markovianity measure for continuous-variable open quantum systems based on the idea put forward in H.-P. Breuer et al.[Phys. Rev. Lett. 103, 210401 (2009);], that is, by quantifying the flow of information from the environment back to the open system. Instead of the trace distance we use here the fidelity to assess distinguishability of quantum states. We employ our measure to evaluate non-Markovianity of two paradigmatic Gaussian channels: the purely damping channel and the quantum Brownian motion channel with Ohmic environment. We consider different classes of Gaussian states and look for pairs of states maximizing the backflow of information. For coherent states we find simple analytical solutions, whereas for squeezed states we provide both exact numerical and approximate analytical solutions in the weak coupling limit.
Five-wave-packet quantum error correction based on continuous-variable cluster entanglement
NASA Astrophysics Data System (ADS)
Hao, Shuhong; Su, Xiaolong; Tian, Caixing; Xie, Changde; Peng, Kunchi
2015-10-01
Quantum error correction protects the quantum state against noise and decoherence in quantum communication and quantum computation, which enables one to perform fault-torrent quantum information processing. We experimentally demonstrate a quantum error correction scheme with a five-wave-packet code against a single stochastic error, the original theoretical model of which was firstly proposed by S. L. Braunstein and T. A. Walker. Five submodes of a continuous variable cluster entangled state of light are used for five encoding channels. Especially, in our encoding scheme the information of the input state is only distributed on three of the five channels and thus any error appearing in the remained two channels never affects the output state, i.e. the output quantum state is immune from the error in the two channels. The stochastic error on a single channel is corrected for both vacuum and squeezed input states and the achieved fidelities of the output states are beyond the corresponding classical limit.
Photon-monitoring attack on continuous-variable quantum key distribution with source in middle
NASA Astrophysics Data System (ADS)
Wang, Yijun; Huang, Peng; Guo, Ying; Huang, Dazu
2014-12-01
Motivated by a fact that the non-Gaussian operation may increase entanglement of an entangled system, we suggest a photon-monitoring attack strategy in the entanglement-based (EB) continuous-variable quantum key distribution (CVQKD) using the photon subtraction operations, where the entangled source originates from the center instead of one of the legal participants. It shows that an eavesdropper, Eve, can steal large information from participants after intercepting the partial beams with the photon-monitoring attach strategy. The structure of the proposed CVQKD protocol is useful in simply analyzing how quantum loss in imperfect channels can decrease the performance of the CVQKD protocol. The proposed attack strategy can be implemented under current technology, where a newly developed and versatile no-Gaussian operation can be well employed with the entangled source in middle in order to access to mass information in the EB CVQKD protocol, as well as in the prepare-and-measure (PM) CVQKD protocol.
Continuous variable quantum optical simulation for time evolution of quantum harmonic oscillators
NASA Astrophysics Data System (ADS)
Deng, Xiaowei; Hao, Shuhong; Guo, Hong; Xie, Changde; Su, Xiaolong
2016-03-01
Quantum simulation enables one to mimic the evolution of other quantum systems using a controllable quantum system. Quantum harmonic oscillator (QHO) is one of the most important model systems in quantum physics. To observe the transient dynamics of a QHO with high oscillation frequency directly is difficult. We experimentally simulate the transient behaviors of QHO in an open system during time evolution with an optical mode and a logical operation system of continuous variable quantum computation. The time evolution of an atomic ensemble in the collective spontaneous emission is analytically simulated by mapping the atomic ensemble onto a QHO. The measured fidelity, which is used for quantifying the quality of the simulation, is higher than its classical limit. The presented simulation scheme provides a new tool for studying the dynamic behaviors of QHO.
Distillation of mixed-state continuous-variable entanglement by photon subtraction
Zhang Shengli; Loock, Peter van
2010-12-15
We present a detailed theoretical analysis for the distillation of one copy of a mixed two-mode continuous-variable entangled state using beam splitters and coherent photon-detection techniques, including conventional on-off detectors and photon-number-resolving detectors. The initial Gaussian mixed-entangled states are generated by transmitting a two-mode squeezed state through a lossy bosonic channel, corresponding to the primary source of errors in current approaches to optical quantum communication. We provide explicit formulas to calculate the entanglement in terms of logarithmic negativity before and after distillation, including losses in the channel and the photon detection, and show that one-copy distillation is still possible even for losses near the typical fiber channel attenuation length. A lower bound for the transmission coefficient of the photon-subtraction beam splitter is derived, representing the minimal value that still allows to enhance the entanglement.
NASA Astrophysics Data System (ADS)
Guo, Ying; Lv, Geli; Zeng, Guihua
2015-11-01
We show that the tolerable excess noise can be dynamically balanced in source preparation while inserting a tunable linear optics cloning machine (LOCM) for balancing the secret key rate and the maximal transmission distance of continuous-variable quantum key distribution (CVQKD). The intensities of source noise are sensitive to the tunable LOCM and can be stabilized to the suitable values to eliminate the impact of channel noise and defeat the potential attacks even in the case of the degenerated linear optics amplifier (LOA). The LOCM-additional noise can be elegantly employed by the reference partner of reconciliation to regulate the secret key rate and the transmission distance. Simulation results show that there is a considerable improvement in the secret key rate of the LOCM-based CVQKD while providing a tunable LOCM for source preparation with the specified parameters in suitable ranges.
Controlling excess noise in fiber-optics continuous-variable quantum key distribution
Lodewyck, Jerome; Debuisschert, Thierry; Tualle-Brouri, Rosa; Grangier, Philippe
2005-11-15
We describe a continuous-variable coherent-states quantum-key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecommunications components, such as integrated-optics modulators, couplers and fast InGaAs photodiodes. The setup is composed of an emitter randomly modulating a coherent state in the complex plane with a doubly Gaussian distribution, and a receiver based on a shot-noise limited time-resolved homodyne detector. By using a reverse reconciliation protocol, the device can transfer a raw key rate up to 1 Mbit/s, with a proven security against Gaussian or non-Gaussian attacks. The dependence of the secret information rate of the present fiber setup is studied as a function of the line transmission and excess noise.
Controlling excess noise in fiber-optics continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Lodewyck, Jérôme; Debuisschert, Thierry; Tualle-Brouri, Rosa; Grangier, Philippe
2005-11-01
We describe a continuous-variable coherent-states quantum-key distribution system working at 1550nm , and entirely made of standard fiber optics and telecommunications components, such as integrated-optics modulators, couplers and fast InGaAs photodiodes. The setup is composed of an emitter randomly modulating a coherent state in the complex plane with a doubly Gaussian distribution, and a receiver based on a shot-noise limited time-resolved homodyne detector. By using a reverse reconciliation protocol, the device can transfer a raw key rate up to 1Mbit/s , with a proven security against Gaussian or non-Gaussian attacks. The dependence of the secret information rate of the present fiber setup is studied as a function of the line transmission and excess noise.
Security of continuous-variable quantum key distribution against general attacks
NASA Astrophysics Data System (ADS)
Leverrier, Anthony
2013-03-01
We prove the security of Gaussian continuous-variable quantum key distribution with coherent states against arbitrary attacks in the finite-size regime. In contrast to previously known proofs of principle (based on the de Finetti theorem), our result is applicable in the practically relevant finite-size regime. This is achieved using a novel proof approach, which exploits phase-space symmetries of the protocols as well as the postselection technique introduced by Christandl, Koenig and Renner (Phys. Rev. Lett. 102, 020504 (2009)). This work was supported by the SNF through the National Centre of Competence in Research ``Quantum Science and Technology'' and through Grant No. 200020-135048, the ERC (grant No. 258932), the Humbolt foundation and the F.R.S.-FNRS under project HIPERCOM.
Practical continuous-variable quantum key distribution without finite sampling bandwidth effects.
Li, Huasheng; Wang, Chao; Huang, Peng; Huang, Duan; Wang, Tao; Zeng, Guihua
2016-09-01
In a practical continuous-variable quantum key distribution system, finite sampling bandwidth of the employed analog-to-digital converter at the receiver's side may lead to inaccurate results of pulse peak sampling. Then, errors in the parameters estimation resulted. Subsequently, the system performance decreases and security loopholes are exposed to eavesdroppers. In this paper, we propose a novel data acquisition scheme which consists of two parts, i.e., a dynamic delay adjusting module and a statistical power feedback-control algorithm. The proposed scheme may improve dramatically the data acquisition precision of pulse peak sampling and remove the finite sampling bandwidth effects. Moreover, the optimal peak sampling position of a pulse signal can be dynamically calibrated through monitoring the change of the statistical power of the sampled data in the proposed scheme. This helps to resist against some practical attacks, such as the well-known local oscillator calibration attack. PMID:27607653
Continuous variable quantum optical simulation for time evolution of quantum harmonic oscillators
Deng, Xiaowei; Hao, Shuhong; Guo, Hong; Xie, Changde; Su, Xiaolong
2016-01-01
Quantum simulation enables one to mimic the evolution of other quantum systems using a controllable quantum system. Quantum harmonic oscillator (QHO) is one of the most important model systems in quantum physics. To observe the transient dynamics of a QHO with high oscillation frequency directly is difficult. We experimentally simulate the transient behaviors of QHO in an open system during time evolution with an optical mode and a logical operation system of continuous variable quantum computation. The time evolution of an atomic ensemble in the collective spontaneous emission is analytically simulated by mapping the atomic ensemble onto a QHO. The measured fidelity, which is used for quantifying the quality of the simulation, is higher than its classical limit. The presented simulation scheme provides a new tool for studying the dynamic behaviors of QHO. PMID:26961962
Vertical Aerosol Backscatter Variability from an Airborne Focused Continuous Wave CO2 Lidar
NASA Technical Reports Server (NTRS)
Jarzembski, Maurice A.; Srivastava, Vandana; Rothermel, Jeffry
1998-01-01
Atmospheric aerosol backscatter measurements using a continuous wave focused Doppler lidar at 9.1 micron wavelength were obtained over western North America and the Pacific Ocean during 13 - 26 September, 1995 as part of National Aeronautics and Space Administration's (NASA) Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission on board the NASA DC8 aircraft. Backscatter variability was measured for approximately 52 flight hours, covering equivalent horizontal distance of approximately 25,000 km in the troposphere. Quasi-vertical backscatter profiles were also obtained during various ascents and descents which ranged between approximately 0.1 to 12.0 km altitude. Aerosol haze layers were encountered at different altitudes. Similarities and differences for aerosol loading over land and over ocean were observed. A mid-tropospheric aerosol backscatter background mode was found with modal value approximately 1O(exp -10)/m/sr, consistent with previous airborne and ground-based datasets.
Continuous-variable quantum key distribution in non-Markovian channels
Vasile, Ruggero; Olivares, Stefano; Paris, MatteoG. A.; Maniscalco, Sabrina
2011-04-15
We address continuous-variable quantum key distribution (QKD) in non-Markovian lossy channels and show how the non-Markovian features may be exploited to enhance security and/or to detect the presence and the position of an eavesdropper along the transmission line. In particular, we suggest a coherent-state QKD protocol which is secure against Gaussian individual attacks based on optimal 1{yields}2 asymmetric cloning machines for arbitrarily low values of the overall transmission line. The scheme relies on specific non-Markovian properties, and cannot be implemented in ordinary Markovian channels characterized by uniform losses. Our results give a clear indication of the potential impact of non-Markovian effects in QKD.
Experimental study on discretely modulated continuous-variable quantum key distribution
Shen Yong; Zou Hongxin; Chen Pingxing; Yuan Jianmin; Tian Liang
2010-08-15
We present a discretely modulated continuous-variable quantum key distribution system in free space by using strong coherent states. The amplitude noise in the laser source is suppressed to the shot-noise limit by using a mode cleaner combined with a frequency shift technique. Also, it is proven that the phase noise in the source has no impact on the final secret key rate. In order to increase the encoding rate, we use broadband homodyne detectors and the no-switching protocol. In a realistic model, we establish a secret key rate of 46.8 kbits/s against collective attacks at an encoding rate of 10 MHz for a 90% channel loss when the modulation variance is optimal.
Quantum key distribution using continuous-variable non-Gaussian states
NASA Astrophysics Data System (ADS)
Borelli, L. F. M.; Aguiar, L. S.; Roversi, J. A.; Vidiella-Barranco, A.
2016-02-01
In this work, we present a quantum key distribution protocol using continuous-variable non-Gaussian states, homodyne detection and post-selection. The employed signal states are the photon added then subtracted coherent states (PASCS) in which one photon is added and subsequently one photon is subtracted from the field. We analyze the performance of our protocol, compared with a coherent state-based protocol, for two different attacks that could be carried out by the eavesdropper (Eve). We calculate the secret key rate transmission in a lossy line for a superior channel (beam-splitter) attack, and we show that we may increase the secret key generation rate by using the non-Gaussian PASCS rather than coherent states. We also consider the simultaneous quadrature measurement (intercept-resend) attack, and we show that the efficiency of Eve's attack is substantially reduced if PASCS are used as signal states.
Long-distance continuous-variable quantum key distribution with a Gaussian modulation
Jouguet, Paul; Kunz-Jacques, Sebastien; Leverrier, Anthony
2011-12-15
We designed high-efficiency error correcting codes allowing us to extract an errorless secret key in a continuous-variable quantum key distribution (CVQKD) protocol using a Gaussian modulation of coherent states and a homodyne detection. These codes are available for a wide range of signal-to-noise ratios on an additive white Gaussian noise channel with a binary modulation and can be combined with a multidimensional reconciliation method proven secure against arbitrary collective attacks. This improved reconciliation procedure considerably extends the secure range of a CVQKD with a Gaussian modulation, giving a secret key rate of about 10{sup -3} bit per pulse at a distance of 120 km for reasonable physical parameters.
Nonexistence of entangled continuous-variable Werner states with positive partial transpose
NASA Astrophysics Data System (ADS)
McNulty, Daniel; Tatham, Richard; Mišta, Ladislav
2014-03-01
We address an open question about the existence of entangled continuous-variable (CV) Werner states with positive partial transpose (PPT). We prove that no such state exists by showing that all PPT CV Werner states are separable. The separability follows by observing that these CV Werner states can be approximated by truncating the states into a finite-dimensional convex mixture of product states. In addition, the constituents of the product states comprise a generalized non-Gaussian measurement which gives, rather surprisingly, a strictly tighter upper bound on quantum discord than photon counting. These results uncover the presence of only negative partial transpose entanglement and illustrate the complexity of more general nonclassical correlations in this paradigmatic class of genuine non-Gaussian quantum states.
Midgley, S. L. W.; Olsen, M. K.; Bradley, A. S.; Pfister, O.
2010-11-15
We examine the feasibility of generating continuous-variable multipartite entanglement in an intracavity concurrent downconversion scheme that has been proposed for the generation of cluster states by Menicucci et al. [Phys. Rev. Lett. 101, 130501 (2008)]. By calculating optimized versions of the van Loock-Furusawa correlations we demonstrate genuine quadripartite entanglement and investigate the degree of entanglement present. Above the oscillation threshold the basic cluster state geometry under consideration suffers from phase diffusion. We alleviate this problem by incorporating a small injected signal into our analysis. Finally, we investigate squeezed joint operators. While the squeezed joint operators approach zero in the undepleted regime, we find that this is not the case when we consider the full interaction Hamiltonian and the presence of a cavity. In fact, we find that the decay of these operators is minimal in a cavity, and even depletion alone inhibits cluster state formation.
Continuous-variable dense coding via a general Gaussian state: Monogamy relation
NASA Astrophysics Data System (ADS)
Lee, Jaehak; Ji, Se-Wan; Park, Jiyong; Nha, Hyunchul
2014-08-01
We study a continuous-variable dense coding protocol, originally proposed to employ a two-mode squeezed state, using a general two-mode Gaussian state as a quantum channel. We particularly obtain conditions to manifest quantum advantage by beating two well-known single-mode schemes, namely, the squeezed-state scheme (best Gaussian scheme) and the number-state scheme (optimal scheme achieving the Holevo bound). We then extend our study to a multipartite Gaussian state and investigate the monogamy of operational entanglement measured by the communication capacity under the dense coding protocol. We show that this operational entanglement represents a strict monogamy relation, by means of Heisenberg's uncertainty principle among different parties; i.e., the quantum advantage for communication can be possible for only one pair of two-mode systems among many parties.
Hemmer, Pernille; Criss, Amy H
2013-11-01
The role of experience in memory, specifically the word frequency (WF) mirror effect showing higher hit rates and lower false alarm rates for low-frequency words, is one of the hallmarks of memory. However, this "regularity of memory" is limited because normative WF has been treated as discrete (low vs. high). We evaluate the extent to which the prototypical WF mirror effect holds when WF is treated as a continuous variable. We find a clear nonmonotonic U-shaped relationship. Hit rates are higher for both low-frequency and high-frequency words. Linear and quadratic regression models were fit to the data at both the item and the participant level, and the quadratic model provided a better fit at both levels. This finding is inconsistent with the empirical and theoretical finding of a mirror effect and requires a novel approach to accounting for the role of experience in episodic memory. PMID:23855550
Generating arbitrary photon-number entangled states for continuous-variable quantum informatics.
Lee, Su-Yong; Park, Jiyong; Lee, Hai-Woong; Nha, Hyunchul
2012-06-18
We propose two experimental schemes that can produce an arbitrary photon-number entangled state (PNES) in a finite dimension. This class of entangled states naturally includes non-Gaussian continuous-variable (CV) states that may provide some practical advantages over the Gaussian counterparts (two-mode squeezed states). We particularly compare the entanglement characteristics of the Gaussian and the non-Gaussian states in view of the degree of entanglement and the Einstein-Podolsky-Rosen correlation, and further discuss their applications to the CV teleportation and the nonlocality test. The experimental imperfection due to the on-off photodetectors with nonideal efficiency is also considered in our analysis to show the feasibility of our schemes within existing technologies. PMID:22714485
Demonstration of a controlled-phase gate for continuous-variable one-way quantum computation.
Ukai, Ryuji; Yokoyama, Shota; Yoshikawa, Jun-ichi; van Loock, Peter; Furusawa, Akira
2011-12-16
We experimentally demonstrate a controlled-phase gate for continuous variables using a cluster-state resource of four optical modes. The two independent input states of the gate are coupled with the cluster in a teleportation-based fashion. As a result, one of the entanglement links present in the initial cluster state appears in the two unmeasured output modes as the corresponding entangling gate acting on the input states. The genuine quantum character of this gate becomes manifest and is verified through the presence of entanglement at the output for a product two-mode coherent input state. By combining our gate with the recently reported module for single-mode Gaussian operations [R. Ukai et al., Phys. Rev. Lett. 106, 240504 (2011)], it is possible to implement any multimode Gaussian operation as a fully measurement-based one-way quantum computation. PMID:22243056
NASA Astrophysics Data System (ADS)
Hu, Li-Yun; Liao, Zeyang; Ma, Shengli; Zubairy, M. Suhail
2016-03-01
We introduce three tunable parameters to optimize the fidelity of quantum teleportation with continuous variables in a nonideal scheme. By using the characteristic-function formalism, we present the condition that the teleportation fidelity is independent of the amplitude of input coherent states for any entangled resource. Then we investigate the effects of tunable parameters on the fidelity with or without the presence of the environment and imperfect measurements by analytically deriving the expression of fidelity for three different input coherent-state distributions. It is shown that, for the linear distribution, the optimization with three tunable parameters is the best one with respect to single- and two-parameter optimization. Our results reveal the usefulness of tunable parameters for improving the fidelity of teleportation and the ability against decoherence.
Monitoring Urban Water Quality Variability Using Continuous In-Situ Sensors
NASA Astrophysics Data System (ADS)
Carey, R. O.; Wollheim, W. M.; Mulukutla, G. K.
2011-12-01
Water quality monitoring using continuous in-situ sensors can improve our understanding of biogeochemical variability in urban watersheds. In New Hampshire, the Lamprey River drains an urbanizing watershed and discharges to the nitrogen (N)-impaired Great Bay estuary. Multiple instruments (Satlantic Submersible Ultraviolet Nitrate Analyzer, Turner Designs C6 Multi-Sensor Platform, Hydrolab MS5, and WET Labs Cycle) were deployed continuously for three seasons (April-November, 2011) in the Lamprey River to evaluate water quality relationships under hydrologically variable conditions and across seasons. Parameters monitored at sub-hourly intervals included nitrate-N (NO3-N), chromophoric dissolved organic matter (CDOM), chlorophyll, turbidity, dissolved oxygen (DO), specific conductivity, and pH; dissolved phosphate (PO4-P) was monitored hourly. Grab samples were also collected to assess instrument performance. Preliminary results from deployment through early August 2011 indicate that baseflow was associated with both elevated NO3-N concentrations and specific conductivity, but daily NO3-N fluxes were greater during storms. Greater discharges corresponded to increased values for CDOM, chlorophyll, and DO concentrations. In addition to diurnal cycles for several parameters (i.e., CDOM, chlorophyll, DO, and pH), NO3-N and PO4-P concentrations peaked during the night and day, respectively, suggesting biotic uptake became important at lower flows. Stormwater generally diluted NO3-N concentrations and specific conductivity, indicating groundwater contamination from the predominance of septic waste management and winter road salt application in suburban communities in the watershed. However, greater NO3-N export during storms revealed the importance of stormwater discharges despite the dilution effect. Studies using high-resolution data to evaluate the effects of stormwater discharge and increasing urbanization are crucial to understanding the significance of varying land
Wang, Chen-Pin; Jo, Booil; Brown, C Hendricks
2014-09-10
We propose a principal stratification approach to assess causal effects in nonrandomized longitudinal comparative effectiveness studies with a binary endpoint outcome and repeated measures of a continuous intermediate variable. Our method is an extension of the principal stratification approach originally proposed for the longitudinal randomized study "Prevention of Suicide in Primary Care Elderly: Collaborative Trial" to assess the treatment effect on the continuous Hamilton depression score adjusting for the heterogeneity of repeatedly measured binary compliance status. Our motivation for this work comes from a comparison of the effect of two glucose-lowering medications on a clinical cohort of patients with type 2 diabetes. Here, we consider a causal inference problem assessing how well the two medications work relative to one another on two binary endpoint outcomes: cardiovascular disease-related hospitalization and all-cause mortality. Clinically, these glucose-lowering medications can have differential effects on the intermediate outcome, glucose level over time. Ultimately, we want to compare medication effects on the endpoint outcomes among individuals in the same glucose trajectory stratum while accounting for the heterogeneity in baseline covariates (i.e., to obtain 'principal effects' on the endpoint outcomes). The proposed method involves a three-step model estimation procedure. Step 1 identifies principal strata associated with the intermediate variable using hybrid growth mixture modeling analyses. Step 2 obtains the stratum membership using the pseudoclass technique and derives propensity scores for treatment assignment. Step 3 obtains the stratum-specific treatment effect on the endpoint outcome weighted by inverse propensity probabilities derived from Step 2. PMID:24577715
Stahler, Gerald J; Mazzella, Silvana; Mennis, Jeremy; Chakravorty, Sanjoy; Rengert, George; Spiga, Ralph
2007-02-23
This study reviewed the medical charts of 271 patients diagnosed with co-morbid mental health and substance-use disorders who were discharged from a hospital acute inpatient unit to various outpatient treatment programs in Philadelphia. Geographic Information Systems (GIS) technology and logistic regression modeling were employed to investigate the effects of individual, neighborhood, and program-level variables on arrival to the first treatment appointment within 30 days of discharge. Four models are presented. The results of the study suggest that having had three or more treatment episodes prior to inpatient hospitalization, and living in a neighborhood in which temporary or transitional, and presumably, other low income housing is located, increased the likelihood of patients continuing with treatment in the community. Discharge to the preadmission address, a chief complaint of bizarre behavior, close proximity of two or more liquor and/or beer stores, a high density of narcotics anonymous (NA) and/or alcoholics anonymous (AA) meetings within the neighborhood, an axis I diagnosis of substance-induced mood disorder, and a urine drug screen positive for heroin reduced the likelihood of attending outpatient treatment. We conclude that geographic and community variables as they relate to substance abuse may add an important dimension to our understanding of patient functioning and well being in the community following inpatient treatment. PMID:16962255
Continuous subcutaneous infusion of lidocaine for persistent hiccup in advanced cancer.
Kaneishi, Keisuke; Kawabata, Masahiro
2013-03-01
Persistent hiccup can cause anorexia, weight loss, disabling sleep deprivation, anxiety, and depression. Therefore, relief of persistent hiccup is important for advanced cancer patients and their family. Most reports on this condition are case series reports advocating the use of baclofen, haloperidol, gabapentin, and midazolam. However, these medications are occasionally ineffective or accompanied by intolerable side effects. The sodium channel blocker lidocaine has been shown to be effective in treating a variety of disorders thought to involve neuropathic mechanisms. Intravenous administration of lidocaine is common but efficacy has also been reported for subcutaneous infusion. In advanced cancer patients, subcutaneous infusion is easy, advantageous, and accompanied by less discomfort. We report a case of severe and sustained hiccup caused by gastric cancer that was successfully treated with a continuous subcutaneous infusion of lidocaine (480 mg (24 ml)/day) without severe side effects. PMID:22661318
NASA Astrophysics Data System (ADS)
Orton, Philip M.; Visbeck, Martin
2009-01-01
We present detailed observations of internally generated turbulence in a sheared, stratified natural flow, as well as an analysis of the external factors leading to its generation and temporal variability. Multi-month time series of vertical profiles of velocity, acoustic backscatter (0.5 Hz), and turbulence parameters were collected with two moored acoustic Doppler current profilers (ADCPs) in the Hudson River estuary, and estuary-long transects of water density were collected 30 times. ADCP backscatter is used for visualization of coherent turbulent structures and evaluation of surface wave biases to the turbulence measurements. Benefits of the continuous long-term turbulence record include our capturing: (1) the seasonality of turbulence due to changing riverflow, (2) hysteresis in stratification and turbulence over the fortnightly cycle of tidal range, and (3) intermittent events such as breaking internal waves. Internal mixing layers (IMLs) are defined as turbulent regions above the logarithmic velocity layer, and the bottom boundary layer (BBL) is defined as the continuously turbulent range of heights above the bed. A cross-correlation analysis reveals how IML and BBL turbulence vary with stratification and external forcing from tidal range, river flow, and winds. Turbulence in both layers is maximal at spring tide and minimal when most stratified, with one exception—IML turbulence at a site with changing channel depth and width is maximal at times of maximum stratification and freshwater input.
Variable stream control engine concept for advanced supersonic aircraft: Features and benefits
NASA Technical Reports Server (NTRS)
Howlett, R. A.
1976-01-01
The Variable Stream Control Engine is studied for advanced supersonic cruise aircraft. Significant environmental and performance improvements relative to first generation supersonic turbojet engines are cited. Two separate flow streams, each with independent burner and nozzle systems are incorporated within the engine. By unique control of the exhaust temperatures and velocities in two coannular streams, significant reduction in jet noise is obtained.
NASA Technical Reports Server (NTRS)
Mendenhall, J. A.; Hearn, D. R.; Lencioni, D. E.
2002-01-01
The performance requirements for the Advanced Land Imager were developed under NASA's New Millennium Program and were intended to facilitate the validation of new sensor technologies and architectures for potential application in future remote sensing missions. The Advanced Land Imager (ALI) was designed and flown well before the Landsat Data Continuity Mission (LDCM) specifications were developed. Nevertheless, the science focus of the ALI technology validation was Landsat data continuity. Therefore, although exact compliance by ALI is not expected, the performance should demonstrate a path to a compliant sensor system. The performance of the ALI, as determined from preflight and flight data, is compared to the LDCM specification. Twenty-one noncompliances have been identified: four data collection, four spectral, six spatial, and seven radiometric (Table I). All but six of these are considered minor. The six major noncompliances are the result of stray light, leaky detectors, and contamination. Appendix A replicates the LDCM specification and contains ALI compliance notes where appropriate. Details of the ALI stray light, contamination, and leaky detectors are provided in Appendix B, C, and D respectively. Additional information pertaining to the calculation of the ALI edge response and coherent noise is presented in Appendix E and F. A list of ALI related publications is provided in Appendix G.
NASA Astrophysics Data System (ADS)
Qin, Hao; Kumar, Rupesh; Alleaume, Romain
2015-10-01
We report here a new side channel attack on a practical continuous-variable (CV) quantum key distribution (QKD) system. Inspired by blinding attack in discrete-variable QKD, we formalize an attack strategy by inserting an external light into a CV QKD system implemented Gaussian-modulated coherent state protocol and show that our attack can compromise its practical security. In this attack, we concern imperfections of a balanced homodyne detector used in CV QKD. According to our analysis, if one inserts an external light into Bob's signal port, due to the imperfect subtraction from the homodyne detector, the leakage of the external light contributes a displacement on the homodyne signal which causes detector electronics saturation. In consequence, Bob's quadrature measurement is not linear with the quadrature sent by Alice. By considering such vulnerability, a potential Eve can launch a full intercept-resend attack meanwhile she inserts an external light into Bob's signal port. By selecting proper properties of the external light, Eve actively controls the induced displacement value from the inserted light which results saturation of homodyne detection. In consequence, Eve can bias the excess noise due to the intercept-resend attack and the external light, such that Alice and Bob believe their excess noise estimation is below the null key threshold and they can still share a secret key. Our attack shows that the detector loopholes also exist in CV QKD, and it seems influence all the CV QKD systems using homodyne detection, since all the practical detectors have finite detection range.
NASA Technical Reports Server (NTRS)
Compagnon, M. A.
1973-01-01
Several variable geometry high Mach inlet concepts, aimed at meeting a system noise objective of 15 EPNdB below FAR part 36, for a long range, Mach 0.9 advanced commercial transport are assessed and compared to a fixed geometry inlet with multiple splitters. The effects of a variable exhaust nozzle (mixed exhaust engine) on noise, inlet geometry requirements, and economics are also presented. The best variable geometry inlet configuration identified is a variable cowl design which relies on a high throat Mach number for additional inlet noise suppression only at takeoff, and depends entirely on inlet wall treatment for noise suppression at approach power. Relative economic penalties as a function of noise level are also presented.
Continuous-time ΣΔ ADC with implicit variable gain amplifier for CMOS image sensor.
Tang, Fang; Bermak, Amine; Abbes, Amira; Benammar, Mohieddine Amor
2014-01-01
This paper presents a column-parallel continuous-time sigma delta (CTSD) ADC for mega-pixel resolution CMOS image sensor (CIS). The sigma delta modulator is implemented with a 2nd order resistor/capacitor-based loop filter. The first integrator uses a conventional operational transconductance amplifier (OTA), for the concern of a high power noise rejection. The second integrator is realized with a single-ended inverter-based amplifier, instead of a standard OTA. As a result, the power consumption is reduced, without sacrificing the noise performance. Moreover, the variable gain amplifier in the traditional column-parallel read-out circuit is merged into the front-end of the CTSD modulator. By programming the input resistance, the amplitude range of the input current can be tuned with 8 scales, which is equivalent to a traditional 2-bit preamplification function without consuming extra power and chip area. The test chip prototype is fabricated using 0.18 μm CMOS process and the measurement result shows an ADC power consumption lower than 63.5 μW under 1.4 V power supply and 50 MHz clock frequency. PMID:24772012
Bell inequalities for continuous-variable systems in generic squeezed states
NASA Astrophysics Data System (ADS)
Martin, Jérôme; Vennin, Vincent
2016-06-01
Bell inequalities for continuous-variable bipartite systems are studied. The inequalities are expressed in terms of pseudo-spin operators, and quantum expectation values are calculated for generic two-mode squeezed states characterized by a squeezing parameter r and a squeezing angle φ . Allowing for generic values of the squeezing angle is especially relevant when φ is not under experimental control, such as in cosmic inflation, where small quantum fluctuations in the early universe are responsible for structures formation. Compared to previous studies restricted to φ =0 and to a fixed orientation of the pseudo-spin operators, allowing for φ ≠0 and optimizing the angular configuration leads to a completely new and rich phenomenology. Two dual schemes of approximation are designed that allow for comprehensive exploration of the squeezing parameter space. In particular, it is found that Bell inequalities can be violated when the squeezing parameter r is large enough, r ≳1.12 , and the squeezing angle φ is small enough, φ ≲0.34 e-r .
Estimation of a non-parametric variable importance measure of a continuous exposure
Chambaz, Antoine; Neuvial, Pierre; van der Laan, Mark J.
2012-01-01
We define a new measure of variable importance of an exposure on a continuous outcome, accounting for potential confounders. The exposure features a reference level x0 with positive mass and a continuum of other levels. For the purpose of estimating it, we fully develop the semi-parametric estimation methodology called targeted minimum loss estimation methodology (TMLE) [23, 22]. We cover the whole spectrum of its theoretical study (convergence of the iterative procedure which is at the core of the TMLE methodology; consistency and asymptotic normality of the estimator), practical implementation, simulation study and application to a genomic example that originally motivated this article. In the latter, the exposure X and response Y are, respectively, the DNA copy number and expression level of a given gene in a cancer cell. Here, the reference level is x0 = 2, that is the expected DNA copy number in a normal cell. The confounder is a measure of the methylation of the gene. The fact that there is no clear biological indication that X and Y can be interpreted as an exposure and a response, respectively, is not problematic. PMID:23336014
Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb
Pooser, Raphael C.; Jing, Jietai
2014-10-20
One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexingmore » in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.« less
Speed ratio control for cars equipped with metal v-belt continuously variable transmission
NASA Astrophysics Data System (ADS)
Zhou, Meilan; Zhang, Bin; Wen, Jiabin
2008-10-01
In order to study the control effect of speed ratio change on fuel economy performance of vehicles under complex working conditions, a mixed fuzzy-PI control strategy is proposed, and a dynamic simulation model is established for the best fuel economy. Simulation and analysis are conducted using the model under different typical operating conditions. Simulation results show that the speed ratio mixed fuzzy-PI controller has a better following characteristics and higher accuracy compared to a conventional fuzzy controller. Even in the case of external disturbance, the target engine speed can still be maintained at the most economic working point. According to the proposed control strategy, road test has been done under various running situations with DEAWOOD MatizII passenger car used as an experimental sample car. The test results verify further that the model established is correct and the control strategy proposed for the speed ratio is valid, and the reasonable match between engine and continuously variable transmission (CVT) is achievable.
Preventing side-channel effects in continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Derkach, Ivan; Usenko, Vladyslav C.; Filip, Radim
2016-03-01
The role of the side channels in the continuous-variable quantum key distribution is studied. It is shown how the information leakage through a side channel from the trusted sender station increases the vulnerability of the protocols to the eavesdropping in the main quantum communication channel. Moreover, the untrusted noise infusion by an eavesdropper on the trusted receiving side breaks the security even for a purely attenuating main quantum channel. As a method to compensate for the effect of the side-channel leakage on the sender side, we suggest several types of manipulations on the side-channel input. It is shown that by applying the modulated coherent light on the input of the side channel that is optimally correlated to the modulation on the main signal and optionally introducing additional squeezing in the case of the squeezed-state protocol, the negative influence of the lossy side channel on the sender side can be completely removed. For the trusted receiving side, the method of optimal monitoring of the residual noise from the side-channel noise infusion is suggested and shown to be able to completely eliminate the presence of the noisy side channel. We therefore prove that the side-channel effects can be completely removed using feasible operations if the trusted parties access the respective parts of the side channels.
Realistic continuous-variable quantum teleportation with non-Gaussian resources
Dell'Anno, F.; De Siena, S.; Illuminati, F.
2010-01-15
We present a comprehensive investigation of nonideal continuous-variable quantum teleportation implemented with entangled non-Gaussian resources. We discuss in a unified framework the main decoherence mechanisms, including imperfect Bell measurements and propagation of optical fields in lossy fibers, applying the formalism of the characteristic function. By exploiting appropriate displacement strategies, we compute analytically the success probability of teleportation for input coherent states and two classes of non-Gaussian entangled resources: two-mode squeezed Bell-like states (that include as particular cases photon-added and photon-subtracted de-Gaussified states), and two-mode squeezed catlike states. We discuss the optimization procedure on the free parameters of the non-Gaussian resources at fixed values of the squeezing and of the experimental quantities determining the inefficiencies of the nonideal protocol. It is found that non-Gaussian resources enhance significantly the efficiency of teleportation and are more robust against decoherence than the corresponding Gaussian ones. Partial information on the alphabet of input states allows further significant improvement in the performance of the nonideal teleportation protocol.
Five-wave-packet quantum error correction based on continuous-variable cluster entanglement
Hao, Shuhong; Su, Xiaolong; Tian, Caixing; Xie, Changde; Peng, Kunchi
2015-01-01
Quantum error correction protects the quantum state against noise and decoherence in quantum communication and quantum computation, which enables one to perform fault-torrent quantum information processing. We experimentally demonstrate a quantum error correction scheme with a five-wave-packet code against a single stochastic error, the original theoretical model of which was firstly proposed by S. L. Braunstein and T. A. Walker. Five submodes of a continuous variable cluster entangled state of light are used for five encoding channels. Especially, in our encoding scheme the information of the input state is only distributed on three of the five channels and thus any error appearing in the remained two channels never affects the output state, i.e. the output quantum state is immune from the error in the two channels. The stochastic error on a single channel is corrected for both vacuum and squeezed input states and the achieved fidelities of the output states are beyond the corresponding classical limit. PMID:26498395
Continuous `stunted' outbursts detected from the cataclysmic variable KIC 9202990 using Kepler data
NASA Astrophysics Data System (ADS)
Ramsay, Gavin; Hakala, Pasi; Wood, Matt A.; Howell, Steve B.; Smale, Alan; Still, Martin; Barclay, Thomas
2016-01-01
Based on early Kepler data, Østensen et al. found that KIC 9202990 showed a 4-h and a two-week photometric period. They suggested the 4-h period was a signature of an orbital period; the longer period was possibly due to precession of an accretion disc and KIC 9202990 was a cataclysmic variable with an accretion disc which is always in a bright state (a nova-like system). Using the full Kepler data set on KIC 9202990 which covers 1421 d (Quarter 2-17), and includes 1-min cadence data from the whole of Quarters 5 and 16, we find that the 4-h period is stable and therefore a signature of the binary orbital period. In contrast, the 10-12 d period is not stable and shows an amplitude between 20 and 50 per cent. This longer period modulation is similar to those nova-like systems which show `stunted' outbursts. We discuss the problems that a precessing disc model has in explaining the observed characteristics and indicate why we favour a stunted outburst model. Although such stunted events are considered to be related to the standard disc instability mechanism, their origin is not well understood. KIC 9202990 shows the lowest amplitude and shortest period of continuous stunted outburst systems, making it an ideal target to better understand stunted outbursts and accretion instabilities in general.
Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb
Pooser, Raphael C.; Jing, Jietai
2014-10-20
One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexing in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.
Five-wave-packet quantum error correction based on continuous-variable cluster entanglement.
Hao, Shuhong; Su, Xiaolong; Tian, Caixing; Xie, Changde; Peng, Kunchi
2015-01-01
Quantum error correction protects the quantum state against noise and decoherence in quantum communication and quantum computation, which enables one to perform fault-torrent quantum information processing. We experimentally demonstrate a quantum error correction scheme with a five-wave-packet code against a single stochastic error, the original theoretical model of which was firstly proposed by S. L. Braunstein and T. A. Walker. Five submodes of a continuous variable cluster entangled state of light are used for five encoding channels. Especially, in our encoding scheme the information of the input state is only distributed on three of the five channels and thus any error appearing in the remained two channels never affects the output state, i.e. the output quantum state is immune from the error in the two channels. The stochastic error on a single channel is corrected for both vacuum and squeezed input states and the achieved fidelities of the output states are beyond the corresponding classical limit. PMID:26498395
System for controlling the pressure of oil in a system for a continuously variable transmission
Miyawaki, M.
1987-06-23
A control system for a continuously variable transmission for transmitting the power of an internal combustion engine to driving wheels through a clutch, having a drive pulley having a hydraulically shiftable disc and a first hydraulic cylinder for shifting the disc, a driven pulley having a hydraulically shiftable disc and a second hydraulic cylinder for operating the disc, a belt engaged with both pulleys, a line pressure control valve having ports and a spool, a transmission ratio control valve having ports and a spool, a first hydraulic circuit having a pump for supplying oil to the first cylinder through the line pressure control valve and transmission ratio control valve, the system comprising: a second hydraulic circuit for supplying oil to the line pressure control valve so as to shift the spool; control valve means provided in the second hydraulic circuit for controlling amount of oil supplied to the line pressure control valve; first means for detecting a large transmission ratio state after disengagement of the clutch and for producing a signal; second means responsive to the signal from the first means for producing a line pressure reducing signal; third means responsive to the line pressure reducing signal for operating the control valve means, so that the spool of the line pressure control valve is shifted to reduce the line pressure.
Quantum hacking: Saturation attack on practical continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Qin, Hao; Kumar, Rupesh; Alléaume, Romain
2016-07-01
We identify and study a security loophole in continuous-variable quantum key distribution (CVQKD) implementations, related to the imperfect linearity of the homodyne detector. By exploiting this loophole, we propose an active side-channel attack on the Gaussian-modulated coherent-state CVQKD protocol combining an intercept-resend attack with an induced saturation of the homodyne detection on the receiver side (Bob). We show that an attacker can bias the excess noise estimation by displacing the quadratures of the coherent states received by Bob. We propose a saturation model that matches experimental measurements on the homodyne detection and use this model to study the impact of the saturation attack on parameter estimation in CVQKD. We demonstrate that this attack can bias the excess noise estimation beyond the null key threshold for any system parameter, thus leading to a full security break. If we consider an additional criterion imposing that the channel transmission estimation should not be affected by the attack, then the saturation attack can only be launched if the attenuation on the quantum channel is sufficient, corresponding to attenuations larger than approximately 6 dB. We moreover discuss the possible countermeasures against the saturation attack and propose a countermeasure based on Gaussian postselection that can be implemented by classical postprocessing and may allow one to distill the secret key when the raw measurement data are partly saturated.
NASA Astrophysics Data System (ADS)
Qi, Bing; Lougovski, Pavel; Pooser, Raphael; Grice, Warren; Bobrek, Miljko
2015-10-01
Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In this paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a "locally" generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct a coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad2 ), which is small enough to enable secure key distribution. This technology also opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.
Continuous-variable versus hybrid schemes for quantum teleportation of Gaussian states
NASA Astrophysics Data System (ADS)
Kogias, Ioannis; Ragy, Sammy; Adesso, Gerardo
2014-05-01
In this paper, we examine and compare two fundamentally different teleportation schemes: the well-known continuous-variable scheme of Vaidman, Braunstein, and Kimble (VBK) and a recently proposed hybrid scheme by Andersen and Ralph (AR). We analyze the teleportation of ensembles of arbitrary pure single-mode Gaussian states using these schemes and see how they fare against the optimal measure-and-prepare strategies—the benchmarks. In the VBK case, we allow for nonunit gain tuning and additionally consider a class of non-Gaussian resources in order to optimize performance. The results suggest that the AR scheme may likely be a more suitable candidate for beating the benchmarks in the teleportation of squeezing, capable of achieving this for moderate resources in comparison to the VBK scheme. Moreover, our quantification of resources, whereby different protocols are compared at fixed values of the entanglement entropy or the mean energy of the resource states, brings into question any advantage due to non-Gaussianity for quantum teleportation of Gaussian states.
NASA Astrophysics Data System (ADS)
Hameer, Sameer
Rotorcraft transmission design is limited by empirical weight trends that are proportional to the power/torque raised to the two-thirds coupled with the relative inexperience industry has with the employment of variable speed transmission to heavy lift helicopters of the order of 100,000 lbs gross weight and 30,000 installed horsepower. The advanced rotorcraft transmission program objectives are to reduce transmission weight by at least 25%, reduce sound pressure levels by at least 10 dB, have a 5000 hr mean time between removal, and also incorporate the use of split torque technology in rotorcraft drivetrains of the future. The major obstacle that challenges rotorcraft drivetrain design is the selection, design, and optimization of a variable speed transmission in the goal of achieving a 50% reduction in rotor speed and its ability to handle high torque with light weight gears, as opposed to using a two-speed transmission which has inherent structural problems and is highly unreliable due to the embodiment of the traction type transmission, complex clutch and brake system. This thesis selects a nontraction pericyclic continuously variable transmission (P-CVT) as the best approach for a single main rotor heavy lift helicopter. The objective is to target and overcome the above mentioned obstacle for drivetrain design. Overcoming this obstacle provides advancement in the state of the art of drivetrain design over existing planetary and split torque transmissions currently used in helicopters. The goal of the optimization process was to decrease weight, decrease noise, increase efficiency, and increase safety and reliability. The objective function utilized the minimization of the weight and the major constraint is the tooth bending stress of the facegears. The most important parameters of the optimization process are weight, maintainability, and reliability which are cross-functionally related to each other, and these parameters are related to the torques and
Colloca, G; Venturino, A; Governato, I
2016-08-01
Various kinetic parameters, based on a minimum of two time points, have been built with CA125 determinations. The aim of this study is to review studies about the clinical application of CA125-related tumor cell kinetics variables in patients with advanced ovarian cancer (AOC) receiving chemotherapy. A literature search for studies about CA125-related variables in patients with AOC was undertaken on three databases, by predefined search criteria, and a selection of studies was performed. Sixty-two studies were selected. CA125-related variables were summarized in three groups: response-related, time-to-event, and other CA125-related tumor cell kinetics variables. Even though CA125 changes and half-life after chemotherapy were the most studied, other variables and two models have been well defined, and often showed an interesting power to predict survival. These kinetics variables are related to the CA125 regression curve, pre- and post-chemotherapy kinetics, or are variables inferred from a population model of CA125 kinetics. PMID:26546024
Kilovoltage energy imaging with a radiotherapy linac with a continuously variable energy range
Roberts, D. A.; Hansen, V. N.; Thompson, M. G.; Poludniowski, G.; Niven, A.; Seco, J.; Evans, P. M.
2012-03-15
Purpose: In this paper, the effect on image quality of significantly reducing the primary electron energy of a radiotherapy accelerator is investigated using a novel waveguide test piece. The waveguide contains a novel variable coupling device (rotovane), allowing for a wide continuously variable energy range of between 1.4 and 9 MeV suitable for both imaging and therapy.Method: Imaging at linac accelerating potentials close to 1 MV was investigated experimentally and via Monte Carlo simulations. An imaging beam line was designed, and planar and cone beam computed tomography images were obtained to enable qualitative and quantitative comparisons with kilovoltage and megavoltage imaging systems. The imaging beam had an electron energy of 1.4 MeV, which was incident on a water cooled electron window consisting of stainless steel, a 5 mm carbon electron absorber and 2.5 mm aluminium filtration. Images were acquired with an amorphous silicon detector sensitive to diagnostic x-ray energies. Results: The x-ray beam had an average energy of 220 keV and half value layer of 5.9 mm of copper. Cone beam CT images with the same contrast to noise ratio as a gantry mounted kilovoltage imaging system were obtained with doses as low as 2 cGy. This dose is equivalent to a single 6 MV portal image. While 12 times higher than a 100 kVp CBCT system (Elekta XVI), this dose is 140 times lower than a 6 MV cone beam imaging system and 6 times lower than previously published LowZ imaging beams operating at higher (4-5 MeV) energies. Conclusions: The novel coupling device provides for a wide range of electron energies that are suitable for kilovoltage quality imaging and therapy. The imaging system provides high contrast images from the therapy portal at low dose, approaching that of gantry mounted kilovoltage x-ray systems. Additionally, the system provides low dose imaging directly from the therapy portal, potentially allowing for target tracking during radiotherapy treatment. There is
A review on continuous-flow microfluidic PCR in droplets: Advances, challenges and future.
Zhang, Yonghao; Jiang, Hui-Rong
2016-03-31
Significant advances have been made in developing microfluidic polymerase chain reaction (PCR) devices in the last two decades. More recently, microfluidic microdroplet technology has been exploited to perform PCR in droplets because of its unique features. For example, it can prevent crossover contamination and PCR inhibition, is suitable for single-cell and single-molecule analyses, and has the potential for system integration and automation. This review will therefore focus on recent developments on droplet-based continuous-flow microfluidic PCR, and the major research challenges. This paper will also discuss a new way of on-chip flow control and a rational design simulation tool, which are required to underpin fully integrated and automated droplet-based microfluidic systems. We will conclude with a scientific speculation of future autonomous scientific discoveries enabled by microfluidic microdroplet technologies. PMID:26965323
Development of ASTM standards in support of advanced ceramics -- continuing efforts
Brinkman, C.R.
1998-02-01
An update is presented of the activities of the American Society for Testing and Materials (ASTM) Committee C-28 on Advanced Ceramics. Since its inception in 1986, this committee, which has five standard producing subcommittees, has written and published over 32 consensus standards. These standards are concerned with mechanical testing of monolithic and composite ceramics, nondestructive examination, statistical analysis and design, powder characterization, quantitative microscopy, fractography, and terminology. These standards ensure optimum material behavior with physical and mechanical property reproducibility, component reliability, and well-defined methods of data treatment and material analysis for both monolithic and composite materials. Committee C-28 continues to sponsor technical symposia and to cooperate in the development of international standards. An update of recent and current activities as well as possible new areas of standardization work will be presented.
NASA Technical Reports Server (NTRS)
Rizk, Magdi H.
1988-01-01
A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.
NASA Technical Reports Server (NTRS)
Rizk, Magdi H.
1988-01-01
A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.
NASA Astrophysics Data System (ADS)
Sun, Jiandong; Fu, Wenyu; Lei, Hong; Tian, E.; Liu, Ziping
2012-11-01
The current research on pulse continuously variable transmission(CVT) is mainly focused on reducing the pulse degree and making pulse degrees a constant value. Current research mainly confined to find out new design parameters by using the method of optimization, and reduce the pulse degree of pulse CVT and its range of variation. But the fact is that the reduction of the pulse degree is not significant. This article presents a new structure of mechanical pulse CVT—the rotational swashplate pulse CVT with driven by helical gear axial meshing. This transmission is simple and compact in structure and low in pulsatile rate (it adopts 6 guide rods), and the pulsatile degree is irrelevant to the transmission ratio. Theoretically, pulsatile rate could be reduced to zero if appropriate curved surface of the swashplate is used. Compared with the connecting rod pulse CVT, the present structure uses helical gear mechanism as transmission part and it avoids unbalanced inertial force in the former model. This paper analyzes the principle of driving of this transmission, presents its mechanical structure, and discusses its motion characteristics. Experimental prototype of this type of CVT has been manufactured. Tests for the transmission efficiency(when the rotational speed of the output shaft is the maximum) and the angular velocity of the output shaft have been carried out, and data have been analyzed. The experimental results show that the speed of the output shaft for the experimental prototype is slightly lower than the theoretical value, and the transmission efficiency of the experimental prototype is about 70%. The pulse degree of the CVT discussed in this paper is less than the existing pulse CVT of other types, and it is irrelevant to the transmission ratio of the CVT. The research provides the new idea to the CVT study.
Albano Farias, L.; Stephany, J.
2010-12-15
We analyze the statistics of observables in continuous-variable (CV) quantum teleportation in the formalism of the characteristic function. We derive expressions for average values of output-state observables, in particular, cumulants which are additive in terms of the input state and the resource of teleportation. Working with a general class of teleportation resources, the squeezed-bell-like states, which may be optimized in a free parameter for better teleportation performance, we discuss the relation between resources optimal for fidelity and those optimal for different observable averages. We obtain the values of the free parameter of the squeezed-bell-like states which optimize the central momenta and cumulants up to fourth order. For the cumulants the distortion between in and out states due to teleportation depends only on the resource. We obtain optimal parameters {Delta}{sub (2)}{sup opt} and {Delta}{sub (4)}{sup opt} for the second- and fourth-order cumulants, which do not depend on the squeezing of the resource. The second-order central momenta, which are equal to the second-order cumulants, and the photon number average are also optimized by the resource with {Delta}{sub (2)}{sup opt}. We show that the optimal fidelity resource, which has been found previously to depend on the characteristics of input, approaches for high squeezing to the resource that optimizes the second-order momenta. A similar behavior is obtained for the resource that optimizes the photon statistics, which is treated here using the sum of the squared differences in photon probabilities of input versus output states as the distortion measure. This is interpreted naturally to mean that the distortions associated with second-order momenta dominate the behavior of the output state for large squeezing of the resource. Optimal fidelity resources and optimal photon statistics resources are compared, and it is shown that for mixtures of Fock states both resources are equivalent.
Green-up dates in the Tibetan Plateau have continuously advanced from 1982 to 2011.
Zhang, Geli; Zhang, Yangjian; Dong, Jinwei; Xiao, Xiangming
2013-03-12
As the Earth's third pole, the Tibetan Plateau has experienced a pronounced warming in the past decades. Recent studies reported that the start of the vegetation growing season (SOS) in the Plateau showed an advancing trend from 1982 to the late 1990s and a delay from the late 1990s to 2006. However, the findings regarding the SOS delay in the later period have been questioned, and the reasons causing the delay remain unknown. Here we explored the alpine vegetation SOS in the Plateau from 1982 to 2011 by integrating three long-term time-series datasets of Normalized Difference Vegetation Index (NDVI): Global Inventory Modeling and Mapping Studies (GIMMS, 1982-2006), SPOT VEGETATION (SPOT-VGT, 1998-2011), and Moderate Resolution Imaging Spectroradiometer (MODIS, 2000-2011). We found GIMMS NDVI in 2001-2006 differed substantially from SPOT-VGT and MODIS NDVIs and may have severe data quality issues in most parts of the western Plateau. By merging GIMMS-based SOSs from 1982 to 2000 with SPOT-VGT-based SOSs from 2001 to 2011 we found the alpine vegetation SOS in the Plateau experienced a continuous advancing trend at a rate of ∼1.04 d·y(-1) from 1982 to 2011, which was consistent with observed warming in springs and winters. The satellite-derived SOSs were proven to be reliable with observed phenology data at 18 sites from 2003 to 2011; however, comparison of their trends was inconclusive due to the limited temporal coverage of the observed data. Longer-term observed data are still needed to validate the phenology trend in the future. PMID:23440201
Namiki, Ryo; Koashi, Masato; Imoto, Nobuyuki
2006-03-15
We investigate the security of continuous-variable quantum key distribution using coherent states and reverse reconciliation against Gaussian individual attacks based on an optimal Gaussian 1{yields}2 cloning machine. We provide an implementation of the optimal Gaussian individual attack. We also find a Bell-measurement attack which works without delayed choice of measurements and has better performance than the cloning attack.
Spectra: the last advance of T-FLaP technology for in continuous oceanographic observations
NASA Astrophysics Data System (ADS)
Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto
2015-04-01
Ocean models have become increasingly useful as computing capabilities and in situ measurement systems have been improved. An operational observing and forecasting system of the ocean properties needs effective data collection programs for model data assimilation and satellite calibration. However, the development of observational networks is strongly limited by the advances of reliable, user-friendly and low cost technologies. These requirements cannot be achieved with current marine measurement technologies, which are too expensive for extensive utilization. For all these reasons in the last decades the use of low cost instrumentations from ships of opportunity (promoted within VOS and SOOP international research programmes), is gaining more and more attention. In order to reduce operative costs and to enhance spatial resolution of data, stand-alone systems provide continuous real-time information about the physical and biological states of the surface waters by moving ships. Following this philosophy, T-FLaP evolution leds to the development of a new low-cost mini ferrybox system, called Spectra, suitable for continuous in situ measures of temperature, conductivity (salinity and density), chlorophyll a and chromophoric dissolved organic matter (CDOM) fluorescence. The philosophy that inspired this instrument is therefore that of Ferrybox, but with miniaturization of components and a considerable reduction in costs. Spectra is composed by an electronic unit, dedicated to the data acquisition, transmission and storage, equipped with a GPS and a hydraulic unit where the measures occur. The measuring cell is a flow-through tubular cell where the water flows. The measuring cell has a modular structure. The design of the measuring cell has been studied in order to ensure that the sensors are in direct contact with the volume of water passing through the probe. In this work a detailed description of Spectra system is given. Moreover, the results of the application of
NASA Technical Reports Server (NTRS)
Papale, William; Chullen, Cinda; Campbell, Colin; Conger, Bruce; McMillin, Summer; Jeng, Frank
2014-01-01
Development activities related to the Rapid Cycle Amine (RCA) Carbon Dioxide (CO2) and Humidity control system have progressed to the point of integrating the RCA into an advanced Primary Life Support System (PLSS 2.0) to evaluate the interaction of the RCA among other PLSS components in a ground test environment. The RCA 2.0 assembly (integrated into PLSS 2.0) consists of a valve assembly with commercial actuator motor, a sorbent canister, and a field-programmable gate array (FPGA)-based process node controller. Continued design and development activities for RCA 3.0 have been aimed at optimizing the canister size and incorporating greater fidelity in the valve actuator motor and valve position feedback design. Further, the RCA process node controller is envisioned to incorporate a higher degree of functionality to support a distributed PLSS control architecture. This paper will describe the progression of technology readiness levels of RCA 1.0, 2.0 and 3.0 along with a review of the design and manufacturing successes and challenges for 2.0 and 3.0 units. The anticipated interfaces and interactions with the PLSS 2.0/2.5/3.0 assemblies will also be discussed.
Rubin, Geoffrey D; Leipsic, Jonathon; Joseph Schoepf, U; Fleischmann, Dominik; Napel, Sandy
2014-06-01
Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography. PMID:24848958
Liao, Ronglih; Podesser, Bruno K.
2012-01-01
The isolated retrograde-perfused Langendorff heart and the isolated ejecting heart have, over many decades, resulted in fundamental discoveries that form the underpinnings of our current understanding of the biology and physiology of the heart. These two experimental methodologies have proven invaluable in studying pharmacological effects on myocardial function, metabolism, and vascular reactivity and in the investigation of clinically relevant disease states such as ischemia-reperfusion injury, diabetes, obesity, and heart failure. With the advent of the genomics era, the isolated mouse heart preparation has gained prominence as an ex vivo research tool for investigators studying the impact of gene modification in the intact heart. This review summarizes the historical development of the isolated heart and provides a practical guide for the establishment of the Langendorff and ejecting heart preparations with a particular emphasis on the murine heart. In addition, current applications and novel methods of recording cardiovascular parameters in the isolated heart preparation will be discussed. With continued advances in methodological recordings, the isolated mouse heart preparation will remain physiologically relevant for the foreseeable future, serving as an integral bridge between in vitro assays and in vivo approaches. PMID:22636675
A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL)
NASA Technical Reports Server (NTRS)
Carroll, Chester C.; Owen, Jeffrey E.
1988-01-01
A direct-execution parallel architecture for the Advanced Continuous Simulation Language (ACSL) is presented which overcomes the traditional disadvantages of simulations executed on a digital computer. The incorporation of parallel processing allows the mapping of simulations into a digital computer to be done in the same inherently parallel manner as they are currently mapped onto an analog computer. The direct-execution format maximizes the efficiency of the executed code since the need for a high level language compiler is eliminated. Resolution is greatly increased over that which is available with an analog computer without the sacrifice in execution speed normally expected with digitial computer simulations. Although this report covers all aspects of the new architecture, key emphasis is placed on the processing element configuration and the microprogramming of the ACLS constructs. The execution times for all ACLS constructs are computed using a model of a processing element based on the AMD 29000 CPU and the AMD 29027 FPU. The increase in execution speed provided by parallel processing is exemplified by comparing the derived execution times of two ACSL programs with the execution times for the same programs executed on a similar sequential architecture.
Extended advance of continuous miner successfully ventilated with a scrubber in a blowing section
Volkwein, J.C.; Thimons, E.D.
1986-01-01
Underground testing was carried out by Ingersoll-Rand, Inc., under contract to the Bureau of Mines to determine the effectiveness of a machine-mounted scrubber system for ventilating the face during an extended advance. A continuous miner equipped with an integral flooded-bed dust scrubber system was instrumented with methanometers and Real-time Aerosol Monitor (RAM) dust monitors. Methane and respirable dust data were collected at brattice setbacks of 7.5 m (current operating distance), 10.5 m, and 15 m (blowing ventilation) during production shifts. Results showed that a suitable machine-mounted scrubber system can adequately ventilate the face at brattice setbacks up to 15 m. No deterioration in ventilation performance was observed as brattice setbacks were increased from 7.5 m to 15 m. The scrubber system effectively controlled face methane levels at large setbacks, though respirable dust levels increased as much as 33 pct at the operator's cab at setbacks greater than 7.5 m.
ERIC Educational Resources Information Center
Rowland, A. Westley, Ed.
The guide's purpose is to provide administrators with essential information that will maintain public confidence in higher education and ensure continued financial support. Six major aspects of institutional advancement are considered: (1) institutional relation (programs to improve communication and understanding among students, administrators,…
ERIC Educational Resources Information Center
Yukl, Gary A.; And Others
1976-01-01
Results of this study indicate that sample group of unskilled laborers were more productive working under a schedule of continuous reinforcement than under a varied schedule, despite higher average earnings during the latter program. (RW)
A Comparison of Methods for Structural Modeling with Polytomous and Continuous Variables.
ERIC Educational Resources Information Center
Berkovits, Ilona; Hancock, Gregory R.
A simulation study compared three methods of estimating parameters within structural equation models (SEM) with polytomous variables. These methods appear in three SEM computer software packages: (1) LISREL (Joreskog and Sorbom, 1996) with PRELIS (Joreskog and Sorbom); (2) EQS (Bentler, 1995); and (3) the new Mplus (Muthen and Muthen, 1998). The…
Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements
NASA Astrophysics Data System (ADS)
Campbell, J. F.; Lin, B.; Nehrir, A. R.; Obland, M. D.; Liu, Z.; Browell, E. V.; Chen, S.; Kooi, S. A.; Fan, T. F.
2015-12-01
Global and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and Atmospheric Carbon and Transport (ACT) - America airborne investigation are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are being investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the mission science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of intervening optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the Earth's surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques and provides very high (at sub-meter level) range resolution. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These techniques are used in a new data processing architecture to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs.
Advanced intensity-modulation continuous-wave lidar techniques for ASCENDS CO2 column measurements
NASA Astrophysics Data System (ADS)
Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. W.; Obland, Michael D.; Meadows, Byron
2015-10-01
Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.
Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for ASCENDS O2 Column Measurements
NASA Technical Reports Server (NTRS)
Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Meadows, Byron
2015-01-01
Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.
25 MHz clock continuous-variable quantum key distribution system over 50 km fiber channel.
Wang, Chao; Huang, Duan; Huang, Peng; Lin, Dakai; Peng, Jinye; Zeng, Guihua
2015-01-01
In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate. To reach high-rate, we have employed a homodyne detector with maximal bandwidth to 300 MHz and an optimal high-efficiency error reconciliation algorithm with processing speed up to 25 Mbps. To optimize the stability of the system, several key techniques are developed, which include a novel phase compensation algorithm, a polarization feedback algorithm, and related stability method on the modulators. Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance. Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions. PMID:26419413
25 MHz clock continuous-variable quantum key distribution system over 50 km fiber channel
Wang, Chao; Huang, Duan; Huang, Peng; Lin, Dakai; Peng, Jinye; Zeng, Guihua
2015-01-01
In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate. To reach high-rate, we have employed a homodyne detector with maximal bandwidth to 300 MHz and an optimal high-efficiency error reconciliation algorithm with processing speed up to 25 Mbps. To optimize the stability of the system, several key techniques are developed, which include a novel phase compensation algorithm, a polarization feedback algorithm, and related stability method on the modulators. Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance. Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions. PMID:26419413
Accidental cloning of a single-photon qubit in two-channel continuous-variable quantum teleportation
Ide, Toshiki; Hofmann, Holger F.
2007-06-15
The information encoded in the polarization of a single photon can be transferred to a remote location by two-channel continuous-variable quantum teleportation. However, the finite entanglement used in the teleportation causes random changes in photon number. If more than one photon appears in the output, the continuous-variable teleportation accidentally produces clones of the original input photon. In this paper, we derive the polarization statistics of the N-photon output components and show that they can be decomposed into an optimal cloning term and completely unpolarized noise. We find that the accidental cloning of the input photon is nearly optimal at experimentally feasible squeezing levels, indicating that the loss of polarization information is partially compensated by the availability of clones.
Chen, Haixia; Zhang, Jing
2007-02-15
We propose a scheme for continuous-variable quantum cloning of coherent states with phase-conjugate input modes using linear optics. The quantum cloning machine yields M identical optimal clones from N replicas of a coherent state and N replicas of its phase conjugate. This scheme can be straightforwardly implemented with the setups accessible at present since its optical implementation only employs simple linear optical elements and homodyne detection. Compared with the original scheme for continuous-variable quantum cloning with phase-conjugate input modes proposed by Cerf and Iblisdir [Phys. Rev. Lett. 87, 247903 (2001)], which utilized a nondegenerate optical parametric amplifier, our scheme loses the output of phase-conjugate clones and is regarded as irreversible quantum cloning.
Quantum hacking of two-way continuous-variable quantum key distribution using Trojan-horse attack
NASA Astrophysics Data System (ADS)
Ma, Hong-Xin; Bao, Wan-Su; Li, Hong-Wei; Chou, Chun
2016-08-01
We present a Trojan-horse attack on the practical two-way continuous-variable quantum key distribution system. Our attack mainly focuses on the imperfection of the practical system that the modulator has a redundancy of modulation pulse-width, which leaves a loophole for the eavesdropper inserting a Trojan-horse pulse. Utilizing the unique characteristics of two-way continuous-variable quantum key distribution that Alice only takes modulation operation on the received mode without any measurement, this attack allows the eavesdropper to render all of the final keys shared between the legitimate parties insecure without being detected. After analyzing the feasibility of the attack, the corresponding countermeasures are put forward. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002) and the National Natural Science Foundation of China (Grant Nos. 11304397 and 61505261).
Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio
2006-03-15
We present a complete analysis of the multipartite entanglement of three-mode Gaussian states of continuous-variable systems. We derive standard forms which characterize the covariance matrix of pure and mixed three-mode Gaussian states up to local unitary operations, showing that the local entropies of pure Gaussian states are bound to fulfill a relationship which is stricter than the general Araki-Lieb inequality. Quantum correlations can be quantified by a proper convex roof extension of the squared logarithmic negativity, the continuous-variable tangle, or contangle. We review and elucidate in detail the proof that in multimode Gaussian states the contangle satisfies a monogamy inequality constraint [G. Adesso and F. Illuminati, New J. Phys8, 15 (2006)]. The residual contangle, emerging from the monogamy inequality, is an entanglement monotone under Gaussian local operations and classical communications and defines a measure of genuine tripartite entanglements. We determine the analytical expression of the residual contangle for arbitrary pure three-mode Gaussian states and study in detail the distribution of quantum correlations in such states. This analysis yields that pure, symmetric states allow for a promiscuous entanglement sharing, having both maximum tripartite entanglement and maximum couplewise entanglement between any pair of modes. We thus name these states GHZ/W states of continuous-variable systems because they are simultaneous continuous-variable counterparts of both the GHZ and the W states of three qubits. We finally consider the effect of decoherence on three-mode Gaussian states, studying the decay of the residual contangle. The GHZ/W states are shown to be maximally robust against losses and thermal noise.
NASA Astrophysics Data System (ADS)
Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio
2006-03-01
We present a complete analysis of the multipartite entanglement of three-mode Gaussian states of continuous-variable systems. We derive standard forms which characterize the covariance matrix of pure and mixed three-mode Gaussian states up to local unitary operations, showing that the local entropies of pure Gaussian states are bound to fulfill a relationship which is stricter than the general Araki-Lieb inequality. Quantum correlations can be quantified by a proper convex roof extension of the squared logarithmic negativity, the continuous-variable tangle, or contangle. We review and elucidate in detail the proof that in multimode Gaussian states the contangle satisfies a monogamy inequality constraint [G. Adesso and F. Illuminati, New J. Phys8, 15 (2006)]. The residual contangle, emerging from the monogamy inequality, is an entanglement monotone under Gaussian local operations and classical communications and defines a measure of genuine tripartite entanglements. We determine the analytical expression of the residual contangle for arbitrary pure three-mode Gaussian states and study in detail the distribution of quantum correlations in such states. This analysis yields that pure, symmetric states allow for a promiscuous entanglement sharing, having both maximum tripartite entanglement and maximum couplewise entanglement between any pair of modes. We thus name these states GHZ/W states of continuous-variable systems because they are simultaneous continuous-variable counterparts of both the GHZ and the W states of three qubits. We finally consider the effect of decoherence on three-mode Gaussian states, studying the decay of the residual contangle. The GHZ/W states are shown to be maximally robust against losses and thermal noise.
Computable criterion for partial entanglement in continuous-variable quantum systems
Gabriel, Andreas; Huber, Marcus; Radic, Sasa; Hiesmayr, Beatrix C.
2011-05-15
A general and computable criterion for k-(in)separability in continuous multipartite quantum systems is presented. The criterion can be experimentally implemented with a finite and comparatively low number of local observables. We discuss in detail how the detection quality can be optimized.
Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F.; Schnabel, Roman
2015-01-01
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components. PMID:26514280
Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F; Schnabel, Roman
2015-01-01
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components. PMID:26514280
NASA Astrophysics Data System (ADS)
Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F.; Schnabel, Roman
2015-10-01
Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.
Continuous brightening of the eruptive variable V2493 Cyg (HBC 722)
NASA Astrophysics Data System (ADS)
Antoniucci, S.; Arkharov, A.; Klimanov, S.; Lorenzetti, D.; Giannini, T.; Di Paola, A.; Larionov, V.
2013-04-01
As anticipated (Lorenzetti et al. 2009 ApJ 693, 1056), we are constantly monitoring the eruptive variable V2493 Cyg (otherwise called HBC 722) in the near-IR with the AZT24 1m-telescope (Campo Imperatore, Italy). Since its outburst in Aug. 2009 (Miller et al. 2011 ApJ 730, 80; ATel #2801, ATel #2854) this source has been widely monitored (Kospal et al. 2011 A&A 527, A133, Lorenzetti et al. 2012 ApJ 749, 188; Semkov et al.
The Importance of Continued Satellite Gravity Missions for Understanding Ocean Mass Variability
NASA Astrophysics Data System (ADS)
Chambers, Don
2010-05-01
Global gravity observations from satellite missions such as GRACE are unique in the way that they observe mass exchanges among the ocean, cryosphere, and land, as well as mass exchanges from one ocean basin to another. No longer does one need to patch together disparate measurements (e.g., sea level, in situ temperature measurements, glacier and ice sheet surface mass balances, unknown land hydrology) to infer changes in the global ocean mass. For the first time, we can directly measure it. We can also observe local fluctuations in the ocean mass caused by changes in wind stress and ocean circulation, not all of which can be modeled accurately. We will review recent results for global ocean mass variability and ocean mass exchange between basins and point out problems with inferring these by other means, such as combinations of altimetry and in situ temperature profilers and from global ocean models. We have only recently been able to appreciate the unique information on low-frequency fluctuations in local and global ocean mass that can be gained from satellite gravity missions. It would be a shame to loose this important new data in the coming years and return to process of inferring ocean mass variability rather than measuring it.
Bowen, Judith L; Hirsh, David; Aagaard, Eva; Kaminetzky, Catherine P; Smith, Marie; Hardman, Joseph; Chheda, Shobhina G
2015-05-01
Continuity of care is a core value of patients and primary care physicians, yet in graduate medical education (GME), creating effective clinical teaching environments that emphasize continuity poses challenges. In this Perspective, the authors review three dimensions of continuity for patient care-informational, longitudinal, and interpersonal-and propose analogous dimensions describing continuity for learning that address both residents learning from patient care and supervisors and interprofessional team members supporting residents' competency development. The authors review primary care GME reform efforts through the lens of continuity, including the growing body of evidence that highlights the importance of longitudinal continuity between learners and supervisors for making competency judgments. The authors consider the challenges that primary care residency programs face in the wake of practice transformation to patient-centered medical home models and make recommendations to maximize the opportunity that these practice models provide. First, educators, researchers, and policy makers must be more precise with terms describing various dimensions of continuity. Second, research should prioritize developing assessments that enable the study of the impact of interpersonal continuity on clinical outcomes for patients and learning outcomes for residents. Third, residency programs should establish program structures that provide informational and longitudinal continuity to enable the development of interpersonal continuity for care and learning. Fourth, these educational models and continuity assessments should extend to the level of the interprofessional team. Fifth, policy leaders should develop a meaningful recognition process that rewards academic practices for training the primary care workforce. PMID:25470307
Romero, Vicente Jose; Ayon, Douglas V.; Chen, Chun-Hung
2003-09-01
A very general and robust approach to solving optimization problems involving probabilistic uncertainty is through the use of Probabilistic Ordinal Optimization. At each step in the optimization problem, improvement is based only on a relative ranking of the probabilistic merits of local design alternatives, rather than on crisp quantification of the alternatives. Thus, we simply ask the question: 'Is that alternative better or worse than this one?' to some level of statistical confidence we require, not: 'HOW MUCH better or worse is that alternative to this one?'. In this paper we illustrate an elementary application of probabilistic ordinal concepts in a 2-D optimization problem. Two uncertain variables contribute to uncertainty in the response function. We use a simple Coordinate Pattern Search non-gradient-based optimizer to step toward the statistical optimum in the design space. We also discuss more sophisticated implementations, and some of the advantages and disadvantages versus non-ordinal approaches for optimization under uncertainty.
Proposal for continuously-variable neutrino beam energy for the NuMI facility
Kostin, Mikhail; Kopp, Sacha; Messier, Mark; Harris, Deborah A.; Hylen, Jim; Para, Adam; /Fermilab
2006-07-01
The NuMI Facility was intended to be flexibly changed between 3 energies of beams, LE, ME, and HE. However, the changeover requires extensive downtime to move and realign horns and the target. We propose to implement a flexible arrangement where the target can be remotely moved in the beamline direction to change the beam energy and the horns remain fixed. In addition to having the attractive feature of keeping the horn optics fixed, the motion of the target can be performed more quickly and hence on a more frequent basis. We discuss potential increases in statistics in the high energy region, systematic cross-checks available, and the improved beam monitoring capabilities with such variable energy beams.
A simple technique for continuous measurement of time-variable gas transfer in surface waters
Bohlke, Johnkarl F.; Harvey, Judson W.; Busenberg, Eurybiades; Tobias, Craig R.
2009-01-01
Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.
A simple technique for continuous measurement of time-variable gas transfer in surface waters
Tobias, C.R.; Böhlke, J.K.; Harvey, J.W.; Busenberg, E.
2009-01-01
Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating wholeecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF 6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF 6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.
Zheng, Zhoutao; Zhu, Wenquan; Chen, Guangsheng; Jiang, Nan; Fan, Deqin; Zhang, Donghai
2016-04-25
The Qinghai-Tibetan Plateau (QTP) is more vulnerable and sensitive to climate change than many other regions worldwide because of its high altitude, permafrost geography, and harsh physical environment. As a sensitive bio-indicator of climate change, plant phenology shift in this region has been intensively studied during the recent decades, primarily based on satellite-retrieved data. However, great controversy still exists regarding the change in direction and magnitudes of spring-summer phenology. Based on a large number (11,000+ records) of long-term and continuous ground observational data for various plant species, our study intended to more comprehensively assess the changing trends of spring-summer phenologymore » and their relationships with climatic change across the QTP. The results indicated a continuous advancement (–2.69 days decade–1) in spring-summer phenology from 1981 to 2011, with an even more rapid advancement during 2000–2011 (–3.13 days decade–1), which provided new field evidence for continuous advancement in spring-summer phenology across the QTP. However, diverse advancing rates in spring-summer phenology were observed for different vegetation types, thermal conditions, and seasons. The advancing trends matched well with the difference in sensitivity of spring-summer phenology to increasing temperature, implying that the sensitivity of phenology to temperature was one of the major factors influencing spring-summer phenology shifts. Besides, increased precipitation could advance the spring-summer phenology. As a result, the response of spring-summer phenology to temperature tended to be stronger from east to west across all species, while the response to precipitation showed no consistent spatial pattern.« less
Adesso, Gerardo; Ericsson, Marie; Illuminati, Fabrizio
2007-08-15
Quantum mechanics imposes 'monogamy' constraints on the sharing of entanglement. We show that, despite these limitations, entanglement can be fully 'promiscuous', i.e., simultaneously present in unlimited two-body and many-body forms in states living in an infinite-dimensional Hilbert space. Monogamy just bounds the divergence rate of the various entanglement contributions. This is demonstrated in simple families of N-mode (N{>=}4) Gaussian states of light fields or atomic ensembles, which therefore enable infinitely more freedom in the distribution of information, as opposed to systems of individual qubits. Such a finding is of importance for the quantification, understanding, and potential exploitation of shared quantum correlations in continuous variable systems. We discuss how promiscuity gradually arises when considering simple families of discrete variable states, with increasing Hilbert space dimension towards the continuous variable limit. Such models are somehow analogous to Gaussian states with asymptotically diverging, but finite, squeezing. In this respect, we find that non-Gaussian states (which in general are more entangled than Gaussian states) exhibit also the interesting feature that their entanglement is more shareable: in the non-Gaussian multipartite arena, unlimited promiscuity can be already achieved among three entangled parties, while this is impossible for Gaussian, even infinitely squeezed states.
NASA Astrophysics Data System (ADS)
Adesso, Gerardo; Ericsson, Marie; Illuminati, Fabrizio
2007-08-01
Quantum mechanics imposes “monogamy” constraints on the sharing of entanglement. We show that, despite these limitations, entanglement can be fully “promiscuous,” i.e., simultaneously present in unlimited two-body and many-body forms in states living in an infinite-dimensional Hilbert space. Monogamy just bounds the divergence rate of the various entanglement contributions. This is demonstrated in simple families of N -mode (N⩾4) Gaussian states of light fields or atomic ensembles, which therefore enable infinitely more freedom in the distribution of information, as opposed to systems of individual qubits. Such a finding is of importance for the quantification, understanding, and potential exploitation of shared quantum correlations in continuous variable systems. We discuss how promiscuity gradually arises when considering simple families of discrete variable states, with increasing Hilbert space dimension towards the continuous variable limit. Such models are somehow analogous to Gaussian states with asymptotically diverging, but finite, squeezing. In this respect, we find that non-Gaussian states (which in general are more entangled than Gaussian states) exhibit also the interesting feature that their entanglement is more shareable: in the non-Gaussian multipartite arena, unlimited promiscuity can be already achieved among three entangled parties, while this is impossible for Gaussian, even infinitely squeezed states.
Ronchi, Paolo; Ambrosoli, Alessandro; Caprioglio, Alberto
2013-01-01
ABSTRACT Objectives The present retrospective study analyzes sagittal cephalometric changes in patients affected by obstructive sleep apnea syndrome submitted to maxillomandubular advancement. Material and Methods 15 adult sleep apnea syndrome (OSAS) patients diagnosed by polysomnography (PSG) and treated with maxillomandubular advancement (MMA) were included in this study. Pre- (T1) and postsurgical (T2) PSG studies assessing the apnea/hypopnea index (AHI) and the lowest oxygen saturation (LSAT) level were compared. Lateral cephalometric radiographs at T1 and T2 measuring sagittal cephalometric variables (SNA, SNB, and ANB) were analyzed, as were the amount of maxillary and mandibular advancement (Co-A and Co-Pog), the distance from the mandibular plane to the most anterior point of the hyoid bone (Mp-H), and the posterior airway space (PAS). Results Postoperatively, the overall mean AHI dropped from 58.7 ± 16 to 8.1 ± 7.8 events per hour (P < 0.001). The mean preoperative LSAT increased from 71% preoperatively to 90% after surgery (P < 0.001). All the patients in our study were successfully treated (AHI < 20 or reduced by 50%). Cephalometric analysis performed after surgery showed a statistically significant correlation between the mean SNA variation and the decrease in the AHI (P = 0.01). The overall mean SNA increase was 6°. Conclusions Our findings suggest that the improvement observed in the respiratory symptoms, namely the apnea/hypopnea episodes, is correlated with the SNA increase after surgery. This finding may help maxillofacial surgeons to establish selective criteria for the surgical approach to sleep apnea syndrome patients. PMID:24422033
Self-optimising control for a class of continuous bioreactor via variable-structure feedback
NASA Astrophysics Data System (ADS)
Lara-Cisneros, Gerardo; Alvarez-Ramírez, José; Femat, Ricardo
2016-04-01
A self-optimising controller is designed for stabilisation of a class of bioreactor exploiting sliding-mode techniques. The stability analysis for the class of bioreactor, in open-loop configuration, suggests that the optimal behaviour, respect to maximal biomass production, occurs in an unstable region (structurally unstable). In this contribution, a variable-structure controller is designed, exploiting the inhibitory effect of substrate concentration under the biomass growth rate, such that the closed-loop system reaches the optimal manifold where the effect induced by the growth rate gradient is compensated (favouring the maximum growth rate). The self-optimising comprises an uncertainty estimator which computes the unknown terms for increasing the robustness issues of the sliding-mode scheme. Numerical experiments illustrate the performance and execution of the control strategy considering different parameter values for biomass growth rate. The robustness and fragility of the proposed controller are also discussed with respect to the modelling uncertainty and small changes in the controller gains, respectively.
NASA Astrophysics Data System (ADS)
Andronov, I. L.; Chinarova, L. L.; Kudashkina, L. S.; Marsakova, V. I.; Tkachenko, M. G.
2016-06-01
We have elaborated a set of new algorithms and programs for advanced time series analysis of (generally) multi-component multi-channel observations with irregularly spaced times of observations, which is a common case for large photometric surveys. Previous self-review on these methods for periodogram, scalegram, wavelet, autocorrelation analysis as well as on "running" or "sub-interval" local approximations were self-reviewed in (2003ASPC..292..391A). For an approximation of the phase light curves of nearly-periodic pulsating stars, we use a Trigonometric Polynomial (TP) fit of the statistically optimal degree and initial period improvement using differential corrections (1994OAP.....7...49A). For the determination of parameters of "characteristic points" (minima, maxima, crossings of some constant value etc.) we use a set of methods self-reviewed in 2005ASPC..335...37A, Results of the analysis of the catalogs compiled using these programs are presented in 2014AASP....4....3A. For more complicated signals, we use "phenomenological approximations" with "special shapes" based on functions defined on sub-intervals rather on the complete interval. E. g. for the Algol-type stars we developed the NAV ("New Algol Variable") algorithm (2012Ap.....55..536A, 2012arXiv1212.6707A, 2015JASS...32..127A), which was compared to common methods of Trigonometric Polynomial Fit (TP) or local Algebraic Polynomial (A) fit of a fixed or (alternately) statistically optimal degree. The method allows determine the minimal set of parameters required for the "General Catalogue of Variable Stars", as well as an extended set of phenomenological and astrophysical parameters which may be used for the classification. Totally more that 1900 variable stars were studied in our group using these methods in a frame of the "Inter-Longitude Astronomy" campaign (2010OAP....23....8A) and the "Ukrainian Virtual Observatory" project (2012KPCB...28...85V).
ERIC Educational Resources Information Center
Tuvi-Arad, Inbal; Blonder, Ron
2010-01-01
In this paper we describe the learning process of a group of experienced chemistry teachers in a specially designed workshop on molecular symmetry and continuous symmetry. The workshop was based on interactive visualization tools that allow molecules and their symmetry elements to be rotated in three dimensions. The topic of continuous symmetry is…
Continuous Improvement in Education. Advancing Teaching--Improving Learning. White Paper
ERIC Educational Resources Information Center
Park, Sandra; Hironaka, Stephanie; Carver, Penny; Nordstrum, Lee
2013-01-01
In recent years, "continuous improvement" has become a popular catchphrase in the field of education. However, while continuous improvement has become commonplace and well-documented in other industries, such as healthcare and manufacturing, little is known about how this work has manifested itself in education. This white paper attempts…
NASA Astrophysics Data System (ADS)
Olsen, M. K.; Cavalcanti, E. G.
2016-07-01
The fully symmetric Gaussian tripartite entangled pure states will not exhibit two-mode Einstein-Podolsky-Rosen (EPR) steering. This means that any two participants cannot share quantum secrets using the security of one-sided device independent quantum key distribution (1SDI-QKD) without involving the third. They are restricted at most to standard quantum key distribution, which is less secure. Here we demonstrate an asymmetric tripartite system that can exhibit bipartite EPR steering, so that two of the participants can use 1SDI-QKD without involving the other. This is possible because the promiscuity relations of continuous-variable tripartite entanglement are different from those of discrete-variable systems. We analyze these properties for two different systems, showing that the asymmetric system exhibits practical properties not found in the symmetric one.
Quantification abilities in angelfish (Pterophyllum scalare): the influence of continuous variables.
Gómez-Laplaza, Luis M; Gerlai, Robert
2013-05-01
Previous studies investigating quantity discrimination have shown that angelfish are able to select the larger of two groups of conspecifics (shoals). The discrimination limits shown by angelfish were similar to those found for other vertebrates when large (≥4) and small quantities (<4) were presented. However, in these studies, no attempt was made to control for non-numerical features of the stimulus shoals and thus the question whether numerical or some quantitative attributes of the shoals were utilized for making the choices could not be answered. Here, we investigate whether angelfish can discriminate between shoals differing in numerical size using non-numerical attributes. We systematically manipulate density, inter-fish distance, and overall space occupied by the shoals, one factor at a time, and analyse the choices angelfish made between the contrasting stimulus shoals. The stimulus shoals consisted of contrasts between large (10 vs. 5) and small (3 vs. 2) number of conspecifics. We found density to be a sufficient condition for discrimination between large shoals as the test subjects preferred the more dense shoal. Manipulation of inter-fish distance indicated that this variable is not a necessary factor in discrimination at either shoal size contrast. Likewise, we found that the size of space occupied by the contrasted shoals also did not significantly influence discrimination. Sensitivity to the density of large shoals indicates that angelfish can discriminate shoal size using this non-numerical cue. Nevertheless, the factors we examined may represent only a subset of all possible non-numerical features upon which angelfish may base their discrimination. Thus, we suggest that further research is required to clarify whether and under what circumstances angelfish may use numerical or non-numerical features when discriminating between shoals of differing size. PMID:23161214
Carlisle, J B; Dexter, F; Pandit, J J; Shafer, S L; Yentis, S M
2015-07-01
In a previous paper, one of the authors (JBC) used a chi-squared method to analyse the means (SD) of baseline variables, such as height or weight, from randomised controlled trials by Fujii et al., concluding that the probabilities that the reported distributions arose by chance were infinitesimally small. Subsequent testing of that chi-squared method, using simulation, suggested that the method was incorrect. This paper corrects the chi-squared method and tests its performance and the performance of Monte Carlo simulations and ANOVA to analyse the probability of random sampling. The corrected chi-squared method and ANOVA method became inaccurate when applied to means that were reported imprecisely. Monte Carlo simulations confirmed that baseline data from 158 randomised controlled trials by Fujii et al. were different to those from 329 trials published by other authors and that the distribution of Fujii et al.'s data were different to the expected distribution, both p < 10(-16) . The number of Fujii randomised controlled trials with unlikely distributions was less with Monte Carlo simulation than with the 2012 chi-squared method: 102 vs 117 trials with p < 0.05; 60 vs 86 for p < 0.01; 30 vs 56 for p < 0.001; and 12 vs 24 for p < 0.00001, respectively. The Monte Carlo analysis nevertheless confirmed the original conclusion that the distribution of the data presented by Fujii et al. was extremely unlikely to have arisen from observed data. The Monte Carlo analysis may be an appropriate screening tool to check for non-random (i.e. unreliable) data in randomised controlled trials submitted to journals. PMID:26032950
Some continuously variable partial snakes of Type 1 and Type 2
Underwood, D.G.
1988-11-30
In order to obtain polarized beam in proton accelerators, Siberian snakes of two types may be needed in order to establish a spin tune independent of energy. We have done a numerical study to find a type II partial snake and to find more exact solutions for the type I partial snakes previously proposed. We find a type II partial snake. We find that the unequal field integrals needed to modify approximate type I snakes to exactly type I snakes with horizontal and vertical bends result in unacceptably large orbit excursions. We find a new type I snake with smaller field integrals at small overall rotation. An 8 magnet type II snake works from 0 to {pi} but more magnets might be used to reduce the excursion at small angle. Also, no type I partial snake with as few as 8 magnets has been found which will work continuously from 0 to {pi}. It appears that horizontal and vertical bends cannot provide solutions for pure type I or type II that allow the field integrals to approach zero as the rotation goes to zero. Versions of both the new type I and type II partial snakes are presently used as rotators in the external polarized beamline at Fermilab. 8 refs., 7 figs.
Continuous Transmission Frequency Modulation Detection under Variable Sonar-Target Speed Conditions
Wang, Yang; Yang, Jun
2013-01-01
As a ranging sensor, a continuous transmission frequency modulation (CTFM) sonar with its ability for range finding and range profile formation works effectively under stationary conditions. When a relative velocity exists between the target and the sonar, the echo signal is Doppler-shifted. This situation causes the output of the sensor to deviate from the actual target range, thus limiting its applications to stationary conditions only. This work presents an approach for correcting such a deviation. By analyzing the Doppler effect during the propagation process, the sensor output can be corrected by a Doppler factor. To obtain this factor, a conventional CTFM system is slightly modified by adding a single tone signal with a frequency that locates out-of-sweep range of the transmitted signal. The Doppler factor can be extracted from the echo. Both verification experiments and performance tests are carried out. Results indicate the validity of the proposed approach. Moreover, ranging precision under different processing setups is discussed. For adjacent multiple targets, the discrimination ability is influenced by displacement and velocity. A discrimination boundary is provided through an analysis. PMID:23486221
Continuous transmission frequency modulation detection under variable sonar-target speed conditions.
Wang, Yang; Yang, Jun
2013-01-01
As a ranging sensor, a continuous transmission frequency modulation (CTFM) sonar with its ability for range finding and range profile formation works effectively under stationary conditions. When a relative velocity exists between the target and the sonar, the echo signal is Doppler-shifted. This situation causes the output of the sensor to deviate from the actual target range, thus limiting its applications to stationary conditions only. This work presents an approach for correcting such a deviation. By analyzing the Doppler effect during the propagation process, the sensor output can be corrected by a Doppler factor. To obtain this factor, a conventional CTFM system is slightly modified by adding a single tone signal with a frequency that locates out-of-sweep range of the transmitted signal. The Doppler factor can be extracted from the echo. Both verification experiments and performance tests are carried out. Results indicate the validity of the proposed approach. Moreover, ranging precision under different processing setups is discussed. For adjacent multiple targets, the discrimination ability is influenced by displacement and velocity. A discrimination boundary is provided through an analysis. PMID:23486221
Abbruzzese, Giovanni; Barone, Paolo; Bonuccelli, Ubaldo; Lopiano, Leonardo; Antonini, Angelo
2012-01-01
Long-term oral therapy with levodopa is associated with the development of motor ﬂuctuations and dyskinesia in a large percentage of patients with Parkinson's disease (PD). Motor complications are associated with a number of non-motor symptoms and have a negative impact on disability and quality of life. There are three therapeutic options available for the management of patients at this advanced stage: high frequency deep brain stimulation, continuous subcutaneous infusion of apomorphine, and continuous intestinal infusion of levodopa/carbidopa. On the basis of published data and in consideration of the risk-beneﬁt proﬁle of current therapeutic strategies, we here propose an algorithm to help clinicians select the most suitable treatment option for patients with advanced PD. PMID:23402675
NASA Astrophysics Data System (ADS)
Krasilenko, Vladimir G.; Nikolskyy, Aleksandr I.; Lazarev, Alexander A.
2015-01-01
We have proposed a design and simulation of hardware realizations of smart multifunctional continuous logic devices (SMCLD) as advanced basic cells of the sensor systems with MIMO- structure for images processing and interconnection. The SMCLD realize function of two-valued, multi-valued and continuous logics with current inputs and current outputs. Such advanced basic cells realize function nonlinear time-pulse transformation, analog-to-digital converters and neural logic. We showed advantages of such elements. It's have a number of advantages: high speed and reliability, simplicity, small power consumption, high integration level. The conception of construction of SMCLD consists in the use of a current mirrors realized on 1.5μm technology CMOS transistors. Presence of 50÷70 transistors, 1 PD and 1 LED makes the offered circuits quite compact. The simulation results of NOT, MIN, MAX, equivalence (EQ), normalize summation, averaging and other functions, that implemented SMCLD, showed that the level of logical variables can change from 0.1μA to 10μA for low-power consumption variants. The SMCLD have low power consumption <1mW and processing time about 1÷11μS at supply voltage 2.4÷3.3V.
Turco, Mary G; Baron, Robert B
2016-01-01
The 2016 World Congress on Continuing Professional Development: Advancing Learning and Care in the Health Professions took place in San Diego, California, March 17-19, 2016. Hosts were the Association for Hospital Medical Education (AHME), Alliance for Continuing Education in the Health Professionals (ACEhp), and Society for Academic Continuing Medical Education (SACME). The target audience was the international community working to improve medical (CME), nursing (CNE), pharmacy (CPE), and interprofessional (CIPE) continuing education (CE) and continuing professional development (CPD). Goals included: addressing patients' concerns and needs; advancing global medical and interprofessional health sciences education; utilizing learning to address health disparities; and promoting international cooperation. The five keynote speakers were: patient advocate Alicia Cole ("Why What We Do Matters: The Patients Voice"); linguist Lorelei Lingard ("Myths about Healthcare Teamwork and Their Implications for How We Understand Competence"); futurist and philosopher Alex Jadad ("What Do We Need to Protect at All Costs in the 21st Century?"); ethicist and change agent Zeke Emanuel ("Learn to Change: Teaching Toward a Shifting Healthcare Horizon"); and technology innovator Stephen Downes ("From Individual to Community: The Learning Is in the Doing"). Organizers announced the new Dave Davis Distinguished Award for Excellence in Mentorship in Continuing Professional Development to honor the career of David Davis, MD, in CME/CPD scholarship in Canada, the United States, and beyond. Participants valued the emphasis on interprofessional education and practice, the importance of integrating the patient voice, the effectiveness of flipped classroom methods, and the power of collective competency theories. Attendee-respondents encouraged Congress planners to continue to strive for a broad global audience and themes of international interest. PMID:27584068
Advanced lung cancer patients' experience with continuity of care and supportive care needs.
Husain, Amna; Barbera, Lisa; Howell, Doris; Moineddin, Rahim; Bezjak, Andrea; Sussman, Jonathan
2013-05-01
As cancer care becomes increasingly complex, the ability to coordinate this care is more difficult for health care providers, patients and their caregivers alike. Despite the widely recognized need for improving continuity and coordination of care, the relationship of continuity of care with patient outcomes has yet to be elucidated. Our study's main finding is that the Continuity and Coordination subscale of the widely used Picker System of Ambulatory Cancer Care Survey is able to distinguish between lung cancer patients with unmet supportive care needs and those without. Specifically, this study shows a new association between this widely implemented continuity and coordination survey and the 'psychological needs' domain, as well as the 'health system and information' domains of supportive care needs. The finding provides support for the idea that interventions to improve continuity may impact tangible indicators of patient care such as supportive care needs being met. The study focuses attention on continuity of care as an important aspect of optimizing outcomes in cancer care. PMID:23274923
Heavner, Karyn; Burstyn, Igor
2015-01-01
Variation in the odds ratio (OR) resulting from selection of cutoffs for categorizing continuous variables is rarely discussed. We present results for the effect of varying cutoffs used to categorize a mismeasured exposure in a simulated population in the context of autism spectrum disorders research. Simulated cohorts were created with three distinct exposure-outcome curves and three measurement error variances for the exposure. ORs were calculated using logistic regression for 61 cutoffs (mean ± 3 standard deviations) used to dichotomize the observed exposure. ORs were calculated for five categories with a wide range for the cutoffs. For each scenario and cutoff, the OR, sensitivity, and specificity were calculated. The three exposure-outcome relationships had distinctly shaped OR (versus cutoff) curves, but increasing measurement error obscured the shape. At extreme cutoffs, there was non-monotonic oscillation in the ORs that cannot be attributed to “small numbers.” Exposure misclassification following categorization of the mismeasured exposure was differential, as predicted by theory. Sensitivity was higher among cases and specificity among controls. Cutoffs chosen for categorizing continuous variables can have profound effects on study results. When measurement error is not too great, the shape of the OR curve may provide insight into the true shape of the exposure-disease relationship. PMID:26305250
Michel Lange, Violaine; Laganaro, Marina
2014-01-01
The literature on advance phonological planning in adjective-noun phrases (NPs) presents diverging results: while many experimental studies suggest that the entire NP is encoded before articulation, other results favor a span of encoding limited to the first word. Although cross-linguistic differences in the structure of adjective-NPs may account for some of these contrasting results, divergences have been reported even among similar languages and syntactic structures. Here we examined whether inter-individual differences account for variability in the span of phonological planning in the production of French NPs, where previous results indicated encoding limited to the first word. The span of phonological encoding is tested with the picture-word interference (PWI) paradigm using phonological distractors related to the noun or to the adjective of the NPs. In Experiment 1, phonological priming effects were limited to the first word in adjective NPs whichever the position of the adjective (pre-nominal or post-nominal). Crucially, phonological priming effects on the second word interacted with speakers' production speed suggesting different encoding strategies for participants. In Experiment 2, we tested this hypothesis further with a larger group of participants. Results clearly showed that slow and fast initializing participants presented different phonological priming patterns on the last element of adjective-NPs: while the first word was primed by a distractor for all speakers, only the slow speaker group presented a priming effect on the second element of the NP. These results show that the span of phonological encoding is modulated by inter-individual strategies: in experimental paradigms some speakers plan word by word whereas others encode beyond the initial word. We suggest that the diverging results reported in the literature on advance phonological planning may partly be reconciled in light of the present results. PMID:24550866
Michel Lange, Violaine; Laganaro, Marina
2014-01-01
The literature on advance phonological planning in adjective-noun phrases (NPs) presents diverging results: while many experimental studies suggest that the entire NP is encoded before articulation, other results favor a span of encoding limited to the first word. Although cross-linguistic differences in the structure of adjective-NPs may account for some of these contrasting results, divergences have been reported even among similar languages and syntactic structures. Here we examined whether inter-individual differences account for variability in the span of phonological planning in the production of French NPs, where previous results indicated encoding limited to the first word. The span of phonological encoding is tested with the picture-word interference (PWI) paradigm using phonological distractors related to the noun or to the adjective of the NPs. In Experiment 1, phonological priming effects were limited to the first word in adjective NPs whichever the position of the adjective (pre-nominal or post-nominal). Crucially, phonological priming effects on the second word interacted with speakers' production speed suggesting different encoding strategies for participants. In Experiment 2, we tested this hypothesis further with a larger group of participants. Results clearly showed that slow and fast initializing participants presented different phonological priming patterns on the last element of adjective-NPs: while the first word was primed by a distractor for all speakers, only the slow speaker group presented a priming effect on the second element of the NP. These results show that the span of phonological encoding is modulated by inter-individual strategies: in experimental paradigms some speakers plan word by word whereas others encode beyond the initial word. We suggest that the diverging results reported in the literature on advance phonological planning may partly be reconciled in light of the present results. PMID:24550866
Profile control of advanced tokamak plasmas in view of continuous operation
NASA Astrophysics Data System (ADS)
Mazon, D.
2015-07-01
The concept of the tokamak is a very good candidate to lead to a fusion reactor. In fact, certain regimes of functioning allow today the tokamaks to attain performances close to those requested by a reactor. Among the various scenarios of functioning nowadays considered for the reactor option, certain named 'advanced scenarios' are characterized by an improvement of the stability and confinement in the plasma core, as well as by a modification of the current profile, notably thank to an auto-generated 'bootstrap' current. The general frame of this paper treats the perspective of a real-time control of advanced regimes. Concrete examples will underline the impact of diagnostics on the identification of plasma models, from which the control algorithms are constructed. Several preliminary attempts will be described.
NASA Technical Reports Server (NTRS)
Englar, Robert J.
1998-01-01
Personnel of the Georgia Tech Research Institute (GTRI) Aerospace and Transportation Lab have completed a four-year grant program to develop and evaluate the pneumatic aerodynamic technology known as Circulation Control (CC) or Circulation Control Wing (CCW) for advanced transport aircraft. This pneumatic technology, which employs low-level blowing from tangential slots over round or near-round trailing edges of airfoils, greatly augments the circulation around a lifting or control surface and thus enhances the aerodynamic forces and moments generated by that surface. Two-dimensional force augmentations as high as 80 times the input blowing momentum coefficient have been recorded experimentally for these blown devices, thus providing returns of 8000% on the jet momentum expended. A further benefit is the absence of moving parts such as mechanical flaps, slats, spoilers, ailerons, elevators and rudders from these pneumatic surfaces, or the use of only very small, simple, blown aerodynamic surfaces on synergistic designs which integrate the lift, drag and control surfaces. The application of these devices to advanced aircraft can offer significant benefits in their performance, efficiency, simplicity, reliability, economic cost of operation, noise reduction, and safety of flight. To further develop and evaluate this potential, this research effort was conducted by GTRI under grant for the NASA Langley Research Center, Applied Aerodynamics Division, Subsonic Aerodynamics Branch, between June 14, 1993 and May 31, 1997.
Development of an advanced, continuous mild gasification process for the production of co-products
Wolfe, R.A.; Wright, R.E.; Im, C.J.; Henkelman, M.R.; O`Neal, G.W.
1992-11-01
The objective of this project is to develop a continuous mild gasification process to convert highly caking coals to coal liquids, char and coke for near term commercial application. Task 3, Bench-Scale Char Upgrading Study, has been underway since September 1989. In char upgrading studies, ``green`` uncured char briquettes have been prepared and calcined in 20-pound batches to evaluate the effects of char, binders, and heating conditions on final coke properties. A total of 150. formulations have been tested thus far in this work. Work on Task 4, Process Development Unit (PDU) Mild Gasification Study, has been in progress since February 1991, with the completion of a Continuous Mild Gasification Unit (CMGU) with a design rate of 1000 lb./hr. Since start-up of the CMGU, there have been 72 runs with a variety of operating conditions and coal types.
A Continuous Quality Improvement Program to Focus a College of Pharmacy on Programmatic Advancement
DiPiro, Joseph T.; Rowen, Randall C.; McNair, David
2013-01-01
Objective. To enhance the achievement of a college of pharmacy’s goals for education, research, and service missions by implementing an excellence program based on the Studer Group model for continuous quality improvement. Methods. The Studer model was combined with university strategic planning for a comprehensive quality-improvement program that was implemented over 5 years. The program included identifying and measuring key performance indicators, establishing specific “pillar” goals, aligning behaviors with goals and values, and training leaders. Results. Assessment of key performance indicators over 5 years demonstrated progress toward achieving college goals for student and faculty satisfaction, research funding, numbers of students seeking formal postgraduate training, and private giving. Conclusions. Implementation of a continuous quality-improvement program based on the Studer program enabled the college to focus on and meet its yearly and strategic goals for all components of its mission. PMID:23966720
Continuously Variable Transmission
NASA Technical Reports Server (NTRS)
Grana, D. C.
1985-01-01
Chain slides along two cones, in novel transmission concept. Transmission includes chain drive between two splined shafts. Chain sprockets follow surfaces of two cones. As one chain sprocket moves toward smaller diameter other chain sprocket moves toward larger diameter, thereby changing "gear" ratio. Movement initiated by tension applied to chain by planetary gear mechanism. Device positive, simple, and efficient over wide range of speed ratios.
Benefits of intermittent/continuous androgen deprivation in patients with advanced prostate cancer
MURESANU, HORIA
2016-01-01
Background and aims In 1941 Huggins described the effect of castration on prostate cancer. gonadotropin-releasing hormone (GNRH) analogues were introduced in 1985. Complete androgen blockade (association of GNRH analogue with antiandrogen) was introduced by Fernand Labrie to achieve suppression of suprarenal testosterone. Long time androgen deprivation lead to androgen independence of the prostate cancer cell. Our principal aim was to demonstrate longer survival rates on prostate cancer patients with intermittent androgen deprivation. Methods 82 patients in the Urology Department of Vasile Goldis West University Arad were included into two groups, with continuous and intermittent androgen deprivation. Treatment efficiency was assessed by the level of testosterone and PSA. Adverse events (AE) and serious adverse events were reported according to Common Terminology Criteria of Adverse Events (CTCAE) of the National Cancer Institute (NCI). Results Evolution towards castrate resistant prostate cancer: 12.5% from the intermittent androgen deprivation group and 23.8% from the continuous androgen deprivation group Mortality rate: 15% of patients from the intermittent androgen deprivation group; 19% of patients from the continuous androgen deprivation group Conclusions Better quality of life (Qol) in periods without treatment due to testosteron recovery; Less AE’s and metabolic syndrome (MS) related complications; Better survival and longer time of disease control and Cost reduction. PMID:27547063
NASA Astrophysics Data System (ADS)
Zhang, Zeyu; Zhu, Chengrui; He, Guangqiang
2015-08-01
Quantum key distribution can be used to share secret keys with information-theoretic security between two legitimate partners for secure communication. In the case of satellite communication, free-space channel is the only way to transmit information, thus research on its properties is of great significance to quantum cryptographic communication. In this paper, we thoroughly analyze the influence of free-space channel fading effects on continuous variable quantum key distribution and for the first time prove that random distribution (such as Rayleigh distribution, Rice distribution and et al.) of free-space channel fading coefficients can be used to increase secret information rates and improve system stability against excess noises. Our results offer academic reference for practical applications of ground-space and space-space quantum communication and global quantum communication network.
Wang Yu; Su Xiaolong; Shen Heng; Tan Aihong; Xie Changde; Peng Kunchi
2010-02-15
One-way quantum computation based on measurement and multipartite cluster entanglement offers the ability to perform a variety of unitary operations only through different choices of measurement bases. Here we present an experimental study toward demonstrating the controlled-X operation, a two-mode gate in which continuous variable (CV) four-partite cluster states of optical modes are utilized. Two quantum teleportation elements are used for achieving the gate operation of the quantum state transformation from input target and control states to output states. By means of the optical cluster state prepared off-line, the homodyne detection and electronic feeding forward, the information carried by the input control state is transformed to the output target state. The presented scheme of the controlled-X operation based on teleportation can be implemented nonlocally and deterministically. The distortion of the quantum information resulting from the imperfect cluster entanglement is estimated with the fidelity.
NASA Astrophysics Data System (ADS)
Liang, Jianwu; Zhou, Jian; Shi, Jinjing; He, Guangqiang; Guo, Ying
2016-02-01
We characterize the efficiency of the practical continuous-variable quantum key distribution (CVQKD) while inserting the heralded noiseless linear amplifier (NLA) before detectors to increase the secret key rate and the maximum transmission distance in Gaussian channels. In the heralded NLA-based CVQKD system, the entanglement source is only placed in the middle while the two participants are unnecessary to trust their source. The intensities of source noise are sensitive to the tunable NLA with the parameter g in a suitable range and can be stabilized to the suitable constant values to eliminate the impact of channel noise and defeat the potential attacks. Simulation results show that there is a well balance between the secret key rate and the maximum transmission distance with the tunable NLA.
Sudjana, J.; Magnin, L.; Garcia-Patron, R.; Cerf, N. J.
2007-11-15
The Gaussian continuous-variable quantum key distribution protocol based on coherent states and heterodyne detection [Phys. Rev. Lett. 93, 170504 (2004)] has the advantage that no active random basis switching is needed on the receiver's side. Its security is, however, not very satisfyingly understood today because the bounds on the secret key rate that have been derived from Heisenberg relations are not attained by any known scheme. Here, we address the problem of the optimal Gaussian individual attack against this protocol, and derive tight upper bounds on the information accessible to an eavesdropper. Interestingly, this protocol is proven to be even more resistant to individual attacks than originally thought. Optical schemes achieving these bounds are also exhibited, which concludes the security analysis of Gaussian protocols against individual attacks.
NASA Astrophysics Data System (ADS)
Haoxiang, Chen; Qi, Chengzhi; Peng, Liu; Kairui, Li; Aifantis, Elias C.
2015-12-01
The occurrence of alternating damage zones surrounding underground openings (commonly known as zonal disintegration) is treated as a "far from thermodynamic equilibrium" dynamical process or a nonlinear continuous phase transition phenomenon. The approach of internal variable gradient theory with diffusive transport, which may be viewed as a subclass of Landau's phase transition theory, is adopted. The order parameter is identified with an irreversible strain quantity, the gradient of which enters into the expression for the free energy of the rock system. The gradient term stabilizes the material behavior in the post-softening regime, where zonal disintegration occurs. The results of a simplified linearized analysis are confirmed by the numerical solution of the nonlinear problem.
NASA Astrophysics Data System (ADS)
Delkhosh, Mojtaba; Saadat Foumani, Mahmoud
2013-05-01
The aim of this research is the optimisation of full-toroidal continuously variable transmission (CVT) in conjunction with the fixed ratio (FR) mechanism, while the optimisation objective is to minimise fuel consumption (FC) of the vehicle in the new European driving cycle. After the dynamic analysis of the power train, a computer model is developed to simulate contact between CVT elements and consequently calculate its efficiency. Then an algorithm is presented to calculate FC of the vehicle in the driving cycle. Then, an optimisation using particle swarm optimisation on the CVT geometry and FR mechanism (which is embedded between CVT and final drive) is carried out to minimise FC. It is found that by utilisation of the optimised CVT; FC will be about 11% and 8% lower, compared with the application of a five-speed manual transmission and conventional CVT, respectively. Finally, effects of the roller tilt angle and oil temperature on the FC are investigated.
Allen, Edward J; Allen, Linda J S; Schurz, Henri
2005-07-01
A discrete-time Markov chain model, a continuous-time Markov chain model, and a stochastic differential equation model are compared for a population experiencing demographic and environmental variability. It is assumed that the environment produces random changes in the per capita birth and death rates, which are independent from the inherent random (demographic) variations in the number of births and deaths for any time interval. An existence and uniqueness result is proved for the stochastic differential equation system. Similarities between the models are demonstrated analytically and computational results are provided to show that estimated persistence times for the three stochastic models are generally in good agreement when the models satisfy certain consistency conditions. PMID:15946709
NASA Astrophysics Data System (ADS)
Krasilenko, Vladimir G.; Nikolskyy, Aleksandr I.; Lazarev, Alexander A.
2013-12-01
We consider design and modeling of hardware realizations of reconfigurable multifunctional continuous logic devices (R MCL D) as advanced components of the next generation high-performance MIMO-systems for the processing and interconnection. The R MCL D realize function of two-valued and continuous logics with current inputs and current outputs on the basis of CMOS current mirrors and circuits which realize the limited difference functions. We show advantages of such elements consisting in encoding of variables by the photocurrent levels, that allows easily providing optical inputs (by photo-detectors (PD)) and optical outputs (by LED). The conception of construction of R MCL D consists in the use of a current mirrors realized on 1.5μm technology CMOS transistors. Presence of 55÷65 transistors, 1 PD and 1 LED makes the offered circuits quite compact and allows their integration in 1D and 2D arrays. In the presentation we consider the capabilities of the offered circuits, show the simulation results and possible prospects of application of the circuits in particular for time-pulse coding for multivalued, continuous, neuro-fuzzy and matrix logics. The simulation results of NOT, MIN, MAX, equivalence (EQ) and other functions, that implemented R MCL D, showed that the level of logical variables can change from 1 μA to 10 μA for low-power consumption variants. The base cell of the R MCL D have low power consumption <1mW and processing time about 1÷11μS at supply voltage 2.4÷3.3V. Modeling of such cells in OrCad is made.
Development of an advanced, continuous mild gasification process for the production of co-products
Wright, R.E.; Wolfe, R.A.; Im, C.J.; Henkelman, M.R.; O`Neal, G.W.; McKinney, D.A.
1993-12-31
The objective of this project is to develop a continuous mild gasification process to convert highly caking coals to coal liquids, char and coke for near term commercial application. Coal liquids after fractionation can be blended with petroleum and used interchangeably with conventional fuels without modifications in gasoline and diesel engines. Char can be used as a carbon source in the production of ferroalloys and in mini-mills. Coke can be produced by upgrading char through briquetting and calcining and for use in the steel industry foundries and blast furnaces. In a step beyond the scope of the project, the plan is to finance, design and construct, in a partnership with others, a plant to produce coal liquid, char and coke in the initial range of 250,000 tons/year. In the Coal Technology Corporation CTC/CLC{reg_sign} Process, coal is continuously moved by interfolded twin screws through a heated retort in the absence of air. The residence time of the coal in the Continuous Mild Gasification Unit (CMGU) is in the range of 20--30 minutes. The coal is heated to controlled temperatures between 800{degree} and 1400{degree}F and is converted into char, condensible hydrocarbon liquids, small quantities of water, and non-condensible fuel gases. The coal derived fuel gases could supply all the required process heat, but for convenience, natural gas is used in the experimental unit. The process concept particularly suitable for highly caking coals which cannot be processed in fluidized bed or moving bed furnaces.
Sameh, Wael M.; Hashad, Mohammed M.; Eid, Ahmed A.; Abou Yousif, Tamer A.; Atta, Mohammed A.
2012-01-01
Objectives Recurrence rates for patients with locally advanced renal cell carcinoma (LARCC) remain high. To date the predictors of recurrence in those patients remain controversial. The aim of the present study was to assess the relapse pattern in those patients and identify predictors for recurrence. Patients and methods We evaluated retrospectively 112 consecutive patients who underwent surgery for LARCC (T3–T4N0M0) between January 2000 and December 2010. Clinical and pathological data were collected from hospital medical records and compiled into a computerized database. Studied variables were age, mode of presentation, Tumour-Node-Metastasis (TNM) stage, Fuhrman nuclear grade, histological subtype, tumour size, venous thrombus level, collecting-system invasion and sarcomatoid differentiation. Recurrence-free survival (RFS) was estimated using the Kaplan–Meier method. Univariate and multivariate analyses were conducted. Results Patients were followed for a mean and median follow-up of 33 and 24 months, respectively, after surgery. During the follow-up, recurrences (distant and/or local) were recorded in 58 patients, representing 52% of the cohort. The mean and median times to recurrence were 25 and 13 months, respectively. Sites of recurrence were multiple in 36 patients (62%), lung only in 14 (24%), and local in eight (14%). RFS rates at 1, 2, and 5 years were 50%, 43% and 34%, respectively, while the median RFS was 23.7 months. Using univariate analysis, RFS after nephrectomy was significantly shorter in patients aged <70 years, symptomatic at presentation, with larger tumours, higher nuclear grade, collecting-system invasion, and/or sarcomatoid differentiation. After multivariate analysis, T-stage, nuclear grade and sarcomatoid differentiation retained their power as independent predictors of RFS (P = 0.032, <0.001 and 0.003, respectively). Conclusions For patients with LARCC, T-stage, grade and sarcomatoid differentiation independently dictate the
Pellerin, Brian; Stauffer, Beth A; Young, Dwane A; Sullivan, Daniel J.; Bricker, Suzanne B.; Walbridge, Mark R; Clyde, Gerard A; Shaw, Denice M
2016-01-01
Sensors and enabling technologies are becoming increasingly important tools for water quality monitoring and associated water resource management decisions. In particular, nutrient sensors are of interest because of the well-known adverse effects of nutrient enrichment on coastal hypoxia, harmful algal blooms, and impacts to human health. Accurate and timely information on nutrient concentrations and loads is integral to strategies designed to minimize risk to humans and manage the underlying drivers of water quality impairment. Using nitrate sensors as an example, we highlight the types of applications in freshwater and coastal environments that are likely to benefit from continuous, real-time nutrient data. The concurrent emergence of new tools to integrate, manage and share large data sets is critical to the successful use of nutrient sensors and has made it possible for the field of continuous nutrient monitoring to rapidly move forward. We highlight several near-term opportunities for Federal agencies, as well as the broader scientific and management community, that will help accelerate sensor development, build and leverage sites within a national network, and develop open data standards and data management protocols that are key to realizing the benefits of a large-scale, integrated monitoring network. Investing in these opportunities will provide new information to guide management and policies designed to protect and restore our nation’s water resources.
Continuous distributed phase-plate advances for high-energy laser systems
NASA Astrophysics Data System (ADS)
Marozas, J. A.; Collins, T. J. B.; Zuegel, J. D.; McKenty, P. W.; Cao, D.; Fochs, S.; Radha, P. B.
2016-05-01
The distributed phase plate (DPP) design code Zhizhoo’ has been used to design full- aperture, continuous near-field transmission optics for a wide variety of high-fidelity focal-spot shapes for high-energy laser systems: OMEGA EP, Dynamic Compression Sector (DCS), and the National Ignition Facility (NIF). The envelope shape, or profile, of the focal spot affects the hydrodynamics of directly driven targets in these laser systems. Controlling the envelope shape to a high degree of fidelity impacts the quality of the ablatively driven implosions. The code Zhizhoo’ not only produces DPP's with great control of the envelope shape, but also spectral and gradient control as well as robustness from near-field phase aberrations. The focal-spot shapes can take on almost any profile from symmetric to irregular patterns and with high fidelity relative to the objective function over many decades of intensity. The control over the near-field phase spectrum and phase gradients offer greater manufacturability of the full- aperture continuous surface-relief pattern. The flexibility and speed of the DPP design code Zhizhoo’ will be demonstrated by showing the wide variety of successful designs that have been made and those that are in progress.
Continuous infusion of 5-fluorouracil with alpha 2b interferon for advanced colorectal carcinoma.
Ferguson, J. E.; Hulse, P.; Lorigan, P.; Jayson, G.; Scarffe, J. H.
1995-01-01
Thirty patients with symptomatic colorectal carcinoma were commenced on treatment with 5-fluorouracil (2.5 g week-1) administered by continuous intravenous infusion and alpha 2b interferon (3 x 10(6) U s.c. three times a week). Six out of 30 patients (20%) achieved a partial response. Three patients (10%) had stable disease and 21 patients (70%) progressed on treatment. Twenty patients (67%) completed ten or more weeks of treatment. In nine patients, treatment was withdrawn after 2-9 weeks because of disease progression or death. One patient's treatment was interrupted by emergency surgery. The median survival for all patients was 210 days (7 months). The principal side-effects were oral mucositis (12/30 patients), nausea (8/30 patients) and transient diarrhoea (4/30 patients), and initial constitutional symptoms due to alpha 2b interferon. The combination of low-dose continuous infusional 5-fluorouracil and low-dose alpha 2b interferon is well tolerated but has no obvious advantage over alternative infusional regimens using 5-fluorouracil as a single agent. PMID:7599051
The Continued Need for Modeling and Scaled Testing to Advance the Hanford Tank Waste Mission
Peurrung, Loni M.; Fort, James A.; Rector, David R.
2013-09-03
Hanford tank wastes are chemically complex slurries of liquids and solids that can exhibit changes in rheological behavior during retrieval and processing. The Hanford Waste Treatment and Immobilization Plant (WTP) recently abandoned its planned approach to use computational fluid dynamics (CFD) supported by testing at less than full scale to verify the design of vessels that process these wastes within the plant. The commercial CFD tool selected was deemed too difficult to validate to the degree necessary for use in the design of a nuclear facility. Alternative, but somewhat immature, CFD tools are available that can simulate multiphase flow of non-Newtonian fluids. Yet both CFD and scaled testing can play an important role in advancing the Hanford tank waste mission—in supporting the new verification approach, which is to conduct testing in actual plant vessels; in supporting waste feed delivery, where scaled testing is ongoing; as a fallback approach to design verification if the Full Scale Vessel Testing Program is deemed too costly and time-consuming; to troubleshoot problems during commissioning and operation of the plant; and to evaluate the effects of any proposed changes in operating conditions in the future to optimize plant performance.
Campbell, Joel F; Lin, Bing; Nehrir, Amin R
2014-02-10
In this theoretical study, modulation techniques are developed to support the Active Sensing of CO_{2} Emissions over Nights, Days, and Seasons (ASCENDS) mission. A continuous wave (CW) lidar system using sine waves modulated by maximum length (ML) pseudo-noise (PN) codes is described for making simultaneous online/offline differential absorption measurements. Amplitude and phase-shift keying (PSK) modulated intensity modulation (IM) carriers, in addition to a hybrid-pulse technique are investigated, which exhibit optimal autocorrelation properties. A method is presented to bandwidth limit the ML sequence based on a filter implemented in terms of Jacobi theta functions, which does not significantly degrade the resolution or introduce sidelobes as a means of reducing aliasing and IM carrier bandwidth. PMID:24663259
Field, D
1999-01-01
A longitudinal study of friendships between young-old and old-old adults found far more continuity than change in amount of contact with friends. Nevertheless, activities with casual friends more often occurred in groups, whereas activities with close friends were more often concerned with exchanging confidences, with sharing interesting experiences and thoughts, and with helping each other. Gender differences are more pronounced than life-course differences. Men declined in number of new friends, in their desire for close friendships, in the less intimate nature of their interactions with friends, and in involvement in beyond-family activities, while women did not change. Questions about closest friends revealed only a trivial difference between men and women in young-old age; but in old-old age, men (but not women) had declined in many measures of friendship. PMID:10498019
Clinical accuracy of a continuous glucose monitoring system with an advanced algorithm.
Bailey, Timothy S; Chang, Anna; Christiansen, Mark
2015-03-01
We assessed the performance of a modified Dexcom G4 Platinum system with an advanced algorithm, in comparison with frequent venous samples measured on a laboratory reference (YSI) during a clinic session and in comparison to self-monitored blood glucose (SMBG) during home use. Fifty-one subjects with diabetes were enrolled in a prospective multicenter study. Subjects wore 1 sensor for 7-day use and participated in one 12-hour in-clinic session on day 1, 4, or 7 to collect YSI reference venous glucose every 15 minutes and capillary SMBG test every 30 minutes. Carbohydrate consumption and insulin dosing and timing were manipulated to obtain data in low and high glucose ranges. In comparison with the laboratory reference method (n = 2,263) the system provided a mean and median absolute relative differences (ARD) of 9.0% and 7.0%, respectively. The mean absolute difference for CGM was 6.4 mg/dL when the YSIs were within hypoglycemia ranges (≤ 70 mg/dL). The percentage in the clinically accurate Clarke error grid A zone was 92.4% and in the benign error B zone was 7.1%. Majority of the sensors (73%) had an aggregated MARD in reference to YSI ≤ 10%. The MARD of CGM-SMBG for home use was 11.3%. The study showed that the point and rate accuracy, clinical accuracy, reliability, and consistency over the duration of wear and across glycemic ranges were superior to current commercial real-time CGM systems. The performance of this CGM is reaching that of a self-monitoring blood glucose meter in real use environment. PMID:25370149
Achieve Continuous Injection of Solid Fuels into Advanced Combustion System Pressures
Derek L. Aldred; Timothy Saunders
2007-03-31
The overall objective of this project is the development of a mechanical rotary-disk feeder, known as the Stamet Posimetric High Pressure Solids Feeder System, to demonstrate feeding of dry granular coal continuously and controllably into pressurized environments of up to 70 kg/cm2 (1,000 psi). This is the Phase III of the ongoing program. Earlier Phases 1 and II successfully demonstrated feeding into pressures up to 35 kg/cm{sup 2} (500 psi). The final report for those phases was submitted in April 2005. Based on the previous work done in Phases I & II using Powder River Basin coal provided by the PSDF facility in Wilsonville, AL, a Phase III feeder system was designed and built to accomplish the target of feeding the coal into a pressure of 70 kg/cm2 (1,000 psi) and to be capable of feed rates of up to 550 kilograms (1,200lbs) per hour. The drive motor system from Phase II was retained for use on Phase III since projected performance calculations indicated it should be capable of driving the Phase III pump to the target levels. The pump & motor system was installed in a custom built test rig comprising an inlet vessel containing an active live-wall hopper mounted on weigh cells in a support frame, transition into the pump inlet, transition from pump outlet and a receiver vessel containing a receiver drum supported on weigh cells. All pressure containment on the rig was rated to105 kg/cm{sup 2} (1,500psi) to accommodate the final pressure requirement of a proposed Phase IV of the program. A screw conveyor and batch hopper were added to transfer coal at atmospheric pressure from the shop floor up into the test rig to enable continuous feeding up to the capacity of the receiving vessel. Control & monitoring systems were up-rated from the Phase II system to cover the additional features incorporated in the Phase III rig, and provide closer control and expanded monitoring of the entire system. A program of testing and modification was carried out in Stamet's facility
Ju, Hee Young; Hong, Che Ry; Shin, Hee Young
2014-10-01
Treatment outcomes of pediatric cancers have improved greatly with the development of improved treatment protocols, new drugs, and better supportive measures, resulting in overall survival rates greater than 70%. Survival rates are highest in acute lymphoblastic leukemia, reaching more than 90%, owing to risk-based treatment through multicenter clinical trials and protocols developed to prevent central nervous system relapse and testicular relapse in boys. New drugs including clofarabine and nelarabine are currently being evaluated in clinical trials, and other targeted agents are continuously being developed. Chimeric antigen receptor-modified T cells are now attracting interest for the treatment of recurrent or refractory disease. Stem cell transplantation is still the most effective treatment for pediatric acute myeloid leukemia (AML). However, in order to reduce treatment-related death after stem cell transplantation, there is need for improved treatments. New drugs and targeted agents are also needed for improved outcome of AML. Surgery and radiation therapy have been the mainstay for brain tumor treatment. However, chemotherapy is becoming more important for patients who are not eligible for radiotherapy owing to age. Stem cell transplant as a means of high dose chemotherapy and stem cell rescue is a new treatment modality and is often repeated for improved survival. Drugs such as temozolomide are new chemotherapeutic options. In order to achieve 100% cure in children with pediatric cancer, every possible treatment modality and effort should be considered. PMID:25379043
NASA Technical Reports Server (NTRS)
Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.
2014-01-01
NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.
2016-01-01
Background Whether radiologically detected progressive disease (PD) is an accurate metric for discontinuing sorafenib treatment in patients with hepatocellular carcinoma (HCC) is unclear. We investigated the efficacy of sorafenib treatment after radiologic confirmation of PD in patients with advanced HCC. Methods We retrospectively analyzed HCC patients treated with sorafenib at Kyushu Medical Center. Six of the 92 patients with radiologically confirmed PD were excluded because they were classified as Child-Pugh C or had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥3; 86 patients were ultimately enrolled. Results Among the 86 patients, 47 continued sorafenib treatment after radiologic confirmation of PD (the continuous group), whereas 39 did not (the discontinuous group). The median survival time (MST) in the continuous group after confirmation was 12.9 months compared with 4.5 months in the discontinuous group (p <0.01). The time to progression in the continuous group after confirmation was 2.6 months compared with 1.4 months in the discontinuous group (p <0.01); it was 4.2 months and 2.1 months in patients who had received sorafenib ≥4 months and <4 months, respectively, before confirmation (p = 0.03). In these subgroups, the post-PD MST was 16.7 months and 9.6 months, respectively (p < 0.01). Independent predictors of overall survival after radiologic detection of PD were (hazard ratio, confidence interval): ECOG PS <2 (0.290, 0.107–0.880), Barcelona Clinical Liver Cancer stage B (0.146, 0.047–0.457), serum α-fetoprotein level ≥400 ng/mL (2.801, 1.355–5.691), and post-PD sorafenib administration (0.279, 0.150–0.510). Conclusion Continuing sorafenib treatment after radiologic confirmation of PD increased survival in patients with advanced HCC. Therefore, radiologically detected PD is not a metric for discontinuation of sorafenib treatment in such patients. PMID:26745625
Strayer, R F; Finger, B W; Alazraki, M P; Cook, K; Garland, J L
2002-09-01
Bioreactor retention time is a key process variable that will influence costs that are relevant to long distance space travel or long duration space habitation. However. little is known about the effects of this parameter on the microbiological treatment options that are being proposed for Advanced Life Support (ALS) systems. Two bioreactor studies were designed to examine this variable. In the first one, six retention times ranging from 1.3 to 21.3 days--were run in duplicate, 81 working-volume continuous stirred tank reactors (CSTR) that were fed ALS wheat residues. Ash-free dry weight loss, carbon mineralization, soluble TOC reduction, changes in fiber content (cellulose, hemicellulose, and lignin), bacterial numbers, and mineral recoveries were monitored. At short retention times--1.33 days--biodegradation was poor (total: 16-20%, cellulose - 12%, hemicellulose - 28%) but soluble TOC was decreased by 75-80% and recovery of major crop inorganic nutrients was adequate, except for phosphorus. A high proportion of the total bacteria (ca. 83%) was actively respiring. At the longest retention time tested, 21.3 days, biodegradation was good (total: 55-60%, cellulose ca. 70%, hemicellulose - ca. 55%) and soluble TOC was decreased by 80%. Recovery of major nutrients, except phosphorus, remained adequate. A very low proportion of total bacteria was actively respiring (ca. 16%). The second bioreactor study used potato residue to determine if even shorter retention times could be used (range 0.25-2.0 days). Although overall biodegradation deteriorated, the degradation of soluble TOC continued to be ca. 75%. We conclude that if the goal of ALS bioprocessing is maximal degradation of crop residues, including cellulose, then retention times of 10 days or longer will be needed. If the goal is to provide inorganic nutrients with the smallest volume/weight bioreactor possible, then a retention time of 1 day (or less) is sufficient. PMID:12139328
NASA Technical Reports Server (NTRS)
Strayer, R. F.; Finger, B. W.; Alazraki, M. P.; Cook, K.; Garland, J. L.
2002-01-01
Bioreactor retention time is a key process variable that will influence costs that are relevant to long distance space travel or long duration space habitation. However. little is known about the effects of this parameter on the microbiological treatment options that are being proposed for Advanced Life Support (ALS) systems. Two bioreactor studies were designed to examine this variable. In the first one, six retention times ranging from 1.3 to 21.3 days--were run in duplicate, 81 working-volume continuous stirred tank reactors (CSTR) that were fed ALS wheat residues. Ash-free dry weight loss, carbon mineralization, soluble TOC reduction, changes in fiber content (cellulose, hemicellulose, and lignin), bacterial numbers, and mineral recoveries were monitored. At short retention times--1.33 days--biodegradation was poor (total: 16-20%, cellulose - 12%, hemicellulose - 28%) but soluble TOC was decreased by 75-80% and recovery of major crop inorganic nutrients was adequate, except for phosphorus. A high proportion of the total bacteria (ca. 83%) was actively respiring. At the longest retention time tested, 21.3 days, biodegradation was good (total: 55-60%, cellulose ca. 70%, hemicellulose - ca. 55%) and soluble TOC was decreased by 80%. Recovery of major nutrients, except phosphorus, remained adequate. A very low proportion of total bacteria was actively respiring (ca. 16%). The second bioreactor study used potato residue to determine if even shorter retention times could be used (range 0.25-2.0 days). Although overall biodegradation deteriorated, the degradation of soluble TOC continued to be ca. 75%. We conclude that if the goal of ALS bioprocessing is maximal degradation of crop residues, including cellulose, then retention times of 10 days or longer will be needed. If the goal is to provide inorganic nutrients with the smallest volume/weight bioreactor possible, then a retention time of 1 day (or less) is sufficient.
Nieuwenhuijsen, Mark J; Donaire-Gonzalez, David; Rivas, Ioar; de Castro, Montserrat; Cirach, Marta; Hoek, Gerard; Seto, Edmund; Jerrett, Michael; Sunyer, Jordi
2015-03-01
Novel technologies, such as smartphones and small personal continuous air pollution sensors, can now facilitate better personal estimates of air pollution in relation to location. Such information can provide us with a better understanding about whether and how personal exposures relate to residential air pollution estimates, which are normally used in epidemiological studies. The aims of this study were to examine (1) the variability in personal air pollution levels during the day and (2) the relationship between modeled home and school estimates and continuously measured personal air pollution exposure levels in different microenvironments (e.g., home, school, and commute). We focused on black carbon as an indicator of traffic-related air pollution. We recruited 54 school children (aged 7-11) from 29 different schools around Barcelona as part of the BREATHE study, an epidemiological study of the relation between air pollution and brain development. For 2 typical week days during 2012-2013, the children were given a smartphone with CalFit software to obtain information on their location and physical activity level and a small sensor, the micro-aethalometer model AE51, to measure their black carbon levels simultaneously and continuously. We estimated their home and school exposure to PM2.5 filter absorbance, which is well-correlated with black carbon, using a temporally adjusted PM2.5 absorbance land use regression (LUR) model. We found considerable variation in the black carbon levels during the day, with the highest levels measured during commuting periods (geometric mean = 2.8 μg/m(3)) and the lowest levels at home (geometric mean = 1.3 μg/m(3)). Hourly temporally adjusted LUR model estimates for the home and school showed moderate to good correlation with measured personal black carbon levels at home and school (r = 0.59 and 0.68, respectively) and lower correlation with commuting trips (r = 0.32 and 0.21, respectively). The correlation between modeled home
NASA Astrophysics Data System (ADS)
Ran, Du; Yang, Zhen-Biao
2016-04-01
We address the entanglement transfer from a bipartite continuous-variable(CV) system to a pair of localized discrete systems. The dynamics behavior can be implemented by two two-level atoms flying through spatially separated identical cavities where two quantized modes are injected. We assume each CV mode couples to one atom via the resonant Jaynes-Cummings interaction. The CV systems are initially prepared in a two-mode anti-correlated SU(2) coherent state, while with the initial atomic states of the cases: |g⟩1|g⟩2, |e⟩1|e⟩2 and |g⟩1|e⟩2, respectively. We find that the entanglement transfer for single-photon excitation case is more efficient than that for multi-photon excitation case. Under same conditions, we also note that the entanglement transfer is more efficient for SU(2) coherent state than for twin-bean (TWB) and pair-coherent (TMC) state. Besides, we show that, for a given total photon number of the initial SU(2) coherent state, the efficiency of entanglement transfer depends upon the distribution of photons in the two CV modes. We also consider the influences of the dissipation and the white noise on the entanglement transfer.
NASA Astrophysics Data System (ADS)
Budianto, A.; Tawi, K. B.; Hussein, M.; Supriyo, B.; Ariyono, S.; Che Kob, M. S.; Ezlamy Zulkifli, Mohd; K, Khairuldean A.; Daraoh, Aishah
2012-09-01
Electro-Mechanical Dual Acting Pulley (EMDAP) Continuously Variable Transmission (CVT) is a transmission utilized by electro-mechanical actuated system. It has a potential to reduce energy consumption because it only needs power during changing CVT ratio and no power is needed to maintain CVT ratio due to self lock mechanism design. This paper proposed simple proportional derivative plus conditional integral (PDCI) controller to control EMDAP CVT ratio which can be simply implemented on a microcontroller. This proposed controller used Astrom-Hagglund method and Ziegler-Nichols formula to tune PDCI gain. The Proportional Derivative controller is directly activated from the start but Integral controller is only activated when the error value reaches error value setting point. Simulation using Matlab/Simulink software was conducted to evaluate PDCI system performance. The simulation results showed PDCI controller has ability to perform maximum overshoot 0.1%, 0.001 steady state error and 0.5s settling time. For clamping condition, settling time is about 11.46s during changing ratio from 2.0 to 0.7, while for release condition, settling time is about 8.33s during changing ratio from 0.7 to 2.0.
Sellon, Debra C; Roberts, Malcolm C; Blikslager, Anthony T; Ulibarri, Catherine; Papich, Mark G
2004-01-01
A randomized, controlled, blinded clinical trial was performed to determine whether butorphanol administered by continuous rate infusion (CRI) for 24 hours after abdominal surgery would decrease pain and surgical stress responses and improve recovery in horses. Thirty-one horses undergoing exploratory celiotomy for abdominal pain were randomly assigned to receive butorphanol CRI (13 microg/kg/h for 24 hours after surgery; treatment) or isotonic saline (control). All horses received flunixin meglumine (1.1 mg/kg IV q12h). There were no significant differences between treatment and control horses in preoperative or operative variables. Treatment horses had significantly lower plasma cortisol concentration compared with control horses at 2, 8, 12, 24, 36, and 48 hours after surgery. Mean weight loss while hospitalized was significantly less for treatment horses than control horses, whether expressed as total decrease in body weight (13.9+/-3.4 and 27.9+/-4.5 kg, respectively) or as a percentage decrease in body weight (2.6+/-0.7 and 6.3+/-1.1%, respectively). Treatment horses were significantly delayed in time to first passage of feces (median times of 15 and 4 hours, respectively). Treatment horses had significantly improved behavior scores during the first 24 hours after surgery, consistent with the conclusion that they experienced less pain during that time. Butorphanol CRI during the immediate postoperative period significantly decreased plasma cortisol concentrations and improved recovery characteristics in horses undergoing abdominal surgery. PMID:15320598
NASA Astrophysics Data System (ADS)
Trapani, Jacopo; Paris, Matteo G. A.
2016-04-01
We address the dynamics of quantum correlations for a bipartite continuous-variable quantum system interacting with its fluctuating environment. In particular, we consider two independent quantum oscillators initially prepared in a Gaussian state, e.g., a squeezed thermal state, and compare the dynamics resulting from local noise, i.e., oscillators coupled to two independent external fields, to that originating from common noise, i.e., oscillators interacting with a single common field. We prove non-Markovianity (nondivisibility) of the dynamics in both regimes and analyze the connections between nondivisibility, backflow of information, and revivals of quantum correlations. Our main results may be summarized as follows: (i) revivals of quantumness are present in both scenarios, however, the interaction with a common environment better preserves the quantum features of the system; (ii) the dynamics is always nondivisible but revivals of quantum correlations are present only when backflow of information is present as well. We conclude that nondivisibility in its own is not a resource to preserve quantum correlations in our system, i.e., it is not sufficient to observe recoherence phenomena. Rather, it represents a necessary prerequisite to obtain backflow of information, which is the true ingredient to obtain revivals of quantumness.
Yan, D.; He, J.; Jing, L.M.
1996-12-31
This paper deals with the continuous heating, varying temperature quenching technique and apparatus of variable cross-section slender rod with low stress. The varying temperature quenching technique means that the different part of the slender rod is quenched at different temperature at the same time. Based on the influence of several factors such as quenching temperature, size in cross-section, original structure of material, cooling rate of quenching and specific volume change etc. on quenching distortion, the quenching technique is used to improve the quenching distortion. Quenching temperature range of the technique is 780 {approximately} 785{degrees}C, 770 {approximately} 775 {degrees}C and 760 {approximately} 765 {degrees}C for different diameter ({phi} 2mm, {phi} 1.5mm and top) part of the rod made of T9 steel separately. To carry out the quenching technique an apparatus is specially designed. The results show that the properties of the rod tempered after quenching by the technique with the apparatus are satisfied and the quenching distortion is much smaller than that produced by wholly heating and quenching at the same temperature for all parts of the rod.
ERIC Educational Resources Information Center
Kerim-Zade, Irina; Pavlov, Vladimir
1989-01-01
Attempts to explore one of the aspects of the systematic organization of the English lexicon: semantico-functional variability. It is concluded that the teaching of English vocabulary should include the teaching of rules concerning the semantico-functional variability of words. (Author/VWL)
Ma, Wendong; Hu, Huaichuan; Shan, Jiafang; Xu, Handong; Wang, Mao; Wu, Zege; Zhu, Liang
2013-01-01
The lower hybrid current drive (LHCD) is an effective approach for auxiliary heating and non-inductive current drive in the experimental advanced superconducting tokamak. The 6 MW/4.6 GHz LHCD system is being designed and installed with twenty-four 250 KW/4.6 GHz high power klystron amplifiers. The test bench operating at 250 KW/4.6 GHz in continuous wave mode has been set up, which can test and train microwave components for the 6 MW/4.6 GHz LHCD system. In this paper, the system architecture and software of the microwave test bench are presented. Moreover, the test results of these klystrons and microwave units are described here in detail. The long term operation of the test bench and improved performance of all microwave component samples indicated that the related technologies on test bench can be applied in the large scale LHCD systems. PMID:23387646
ERIC Educational Resources Information Center
Rhemtulla, Mijke; Brosseau-Liard, Patricia E.; Savalei, Victoria
2012-01-01
A simulation study compared the performance of robust normal theory maximum likelihood (ML) and robust categorical least squares (cat-LS) methodology for estimating confirmatory factor analysis models with ordinal variables. Data were generated from 2 models with 2-7 categories, 4 sample sizes, 2 latent distributions, and 5 patterns of category…
Prior Knowledge or Advance Organizers as Effective Variables in Chemical Learning
ERIC Educational Resources Information Center
Fensham, P. J.; West, L. H. T.
1976-01-01
This report describes an attempt to apply a critical empirical test to some predictions from Ausubel's theory concerning the subsuming role of advance organizers. Alternative explanations are proposed and subsequent predictions tested. (BT)
NASA Astrophysics Data System (ADS)
Nardi, F.; Grimaldi, S.; Petroselli, A.
2012-12-01
Remotely sensed Digital Elevation Models (DEMs), largely available at high resolution, and advanced terrain analysis techniques built in Geographic Information Systems (GIS), provide unique opportunities for DEM-based hydrologic and hydraulic modelling in data-scarce river basins paving the way for flood mapping at the global scale. This research is based on the implementation of a fully continuous hydrologic-hydraulic modelling optimized for ungauged basins with limited river flow measurements. The proposed procedure is characterized by a rainfall generator that feeds a continuous rainfall-runoff model producing flow time series that are routed along the channel using a bidimensional hydraulic model for the detailed representation of the inundation process. The main advantage of the proposed approach is the characterization of the entire physical process during hydrologic extreme events of channel runoff generation, propagation, and overland flow within the floodplain domain. This physically-based model neglects the need for synthetic design hyetograph and hydrograph estimation that constitute the main source of subjective analysis and uncertainty of standard methods for flood mapping. Selected case studies show results and performances of the proposed procedure as respect to standard event-based approaches.
NASA Technical Reports Server (NTRS)
Gallo, C.; Kasuba, R.; Pintz, A.; Spring, J.
1986-01-01
The dynamic analysis of a horizontal axis fixed pitch wind turbine generator (WTG) rated at 56 kW is discussed. A mechanical Continuously Variable Transmission (CVT) was incorporated in the drive train to provide variable speed operation capability. One goal of the dynamic analysis was to determine if variable speed operation, by means of a mechanical CVT, is capable of capturing the transient power in the WTG/wind environment. Another goal was to determine the extent of power regulation possible with CVT operation.
Seddon, Johanna M.; Reynolds, Robyn; Maller, Julian; Fagerness, Jesen A.; Daly, Mark J.; Rosner, Bernard
2013-01-01
Purpose The joint effects of genetic, ocular, and environmental variables were evaluated and predictive models for prevalence and incidence of AMD were assessed. Methods Participants in the multicenter Age-Related Eye Disease Study (AREDS) were included in a prospective evaluation of 1446 individuals, of which 279 progressed to advanced AMD (geographic atrophy or neovascular disease) and 1167 did not progress during 6.3 years of follow-up. For prevalent AMD, 509 advanced cases were compared with 222 controls. Covariates for the incidence analysis included age, sex, education, smoking, body mass index (BMI), baseline AMD grade, and the AREDS vitamin–mineral treatment assignment. DNA specimens were evaluated for six variants in five genes related to AMD. Unconditional logistic regression analyses were performed for prevalent and incident advanced AMD. An algorithm was developed and receiver operating characteristic curves and C statistics were calculated to assess the predictive ability of risk scores to discriminate progressors from nonprogressors. Results All genetic polymorphisms were independently related to prevalence of advanced AMD, controlling for genetic factors, smoking, BMI, and AREDS treatment. Multivariate odds ratios (ORs) were 3.5 (95% confidence interval [CI], 1.7–7.1) for CFH Y402H; 3.7 (95% CI, 1.6 – 8.4) for CFH rs1410996; 25.4 (95% CI, 8.6 –75.1) for LOC387715 A69S (ARMS2); 0.3 (95% CI, 0.1– 0.7) for C2 E318D; 0.3 (95% CI, 0.1– 0.5) for CFB; and 3.6 (95% CI, 1.4 –9.4) for C3 R102G, comparing the homozygous risk/protective genotypes to the referent genotypes. For incident AMD, all these variants except CFB were significantly related to progression to advanced AMD, after controlling for baseline AMD grade and other factors, with ORs from 1.8 to 4.0 for presence of two risk alleles and 0.4 for the protective allele. An interaction was seen between CFH402H and treatment, after controlling for all genotypes. Smoking was independently
Ikeda, O. Kusunoki, S.; Kudoh, K.; Takamori, H.; Tsuji, T.; Kanemitsu, K.; Yamashita, Y.
2006-06-15
Purpose. To evaluate the effects of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in patients with advanced pancreatic carcinoma. Methods. CTAI was performed in 17 patients with stage IV pancreatic cancer with (n = 11) or without (n = 6) liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The inferior pancreatic artery (IPA) was embolized to achieve delivery of the pancreatic blood supply through only the celiac artery. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. Treatment effects were evaluated based on the primary tumor size, liver metastasis, and survival time and factors such as tumor size, tumor location, and stage of pancreatic carcinoma; the embolized arteries were analyzed with respect to treatment effects and prognosis. Results. A catheter was fixed in the gastroduodenal artery and splenic artery in 10 and 7 patients, respectively. Complete peripancreatic arterial occlusion was successful in 10 patients. CT showed a decrease in tumor size in 6 of 17 (35%) patients and a decrease in liver metastases in 6 of 11 (55%) patients. The survival time ranged from 4 to 18 months (mean {+-} SD, 8.8 {+-} 1.5 months). Complete embolization of arteries surrounding the pancreas was achieved in 10 patients; they manifested superior treatment effects and prognoses (p < 0.05). Conclusion. In patients with advanced pancreatic cancer, long-term CTAI with systemic chemotherapy appeared to be effective not only against the primary tumor but also against liver metastases. Patients with successfully occluded peripancreatic arteries tended to survive longer.
2014-01-01
Background Prostate cancer is the most common cancer in older men in the United States (USA) and Western Europe. Androgen deprivation (AD) constitutes, in most cases, the first-line of treatment for these cases. The negative impact of CAD in quality of life, secondary to the adverse events of sustained hormone deprivation, plus the costs of this therapy, motivated the intermittent treatment approach. The objective of this study is to to perform a systematic review and meta-analysis of all randomized controlled trials that compared the efficacy and adverse events profile of intermittent versus continuous androgen deprivation for locally advanced, recurrent or metastatic hormone-sensitive prostate cancer. Methods Several databases were searched, including MEDLINE, EMBASE, LILACS, and CENTRAL. The endpoints were overall survival (OS), cancer-specific survival (CSS), time to progression (TTP) and adverse events. We performed a meta-analysis (MA) of the published data. The results were expressed as Hazard Ratio (HR) or Risk Ratio (RR), with their corresponding 95% Confidence Intervals (CI 95%). Results The final analysis included 13 trials comprising 6,419 patients with hormone-sensitive prostate cancer. TTP was similar in patients who received intermittent androgen deprivation (IAD) or continuous androgen deprivation (CAD) (fixed effect: HR = 1.04; CI 95% = 0.96 to 1.14; p = 0.3). OS and CSS were also similar in patients treated with IAD or CAD (OS: fixed effect: HR = 1.02; CI 95% = 0.95 to 1.09; p = 0.56 and CSS: fixed effect: HR = 1.06; CI 95% = 0.96 to 1.18; p = 0.26). Conclusion Overall survival was similar between IAD and CAD in patients with locally advanced, recurrent or metastatic hormone-sensitive prostate cancer. Data on CSS are weak and the benefits of IAD on this outcome remain uncertain. Impact in QoL was similar for both groups, however, sexual activity scores were higher and the incidence of hot flushes was lower in
ERIC Educational Resources Information Center
van Dijk, Marijn; van Geert, Paul
2007-01-01
Current individual-based, process-oriented approaches (dynamic systems theory and the microgenetic perspective) have led to an increase of variability-centred studies in the literature. The aim of this article is to propose a technique that incorporates variability in the analysis of the "shape" of developmental change. This approach is…
Boylan, Christopher; McWilliam, Alan; Johnstone, Emily; Rowbottom, Carl
2012-01-01
A recent control system update for Elekta linear accelerators includes the ability to deliver volumetric-modulated arc therapy (VMAT) with continuously variable dose rate (CVDR), rather than a number of fixed binned dose rates (BDR). The capacity to select from a larger range of dose rates allows the linac to maintain higher gantry speeds, resulting in faster, smoother deliveries. The purpose of this study is to investigate two components of CVDR delivery - the increase in average dose rate and gantry speed, and a determination of their effects on beam stability, MLC positioning, and overall plan dosimetry. Initially, ten VMAT plans (5 prostate, 5head and neck) were delivered to a Delta4 dosimetric phantom using both the BDR and CVDR systems. The plans were found to be dosimetrically robust using both delivery methods, although CVDR was observed to give higher gamma pass rates at the 2%/2 mm gamma level for prostates (p < 0.01). For the dual arc head-and-neck plans, CVDR delivery resulted in improved pass rates at all gamma levels (2%/2 mm to 4%/4 mm) for individual arc verifications (p < 0.01), but gave similar results to BDR when both arcs were combined. To investigate the impact of increased gantry speed on MLC positioning, a dynamic leaf-tracking tool was developed using the electronic portal imaging device (EPID). Comparing the detected MLC positions to those expected from the plan, CVDR was observed to result in a larger mean error compared to BDR (0.13 cm and 0.06 cm, respectively, p < 0.01). The EPID images were also used to monitor beam stability during delivery. It was found that the CVDR deliveries had a lower standard deviation of the gun-target (GT) and transverse (AB) profiles (p < 0.01). This study has determined that CVDR may offer a dosimetric advantage for VMAT plans. While the higher gantry speed of CVDR appears to increase deviations in MLC positioning, the relative effect on dosimetry is lower than the positive impact of a flatter and more
NASA Astrophysics Data System (ADS)
Gao, J.
2014-12-01
Reducing modeling error is often a major concern of empirical geophysical models. However, modeling errors can be defined in different ways: When the response variable is continuous, the most commonly used metrics are squared (SQ) and absolute (ABS) errors. For most applications, ABS error is the more natural, but SQ error is mathematically more tractable, so is often used as a substitute with little scientific justification. Existing literature has not thoroughly investigated the implications of using SQ error in place of ABS error, especially not geospatially. This study compares the two metrics through the lens of bias-variance decomposition (BVD). BVD breaks down the expected modeling error of each model evaluation point into bias (systematic error), variance (model sensitivity), and noise (observation instability). It offers a way to probe the composition of various error metrics. I analytically derived the BVD of ABS error and compared it with the well-known SQ error BVD, and found that not only the two metrics measure the characteristics of the probability distributions of modeling errors differently, but also the effects of these characteristics on the overall expected error are different. Most notably, under SQ error all bias, variance, and noise increase expected error, while under ABS error certain parts of the error components reduce expected error. Since manipulating these subtractive terms is a legitimate way to reduce expected modeling error, SQ error can never capture the complete story embedded in ABS error. I then empirically compared the two metrics with a supervised remote sensing model for mapping surface imperviousness. Pair-wise spatially-explicit comparison for each error component showed that SQ error overstates all error components in comparison to ABS error, especially variance-related terms. Hence, substituting ABS error with SQ error makes model performance appear worse than it actually is, and the analyst would more likely accept a
Variables in Second Language Attrition: Advancing the State of the Art
ERIC Educational Resources Information Center
Bardovi-Harlig, Kathleen; Stringer, David
2010-01-01
This article provides a comprehensive synthesis of research on language attrition to date, with a view to establishing a theoretically sound basis for future research in the domain of second language (L2) attrition. We identify the variables that must be tracked in populations who experience language loss, and we develop a general model for the…
ERIC Educational Resources Information Center
Sanchez, Erin N.; Aujla, Imogen J.; Nordin-Bates, Sanna
2013-01-01
This study is a qualitative enquiry into cultural background variables--social support, values, race/ethnicity and economic means--in the process of dance talent development. Seven urban dance students in pre-vocational training, aged 15-19, participated in semi-structured interviews. Interviews were inductively analysed using QSR International…
Nonlinguistic Variables in Advanced Second Language Reading: Learners' Self-Assessment and Enjoyment
ERIC Educational Resources Information Center
Brantmeier, Cindy
2005-01-01
The present study on second language (L2) reading and individual difference variables (IDVs) examines learners' self-assessed ability level and enjoyment and the effects of these factors on two different measures of comprehension. The investigation controls for topic familiarity differences by gender and the study utilizes the authentic short…
ERIC Educational Resources Information Center
Kelava, Augustin; Werner, Christina S.; Schermelleh-Engel, Karin; Moosbrugger, Helfried; Zapf, Dieter; Ma, Yue; Cham, Heining; Aiken, Leona S.; West, Stephen G.
2011-01-01
Interaction and quadratic effects in latent variable models have to date only rarely been tested in practice. Traditional product indicator approaches need to create product indicators (e.g., x[superscript 2] [subscript 1], x[subscript 1]x[subscript 4]) to serve as indicators of each nonlinear latent construct. These approaches require the use of…
NASA Technical Reports Server (NTRS)
Nguyen, Nhan; Ting, Eric; Lebofsky, Sonia
2015-01-01
This paper presents data analysis of a flexible wing wind tunnel model with a variable camber continuous trailing edge flap (VCCTEF) design for drag minimization tested at the University of Washington Aeronautical Laboratory (UWAL). The wind tunnel test was designed to explore the relative merit of the VCCTEF concept for improved cruise efficiency through the use of low-cost aeroelastic model test techniques. The flexible wing model is a 10%-scale model of a typical transport wing and is constructed of woven fabric composites and foam core. The wing structural stiffness in bending is tailored to be half of the stiffness of a Boeing 757-era transport wing while the torsional stiffness is about the same. This stiffness reduction results in a wing tip deflection of about 10% of the wing semi-span. The VCCTEF is a multi-segment flap design having three chordwise camber segments and five spanwise flap sections for a total of 15 individual flap elements. The three chordwise camber segments can be positioned appropriately to create a desired trailing edge camber. Elastomeric material is used to cover the gaps in between the spanwise flap sections, thereby creating a continuous trailing edge. Wind tunnel data analysis conducted previously shows that the VCCTEF can achieve a drag reduction of up to 6.31% and an improvement in the lift-to-drag ratio (L=D) of up to 4.85%. A method for estimating the bending and torsional stiffnesses of the flexible wingUWAL wind tunnel model from static load test data is presented. The resulting estimation indicates that the stiffness of the flexible wing is significantly stiffer in torsion than in bending by as much as 9 to 1. The lift prediction for the flexible wing is computed by a coupled aerodynamic-structural model. The coupled model is developed by coupling a conceptual aerodynamic tool Vorlax with a finite-element model of the flexible wing via an automated geometry deformation tool. Based on the comparison of the lift curve slope
ERIC Educational Resources Information Center
Bornstein, Marc H.; Gini, Motti; Suwalsky, Joan T. D.; Putnick, Diane L.; Haynes, O. Maurice
2006-01-01
Emotional availability (EA) is a prominent index of socioemotional adaptation in the parent-child dyad. Can basic psychometric properties of EA be looked at from both variable (scale) and person (cluster) points of view in individuals and in dyads? Is EA stable and continuous over a short period of time? This methodological study shows significant…
Leverrier, Anthony; Grangier, Philippe
2010-06-15
In this article, we give a simple proof of the fact that the optimal collective attacks against continuous-variable quantum key distribution with a Gaussian modulation are Gaussian attacks. Our proof, which makes use of symmetry properties of the protocol in phase space, is particularly relevant for the finite-key analysis of the protocol and therefore for practical applications.
Quintana, D S; Alvares, G A; Heathers, J A J
2016-01-01
The number of publications investigating heart rate variability (HRV) in psychiatry and the behavioral sciences has increased markedly in the last decade. In addition to the significant debates surrounding ideal methods to collect and interpret measures of HRV, standardized reporting of methodology in this field is lacking. Commonly cited recommendations were designed well before recent calls to improve research communication and reproducibility across disciplines. In an effort to standardize reporting, we propose the Guidelines for Reporting Articles on Psychiatry and Heart rate variability (GRAPH), a checklist with four domains: participant selection, interbeat interval collection, data preparation and HRV calculation. This paper provides an overview of these four domains and why their standardized reporting is necessary to suitably evaluate HRV research in psychiatry and related disciplines. Adherence to these communication guidelines will help expedite the translation of HRV research into a potential psychiatric biomarker by improving interpretation, reproducibility and future meta-analyses. PMID:27163204
NASA Astrophysics Data System (ADS)
Laviola, Marianna; Hajny, Ondrej; Roubik, Karel
2014-10-01
High frequency oscillatory ventilation (HFOV) is an alternative mode of mechanical ventilation. HFOV has been shown to provide adequate ventilation and oxygenation in acute respiratory distress syndrome (ARDS) patients and may represent an effective lung-protective ventilation in patients where conventional ventilation is failing. The aim of this study is to evaluate effects of continuous distending pressure (CDP) on variables that contribute to the oxygenation in healthy and ARDS lung model pigs. Methods. In order to simulate a lung disease, lung injury was induced by lavage with normal saline with detergent in three pigs. HFOV ventilation was applied before and after the lung lavage. CDP was stepwise increased by 2 cmH2O, until the maximum CDP (before the lung lavage 32 cmH2O and after the lung lavage 42 cmH2O) and then it was stepwise decreased by 2 cmH2O to the initial value. In this paper we analyzed the following parameters acquired during our experiments: partial pressure of oxygen in arterial blood (PaO2), cardiac output (CO) and mixed venous blood oxygen saturation (SvO2). In order to find how both PaO2 and CO affected SvO2 during the increase of CDP before and after lavage, a nonlinear regression fitting of the response in SvO2 on the predictors (PaO2 and CO) was implemented. Results. Before the lavage, with increasing of CDP, PaO2 remained constant, CO strongly decreased and SvO2 slightly decreased. After the lavage, with increasing of CDP, PaO2 strongly increased, CO decreased and SvO2 increased. So, development of SvO2 followed the PaO2 and CO trends. Changes in PaO2 and CO occur at decisive CDP step and it was much higher after the lung lavage compared to the healthy lungs. The implemented nonlinear model gives a good goodness of fitting in all three pigs. The values of PaO2 and CO estimated coefficients changed at the same decisive step of CDP identified by the trends. Also the algorithm identified a CDP step much higher after the lung lavage
The Climate Variability & Predictability (CVP) Program at NOAA - DYNAMO Recent Project Advancements
NASA Astrophysics Data System (ADS)
Lucas, S. E.; Todd, J. F.; Higgins, W.
2013-12-01
The Climate Variability & Predictability (CVP) Program supports research aimed at providing process-level understanding of the climate system through observation, modeling, analysis, and field studies. This vital knowledge is needed to improve climate models and predictions so that scientists can better anticipate the impacts of future climate variability and change. To achieve its mission, the CVP Program supports research carried out at NOAA and other federal laboratories, NOAA Cooperative Institutes, and academic institutions. The Program also coordinates its sponsored projects with major national and international scientific bodies including the World Climate Research Programme (WCRP), the International Geosphere-Biosphere Programme (IGBP), and the U.S. Global Change Research Program (USGCRP). The CVP program sits within the Earth System Science (ESS) Division at NOAA's Climate Program Office. Dynamics of the Madden-Julian Oscillation (DYNAMO): The Indian Ocean is one of Earth's most sensitive regions because the interactions between ocean and atmosphere there have a discernable effect on global climate patterns. The tropical weather that brews in that region can move eastward along the equator and reverberate around the globe, shaping weather and climate in far-off places. The vehicle for this variability is a phenomenon called the Madden-Julian Oscillation, or MJO. The MJO, which originates over the Indian Ocean roughly every 30 to 90 days, is known to influence the Asian and Australian monsoons. It can also enhance hurricane activity in the northeast Pacific and Gulf of Mexico, trigger torrential rainfall along the west coast of North America, and affect the onset of El Niño. CVP-funded scientists participated in the DYNAMO field campaign in 2011-12. Results from this international campaign are expected to improve researcher's insights into this influential phenomenon. A better understanding of the processes governing MJO is an essential step toward
Vokes, E E; Schilsky, R L; Choi, K E; Magid, D M; Guarnieri, C M; Whaling, S M; Ratain, M J; Weichselbaum, R R; Panje, W R
1989-01-01
This study was designed to evaluate the safety, reliability, and patient acceptance of outpatient continuous intravenous infusion (CVI) chemotherapy. Twenty-two patients with locally advanced head and neck cancer received induction chemotherapy with methotrexate, cisplatin and a 5-day CVI of 5-fluorouracil (5-FU). Patients were randomized to receive the 5-FU portion of cycle 1 either by a standard inpatient CVI chemotherapy delivery device (standard pump) or by the Infusor (Baxter Healthcare Corporation, Deerfield, IL), a portable chemotherapy delivery system that provides a constant flow of drug over a period of 24 hours. For cycle 2, patients crossed over to the alternative drug delivery method. Patients receiving chemotherapy via the Infusor could choose to be either inpatients or outpatients. Daily plasma concentrations of 5-FU were determined during the first two cycles of chemotherapy. There was no significant difference in the mean steady state plasma 5-FU levels achieved with either drug delivery method (329.7 +/- 95.8 ng/ml for infusor cycles vs. 352.8 +/- 114.9 ng/ml for standard pump cycles). Clinical toxicities consisted primarily of mucositis for both methods of drug delivery. Eight patients declined to receive CVI chemotherapy as outpatients citing as reasons fear of malfunction of the device, inconvenience of the frequent clinic visits necessitated by daily monitoring of plasma 5-FU concentrations, and restrictions in daily home activities. Eleven patients underwent CVI chemotherapy via Infusor as outpatients. All reported outpatient CVI chemotherapy as convenient and effective and, when eligible, chose it again in subsequent cycles. A comparison of estimated costs revealed reductions in daily costs of +366.00 (+2,200.00 per cycle) for outpatient chemotherapy. Outpatient CVI chemotherapy is a reliable drug delivery method that was accepted by a majority of patients in this study. These factors may help to establish outpatient CVI chemotherapy as a
A Damage Model for the Simulation of Delamination in Advanced Composites under Variable-Mode Loading
NASA Technical Reports Server (NTRS)
Turon, A.; Camanho, P. P.; Costa, J.; Davila, C. G.
2006-01-01
A thermodynamically consistent damage model is proposed for the simulation of progressive delamination in composite materials under variable-mode ratio. The model is formulated in the context of Damage Mechanics. A novel constitutive equation is developed to model the initiation and propagation of delamination. A delamination initiation criterion is proposed to assure that the formulation can account for changes in the loading mode in a thermodynamically consistent way. The formulation accounts for crack closure effects to avoid interfacial penetration of two adjacent layers after complete decohesion. The model is implemented in a finite element formulation, and the numerical predictions are compared with experimental results obtained in both composite test specimens and structural components.
NASA Astrophysics Data System (ADS)
Hostettler, Jacob
Various environmental and economic factors have lead to increased global investment in alternative energy technologies such as solar and wind power. Although methodologies for synchronous generator control are well researched, wind turbines present control systems challenges not presented by traditional generation. The varying nature of wind makes achieving synchronism with the existing electrical power grid a greater challenge. Departing from early use of induction machines, permanent magnet synchronous generators have become the focus of power systems and control systems research into wind energy systems. This is due to their self excited nature, along with their high power density. The problem of grid synchronism is alleviated through the use of high performance power electronic converters. In achievement of the optimal levels of efficiency, advanced control systems techniques oer promise over more traditional approaches. Research into sliding mode control, and linear matrix inequalities with nite time boundedness and Hinfinity performance criteria, when applied to the dynamical models of the system, demonstrate the potential of these control methodologies as future avenues for achieving higher levels of performance and eciency in wind energy.
NASA Astrophysics Data System (ADS)
Janes, Victoria; Holman, Ian; O'Donnell, Greg; Birkinshaw, Stephen; Kilsby, Chris
2015-04-01
Channel bank erosion processes are influenced by numerous factors resulting in high spatial and temporal variability of sediment production. The representation of channel bank erosion is overly simplistic within most catchment models, despite its significance to catchment sediment budgets. Within this study, the physically-based distributed SHETRAN model is modified to incorporate bank vegetation and channel sinuosity factors that influence spatial and temporal bank erosion rates. The modified model simulates the temporal variation of bank erosion in response to high magnitude events with the potential to remove bank vegetation and de-stabilise banks, thereby increasing erodibility. As vegetation re-establishes, simulated bank erodibility decreases. During the recovery period, banks have increased vulnerability to further high magnitude events that will result in increased bank erosion. This enables the model to represent the impact of flood clustering on sediment generation. The modified model also represents the spatial variation of bank erosion as a result of varying channel planform. Channel geometry has also been linked to bank erosion rates as a result of flow circulation within channels. Channel sinuosity shows a non-linear relationship with bank erosion, with bank erosion increasing up to a threshold value of sinuosity and decreasing as sinuosity increases above this point. The original and modified models have been applied to the Eden catchment in north east England. Bank erosion data derived from a GIS overlay methodology covering 150 years has been used to validate the models, indicating annual sediment generation from bank erosion processes within the catchment is 410-4500 t yr-1, equivalent to 2-11% of the catchment sediment budget. Comparison of the original and modified models highlights the improved ability of the modified model to simulate annual variation of bank eroded sediment production; annual sediment production from the original model ranged
NASA Astrophysics Data System (ADS)
Castillo, Martin
2016-07-01
Screens and displays consume tremendous amounts of power. Global trends to significantly consume less power and increase battery life have led to the reinvestigation of electroluminescent materials. The state of the art in ZnS materials has not been furthered in the past 30 years and there is much potential in improving electroluminescent properties of these materials with advanced processing techniques. Self-propagating high temperature synthesis (SHS) utilises a rapid exothermic process involving high energy and nonlinearity coupled with a high cooling rate to produce materials formed outside of normal equilibrium boundaries thus possessing unique properties. The elimination of gravity during this process allows capillary forces to dominate mixing of the reactants which results in a superior and enhanced homogeneity in the product materials. ZnS type materials have been previously conducted in reduced gravity and normal gravity. It has been claimed in literature that a near perfect phases of ZnS wurtzite was produced. Although, the SHS of this material is possible at high pressures, there has been no quantitative information on the actual crystal structures and lattice parameters that were produced in this work. Utilising this process with ZnS doped with Cu, Mn, or rare earth metals such as Eu and Pr leads to electroluminescence properties, thus making this an attractive electroluminescent material. The work described here will revisit the synthesis of ZnS via high pressure SHS and will re-examine the work performed in both normal gravity and in reduced gravity within the ZARM drop tower facility. Quantifications in the lattice parameters, crystal structures, and phases produced will be presented to further explore the unique structure-property performance relationships produced from the SHS of ZnS materials.
Advances in Understanding Top-of-Atmosphere Radiation Variability from Satellite Observations
NASA Astrophysics Data System (ADS)
Loeb, Norman G.; Kato, Seiji; Su, Wenying; Wong, Takmeng; Rose, Fred G.; Doelling, David R.; Norris, Joel R.; Huang, Xianglei
2012-07-01
This paper highlights how the emerging record of satellite observations from the Earth Observation System (EOS) and A-Train constellation are advancing our ability to more completely document and understand the underlying processes associated with variations in the Earth's top-of-atmosphere (TOA) radiation budget. Large-scale TOA radiation changes during the past decade are observed to be within 0.5 Wm-2 per decade based upon comparisons between Clouds and the Earth's Radiant Energy System (CERES) instruments aboard Terra and Aqua and other instruments. Tropical variations in emitted outgoing longwave (LW) radiation are found to closely track changes in the El Niño-Southern Oscillation (ENSO). During positive ENSO phase (El Niño), outgoing LW radiation increases, and decreases during the negative ENSO phase (La Niña). The coldest year during the last decade occurred in 2008, during which strong La Nina conditions persisted throughout most of the year. Atmospheric Infrared Sounder (AIRS) observations show that the lower temperatures extended throughout much of the troposphere for several months, resulting in a reduction in outgoing LW radiation and an increase in net incoming radiation. At the global scale, outgoing LW flux anomalies are partially compensated for by decreases in midlatitude cloud fraction and cloud height, as observed by Moderate Resolution Imaging Spectrometer and Multi-angle Imaging SpectroRadiometer, respectively. CERES data show that clouds have a net radiative warming influence during La Niña conditions and a net cooling influence during El Niño, but the magnitude of the anomalies varies greatly from one ENSO event to another. Regional cloud-radiation variations among several Terra and A-Train instruments show consistent patterns and exhibit marked fluctuations at monthly timescales in response to tropical atmosphere-ocean dynamical processes associated with ENSO and Madden-Julian Oscillation.
Aljarrah, Mazen; Oatway, Lori; Albers, Susan; Bergen, Colin
2014-01-01
The aim of this study was to estimate variability, broad sense heritability, and genetic advance for dry matter yield (DMY), days to anthesis (ANTH), plant height (HT), in-vitro fiber digestibility-30h (IVFD), lignin (LIGN), starch (STAR %), crude protein content (CP %), acid detergent fiber (ADF) and neutral detergent fiber (NDF) in spring triticale genotypes. Eighteen genotypes were tested at the Field Crop Development Centre (FCDC) in Lacombe, Alberta in 2010-2011 and 2011-2012 growing season. The experimental design was randomized complete block design with 3 replicates. Combined analysis of variance was carried out using SAS Enterprise 4.2 statistical package. Heritability was estimated following the variance component method. Simple correlation coefficients were determined among all traits using two years average data. The genotype mean squares were significant (P ≤ 0.05) for DMY, ANTH, HT, IFVD, ADF, NDF, STAR %, LIGN, and CP %. The effect of year was also highly significant on all studied traits. The phenotypic coefficient of variation was higher than the genetic coefficient of variation for all traits, indicating high influence of the environment on these traits. The significant genetic variability and the high heritability combined with high genetic advance of HT, STAR% and ADF in triticale genotypes suggested that selection could be successfully practiced for those traits. Correlation analysis showed significant and positive correlation of DMY with ANTH and HT, indicating that late and tall genotypes are more suitable as a forage type and they tend to produce more biomass yield. However, DMY did not show any significant correlation with the digestibility. IVFD and STAR % were negatively correlated with LIGN. In general, these results indicated that breeding for low lignin and high starch content will improve the digestibility in triticale genotypes. The preliminary results of this study were promising. Further research must include more diverse
NASA Astrophysics Data System (ADS)
Ismail, S.; Lin, B.; Nehrir, A. R.; Browell, E. V.; Harrison, F. W.; Dobler, J. T.; Kooi, S. A.; Obland, M. D.; Meadows, B. L.; Campbell, J. F.; CHEN, S.; Collins, J. E.; Refaat, T.; Yang, M. M.; Choi, Y.; Dijoseph, M. S.
2013-12-01
NASA Langley, in collaboration with Exelis, is developing and demonstrating an intensity-modulated continuous-wave (IM-CW) Laser Absorption Spectrometer approach for the Active Sensing of CO2 Emission over Nights, Days, and Seasons (ASCENDS) space mission. A Multi-functional Fiber Laser Lidar (MFLL) LAS system developed by Exelis has been used previously to demonstrate high precision CO2 column measurements from several different aircraft platforms. In addition, the MFLL system was recently operated from the NASA DC-8 aircraft during the February-March 2013 ASCENDS flight campaign. The objectives of this campaign included making CO2 column measurements under a variety of background, cloud, and surface conditions, including over snow and tall forests; and evaluating the capability of the LAS systems to retrieve the average CO2 mixing ratio columns from the simultaneous CO2 and O2 column measurements. Nine flights were conducted during the 2013 campaign, including flights over vegetation in the Central Valley of California; playa of Railroad Valley in Nevada, which coincided with an overpass of the GOSAT (Greenhouse Gas Observing Satellite); snow in the Rocky Mountains; forests of California/Oregon coastal region; snow in the Northern Plains; and desert of Arizona. Balloon sondes were launched in conjunction with flights in California and Nevada to obtain atmospheric pressure, temperature and water vapor profiles. In situ CO2 measurements were made with the AVOCET (Atmospheric Vertical Observations of CO2 in the Earth's Troposphere) and Picarro instruments onboard the DC-8 to compare with MFLL measurements. A new, compact, tactical dewar/detector that is a part of NASA Langley's ACES (ASCENDS CarbonHawk Experiment Simulator) project was tested as part of the MFLL during the field campaign. This system demonstrated a new technology applicable for space by reducing mass and volume; enhancing detection bandwidth and service free operation time; and improving the
Sharma, Meena Kumari; Kazmi, Absar Ahmad
2015-01-01
A laboratory-scale study was carried out to investigate the effects of physical properties of the supporting media and variable hydraulic shock loads on the hydraulic characteristics of an advanced onsite wastewater treatment system. The system consisted of two upflow anaerobic reactors (a septic tank and an anaerobic filter) accommodated within a single unit. The study was divided into three phases on the basis of three different supporting media (Aqwise carriers, corrugated ring and baked clay) used in the anaerobic filter. Hydraulic loadings were based on peak flow factor (PFF), varying from one to six, to simulate the actual conditions during onsite wastewater treatment. Hydraulic characteristics of the system were identified on the basis of residence time distribution analyses. The system showed a very good hydraulic efficiency, between 0.86 and 0.93, with the media of highest porosity at the hydraulic loading of PFF≤4. At the higher hydraulic loading of PFF 6 also, an appreciable hydraulic efficiency of 0.74 was observed. The system also showed good chemical oxygen demand and total suspended solids removal efficiency of 80.5% and 82.3%, respectively at the higher hydraulic loading of PFF 6. Plug-flow dispersion model was found to be the most appropriate one to describe the mixing pattern of the system, with different supporting media at variable loading, during the tracer study. PMID:25428652
Marcus, Tamar; Boch, Steffen; Durka, Walter; Fischer, Markus; Gossner, Martin M.; Müller, Jörg; Schöning, Ingo; Weisser, Wolfgang W.
2015-01-01
Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwäbische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes. PMID:26641644
NASA Astrophysics Data System (ADS)
Christ, Andreas; Lupo, Cosmo; Reichelt, Matthias; Meier, Torsten; Silberhorn, Christine
2014-08-01
Parametric down-conversion (PDC) forms one of the basic building blocks for quantum optical experiments. However, the intrinsic multimode spectral-temporal structure of pulsed PDC often poses a severe hindrance for the direct implementation of the heralding of pure single-photon states or, for example, continuous-variable entanglement distillation experiments. To get rid of multimode effects narrowband frequency filtering is frequently applied to achieve a single-mode behavior. A rigorous theoretical description to accurately describe the effects of filtering on PDC, however, is still missing. To date, the theoretical models of filtered PDC are rooted in the discrete-variable domain and only account for filtering in the low-gain regime, where only a few photon pairs are emitted at any single point in time. In this paper we extend these theoretical descriptions and put forward a simple model, which is able to accurately describe the effects of filtering on PDC in the continuous-variable domain. This developed straightforward theoretical framework enables us to accurately quantify the tradeoff between suppression of higher-order modes, reduced purity, and lowered Einstein-Podolsky-Rosen entanglement, when narrowband filters are applied to multimode type-II PDC.
Rotenberg, A; Muller, R U
1997-01-01
A key feature of perception is that the interpretation of a single, continuously available stimulus can change from time to time. This aspect of perception is well illustrated by the use of ambiguous figures that can be seen in two different ways. When people view such a stimulus they almost universally describe what they are seeing as jumping between two states. If it is agreed that this perceptual phenomenon is causally linked to the activity of nerve cells, the state jumps would have to occur in conjunction with changes in neural activity somewhere in the nervous system. Our experiments suggest that hippocampal place cells are part of a perceptual system. We conducted variations of a 'cue-card rotation' experiment on rats in which the angular position of a prominent visual stimulus on the wall of cylinder is changed in the rat's presence. The three main results are that (i) place-cell firing fields remain stationary if the cue is rotated by 180 degrees, so the relation between the cue and the field is altered; (ii) firing fields rotate by 45 degrees when the cue is rotated by 45 degrees, so the relation between the field and the card is maintained; and (iii) if the cue is first rotated by 180 degrees and then rotated in a series of 45 degrees steps, the field winds up at a different angular position relative to the card when the card is back in its original position. Thus, place cells can fire in two different ways in response to a continuously viewed stimulus. We conclude that place cells reveal that the hippocampal mapping system also has properties expected of a perceptual system. PMID:9368939
Hopp, Faith Pratt; Thornton, Nancy; Martin, Lindsey; Zalenski, Robert
2012-01-01
This study addresses the need for more information about how urban African-American elders experience advanced heart failure. Participants included 35 African Americans aged 60 and over with advanced heart failure, identified through records from a community hospital in Detroit, Michigan. Four focus groups (n = 13) and 22 individual interviews were conducted. We used thematic analysis to examine qualitative focus groups and interviews. Themes identified included life disruption, which encompassed the sub-themes of living scared, making sense of heart failure, and limiting activities. Resuming life was a contrasting theme involving culturally relevant coping strategies, and included the sub-themes of resiliency, spirituality, and self-care that helped patients regain and maintain a sense of self amid serious illness. Participants faced numerous challenges and invoked a variety of strategies to cope with their illness, and their stories of struggles, hardship, and resilience can serve as a model for others struggling with advanced illness. PMID:22352363
Tan, Wan Ling
2016-01-01
Squamous cell carcinoma (SCC) of the lung represents about 20-30% of non-small cell lung cancers (NSCLC) and is associated with a poorer prognosis with limited treatment options. Erlotinib is an approved, standard second-line therapy in this setting, besides docetaxel. The LUX-Lung 8 study has shown superior overall survival (OS), progression-free survival (PFS), as well as disease control rates for treatment with afatinib compared to erlotinib in this head-to-head trial in patients with previously treated advanced SCC of the lung, with manageable side effect profile. This is the first and largest prospective phase III trial comparing two different tyrosine kinase inhibitors in patients with advanced SCC of the lung. Whether the results would be practice-changing remains to be seen, especially with the advent of novel immunotherapeutic agents such as nivolumab, which is recently approved for advanced lung SCC. PMID:26958503
NASA Astrophysics Data System (ADS)
Meier, Stephen R.
Since the introduction of the Hodgkin-Huxley equations, used to describe the excitation of neurons, the Nernst equilibria for individual ion channels have assumed to be constant in time. Recent biological recordings call into question the validity of this assumption. Very little theoretical work has been done to address the issue of accounting for these non-static Nernst equilibria using the Hodgkin-Huxley formalism. This body of work incorporates non-static Nernst equilibria into the generalized Hodgkin-Huxley formalism by considering the first-order effects of the Nernst equation. It is further demonstrated that these effects are likely dominate in neurons with diameters much smaller than that of the squid giant axon and permeate important information processing regions of the brain such as the hippocampus. Particular results of interest include single-cell bursting due to the interplay of spatially separated neurons, pattern formation via spiral waves within a soliton-like regime, and quantifiable shifts in the multifractality of hippocampal neurons under the administration of various drugs at varying dosages. This work provides a new perspective on the variability of Nernst equilibria and demonstrates its utility in areas such as pharmacology and information processing.
NASA Astrophysics Data System (ADS)
Runnoe, Jessie C.; Eracleous, Michael; Mathes, Gavin; Pennell, Alison; Boroson, Todd; Sigurðsson, Steinn; Bogdanović, Tamara; Halpern, Jules P.; Liu, Jia
2015-11-01
We present new spectroscopic observations that are part of our continuing monitoring campaign of 88 quasars at z < 0.7 whose broad Hβ lines are offset from their systemic redshifts by a few thousand km s-1. These quasars have been considered as candidates for hosting supermassive black hole binaries (SBHBs) by analogy with single-lined spectroscopic binary stars. We present the data and describe our improved analysis techniques, which include an extensive evaluation of uncertainties. We also present a variety of measurements from the spectra that are of general interest and will be useful in later stages of our analysis. Additionally, we take this opportunity to study the variability of the optical continuum and integrated flux of the broad Hβ line. We compare the variability properties of the SBHB candidates to those of a sample of typical quasars with similar redshifts and luminosities observed multiple times during the Sloan Digital Sky Survey. We find that the variability properties of the two samples are similar (variability amplitudes of 10%-30% on timescales of approximately 1-7 years) and that their structure functions can be described by a common model with parameters characteristic of typical quasars. These results suggest that the broad-line regions of SBHB candidates have a similar extent as those of typical quasars. We discuss the implications of this result for the SBHB scenario and the ensuing constraints on the orbital parameters.
NASA Astrophysics Data System (ADS)
Araya Rodriguez, E.
1998-11-01
In the last months of January and February, it was the Second Astronomical Observation Regional Campaign TAD/IAU in the Suyapa Astronomical Observatory, Tegucigalpa, Honduras; sponsored by the International Astronomical Union, Honduras Government and the Universidad Nacional Autonoma de Honduras. In that opportunity, during the campaign, it began a variable star observation program, according to international regulation of the American Association of Variable Stars Observers (AAVSO). The activities were about the use of general experimental techniques that allow people to do studies naked eye, with telescopes or photometers depending on the observed star magnitude. The continuation in Costa Rica of that research added to some gotten results will be presented in this work.
Gong, Yan-Xiao; Zhang, ShengLi; Xu, P; Zhu, S N
2016-03-21
We propose to generate a single-mode-squeezing two-mode squeezed vacuum state via a single χ^{(2)} nonlinear photonic crystal. The state is favorable for existing Gaussian entanglement distillation schemes, since local squeezing operations can enhance the final entanglement and the success probability. The crystal is designed for enabling three concurrent quasi-phase-matching parametric-down conversions, and hence relieves the auxiliary on-line bi-side local squeezing operations. The compact source opens up a way for continuous-variable quantum technologies and could find more potential applications in future large-scale quantum networks. PMID:27136831
NASA Technical Reports Server (NTRS)
Berton, Jeffrey J.
2002-01-01
Advanced, large commercial turbofan engines using low-fan-pressure-ratio, very high bypass ratio thermodynamic cycles can offer significant fuel savings over engines currently in operation. Several technological challenges must be addressed, however, before these engines can be designed. To name a few, the high-diameter fans associated with these engines pose a significant packaging and aircraft installation challenge, and a large, heavy gearbox is often necessary to address the differences in ideal operating speeds between the fan and the low-pressure turbine. Also, the large nacelles contribute aerodynamic drag penalties and require long, heavy landing gear when mounted on conventional, low wing aircraft. Nevertheless, the reduced fuel consumption rates of these engines are a compelling economic incentive, and fans designed with low pressure ratios and low tip speeds offer attractive noise-reduction benefits. Another complication associated with low-pressure-ratio fans is their need for variable flow-path geometry. As the design fan pressure ratio is reduced below about 1.4, an operational disparity is set up in the fan between high and low flight speeds. In other words, between takeoff and cruise there is too large a swing in several key fan parameters-- such as speed, flow, and pressure--for a fan to accommodate. One solution to this problem is to make use of a variable-area fan nozzle (VAFN). However, conventional, hydraulically actuated variable nozzles have weight, cost, maintenance, and reliability issues that discourage their use with low-fan-pressure-ratio engine cycles. United Technologies Research, in cooperation with NASA, is developing a revolutionary, lightweight, and reliable shape memory alloy actuator system that can change the on-demand nozzle exit area by up to 20 percent. This "smart material" actuation technology, being studied under NASA's Ultra-Efficient Engine Technology (UEET) Program and Revolutionary Concepts in Aeronautics (Rev
ERIC Educational Resources Information Center
James, Carmela N.
2013-01-01
The purpose of this study was to examine the attrition rate of the African American high school student enrolled in advanced academics by looking at the effects of specific quantifiable variables on state-trait anxiety scores. More specifically, this study was concerned with the influence of demographic and school related factors on the…
NASA Technical Reports Server (NTRS)
Johnston, Richard P.
1992-01-01
Satellite surveillance in such areas as the Antarctic indicates that from time to time concentration of ozone grows and shrinks. An effort to obtain useful atmospheric data for determining the causes of ozone depletion would require a flight capable of reaching altitudes of at least 100,000 ft and flying subsonically during the sampling portion of the mission. A study of a heat rejection system for an advanced variable cycle diesel (AVCD) engine was conducted. The engine was installed in an extreme altitude, high altitude advanced research platform. Results indicate that the waste heat from an AVCD engine propulsion system can be rejected at the maximum cruise altitude of 120,000 ft. Fifteen performance points, reflecting the behavior of the engine as the vehicle proceeded through the mission, were used to characterize the heat exchanger operation. That portion of the study is described in a appendix titled, 'A Detailed Study of the Heat Rejection System for an Extreme Altitude Atmospheric Sampling Aircraft,' by a consultant, Mr. James Bourne, Lytron, Incorporated.
NASA Astrophysics Data System (ADS)
Li, Zhen; Ma, Sheng-li; Yang, Zhi-peng; Fang, Ai-ping; Li, Pen-bo; Gao, Shao-yan; Li, Fu-li
2016-04-01
We consider a system consisting of four independent chains of coupled single-mode superconducting transmission line resonators and a gap-tunable qubit. When the first four resonators of the chains are coupled to the qubit properly driven by multicolor fields, we show that the resonators can be prepared in continuous-variable quadripartite cluster states via the decay of the qubit to its ground state. Moreover, the resulting cluster states can be replicated in the other resonators in column via the nearest-neighbor swapping interaction of the resonators. This means that one can generate a set of cluster states, each of which involves the four resonators from the different chains. By a similar protocol, we show that the generation and replication of continuous-variable quadripartite Greenberger-Horne-Zeilinger states in the chains of the resonators can be achieved. The numerical simulation shows that the present scheme is realizable in current accessible on-chip quantum circuit experiments. The present result may have a potential application for the realization of a large-scale one-way quantum computation.
Hydrological flow predictions in ungauged and sparsely gauged watersheds use regionalization or classification of hydrologically similar watersheds to develop empirical relationships between hydrologic, climatic, and watershed variables. The watershed classifications may be based...
Boss, D. S.; Schwartz, G. K.; Middleton, M. R.; Amakye, D. D.; Swaisland, H.; Midgley, R. S.; Ranson, M.; Danson, S.; Calvert, H.; Plummer, R.; Morris, C.; Carvajal, R. D.; Chirieac, L. R.; Schellens, J. H. M.; Shapiro, G. I.
2010-01-01
Background: AZD5438 is an orally bioavailable inhibitor of cyclin E-cdk2, cyclin A-cdk2 and cyclin B-cdk1 complexes. Three phase I studies assessed the clinical safety, tolerability, pharmacokinetics and pharmacodynamics of AZD5438 when administered in different dosing schedules. Patients and methods: AZD5438 was administered four times daily, once every 7 days (study 1), for 14 consecutive days followed by 7 days of rest (study 2), or continuously (study 3), to patients with advanced solid tumours. Dose escalation proceeded until the emergence of dose-limiting toxic effects. Results: Sixty-four patients were included across the three studies (19, 17 and 28, respectively). Nausea and vomiting were the most common adverse events. When dosed continuously, 40 mg four times daily was considered intolerable, and due to safety issues, all studies were terminated prematurely. Consequently, no intolerable dose was identified during the weekly schedule. Pharmacokinetics demonstrated dose-proportional exposure, high interpatient variability and accumulation after multiple doses. Skin biopsies indicated reduced retinoblastoma protein phosphorylation at cdk2 phospho-sites; other pharmacodynamic assessments did not reveal consistent trends. Conclusions: AZD5438 was generally well tolerated in a weekly dosing schedule, but not in continuous schedules. The clinical development programme for AZD5438 was discontinued owing to tolerability and exposure data from these studies. PMID:19825886
Roberts, Brian J; Mulholland, Patrick J; Hill, Walter
2007-01-01
Headwater streams are key sites of nutrient and organic matter processing and retention, but little is known about temporal variability in gross primary production (GPP) and ecosystem respiration (ER) rates as a result of the short duration of most ecosystem metabolism measurements in lotic ecosystems. We examined temporal variability and controls on ecosystem metabolism by measuring daily rates continuously for two years in Walker Branch, a first-order deciduous forest stream. Four important scales of temporal variability in ecosystem metabolism rates were identified: (1) seasonal, (2) day-to-day, (3) episodic (storm-related), and (4) inter-annual. Seasonal patterns were largely controlled by the leaf phenology and productivity of the deciduous riparian forest. Walker Branch was strongly net heterotrophic throughout the year with the exception of the open-canopy spring when GPP and ER rates were similar. Day-to-day variability in weather conditions influenced light reaching the streambed, resulting in high day-to-day variability in GPP particularly during spring (daily light levels explained 84% of the variance in daily GPP in April). Episodic storms depressed GPP for several days in spring, but increased GPP in autumn by removing leaves shading the streambed. Storms depressed ER initially, but then stimulated ER to 2-3 times pre-storm levels for several days. Walker Branch was strongly net heterotrophic in both years of the study (NEP = -1156 and -773 g O2 m-2 y-1), with annual GPP being similar (488 and 519 g O2 m-2 y-1) but annual ER being higher in 2004 than 2005 (-1645 vs. -1292 g O2 m-2 y-1). Inter-annual variability in ecosystem metabolism (assessed by comparing 2004 and 2005 rates with previous measurements) was the result of the storm frequency and timing and the size of the spring macroalgal bloom. Changes in local climate can have substantial impacts on stream ecosystem metabolism rates and ultimately influence the carbon source and sink properties of
Moussavi, Gholamreza; Shekoohiyan, Sakine
2016-11-15
This work was aimed at investigating the performance of the continuous-flow VUV photoreactor as a novel chemical-less advanced process for simultaneously oxidizing acetaminophen (ACT) as a model of pharmaceuticals and reducing nitrate in a single reactor. Solution pH was an important parameter affecting the performance of VUV; the highest ACT oxidation and nitrate reduction attained at solution pH between 6 and 8. The ACT was oxidized mainly by HO while the aqueous electrons were the main working agents in the reduction of nitrate. The performance of VUV photoreactor improved with the increase of hydraulic retention time (HRT); the complete degradation of ACT and ∼99% reduction of nitrate with 100% N2 selectivity achieved at HRT of 80min. The VUV effluent concentrations of nitrite and ammonium at HRT of 80min were below the drinking water standards. The real water sample contaminated with the ACT and nitrate was efficiently treated in the VUV photoreactor. Therefore, the VUV photoreactor is a chemical-less advanced process in which both advanced oxidation and advanced reduction reactions are accomplished. This unique feature possesses VUV photoreactor as a promising method of treating water contaminated with both pharmaceutical and nitrate. PMID:27434736
ERIC Educational Resources Information Center
Stanford Univ., CA. School Mathematics Study Group.
This text is the fourth of five in the Secondary School Advanced Mathematics (SSAM) series which was designed to meet the needs of students who have completed the Secondary School Mathematics (SSM) program, and wish to continue their study of mathematics. This text begins with a brief discussion of quadratic equations which motivates the…
Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H. ); Duthie, R.G. ); Wootten, J.M. )
1991-09-01
Under US DOE sponsorship, a project team consisting of the Institute of Gas Technology, Peabody Holding Company, and Bechtel Group, Inc. has been developing an advanced, mild gasification process to process all types of coal and to produce solid and condensable liquid co-products that can open new markets for coal. The three and a half year program (September 1987 to June 1991) consisted of investigations in four main areas. These areas are: (1) Literature Survey of Mild Gasification Processes, Co-Product Upgrading and Utilization, and Market Assessment; (2) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (3) Bench-Scale Char Upgrading Study; (4) Mild Gasification Technology Development: System Integration Studies. In this report, the literature and market assessment of mild gasification processes are discussed.
Cryptographie quantique à variables continues
NASA Astrophysics Data System (ADS)
Bencheikh, K.; Jankovic, A.; Symul, T.; Levenson, J. A.
2002-06-01
Nous avons élaboré un protocole de cryptographie quantique qui permet de générer et de distribuer une clé secrète aléatoire. Le protocole repose sur l'utilisation de paires de champs électromagnétiques dont les quadratures présentent des corrélations quantiques de type Einstein-Podolsky-Rosen. Les fluctuations quantiques instantanése constituent les bits aléatoires de la clé secrète, et la dégradation irréversible des corrélations quantiques des quadratures causée par une tierce personne permet de la détecter et de garantir la sécurité d'échange.
Rasmussen, Teresa; Gatotho, Jackline
2014-01-01
The population of Johnson County, Kansas increased by about 24 percent between 2000 and 2012, making it one of the most rapidly developing areas of Kansas. The U.S. Geological Survey, in cooperation with the Johnson County Stormwater Management Program, began a comprehensive study of Johnson County streams in 2002 to evaluate and monitor changes in stream quality. The purpose of this report is to describe water-quality variability and constituent transport for streams representing the five largest watersheds in Johnson County, Kansas during 2003 through 2011. The watersheds ranged in urban development from 98.3 percent urban (Indian Creek) to 16.7 percent urban (Kill Creek). Water-quality conditions are quantified among the watersheds of similar size (50.1 square miles to 65.7 square miles) using continuous, in-stream measurements, and using regression models developed from continuous and discrete data. These data are used to quantify variability in concentrations and loads during changing streamflow and seasonal conditions, describe differences among sites, and assess water quality relative to water-quality standards and stream management goals. Water quality varied relative to streamflow conditions, urbanization in the upstream watershed, and contributions from wastewater treatment facilities and storm runoff. Generally, as percent impervious surface (a measure of urbanization) increased, streamflow yield increased. Water temperature of Indian Creek, the most urban site which is also downstream from wastewater facility discharges, was higher than the other sites about 50 percent of the time, particularly during winter months. Dissolved oxygen concentrations were less than the Kansas Department of Health and Environment minimum criterion of 5 milligrams per liter about 15 percent of the time at the Indian Creek site. Dissolved oxygen concentrations were less than the criterion about 10 percent of the time at the rural Blue River and Kill Creek sites, and less than
Ran, Du; Hu, Chang-Sheng; Yang, Zhen-Biao
2016-01-01
We study the entanglement transfer from a two-mode continuous variable system (initially in the two-mode SU(2) cat states) to a couple of discrete two-state systems (initially in an arbitrary mixed state), by use of the resonant Jaynes-Cummings (JC) interaction. We first quantitatively connect the entanglement transfer to non-Gaussianity of the two-mode SU(2) cat states and find a positive correlation between them. We then investigate the behaviors of the entanglement transfer and find that it is dependent on the initial state of the discrete systems. We also find that the largest possible value of the transferred entanglement exhibits a variety of behaviors for different photon number as well as for the phase angle of the two-mode SU(2) cat states. We finally consider the influences of the noise on the transferred entanglement. PMID:27553881
Ruhl, C.A.; Schoellhamer, D.H.; Stumpf, R.P.; Lindsay, C.L.
2001-01-01
Analysis of suspended-sediment concentration data in San Francisco Bay is complicated by spatial and temporal variability. In situ optical backscatterance sensors provide continuous suspended-sediment concentration data, but inaccessibility, vandalism, and cost limit the number of potential monitoring stations. Satellite imagery reveals the spatial distribution of surficial-suspended sediment concentrations in the Bay; however, temporal resolution is poor. Analysis of the in situ sensor data in conjunction with the satellite reflectance data shows the effects of physical processes on both the spatial and temporal distribution of suspended sediment in San Francisco Bay. Plumes can be created by large freshwater flows. Zones of high suspended-sediment concentrations in shallow subembayments are associated with wind-wave resuspension and the spring-neap cycle. Filaments of clear and turbid water are caused by different transport processes in deep channels, as opposed to adjacent shallow water.
NASA Astrophysics Data System (ADS)
Mandarino, Antonio; Bina, Matteo; Porto, Carmen; Cialdi, Simone; Olivares, Stefano; Paris, Matteo G. A.
2016-06-01
We experimentally address the significance of fidelity as a figure of merit in quantum state reconstruction of discrete (DV) and continuous-variable (CV) quantum optical systems. In particular, we analyze the use of fidelity in quantum homodyne tomography of CV states and maximum-likelihood polarization tomography of DV ones, focusing attention on nonclassicality, entanglement, and quantum discord as a function of fidelity to a target state. Our findings show that high values of fidelity, despite well quantifying geometrical proximity in the Hilbert space, may be obtained for states displaying opposite physical properties, e.g., quantum or semiclassical features. In particular, we analyze in detail the quantum-to-classical transition for squeezed thermal states of a single-mode optical system and for Werner states of a two-photon polarization qubit system.
Joseph, Jeffrey I; Torjman, Marc C; Strasma, Paul J
2015-07-01
Hyperglycemia, hypoglycemia, and glycemic variability have been associated with increased morbidity, mortality, length of stay, and cost in a variety of critical care and non-critical care patient populations in the hospital. The results from prospective randomized clinical trials designed to determine the risks and benefits of intensive insulin therapy and tight glycemic control have been confusing; and at times conflicting. The limitations of point-of-care blood glucose (BG) monitoring in the hospital highlight the great clinical need for an automated real-time continuous glucose monitoring system (CGMS) that can accurately measure the concentration of glucose every few minutes. Automation and standardization of the glucose measurement process have the potential to significantly improve BG control, clinical outcome, safety and cost. PMID:26078254
Ran, Du; Hu, Chang-Sheng; Yang, Zhen-Biao
2016-01-01
We study the entanglement transfer from a two-mode continuous variable system (initially in the two-mode SU(2) cat states) to a couple of discrete two-state systems (initially in an arbitrary mixed state), by use of the resonant Jaynes-Cummings (JC) interaction. We first quantitatively connect the entanglement transfer to non-Gaussianity of the two-mode SU(2) cat states and find a positive correlation between them. We then investigate the behaviors of the entanglement transfer and find that it is dependent on the initial state of the discrete systems. We also find that the largest possible value of the transferred entanglement exhibits a variety of behaviors for different photon number as well as for the phase angle of the two-mode SU(2) cat states. We finally consider the influences of the noise on the transferred entanglement. PMID:27553881
Bahman Habibzadeh
2010-01-31
The project began under a corporative agreement between Mack Trucks, Inc and the Department of Energy starting from September 1, 2005. The major objective of the four year project is to demonstrate a 10% efficiency gain by operating a Volvo 13 Litre heavy-duty diesel engine at a constant or narrow speed and coupled to a continuously variable transmission. The simulation work on the Constant Speed Engine started on October 1st. The initial simulations are aimed to give a basic engine model for the VTEC vehicle simulations. Compressor and turbine maps are based upon existing maps and/or qualified, realistic estimations. The reference engine is a MD 13 US07 475 Hp. Phase I was completed in May 2006 which determined that an increase in fuel efficiency for the engine of 10.5% over the OICA cycle, and 8.2% over a road cycle was possible. The net increase in fuel efficiency would be 5% when coupled to a CVT and operated over simulated highway conditions. In Phase II an economic analysis was performed on the engine with turbocompound (TC) and a Continuously Variable Transmission (CVT). The system was analyzed to determine the payback time needed for the added cost of the TC and CVT system. The analysis was performed by considering two different production scenarios of 10,000 and 60,000 units annually. The cost estimate includes the turbocharger, the turbocompound unit, the interstage duct diffuser and installation details, the modifications necessary on the engine and the CVT. Even with the cheapest fuel and the lowest improvement, the pay back time is only slightly more than 12 months. A gear train is necessary between the engine crankshaft and turbocompound unit. This is considered to be relatively straight forward with no design problems.
Serkies, Krystyna; Dziadziuszko, Rafal; Jassem, Jacek
2012-03-01
Purpose: To evaluate the feasibility and efficacy of definitive continuous 7-days-a-week pelvic irradiation without breaks between external beam radiotherapy and brachytherapy in locally advanced cervical cancer. Methods and Materials: Between November 1998 and December 1999, 30 patients with International Federation of Obstetrics and Gynecology Stage IIB or IIIB cervical cancer were included in a prospective Phase I/II study of continuous 7-days-a-week pelvic irradiation, to the total Manchester point B dose of 40.0-57.6 Gy. The first 13 patients (Group A) were given a daily tumor dose of 1.6 Gy, and the remaining 17 patients (Group B) were given 1.8 Gy. One or two immediate brachytherapy applications (point A dose 10-20 Gy, each) were performed in 28 cases. Results: Two patients did not complete the irradiation because of apparent early progression of disease during the irradiation. Eleven of the 28 evaluable patients (39%; 45% and 35% in Groups A and B, respectively) completed their treatment within the prescribed overall treatment time. Acute toxicity (including severe European Organisation for Research and Treatment of Cancer/Radiation Therapy Oncology Group Grade 3 and 4 effects in 40%) was experienced by 83% of patients and resulted in unplanned treatment interruptions in 40% of all patients (31% and 47% of patients in Groups A and B, respectively). Severe intestinal side effects occurred in 31% and 41% of Patients in Groups A and B, respectively (p = 0.71). The 5-year overall survival probability was 33%. Cancer recurrence occurred in 63% of patients: 20% inside and 57% outside the pelvis. Cumulative incidence of late severe bowel and urinary bladder toxicity at 24 months was 15%. Conclusion: Continuous irradiation in locally advanced cervical cancer is associated with a high incidence of severe acute toxicity, resulting in unplanned treatment interruptions. Late severe effects and survival after continuous radiotherapy do not substantially differ from
NASA Astrophysics Data System (ADS)
Lawler, D. M.
2008-01-01
In most episodic erosion and deposition systems, knowledge of the timing of geomorphological change, in relation to fluctuations in the driving forces, is crucial to strong erosion process inference, and model building, validation and development. A challenge for geomorphology, however, is that few studies have focused on geomorphological event structure (timing, magnitude, frequency and duration of individual erosion and deposition events), in relation to applied stresses, because of the absence of key monitoring methodologies. This paper therefore (a) presents full details of a new erosion and deposition measurement system — PEEP-3T — developed from the Photo-Electronic Erosion Pin sensor in five key areas, including the addition of nocturnal monitoring through the integration of the Thermal Consonance Timing (TCT) concept, to produce a continuous sensing system; (b) presents novel high-resolution datasets from the redesigned PEEP-3T system for river bank system of the Rivers Nidd and Wharfe, northern England, UK; and (c) comments on their potential for wider application throughout geomorphology to address these key measurement challenges. Relative to manual methods of erosion and deposition quantification, continuous PEEP-3T methodologies increase the temporal resolution of erosion/deposition event detection by more than three orders of magnitude (better than 1-second resolution if required), and this facility can significantly enhance process inference. Results show that river banks are highly dynamic thermally and respond quickly to radiation inputs. Data on bank retreat timing, fixed with PEEP-3T TCT evidence, confirmed that they were significantly delayed up to 55 h after flood peaks. One event occurred 13 h after emergence from the flow. This suggests that mass failure processes rather than fluid entrainment dominated the system. It is also shown how, by integrating turbidity instrumentation with TCT ideas, linkages between sediment supply and sediment
Olea, R.A.; Houseknecht, D.W.; Garrity, C.P.; Cook, T.A.
2011-01-01
Shale gas is a form of continuous unconventional hydrocarbon accumulation whose resource estimation is unfeasible through the inference of pore volume. Under these circumstances, the usual approach is to base the assessment on well productivity through estimated ultimate recovery (EUR). Unconventional resource assessments that consider uncertainty are typically done by applying analytical procedures based on classical statistics theory that ignores geographical location, does not take into account spatial correlation, and assumes independence of EUR from other variables that may enter into the modeling. We formulate a new, more comprehensive approach based on sequential simulation to test methodologies known to be capable of more fully utilizing the data and overcoming unrealistic simplifications. Theoretical requirements demand modeling of EUR as areal density instead of well EUR. The new experimental methodology is illustrated by evaluating a gas play in the Woodford Shale in the Arkoma Basin of Oklahoma. Differently from previous assessments, we used net thickness and vitrinite reflectance as secondary variables correlated to cell EUR. In addition to the traditional probability distribution for undiscovered resources, the new methodology provides maps of EUR density and maps with probabilities to reach any given cell EUR, which are useful to visualize geographical variations in prospectivity.
Hogsett, R.F.; Jha, M.C.
1991-12-01
Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.
Not Available
1992-11-01
This report contains the material balance data for Wyodak, Indiana No. 3, and Cannelton coals that were tested in the mild gasification program. Data include tests conducted using the 1- to 4-lb/hr continuous fluid-bed reactor (CFBR) and the 100-lb/hr Process Research Unit (PRU). All raw analysis data were reduced to calculate product yields as a percentage of the product mass divided by the maf coal feed. The material closure was then determined, and losses were assigned to one or a combination of the three product streams: char, condensate (includes condensed steam), and gas. Mass was added proportionally to each constituent of the stream until the closure was 100%.
Not Available
1992-11-01
This report contains the material balance data for Wyodak, Indiana No. 3, and Cannelton coals that were tested in the mild gasification program. Data include tests conducted using the 1- to 4-lb/hr continuous fluid-bed reactor (CFBR) and the 100-lb/hr Process Research Unit (PRU). All raw analysis data were reduced to calculate product yields as a percentage of the product mass divided by the maf coal feed. The material closure was then determined, and losses were assigned to one or a combination of the three product streams: char, condensate (includes condensed steam), and gas. Mass was added proportionally to each constituent of the stream until the closure was 100%.
Santos García, Diego; Martínez Castrillo, Juan Carlos; Puente Périz, Víctor; Seoane Urgorri, Agustín; Fernández Díez, Servando; Benita León, Vicente; Udaeta Baldivieso, Beatriz; Campolongo Perillo, Antonia; Mariscal Pérez, Natividad
2016-06-01
Patients with Parkinson's disease often have a good initial response to dopaminergic therapy but later usually develop motor fluctuations and dyskinesia. In these patients, continuous infusion of levodopa-carbidopa intestinal gel (LCIG) allows for maintaining adequate dopamine levels and for improving motor and nonmotor symptoms, as well as quality of life and autonomy. Adequate candidate selection and follow-up are crucial for treatment success. Management should be multidisciplinary, and patient and caregiver education is a priority. This expert consensus document has been developed by a team of neurologists, gastroenterologists and nurses who have a vast experience in LCIG therapy, with an intention to provide knowledge and tools to facilitate patient management throughout all phases of LCIG treatment process. PMID:27075968
O`Neal, G.W.
1996-01-01
Efforts continued to obtain financing for a commercial continuous formed coke plant. Discussions were held with two steel companies that are interested in producing coke for their use in steel production and foundry operations. Planning for production of 40 tons of foundry formed coke is underway. This coke will be used in two 20-ton tests at General Motors` foundries. During this production, it is planned to determine if a tunnel kiln can be used as a coking furnace as an alternative for a rotary hearth. A rotary hearth is about three times more costly than a competitive-sized tunnel kiln. Work continued on using Western non-caking coals to produce formed coke. Successful tests were made by using Eastern caking coals and other binders to permit using up to 50% of the cheaper Western non-caking coals in formed coke production. The primary objective of this project is to develop an advanced continuous mild gasification process and product upgrading processes which will be capable of eventual commercialization.
Ando, M.; Watanabe, T.; Sasaki, Y.; Ying, D. F.; Omuro, Y.; Katsumata, N.; Narabayashi, M.; Tokue, Y.; Fujii, H.; Igarashi, T.; Wakita, H.; Ohtsu, T.; Itoh, K.; Adachi, I.; Taguchi, T.
1998-01-01
To determine the maximum-tolerated doses (MTDs), the dose-limiting toxicities (DLTs) and the recommended doses for further trials of docetaxel in combination with a 5-day continuous infusion of 5-fluorouracil (5-FU) in advanced or recurrent breast cancer patients who had been treated previously with at least one chemotherapeutic regimen, patients were treated with docetaxel as a 1-h infusion on day 1 followed by 5-FU as a continuous infusion on days 1 through 5 every 3-4 weeks. Three or six patients were assessed at the following escalating dose levels of docetaxel/5-FU per day: 40/150, 40/300, 50/300, 50/500 and 60/500 mg m(-2). Nineteen patients entered this trial, of whom 18 could be assessed for adverse event and therapeutic efficacy. The DLTs were neutropenia and diarrhoea. The MTDs were 60 mg m(-2) of docetaxel on day 1 and 500 mg m(-2) per day of 5-day continuous infusion of 5-FU. One of 18 patients achieved a complete response and eight achieved partial response (over all response rate: 50%). The recommended doses of docetaxel and 5-day continuous infusion of 5-FU for a phase II trial are 50 mg m(-2) and 500 mg m(-2) per day every 3 or 4 weeks. PMID:9667671
NASA Astrophysics Data System (ADS)
Saprygin, V. V.
2011-12-01
The goal of this study was to apply continuous fluorometric and remote estimation of chlorophyll-a concentration (Cchl) techniques to complex turbid waters of Azov Sea and explore Cchl temporal variation and spatial pattern. Azov Sea is the shallowest sea in the world with maximum depth below 15 m. Its maximum salinity is about 14%; total suspended solids and chlorophyll-a concentrations reach 120 [tex]g m^{-3}[/tex] and 100 [tex]mg m^{-3}[/tex] respectively in Taganrog Bay, daily production varies up to 3.5 [tex]gC_{org} m^{-3}[/tex]. Chlorophyll-a concentrations were measured in 2008-2010 year-round spectrophotometrically, 446 water samples were taken to calibrate fluorometerical and remote sensing data. The highest recorded concentration was 149.3, the lowest - 0.3 [tex]mg m^{-3}[/tex]. Continuous-flow fluorometer was applied in the course of 3 expeditions to Taganrog Bay to measure chlorophyll-a fluorescence (Fchl) each 30 meters along the ship path. Two-cuvette fluorometer was used to discount the influence of dissolved organic matter. Fchl measurements were calibrated and Cchl profiles derieved to estimate Cchl spatial heterogeneity in close scale. Fchl measurements were also made during moorings each 6 seconds to estimate temporal Cchl variability. Recently published algorithm based on reflectance in the red and the near-infrared (NIR) spectral regions was applied to MERIS data for the remote estimation of Cchl. Taking in account fluorometric Cchl spatial heterogeneity estimation, the algorithm for culling the outliers in Cchl fields derived from satellite data was developed. 74 images were processed to Cchl maps and then averaged monthly. Consequently, Cchl spatial distribution and seasonal variability were studied. Spectrophotometric, flourumetric measurements and values obtained by NIR-red algorithm showed strong correlation in turbid Case II waters of Azov Sea. Fluorometric and remote measurements showed high Cchl variations in short and long terms
Singh, Ravendra; Sahay, Abhishek; Karry, Krizia M; Muzzio, Fernando; Ierapetritou, Marianthi; Ramachandran, Rohit
2014-10-01
It is desirable for a pharmaceutical final dosage form to be manufactured through a quality by design (QbD)-based approach rather than a quality by testing (QbT) approach. An automatic feedback control system coupled with PAT tools that is part of the QbD paradigm shift, has the potential to ensure that the pre-defined end product quality attributes are met in a time and cost efficient manner. In this work, an advanced hybrid MPC-PID control architecture coupled with real time inline/online monitoring tools and principal components analysis (PCA) based additional supervisory control layer has been proposed for a continuous direct compaction tablet manufacturing process. The advantages of both MPC and PID have been utilized in a hybrid scheme. The control hardware and software integration and implementation of the control system has been demonstrated using feeders and blending unit operation of a continuous tablet manufacturing pilot plant and an NIR based PAT tool. The advanced hybrid MPC-PID control scheme leads to enhanced control loop performance of the critical quality attributes in comparison to a regulatory (e.g. PID) control scheme indicating its potential to improve pharmaceutical product quality. PMID:24974987
Ness, R.O. Jr.; Runge, B.; Sharp, L.
1992-11-01
The University of North Dakota Energy and Environmental Research Center (EERC) and the AMAX Research and Development Center are cooperating in the development of a Mild Gasification process that will rapidly devolatilize coals of all ranks at relatively low temperatures between 930[degree] and 1470[degree]F (500[degree]and 800[degree]C) and near atmospheric pressure to produce primary products that include a reactive char, a hydrocarbon condensate, and a low-Btu gas. These will be upgraded in a coal refinery'' system having the flexibility to optimize products based on market demand. Task 2 of the four-task development sequence primarily covered bench-scale testing on a 10-gram thermogravimetric analyzer (TGA) and a 1 to 4-lb/hr continuous fluidized-bed reactor (CFBR). Tests were performed to determine product yields and qualities for the two major test coals-one a high-sulfur bituminous coal from the Illinois Basin (Indiana No. 3) and the other a low-sulfur subbituminous coal from the Powder River Basin (Wyodak). Results from Task 3, on product upgrading tests performed by AMAX Research and Development (R D), are also reported. Task 4 included the construction, operation of a Process Research Unit (PRU), and the upgrading of the products. An economic evaluation of a commercial facility was made, based on the data produced in the PRU, CFBR, and the physical cleaning steps.
Ness, R.O. Jr.; Runge, B.; Sharp, L.
1992-11-01
The University of North Dakota Energy and Environmental Research Center (EERC) and the AMAX Research and Development Center are cooperating in the development of a Mild Gasification process that will rapidly devolatilize coals of all ranks at relatively low temperatures between 930{degree} and 1470{degree}F (500{degree}and 800{degree}C) and near atmospheric pressure to produce primary products that include a reactive char, a hydrocarbon condensate, and a low-Btu gas. These will be upgraded in a ``coal refinery`` system having the flexibility to optimize products based on market demand. Task 2 of the four-task development sequence primarily covered bench-scale testing on a 10-gram thermogravimetric analyzer (TGA) and a 1 to 4-lb/hr continuous fluidized-bed reactor (CFBR). Tests were performed to determine product yields and qualities for the two major test coals-one a high-sulfur bituminous coal from the Illinois Basin (Indiana No. 3) and the other a low-sulfur subbituminous coal from the Powder River Basin (Wyodak). Results from Task 3, on product upgrading tests performed by AMAX Research and Development (R&D), are also reported. Task 4 included the construction, operation of a Process Research Unit (PRU), and the upgrading of the products. An economic evaluation of a commercial facility was made, based on the data produced in the PRU, CFBR, and the physical cleaning steps.
Caligiuri, M A; Murray, C; Soiffer, R J; Klumpp, T R; Seiden, M; Cochran, K; Cameron, C; Ish, C; Buchanan, L; Perillo, D
1991-12-01
In previous clinical trials, recombinant interleukin-2 (rIL-2) has been infused at high doses over short periods of time to generate lymphokine-activated killer (LAK) cells in vivo. These trials have been limited by severe toxicities, and the immunologic effects of rIL-2 have been transient. The present study was designed to assess the toxicity and immunologic effects of prolonged administration of low doses of rIL-2. In this phase I study, patients with advanced cancer were scheduled to receive intravenous (IV) infusion of rIL-2 without interruption for 3 months in an outpatient setting. Twenty-one patients received rIL-2 at doses ranging from 0.5 x 10(5) to 6.0 x 10(5) U/m2/d. Treatment was extremely well tolerated, and no patient experienced grade 3 or grade 4 toxicity. The lowest dose level (0.5 x 10(5) U/m2/d) did not have demonstrable immunologic activity. At doses of 1.5 x 10(5) and 4.5 x 10(5) U/m2/d, rIL-2 infusion resulted in the specific expansion of natural-killer (NK) cells (sixfold and ninefold increases, respectively, at these two dose levels) without any changes in B cells, T cells, neutrophils, or monocytes. Grade 2 toxicity was observed at the dose of 6.0 x 10(5) U/m2/d, as three patients required interruption of therapy and two patients who completed therapy developed transient hypothyroidism. In patients with increased NK cells, enhancement of non-major histocompatibility complex (MHC)-restricted cytotoxicity and increased generation of LAK cells in vitro were also demonstrated. Therapy with low-dose rIL-2 can be given safely in an uninterrupted fashion for prolonged periods of time in an outpatient setting. This results in selective expansion of NK cells in vivo with minimal toxicity. Further investigation of this schedule for immunomodulation in vivo should be pursued in phase II studies of both malignant and immunodeficient disease states. PMID:1960552
NASA Astrophysics Data System (ADS)
Smith, J. P.; Baxi, C. B.; Reis, E.; Schaffer, M. J.; Schaubel, K. M.; Menon, M. M.
1991-11-01
A cryocondensation pump will be installed in the baffle chamber of the DIII-D tokamak in the spring of 1992. The design is complete and fabrication of this pump is in progress. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long, in the lower outer corner of the vacuum vessel interior. It consists of a 1 m(exp 2) liquid helium cooled surface surrounded by a liquid nitrogen cooled shield to limit the heat load on the helium cooled surface. The stainless steel liquid nitrogen shell has a copper coating on it to enhance thermal conductivity, but the coating is broken to keep the toroidal electrical resistance high. The liquid nitrogen cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. The whole pump is supported off the water cooled vacuum vessel wall. Key design considerations were: how to accommodate the temperature differences between the various components, developing low heat leak paths for the various supports, and maintaining electrical insulation in a low pressure environment in the presence of induced voltage spikes. A single point ground for the system was used to limit disruption induced currents and the resulting electro-mechanical forces on the pump. A testing program was used to develop coating techniques to enhance heat transfer and emissivity of the various surfaces. Fabrication tests were done to determine the best method of attaching the liquid nitrogen flow tubes to their shield surfaces. A prototype sector of the pump was built to verify fabrication and assembly techniques.
Vega, A; Abad, S; Verdalles, U; Aragoncillo, I; Velazquez, K; Quiroga, B; Escudero, V; López-Gómez, JM
2014-01-01
Background: Anemia is a prevalent situation in patients with chronic kidney disease (CKD) and can be well managed with erythropoiesis-stimulating agents (ESAs). Continuous erythropoietin receptor activator (CERA) has a long half-life that allows to be administered once monthly. The lowest recommended dose for patients with non dialysis CKD is 120 μg per month. The objectives were to assess the efficacy of subcutaneous monthly dosing of CERA in CKD stages 4 and 5 not on dialysis, and to determine the equivalent dose to epoetin β and darbepoetin α. Methods: This is a cohort study. A 30-patient group that ESAs was changed to CERA (μg/month) was used as treatment group. We used the following clinically-based equivalent dosing: epoetin β (IU/week) and darbepoetin α (μg/week): 3000/15= 50; 4000/20=75; 6000/30=100; 8000/40=150. Another group of 30 patients with similar characteristics was used as control group and received the same epoetin β and darbepoetin α doses. Results: The mean CERA initial dose and at 6 months was 81.9 ± 35.2 and 82.0 ± 37.82 μg/month (p=0.37). The mean erythropoietin resistance index (ERI) and hemoglobin at baseline and at 6 months in the CERA group and in the control group were not statistically significant. Conclusion: Monthly dosing treatment with CERA is safe and effective. A dose of 75-100 μg/month is enough to maintain stable levels of hemoglobin. Hippokratia 2014; 18 (4): 315-318. PMID:26052197
NASA Technical Reports Server (NTRS)
Parlett, L. P.; Shivers, J. P.
1976-01-01
A low-speed wind-tunnel investigation was conducted in a full-scale tunnel to determine the performance and static stability and control characteristics of a large-scale model of a blended-arrow advanced supersonic transport configuration incorporating variable-cycle engines and vectoring exhaust nozzles. Configuration variables tested included: (1) engine mode (cruise or low-speed), (2) engine exit nozzle deflection, (3) leading-edge flap geometry, and (4) trailing-edge flap deflection. Test variables included values of C sub micron from 0 to 0.38, values of angle of attack from -10 degrees to 30 degrees, values of angle of sideslip, from -5 degrees to 5 degrees, and values of Reynolds number, from 3.5 million to 6.8 million.
NASA Astrophysics Data System (ADS)
Li, Feng; Wu, Hongbin; Qin, Minghan
2016-02-01
In order to study the effects of processing parameters on the continuous variable cross-section direct extrusion (CVCDE), taking 7A09 aluminium alloy for example, the extrusion speed and forming temperature and the friction factor as key processing parameters are applied to research by finite element (FE) simulation. The research result showed that the extrusion speed had a significant influence on the maximum temperature of the billet, at the same time, both decreasing the friction factor and increasing forming temperature within a certain range were beneficial to reduce extrusion load. Both forming temperature and the extrusion speed were inversely linked to extrusion load, but the friction factor was directly proportional to extrusion load. Forming temperature had a far more important influence on extrusion load by comparison: when forming temperature increased from 380∘ to 430∘C, the peak value of extrusion load decreased by 25.6% and the flow uniformity of extruded product got improved. The process window based on both the press limit and surface defects limit was established and the most reasonable forming temperature was 405∘C under this process condition, which provided theoretical basis for formulation process of 7A09 aluminium alloy on the CVCDE extrusion.
NASA Technical Reports Server (NTRS)
Nguyen, Nhan; Ting, Eric; Nguyen, Daniel; Dao, Tung; Trinh, Khanh
2013-01-01
This paper presents a coupled vortex-lattice flight dynamic model with an aeroelastic finite-element model to predict dynamic characteristics of a flexible wing transport aircraft. The aircraft model is based on NASA Generic Transport Model (GTM) with representative mass and stiffness properties to achieve a wing tip deflection about twice that of a conventional transport aircraft (10% versus 5%). This flexible wing transport aircraft is referred to as an Elastically Shaped Aircraft Concept (ESAC) which is equipped with a Variable Camber Continuous Trailing Edge Flap (VCCTEF) system for active wing shaping control for drag reduction. A vortex-lattice aerodynamic model of the ESAC is developed and is coupled with an aeroelastic finite-element model via an automated geometry modeler. This coupled model is used to compute static and dynamic aeroelastic solutions. The deflection information from the finite-element model and the vortex-lattice model is used to compute unsteady contributions to the aerodynamic force and moment coefficients. A coupled aeroelastic-longitudinal flight dynamic model is developed by coupling the finite-element model with the rigid-body flight dynamic model of the GTM.
Julious, Steven A; Cooper, Cindy L; Campbell, Michael J
2015-01-01
Sample size justification is an important consideration when planning a clinical trial, not only for the main trial but also for any preliminary pilot trial. When the outcome is a continuous variable, the sample size calculation requires an accurate estimate of the standard deviation of the outcome measure. A pilot trial can be used to get an estimate of the standard deviation, which could then be used to anticipate what may be observed in the main trial. However, an important consideration is that pilot trials often estimate the standard deviation parameter imprecisely. This paper looks at how we can choose an external pilot trial sample size in order to minimise the sample size of the overall clinical trial programme, that is, the pilot and the main trial together. We produce a method of calculating the optimal solution to the required pilot trial sample size when the standardised effect size for the main trial is known. However, as it may not be possible to know the standardised effect size to be used prior to the pilot trial, approximate rules are also presented. For a main trial designed with 90% power and two-sided 5% significance, we recommend pilot trial sample sizes per treatment arm of 75, 25, 15 and 10 for standardised effect sizes that are extra small (≤0.1), small (0.2), medium (0.5) or large (0.8), respectively. PMID:26092476
Andree, Stefan; Reble, Carina; Helfmann, Jurgen; Gersonde, Ingo; Illing, Gerd
2010-01-01
We present a new variant of a noncontact, oblique incidence spatially resolved reflectance setup. The continuously variable source detector separation enables adaptation to high and low albedo samples. Absorption (μ(a)) and reduced scattering coefficients (μ(') (s)) are determined in the wavelength range of 400-1000 nm using a lookup table, calculated by a Monte Carlo simulation of the light transport. The method is characterized by an silicone phantom study covering a wide parameter range 0.01 mm(-1) ≤ μ(a) ≤ 2.5 mm(-1) and 0.2 mm(-1) ≤ μ(') (s) ≤ 10 mm(-1), which includes the optical parameters of tissue in the visible and near infrared. The influence of the incident angle and the detection aperture on the simulated remission was examined. Using perpendicular incidence and 90-deg detection aperture in the Monte Carlo simulation in contrast to the experimental situation with 30-deg incidence and 4.6-deg detection aperture is shown to be valid for the parameter range μ(') (s) > 1 mm(-1) and μ(a) < 1.2 mm(-1). A Mie calculation is presented, showing that a decreasing reduced scattering coefficient for increasing absorption can be the consequence of real physics instead of cross talk. PMID:21198213
Torimoto, Keiichi; Okada, Yosuke; Arao, Tadashi; Mori, Hiroko; Yamamoto, Sunao; Narisawa, Manabu; Kurozumi, Akira; Tanaka, Yoshiya
2014-01-01
A 48-year-old woman was diagnosed and treated for Graves' disease (GD) in 1999 but she discontinued treatment at her own discretion. In 2011, she was admitted to a local hospital for management of thyrotoxic crisis. Treatment with propylthiouracil, iodide potassium (KI), and prednisolone (PSL) was started, which resulted in improvement of the general condition. PSL and KI were discontinued before she was transferred to our hospital. At the local hospital, fasting plasma glucose (FPG) was 212 mg/dL and hemoglobin A1c concentration was 11.2%; intensive insulin therapy had been instituted. Upon admission to our hospital, FPG level was 122 mg/dL, but insulin secretion was compromised, suggesting aggravation of thyroid function and deterioration of glycemic control. The FPG level increased to 173 mg/dL; continuous glucose monitoring (CGM) identified dawn phenomenon at approximately 0400 h. Resumption of KI resulted in improvement of FPG and disappearance of the dawn phenomenon, as assessed by CGM. These results indicate that in patients with compromised insulin secretion, hyperthyroidism can induce elevation of not only postprandial blood glucose, but also FPG level due to the dawn phenomenon and that the dawn phenomenon can be alleviated with improvement in thyroid function. To our knowledge, no studies have assessed glucose variability by CGM before and after treatment of Graves' disease. The observations made in this case shed light on the understanding of abnormal glucose metabolism associated with Graves' disease. PMID:24420389
Nusca, Annunziata; Lauria Pantano, Angelo; Melfi, Rosetta; Proscia, Claudio; Maddaloni, Ernesto; Contuzzi, Rocco; Mangiacapra, Fabio; Palermo, Andrea; Manfrini, Silvia; Pozzilli, Paolo; Di Sciascio, Germano
2015-01-01
Poor glycemic control is associated with unfavorable outcome in patients undergoing percutaneous coronary intervention (PCI), irrespective of diabetes mellitus. However a complete assessment of glycemic status may not be fully described by glycated hemoglobin or fasting blood glucose levels, whereas daily glycemic fluctuations may influence cardiovascular risk and have even more deleterious effects than sustained hyperglycemia. Thus, this paper investigated the effectiveness of a continuous glucose monitoring (CGM), registering the mean level of glycemic values but also the extent of glucose excursions during coronary revascularization, in detecting periprocedural outcome such as renal or myocardial damage, assessed by serum creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and troponin I levels. High glycemic variability (GV) has been associated with worse postprocedural creatinine and NGAL variations. Moreover, GV, and predominantly hypoglycemic variations, has been observed to increase in patients with periprocedural myocardial infarction. Thus, our study investigated the usefulness of CGM in the setting of PCI where an optimal glycemic control should be achieved in order to prevent complications and improve outcome. PMID:26273664
Wohl, David A.; Kendall, Michelle A.; Feinberg, Judith; Alston-Smith, Beverly; Owens, Susan; Chafey, Suzette; Marco, Michael; Maxwell, Sharon; Benson, Constance; Keiser, Philip; van der Horst, Charles; Jacobson, Mark A.
2013-01-01
Introduction Despite the efficacy and tolerability of modern antiretroviral therapy (ART), many patients with advanced AIDS prescribed these regimens do not achieve viral suppression or immune reconstitution as a result of poor adherence, drug resistance, or both. The clinical outcomes of continued ART prescription for such patients have not been well characterized. Methods We examined the causes and predictors of all-cause mortality, AIDS-defining conditions, and serious non-AIDS-defining events among a cohort of participants in a clinical trial of pre-emptive therapy for CMV disease. We focused on participants who, despite ART had failed to achieve virologic suppression and substantive immune reconstitution. Results 233 ART-receiving participants entered with a median baseline CD4+ T cell count of 30/mm3 and plasma HIV RNA of 5 log10 copies/mL. During a median 96 weeks of follow-up, 24.0% died (a mortality rate of 10.7/100 patient-years); 27.5% reported a new AIDS-defining condition, and 22.3% a new serious non-AIDS event. Of the deaths, 42.8% were due to an AIDS-defining condition, 44.6% were due to a non-AIDS-defining condition, and 12.5% were of unknown etiology. Decreased risk of mortality was associated with baseline CD4+ T cell count ≥25/mm3 and lower baseline HIV RNA. Conclusions Among patients with advanced AIDS prescribed modern ART who achieve neither virologic suppression nor immune reconstitution, crude mortality percentages appear to be lower than reported in cohorts of patients studied a decade earlier. Also, in contrast to the era before modern ART became available, nearly half of the deaths in our modern-era study were caused by serious non-AIDS-defining events. Even among the most advanced AIDS patients who were not obtaining apparent immunologic and virologic benefit from ART, continued prescription of these medications appears to alter the natural history of AIDS—improving survival and shifting the causes of death from AIDS- to non
ERIC Educational Resources Information Center
Howard, Martin
2012-01-01
Situated within the recent new wave of second language acquisition studies investigating the acquisition of sociolinguistic variation, this article draws on a longitudinal database of advanced French interlanguage to explore a number of issues that have not yet been extensively investigated. They concern the issue of individual variation in the…
O`Neal, G.W.
1996-04-01
Determination of the best furnace for a commercial coke plant is underway. A shuttle or tunnel kiln has economic advantage over a rotary hearth design. Production of 20 tons of coke in a small shuttle kiln is near completion which will provide experience for this design. Twenty tons of CTC continuous coke are being produced for testing at a General Motors` foundry. The production is approximately 75 percent complete. During this production, variables of the process are being studied to aid in design of a commercial coke plant. Raw material composition, blending, briquetting variables, and calcining heat profile are the major areas of interest. Western SynCoal Company produces a dried coal product from sub-bituminous coal. This upgraded product was evaluated for producing coke products by blending char from this coal product with the coal product along with suitable binders. The green briquettes were then calcined to produce coke. The resulting coke was judged to be usable as part of a cupola coke charge or as a fuel in cement kilns and sugar beet furnaces.
NASA Astrophysics Data System (ADS)
Teneva, L. T.; Dunbar, R. B.; Mucciarone, D. A.; Fleischfresser, J. D.
2011-12-01
There is growing evidence that ocean acidification (OA) will have significantly detrimental impacts on coral reef calcification and community composition. However, the rates of coral reef response to ocean pH changes and the implications of for ecosystem resilience remain largely unknown. Our ability to make more accurate predictions of OA impacts on coral reefs hinges on an improved capacity for temporal and spatial measurements of coral reef carbon budgets. Here we report on in situ results from a 6 day deployment during April 2011 over a Palauan coral reef. Our experimental approach uses a custom-made automated continuous flow system capable of resolving pH, temperature, and salinity on a 10-second timescale, and Dissolved Inorganic Carbon (DIC) on a 5-minute timescale. In addition, discrete water samples were collected for alkalinity measurements every 3-4 hours in order to capture the essential carbonate variables. We observe higher diurnal amplitude in the DIC and alkalinity signal that is commensurate with greater diurnal tidal range. The highest diurnal alkalinity signal of 100 umol/kg was observed on the first day of the experiment and it progressively decreased throughout the week to 50 umol/kg. A similar trend occurred with DIC, with highest diurnal DIC of 250 umol/kg, decreasing to 100 umol/kg at the end of deployment. Maxima in DIC and alkalinity occurred around 10-11am, and minima occurred near dusk. The diurnal signal in pH ranged 8.0-8.1, with semidiurnal maxima at 2-3am and again~12 hours later. Conversely, minima occurred in mid-morning and again at ~10pm. Our results clearly demonstrate that coral community calcification and photosynthesis affect the surrounding waters' carbon chemistry. In this setting, however, the hydrodynamics - in particular, strong tidal influence -are likely the most significant factor determining the carbon chemistry conditions within the reef community. Highly-resolved natural variability in coral reef metabolism from
Brown, D J F; Milroy, R; Preston, T; McMillan, D C
2007-01-01
Background The Glasgow Prognostic Score (GPS), an inflammation‐based prognostic score formed from standard thresholds of C reactive protein (CRP) and albumin, has prognostic value in patients with advanced cancer. Little is known about the general biochemical disturbance associated with the systemic inflammatory response in cancer. Aim To examine the relationship between the GPS and blood biochemistry in patients with advanced lung and gastrointestinal cancer. Methods The GPS (albumin <35 g/l = 1 and CRP >10 mg/l = 1 combined to form a prognostic score of 0 (normal) and 1 or 2 (abnormal)) and a variety of biochemical variables were examined in patients (n = 50) with advanced lung or gastrointestinal cancer and in a healthy control group (n = 13). Results The GPS was normal in all the controls, but abnormal in 78% of the cancer group. Serum levels of sodium, chloride, creatine kinase, zinc and vitamin D were lower in the cancer group (all p<0.01), whereas levels of calcium, copper (both p<0.05), alkaline phosphatase, γ‐glutamyl transferase (both p<0.001) and lactate dehydrogenase (p<0.10) were raised. In the patient group, with increasing GPS, there was a median reduction in Karnofsky Performance Status (25%), haemoglobin (22%), sodium (3%), zinc (15%) and survival (93%, all p<0.05) and a median increase in white cell count (129%), alkaline phosphatase (217%), γ‐glutamyl transferase (371%) and lactate dehydrogenase (130%, all p<0.05). CRP levels were strongly and similarly correlated with alkaline phosphatase and γ‐glutamyl transferase, accounting for more than 25% of the variation in their activities. Conclusion Several correlations were seen between biochemical variables and increasing GPS. In particular, chronic activation of the systemic inflammatory response in cancer was associated with increase in γ‐glutamyl transferase and alkaline phosphatase activity in patients with advanced lung and gastrointestinal cancer. PMID:16644880
ERIC Educational Resources Information Center
Karplus, Robert; And Others
Reported are the results of a study of the Piagetian formal thought range of 3600 students, 13 to 15 years old, in seven countries: Denmark, Sweden, Italy, United States, Austria, Germany, and Great Britain. Cognitive measurement was obtained by group administration of two tasks to assess proportional reasoning and control of variables. Overall…
ERIC Educational Resources Information Center
Shores, Melanie L.; Shannon, David M.; Smith, Tommy G.
2010-01-01
A total of 761 students (58.1% female) from selected fifth- and sixth-grade mathematics classrooms in Alabama were examined to investigate the relationships between individual learner variables (gender, ethnicity, socioeconomic status [SES]) and mathematics performance. Specifically, this portion of the study examined individual learner variables…
NASA Technical Reports Server (NTRS)
Ippolito, Corey; Nguyen, Nhan; Totah, Joe; Trinh, Khanh; Ting, Eric
2013-01-01
In this paper, we describe an initial optimization study of a Variable-Camber Continuous Trailing-Edge Flap (VCCTEF) system. The VCCTEF provides a light-weight control system for aircraft with long flexible wings, providing efficient high-lift capability for takeoff and landing, and greater efficiency with reduced drag at cruising flight by considering the effects of aeroelastic wing deformations in the control law. The VCCTEF system is comprised of a large number of distributed and individually-actuatable control surfaces that are constrained in movement relative to neighboring surfaces, and are non-trivially coupled through structural aeroelastic dynamics. Minimzation of drag results in a constrained, coupled, non-linear optimization over a high-dimension search space. In this paper, we describe the modeling, analysis, and optimization of the VCCTEF system control inputs for minimum drag in cruise. The purpose of this initial study is to quantify the expected benefits of the system concept. The scope of this analysis is limited to consideration of a rigid wing without structural flexibility in a steady-state cruise condition at various fuel weights. For analysis, we developed an optimization engine that couples geometric synthesis with vortex-lattice analysis to automate the optimization procedure. In this paper, we present and describe the VCCTEF system concept, optimization approach and tools, run-time performance, and results of the optimization at 20%, 50%, and 80% fuel load. This initial limited-scope study finds the VCCTEF system can potentially gain nearly 10% reduction in cruise drag, provides greater drag savings at lower operating weight, and efficiency is negatively impacted by the severity of relative constraints between control surfaces.
NASA Astrophysics Data System (ADS)
Svensson, Johan; Ramírez López, Pavel E.; Jalali, Pooria N.; Cervantes, Michel
2015-06-01
One of the main targets for Continuous Casting (CC) modelling is the actual prediction of defects during transient events. However, the majority of CC models are based on a statistical approach towards flow and powder performance, which is unable to capture the subtleties of small variations in casting conditions during real industrial operation or the combined effects of such changes leading eventually to defects. An advanced Computational Fluid Dynamics (CFD) model; which accounts for transient changes on lubrication during casting due to turbulent flow dynamics and mould oscillation has been presented on MCWASP XIV (Austria) to address these issues. The model has been successfully applied to the industrial environment to tackle typical problems such as lack of lubrication or unstable flows. However, a direct application to cracking had proven elusive. The present paper describes how results from this advanced CFD-CC model have been successfully coupled to structural Finite Element Analysis (FEA) for prediction of stress-strains as a function of irregular lubrication conditions in the mould. The main challenge for coupling was the extraction of the solidified shell from CFD calculations (carried out with a hybrid structured mesh) and creating a geometry by using iso-surfaces, re-meshing and mapping loads (e.g. temperature, pressure and external body forces), which served as input to mechanical stress-strain calculations. Preliminary results for CC of slabs show that the temperature distribution within the shell causes shrinkage and thermal deformation; which are in turn, the main source of stress. Results also show reasonable stress levels of 10-20 MPa in regions, where the shell is thin and exposed to large temperature gradients. Finally, predictions are in good agreement with prior works where stresses indicate compression at the slab surface, while tension is observed at the interior; generating a characteristic stress-strain state during solidification in CC.
Kollmannsberger, C; Quietzsch, D; Haag, C; Lingenfelser, T; Schroeder, M; Hartmann, J T; Baronius, W; Hempel, V; Clemens, M; Kanz, L; Bokemeyer, C
2000-01-01
To evaluate the toxicity and efficacy of combination chemotherapy with paclitaxel, cisplatin and 24 h continuous infusion of 5-FU/folinic acid in patients (pts) with unresectable, locally advanced or metastatic gastric adenocarcinoma. Forty-five chemotherapy-naive pts (28 male and 17 female) with a median age of 60 years (range 35–74) were enrolled. 5-FU 2 g/m2was given weekly over 24 h i.v. preceded by folinic acid 500 mg/m2as a 2 h infusion. Paclitaxel 175 mg/m2was administered as a 3 h-infusion on days 1 and 22 and cisplatin 50 mg/m2as 1 h infusion on days 8 and 29. Six weeks of therapy (days 1, 8, 15, 22, 29, 36) followed by 2 weeks rest were considered one cycle. A median of 3 cycles (range 1–4) were administered to 45 pts assessable for response, survival and toxicity. Five pts (11%) obtained a CR and 18 pts (40%) a PR (ORR 51%; 95% Cl: 35.8–66.3%). Responses were achieved in the liver, lymph nodes, lungs and at the site of the primary tumour. Nine pts (20%) had stable disease. Thirteen pts (29%) were considered to have failed treatment, 8 pts (18%) due to progressive disease and 5 pts (11%) who did not receive one complete cycle of therapy due to acute non-haematologic toxicity. The median progression-free and overall survival times were 9 months (range 1–36+) and 14 months (range 2–36+), respectively. Neutropenia WHO III°/IV° occurred in 7 pts (15%) with only 1 pt having grade IV. Additional non-haematologic WHO III°/IV° toxicities included nausea/vomiting in 5 (11%), alopecia in 22 (49%), and diarrhoea in 1 patient each (2%). Dose reductions or treatment delays were necessary in 8 pts (17%), mainly due to neutropenia. All pts were treated on an outpatient basis. The combination of paclitaxel, cisplatin and continuously infused 5-FU/folinic acid appears to be a highly active regimen for the treatment of pts with advanced gastric cancer. While the overall acceptable toxicity allows its use in the palliative setting, it may also be an attractive
Sharples, Linda D; Clutterbuck-James, Abigail L; Glover, Matthew J; Bennett, Maxine S; Chadwick, Rebecca; Pittman, Marcus A; Quinnell, Timothy G
2016-06-01
Obstructive sleep apnoea-hypopnoea (OSAH) causes excessive daytime sleepiness, impairs quality-of-life, and increases cardiovascular disease and road traffic accident risks. Continuous positive airway pressure (CPAP) treatment and mandibular advancement devices (MAD) have been shown to be effective in individual trials but their effectiveness particularly relative to disease severity is unclear. A MEDLINE, Embase and Science Citation Index search updating two systematic reviews to August 2013 identified 77 RCTs in adult OSAH patients comparing: MAD with conservative management (CM); MAD with CPAP; or CPAP with CM. Overall MAD and CPAP significantly improved apnoea-hypopnoea index (AHI) (MAD -9.3/hr (p < 0.001), CPAP -25.4 (p < 0.001)). In direct comparisons mean AHI and Epworth sleepiness scale score were lower (7.0/hr (p < 0.001) and 0.67 (p = 0.093) respectively) for CPAP. There were no CPAP vs. MAD trials in mild OSAH but in comparisons with CM, MAD and CPAP reduced ESS similarly (MAD 2.01 (p < 0.001); CPAP 1.23 (p = 0.012). Both MAD and CPAP are clinically effective in the treatment of OSAH. Although CPAP has a greater treatment effect, MAD is an appropriate treatment for patients who are intolerant of CPAP and may be comparable to CPAP in mild disease. PMID:26163056
Loukriz, Abdelhamid; Haddadi, Mourad; Messalti, Sabir
2016-05-01
Improvement of the efficiency of photovoltaic system based on new maximum power point tracking (MPPT) algorithms is the most promising solution due to its low cost and its easy implementation without equipment updating. Many MPPT methods with fixed step size have been developed. However, when atmospheric conditions change rapidly , the performance of conventional algorithms is reduced. In this paper, a new variable step size Incremental Conductance IC MPPT algorithm has been proposed. Modeling and simulation of different operational conditions of conventional Incremental Conductance IC and proposed methods are presented. The proposed method was developed and tested successfully on a photovoltaic system based on Flyback converter and control circuit using dsPIC30F4011. Both, simulation and experimental design are provided in several aspects. A comparative study between the proposed variable step size and ﬁxed step size IC MPPT method under similar operating conditions is presented. The obtained results demonstrate the efficiency of the proposed MPPT algorithm in terms of speed in MPP tracking and accuracy. PMID:26337741
NASA Astrophysics Data System (ADS)
Lobo, Julio; Antoniu Popescu, I.
2010-08-01
We present two new Monte Carlo sources for the DOSXYZnrc code, which can be used to compute dose distributions due to continuously variable beam configurations. These sources support a continuously rotating gantry and collimator, dynamic multileaf collimator (MLC) motion, variable monitor unit (MU) rate, couch rotation and translation in any direction, arbitrary isocentre motion with respect to the patient and variable source-to-axis distance (SAD). These features make them applicable to Monte Carlo simulations for RapidArc™, Elekta VMAT, TomoTherapy™ and CyberKnife™. Unique to these sources is the synchronization between the motion in the DOSXYZnrc geometry and the motion within the linac head, represented by a shared library (either a BEAMnrc accelerator with dynamic component modules, or an external library). The simulations are achieved in single runs, with no intermediate phase space files.
NASA Astrophysics Data System (ADS)
Olteanu, S. C.; Aitouche, A.; Belkoura, L.
2014-12-01
The article's goals are to illustrate the feasibility of implementing a Takagi Sugeno state observer on an embedded microcontroller based platform and secondly to present a methodology for validating a physical embedded system using a Hardware In The Loop architecture, where a simulation software replaces the process. As an application, a three water tank system was chosen. For the validation part, LMS AMESim software is employed to reproduce the process behaviour. The interface to the embedded platform is assured by Simulink on a Windows operating system, chosen as it is the most commonly used operating system. The lack of real time behaviour of the operating system is compensated by a real time kernel that manages to offer deterministic response times. The Takagi-Sugeno observer in the case of this process has the complex form that considers the premise variables to be unmeasurable. The embedded system consists of two Arduino boards connected in parallel, thus offering distributed resources.
D. L. Knudson; J. L. Rempe
2012-02-01
New materials are being considered for fuel, cladding, and structures in next generation and existing nuclear reactors. These materials can undergo significant dimensional and physical changes during high temperature irradiations. Currently, such changes are determined by repeatedly irradiating a specimen for a specified period of time in the Advanced Test Reactor (ATR) and then removing it from the reactor for evaluation. The labor and time to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data and may disturb the phenomena of interest. To resolve these issues, an instrumented creep testing capability is being developed for specimens irradiated in pressurized water reactor (PWR) coolant conditions in the ATR at the Idaho National Laboratory (INL). This paper reports the status of INL efforts to develop this testing capability. In addition to providing an overview of in-pile creep test capabilities available at other test reactors, this paper focuses on efforts to design and evaluate a prototype test rig in an autoclave at INL's High Temperature Test Laboratory (HTTL).
D. L. Knudson; J. L. Rempe
2012-02-01
New materials are being considered for fuel, cladding and structures in next generation and existing nuclear reactors. These materials can undergo significant dimensional and physical changes during high temperature irradiations. Currently, such changes are determined by repeatedly irradiating a specimen for a specified period of time in the Advanced Test Reactor (ATR) and then removing it from the reactor for evaluation. The labor and time to remove, examine and return irradiated samples for each measurement make this approach very expensive. In addition, such techniques provide limited data and may disturb the phenomena of interest. To resolve these issues, an instrumented creep testing capability is being developed for specimens irradiated under pressurized water reactor coolant conditions in the ATR at the Idaho National Laboratory (INL). This paper reports the status of INL efforts to develop this testing capability. In addition to providing an overview of in-pile creep test capabilities available at other test reactors, this paper focuses on efforts to design and evaluate a prototype test rig in an autoclave at INL’s High Temperature Test Laboratory.
NASA Technical Reports Server (NTRS)
Mcardle, Jack G.
1986-01-01
A variable inlet guide van (VIGV) type convertible engine that could be used to power future high-speed rotorcraft was tested on an outdoor stand. The engine ran stably and smoothly in the turbofan, turboshaft, and dual (combined fan and shaft) power modes. In the turbofan mode with the VIGV open fuel consumption was comparable to that of a conventional turbofan engine. In the turboshaft mode with the VIGV closed fuel consumption was higher than that of present turboshaft engines because power was wasted in churning fan-tip airflow. In dynamic performance tests with a specially built digital engine control and using a waterbrake dynamometer for shaft load, the engine responded effectively to large steps in thrust command and shaft torque. Previous mission analyses of a conceptual X-wing rotorcraft capable of 400-knot cruise speed were revised to account for more fan-tip churning power loss than was originally estimated. The new calculations confirm that using convertible engines rather than separate lift and cruise engines would result in a smaller, lighter craft with lower fuel use and direct operating cost.
Clunie, R.; Guibord, R.; Gregoire, R.
1994-01-01
Saunders Brothers' wood products company has watched the steady growth of its neighboring community in Westbrook to the point where neighborhood housing is now within a few feet of the plant property. The Saunders Brothers' boiler plant consists of two HRT boilers which burn only bark and wood sawmill wastes and shavings generated by the manufacturing plant. Although technically in compliance with State of Maine environmental laws, Saunders Brothers was concerned with the visible emissions and fly ash emanating from the plant site. Wishing to maintain its status as a good neighbor, in 1989 Saunders Brothers' boiler plant was extensively renovated. Part of these modifications consisted of changing over to automatic microprocessor combustion controls and installing AC variable frequency drives on the combustion air fans and fuel feed screws. The purpose of adopting the microprocessor-based combustion control approach to solve the air pollution problem at Saunders Brothers was two-fold. The control package takes complete control of the fuel feed and combustion processes. By accurately metering the fuel supply and the air supply to the firebox, usual large air volumes and resultant velocities are reduced and controlled. At the same time all particulate emissions are greatly reduced, and all visible emissions are eliminated. A side benefit of installing the new combustion control system was an expected fuel savings of approximately 20% to 25%.
NASA Technical Reports Server (NTRS)
Richards, Paul L.
2005-01-01
Mechanical heat switches are used in conjunction with sorption refrigerators, adiabatic demagnetization refrigerators and for other cryogenic tasks including the pre-cooling cryogenic systems. They use a mechanical actuator which closes Au plated Cu jaws on an Au plated Cu bar. The thermal conductance in the closed position is essentially independent of the area of the jaws and proportional to the force applied. It varies linearly with T. It is approximately 10mW/K for 200 N at 1.5K. In some applications, the heat switch can be driven from outside the cryostat by a rotating rod and a screw. Such heat switches are available commercially from several sources. In other applications, including systems for space, it is desirable to drive the switch using a cold linear motor, or solenoid. Superconducting windings are used at temperatures s 4.2K to minimize power dissipation, but are not appropriate for pre-cooling a system at higher temperatures. This project was intended to improve the design of solenoid activated mechanical heat switches and to provide such switches as required to support the development of Advanced Adiabatic Demagnetization Refrigerators for Continuous Cooling from 10 K to 50 mK at GSFC. By the time funding began in 5/1/01, the immediate need for mechanical heat switches at GSFC had subsided but, at the same time, the opportunity had arisen to improve the design of mechanical heat switching by incorporating a "latching solenoid". In this device, the solenoid current is required only for changing the state of the switch and not during the whole time that the switch is closed.
NASA Astrophysics Data System (ADS)
Pal, Sandip; Haeffelin, Martial
2015-12-01
The atmospheric boundary layer (ABL) depth, zi, is a fundamental variable of ABL and a climatologically important quantity. The exchange of energy between the Earth's surface and the atmosphere is governed by turbulent mixing processes in the daytime ABL, and thus, zi is important for scaling turbulence and diffusion in both meteorological and air quality models. A long-term data set of zi was derived at the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA) observatory near Paris, using measurements obtained from a ground-based vertically pointing aerosol lidar and an autonomous algorithm STRAT+. Using multiparameter observational data sets covering a 5 year period (October 2008 to September 2013), this study aims to explore two interconnected ABL research topics: brief climatology involving multiscale temporal zi variability (diurnal, seasonal, annual, and interannual) and the relationship between zi and near-surface thermodynamic parameters to determine meteorological processes governing zi variability. Both the zi and the growth rate over SIRTA showed large seasonal variability with higher mean values in spring (1633 m and 225 m h-1) and summer (1947 m and 247 m h-1) than in autumn (1439 m and 196 m h-1) and winter (1033 m and 149 m h-1). Seasonal variability of daytime maximum zi is found to be strongly and linearly correlated with downwelling solar radiation at the surface (r = 0.92), while the dependence between daytime maximum zi and sensible heat flux (SHF) at seasonal scales is not fully linear, in particular, for summer months. Interannual variability is studied using deseasonalized monthly-mean anomalies of each variable. Conditional sampling and linear regression analyses between the anomalies of deseasonalized SHF and daytime maximum zi, show (1) stronger correlation between the two parameters for the soil conditions compared to the wet soil conditions, (2) that zi anomalies were more dependent on SHF anomalies for negative
NASA Technical Reports Server (NTRS)
Bayless, E. O., Jr.
1991-01-01
Technological advances generate within themselves dissatisfactions that lead to further advances in a process. A series of advances in welding technology which culminated in the Variable Polarity Plasma Arc (VPPA) Welding Process and an advance instituted to overcome the latest dissatisfactions with the process: automated VPPA welding are described briefly.
Jamiołkowska, Milena; Jamiołkowska, Izabela; Łuczyński, Włodzimierz; Tołwińska, Joanna; Bossowski, Artur; Głowińska Olszewska, Barbara
2016-01-01
Children with type 1 diabetes (T1DM) are the high-risk group of accelerated atherosclerosis. Real-time continuous glucose monitoring (RT-CGM) provides possibilities for the detection of glycaemic variability, newly recognized cardiovascular risk factor. The aim of the study was to assess the usefulness of RT-CGM as an educational tool to find and reduce glycaemic variability in order to improve endothelial function in T1DM adolescents. Forty patients aged 14.6 years were recruited. The study was based on one-month CGM sensors use. Parameters of glycaemic variability were analyzed during first and last sensor use, together with brachial artery flow-mediated dilatation (FMD) to assess endothelial function. In the whole group, FMD improvement was found (10.9% to 16.6%, p < 0.005), together with decrease in all studied glycaemic variability parameters. In patients with HbA1c improvement compared to the group without HbA1c improvement, we found greater increase of FMD (12% to 19%, p < 0.005 versus 8.2% to 11.3%, p = 0.080) and greater improvement of glucose variability. RT-CGM can be considered as an additional tool that offers T1DM adolescents the quick reaction to decrease glycaemic variability in short time observation. Whether such approach might influence improvement in endothelial function and reduction of the risk of future cardiovascular disease remains to be elucidated. PMID:26649320
NASA Astrophysics Data System (ADS)
Fovet, O.; Thelusma, G.; Humbert, G.; Dupas, R.; Jaffrezic, A.; Grimaldi, C.; Faucheux, M.; Gilliet, N.; Hamon, Y.; Gruau, G.
2015-12-01
Storm events are hot moments of emission for several dissolved and particulate chemical species at major stake for water quality (e.g. dissolved organic carbon DOC, suspended sediments, phosphorus, NH4). During such events, the solutes or particles are exported from heterogeneous sources through various pathways to stream or are possibly stored in retention hot spots temporary. This leads to specific integrated signals at the outlet at the scale of storm events. The dynamics of such events are also very short especially in headwater catchments where their total duration ranges over 10h to 3 days, with very quick variations in stream flow and concentrations at the outlet occurring in a few hours. Thus for investigating properly event processes, high frequency monitoring of flow and water quality is required. We analysed 103 storm events in a 5 km2 agricultural headwater catchment, part of the AgrHys Observatory, on the basis of a 3-year-long data set which combined meterological (Rainfall), hydrological (flow and piezometry), and water quality (turbidity, conductivity, DOC and NO3 concentrations) data recorded at very high frequencies (from 1 to 20 min) thanks to dedicated sensors. We described the storm events using simple (1 variable) and combined (2 variables) descriptors for characterizing level and dynamics of flow (Q), groundwater levels, and concentrations (C) but also the C-Q relationships. Three intra annual periods have been previously defined for base flow dynamic according to shallow groundwater table variations so that they correspond to different connectivity status in the catchment. The seasonal and inter-annual variability of the storm events have been analysed using the descriptors and based on these predefined periods. Principal component analysis based on storm chemical descriptors led to discriminate these three seasons while storm hydrological descriptors are less variable between them. Finally we used a clustering method to build a typology of
NASA Astrophysics Data System (ADS)
Casey, J. G.; Collier, A. M.; Hannigan, M.; Piedrahita, R.; Vaughn, B. H.; Sherwood, O.
2015-12-01
In recent years, aided by the advent of horizontal drilling used in conjunction with hydraulic fracturing, oil and gas production in basins around the United States has increased significantly. A study was conducted in two oil and gas basins during the spring and summer of 2015 to investigate the spatial and temporal variability of several atmospheric trace gases that can be influenced by oil and gas extraction including methane, ozone, and carbon dioxide. Fifteen air quality monitors were distributed across the Denver Julesburg Basin in Northeast Colorado, and the San Juan Basin, which stretches from Southwest Colorado into Northwest New Mexico in Four Corners Region. Spatial variability in ozone was observed across each basin. The presence of dynamic short-term trends observed in the mole fraction of methane and carbon dioxide indicate the extent to which each site is uniquely impacted by local emission sources. Diurnal trends of these two constituents lead toward a better understanding of local pooling of emissions that can be influenced by topography, the planetary boundary layer height, atmospheric stability, as well as the composition and flux of local and regional emissions sources.
Fox-Rabinovitz, M; Cote, J
2009-06-05
The joint U.S-Canadian project has been devoted to: (a) decadal climate studies using developed state-of-the-art GCMs (General Circulation Models) with enhanced variable and uniform resolution; (b) development and implementation of advanced numerical techniques; (c) research in parallel computing and associated numerical methods; (d) atmospheric chemistry experiments related to climate issues; (e) validation of regional climate modeling strategies for nested- and stretched-grid models. The variable-resolution stretched-grid (SG) GCMs produce accurate and cost-efficient regional climate simulations with mesoscale resolution. The advantage of the stretched grid approach is that it allows us to preserve the high quality of both global and regional circulations while providing consistent interactions between global and regional scales and phenomena. The major accomplishment for the project has been the successful international SGMIP-1 and SGMIP-2 (Stretched-Grid Model Intercomparison Project, phase-1 and phase-2) based on this research developments and activities. The SGMIP provides unique high-resolution regional and global multi-model ensembles beneficial for regional climate modeling and broader modeling community. The U.S SGMIP simulations have been produced using SciDAC ORNL supercomputers. Collaborations with other international participants M. Deque (Meteo-France) and J. McGregor (CSIRO, Australia) and their centers and groups have been beneficial for the strong joint effort, especially for the SGMIP activities. The WMO/WCRP/WGNE endorsed the SGMIP activities in 2004-2008. This project reflects a trend in the modeling and broader communities to move towards regional and sub-regional assessments and applications important for the U.S. and Canadian public, business and policy decision makers, as well as for international collaborations on regional, and especially climate related issues.
Goutaland, F.; Marin, E.; Michalon, J. Y.; Boukenter, A.
2009-05-04
We report on the space-selective precipitation of silver nanoparticles in silica-based and silver-exchanged soda-lime glasses by simultaneous continuous wave ultraviolet exposure and heat treatment. In silica-based glasses, we explain that simultaneous treatments lead to much higher silver nanoparticles concentration than similar treatments performed into two separated steps by minimizing the detrimental influence of oxidation on the nanoparticles' growth. In the case of silver-exchanged soda-lime glasses, nanoparticles are observed with both small and larger diameters of about 1 and 7 nm, whose concentrations depend both on the laser power density and on the heating temperature.
NASA Technical Reports Server (NTRS)
Baber, H. T., Jr.
1979-01-01
Credence to systems weights and assurance that the noise study AST concept can be balanced were studied. Current titanium structural technology is assumed. A duct-burning turbofan variable stream control engine (VSCE), with noise reduction potential through use of a coannular nozzle was used. With 273 passengers, range of the AST-105-1 for a cruise Mach number of 2.62 is essentially transpacific. Lift-to-drag ratio is slightly higher than for previous AST configurations. It is trimmable over a center-of-gravity range of 4.7m (15.5 ft). Inherent high positive effective dihedral, typical of arrow-wing configurations in high-lift approach, would limit AST-105-1 to operating in crosswinds of 11.6 m/sec (22.4 kt), or less, with 75 percent of available lateral control. Normal power takeoff with cutback results in noise in excess of Federal Aviation Regulation Part 36 but less than for conventional procedure takeoff. Results of advanced (noncertificated) programmed throttle takeoff and approach procedures, not yet optimized, indicate that such can be an important additional method noise reduction.
NASA Astrophysics Data System (ADS)
Wang, Jianhua; Cheng, Lianglun; Wang, Tao; Peng, Xiaodong
2016-03-01
Table look-up operation plays a very important role during the decoding processing of context-based adaptive variable length decoding (CAVLD) in H.264/advanced video coding (AVC). However, frequent table look-up operation can result in big table memory access, and then lead to high table power consumption. Aiming to solve the problem of big table memory access of current methods, and then reduce high power consumption, a memory-efficient table look-up optimized algorithm is presented for CAVLD. The contribution of this paper lies that index search technology is introduced to reduce big memory access for table look-up, and then reduce high table power consumption. Specifically, in our schemes, we use index search technology to reduce memory access by reducing the searching and matching operations for code_word on the basis of taking advantage of the internal relationship among length of zero in code_prefix, value of code_suffix and code_lengh, thus saving the power consumption of table look-up. The experimental results show that our proposed table look-up algorithm based on index search can lower about 60% memory access consumption compared with table look-up by sequential search scheme, and then save much power consumption for CAVLD in H.264/AVC.
Tsushima, K; Sakata, Y; Shiratori, Y; Sakamoto, J; Koeda, J; Yamada, Y; Soma, N; Tamura, K; Yoshiwara, A; Soma, Y
1991-12-01
We treated a patient with advanced cholangiocarcinoma with a new combination chemotherapy (modified MQF). The regimen consisted of intra-arterial administration of MMC (20 mg/body) and CQ (4 mg/body), protracted continuous infusion of 5-FU (500 mg/body) and intravenous administration of low-dose leucovorin (30 mg/body). More than 50% reduction in the liver tumor for over 4 weeks was obtained by the therapy. As for toxicity, diarrhea and stomatitis were observed. PMID:1660702
Friedrich, Jan O; Adhikari, Neill KJ; Beyene, Joseph
2008-01-01
Background Meta-analysis of continuous outcomes traditionally uses mean difference (MD) or standardized mean difference (SMD; mean difference in pooled standard deviation (SD) units). We recently used an alternative ratio of mean values (RoM) method, calculating RoM for each study and estimating its variance by the delta method. SMD and RoM allow pooling of outcomes expressed in different units and comparisons of effect sizes across interventions, but RoM interpretation does not require knowledge of the pooled SD, a quantity generally unknown to clinicians. Objectives and methods To evaluate performance characteristics of MD, SMD and RoM using simulated data sets and representative parameters. Results MD was relatively bias-free. SMD exhibited bias (~5%) towards no effect in scenarios with few patients per trial (n = 10). RoM was bias-free except for some scenarios with broad distributions (SD 70% of mean value) and medium-to-large effect sizes (0.5–0.8 pooled SD units), for which bias ranged from -4 to 2% (negative sign denotes bias towards no effect). Coverage was as expected for all effect measures in all scenarios with minimal bias. RoM scenarios with bias towards no effect exceeding 1.5% demonstrated lower coverage of the 95% confidence interval than MD (89–92% vs. 92–94%). Statistical power was similar. Compared to MD, simulated heterogeneity estimates for SMD and RoM were lower in scenarios with bias because of decreased weighting of extreme values. Otherwise, heterogeneity was similar among methods. Conclusion Simulation suggests that RoM exhibits comparable performance characteristics to MD and SMD. Favourable statistical properties and potentially simplified clinical interpretation justify the ratio of means method as an option for pooling continuous outcomes. PMID:18492289
Leong, Tora; Rehman, Michaela B.; Pastormerlo, Luigi Emilio; Harrell, Frank E.; Coats, Andrew J. S.; Francis, Darrel P.
2014-01-01
Background Clinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies. Objectives We studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO2), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF). Data Sources and Eligibility Criteria Studies testing pVO2, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed. Methods First, we examined studies testing pVO2, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk. Results 33 studies (8946 patients) tested a pVO2 threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10–18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO2 (r = 0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p = 0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r = 0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r = 0.86 (p<0.0001). Second, survival simulations always discovered a “most significant” threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r = 0.99, p<0.001). Limitations This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds. Key Findings First, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO2, EF or BNP. Second
Mandibular Advancement Splints.
Bamagoos, Ahmad A; Sutherland, Kate; Cistulli, Peter A
2016-09-01
Although mandibular advancement splints (MAS) are not as efficacious as continuous positive airway pressure (CPAP) in reducing obstructive respiratory events, patient adherence and preference are greater than CPAP. Additionally, the effectiveness of both treatments on general health outcomes, cognitive function, and quality of life appears to be equivalent. The main barrier for the implementation of MAS treatment in clinical practice is the interindividual variability in response to MAS treatment. Several prediction tools have been proposed to enhance patient selection for MAS treatment. Phenotyping obstructive sleep apnea patients may reveal patient characteristics that enable the prediction of response to MAS treatment. PMID:27542880
Library of Continuation Algorithms
2005-03-01
LOCA (Library of Continuation Algorithms) is scientific software written in C++ that provides advanced analysis tools for nonlinear systems. In particular, it provides parameter continuation algorithms. bifurcation tracking algorithms, and drivers for linear stability analysis. The algorithms are aimed at large-scale applications that use Newtons method for their nonlinear solve.
2014-01-01
Background This study investigated effects on cardiovascular parameters during anaesthesia with isoflurane (ISO, 2–3 Vol%), ketamine-xylazine (KX, 100 mg•kg−1 + 5 mg•kg−1) or a combination of medetomidine-midazolam-fentanyl (MMF, 0.15 mg•kg−1 + 2.0 mg•kg−1 + 0.005 mg•kg−1) in rats throughout induction, maintenance and recovery from anaesthesia. Rats were instrumented with a telemetric system for the measurement of systolic, diastolic and mean arterial pressure (SAP, DAP, MAP), pulse pressure (PP), heart rate (HR) and core body temperature (BT). The parameters were continuously measured before, during and after each type of anaesthesia. Forty minutes after induction, ISO delivery was terminated and MMF was antagonized with atipamezole-flumazenil-naloxone (AFN, 0.75 mg•kg−1 + 0.2 mg•kg−1 + 0.12 mg•kg−1) whereas KX was not antagonized. Results Differences were observed between anaesthesias with KX (301 min) lasting much longer than MMF (45 min) and ISO (43 min). HR in ISO (x¯ = 404 ± 25 bpm) increased during the time of surgical tolerance whereas a HR decrease was observed in KX (x¯ = 255 ± 26 bpm) and MMF (x¯ = 209 ± 24 bpm). In ISO (MAP during time of surgical tolerance: x¯ = 89 ± 12.3 mmHg) and KX (MAP during wake-up period: x¯ = 84 ± 8.5 mmHg) mild hypotensive values were observed, whereas blood pressure (BP) in MMF (MAP during time of surgical tolerance: x¯ = 138 ± 9.9 mmHg) increased. Despite keeping animals on a warming pad, a loss of BT of about 1°C was seen in all groups. Additionally, we observed a peaked increase of HR (x¯ = 445 ± 20 bpm) during the wake-up period with ISO and an increase of PP (x¯ = 59 ± 8.5 mmHg) in MMF during the time of surgical tolerance. Conclusion The anaesthesias influenced very differently the cardiovascular parameters measured in Wistar rats. ISO caused mild hypotension and increased HR whereas MMF produced a
Jarvie, H P; Neal, C; Smart, R; Owen, R; Fraser, D; Forbes, I; Wade, A
2001-01-29
A combination of continuous (15-min) pH, conductivity and temperature measurements and fortnightly spot-sampled water quality data were used to examine temporal variability and extremes in river water quality in an upland Scottish river: the River Dee at Mar Lodge. An empirical relationship was established for Gran-alkalinity by multiple regression against flow and conductivity for the fortnightly data. Applying this relationship to the continuous data, an estimate of continuous Gran-alkalinity was calculated. The continuous Gran-alkalinity record was used as (1) a conservative tracer in a simple two-component mixing model to determine the relative proportions of near-surface runoff and deeper groundwater contributing to stream flow; (2) to deconvolute the contribution of weathering and sea-salt contributions to stream conductivity; and (3) to calculate the excess partial pressure of carbon dioxide in stream water. The episodic variations in pH, weathering and sea-salt conductivity and excess partial pressures of carbon dioxide (EpCO2) associated with high flow events in the River Dee suggest that hydrological pathways play an important role in determining stream chemistry. The results of the hydrograph separation indicate that groundwater provides an important contribution to stream flow, and that there are large and hydrologically active stores of groundwater within the upper River Dee catchment. Sea-salts have an important influence on stream conductivity, particularly with the onset of storm runoff following summer drought periods. This suggests that sea-salts are concentrated in the upper soil horizons by dry deposition and/or evapotranspiration. EpCO2 behaves non-conservatively and shows marked diurnal variability under low-flow conditions during summer, inducing diurnal pH variations, and indicating the importance of within-river biological processes. This study emphasises the very intermittent nature of water quality extremes with stream spates and the
O`Neal, G.W.
1998-04-01
Two 20-ton CTC formed coke production runs were completed. The product from the first run tested at a General Motors` production cupola at a 12.5 percent of total coke charge level successfully. The second 20 tons of CTC formed coke will be evaluated in early August at a General Motors` research facility at Marquette, Michigan, using a 100 percent CTC formed coke charge. Design of a commercial plant continued with emphasis given to the calcining and briquetting operations.
NASA Technical Reports Server (NTRS)
Wolfson, R. G.; Sibley, C. B.
1978-01-01
The three components required to modify the furnace for batch and continuous recharging with granular silicon were designed. The feasibility of extended growth cycles up to 40 hours long was demonstrated by a recharge simulation experiment; a 6 inch diameter crystal was pulled from a 20 kg charge, remelted, and pulled again for a total of four growth cycles, 59-1/8 inch of body length, and approximately 65 kg of calculated mass.
Franz, D.G.
1987-01-01
The project involved the development of preliminary design parameters for two different types of gas-fired furnaces capable of reheating thin sections (i.e., 1-inch thick) of continuously cast steel. These reheated thin steel sections are sent directly into with Hot Strip Mill finishing stands without further reductions. For the Hot Strip Mill configurations where a thin section continuous caster may be close coupled in-line with the finishing stands, a roller hearth furnace was developed. This furnace was designed to reheat the as-cast thin section in flat form at a production rate of 250 tons/hour. For the Hot Strip Mill configuration where a thin section caster may have to be located remote from the finishing stands, a car bottom furnace was developed. This furnace was designed to reheat the thin section in coiled form at a production rate of 125 tons/hour. Either of these thin section reheat furnaces will require only 32% of the fuel requirement of existing reheat furnace operations that process continuously cast steel slabs.
NASA Astrophysics Data System (ADS)
Hübner, M.; Achtner, B.; Kraus, M.; Siemens, C.; Münzberg, M.
2016-05-01
Current designs of combined VIS-color/SWIR camera optics use constant F-number over the full field of view (FOV) range. Especially in the SWIR, limited space for the camera integration in existing system volumes and relatively high pitch dimensions of 15μm or even 20μm force the use of relatively high F- numbers to accomplish narrow fields of view less than 2.0° with reasonable resolution for long range observation and targeting applications. Constant F-number designs are already reported and considered [1] for submarine applications. The comparison of electro-optical performance was based on the given detector noise performance and sensitivity data by the detector manufacturer [1] and further modelling of the imaging chain within linear MTF system theory. The visible channel provides limited twilight capability at F/2.6 but in the SWIR the twilight capability is degraded due to the relatively high F-number of F/7 or F/5.25 for 20 μm and 15 μm pitch, respectively. Differences between prediction and experimental verification of sensitivity in terms of noise equivalent irradiance (NEI) and scenery based limiting illumination levels are shown for the visible and the SWIR spectral range. Within this context, currently developed improvements using optical zoom designs for the multispectral SWIR/VIS camera optics with continuously variable Fnumber are discussed, offering increased low light level capabilities at wide and medium fields of view while still enabling a NFOV < 2° with superior long range targeting capabilities under limited atmospherical sight conditions at daytime.
Knight, R.A.; Gissy, J.L.; Onischak, M.; Babu, S.P.; Carty, R.H.; Duthie, R.G.; Wootten, J.M.
1991-09-01
Under US DOE sponsorship, a project team consisting of the Institute of Gas Technology, Peabody Holding Company, and Bechtel Group, Inc. has been developing an advanced, mild gasification process to process all types of coal and to produce solid and condensable liquid co-products that can open new markets for coal. The three and a half year program (September 1987 to June 1991) consisted of investigations in four main areas. These areas are: (1) Literature Survey of Mild Gasification Processes, Co-Product Upgrading and Utilization, and Market Assessment; (2) Mild Gasification Technology Development: Process Research Unit Tests Using Slipstream Sampling; (3) Bench-Scale Char Upgrading Study; (4) Mild Gasification Technology Development: System Integration Studies. In this report, the literature and market assessment of mild gasification processes are discussed.
Ushakov, I B
2012-01-01
Sprung from the national physiological science and aviation medicine, space physiology and medicine of today is an intensely evolving discipline cradled and fostered by the Russian scientists who made major contributions both to individual branches of physiology and general research methodology. Upholding the best traditions, space physiology and medicine specialists retain leadership in many areas and ensure intergeneration continuity in research work. Among these areas are investigations into the physiological mechanisms of water-electrolyte turnover in animals and humans in the course of space flight and ground-based model experiments. PMID:23457961
Continuously variable voltage-controlled phase shifter
NASA Technical Reports Server (NTRS)
Johns, C. E.
1970-01-01
Phase shifter circuit adjusts the phase relationship between a locally generated reference frequency and a received RF signal applied to a phase-coherent detector. It is small enough to be integrated into a receiver subassembly and operates on command from remote control panels.
Holonomic Quantum Control with Continuous Variable Systems
NASA Astrophysics Data System (ADS)
Albert, Victor V.; Shu, Chi; Krastanov, Stefan; Shen, Chao; Liu, Ren-Bao; Yang, Zhen-Biao; Schoelkopf, Robert J.; Mirrahimi, Mazyar; Devoret, Michel H.; Jiang, Liang
2016-04-01
Universal computation of a quantum system consisting of superpositions of well-separated coherent states of multiple harmonic oscillators can be achieved by three families of adiabatic holonomic gates. The first gate consists of moving a coherent state around a closed path in phase space, resulting in a relative Berry phase between that state and the other states. The second gate consists of "colliding" two coherent states of the same oscillator, resulting in coherent population transfer between them. The third gate is an effective controlled-phase gate on coherent states of two different oscillators. Such gates should be realizable via reservoir engineering of systems that support tunable nonlinearities, such as trapped ions and circuit QED.
Experimental characterization of continuous-variable entanglement
Bowen, W.P.; Schnabel, R.; Lam, P.K.; Ralph, T.C.
2004-01-01
We present an experimental analysis of quadrature entanglement produced from a pair of amplitude squeezed beams. The correlation matrix of the state is characterized within a set of reasonable assumptions, and the strength of the entanglement is gauged using measures of the degree of inseparability and the degree of Einstein-Podolsky-Rosen (EPR) paradox. We introduce controlled decoherence in the form of optical loss to the entangled state, and demonstrate qualitative differences in the response of the degrees of inseparability and EPR paradox to this loss. The entanglement is represented on a photon number diagram that provides an intuitive and physically relevant description of the state. We calculate efficacy contours for several quantum information protocols on this diagram, and use them to predict the effectiveness of our entanglement in those protocols.
Reversibility of continuous-variable quantum cloning
Filip, Radim; Marek, Petr; Fiurasek, Jaromir
2004-01-01
We analyze a reversibility of optimal Gaussian 1{yields}2 quantum cloning of a coherent state using only local operations on the clones and classical communication between them and propose a feasible experimental test of this feature. Performing Bell-type homodyne measurement on one clone and anticlone, an arbitrary unknown input state (not only a coherent state) can be restored in the other clone by applying appropriate local unitary displacement operation. We generalize this concept to a partial reversal of the cloning using only local operations and classical communication (LOCC) and we show that this procedure converts the symmetric cloner to an asymmetric cloner. Further, we discuss a distributed LOCC reversal in optimal 1{yields}M Gaussian cloning of coherent states which transforms it to optimal 1{yields}M{sup '} cloning for M{sup '}
Quantum repeater with continuous variable encoding
NASA Astrophysics Data System (ADS)
Li, Linshu; Albert, Victor V.; Michael, Marios; Muralidharan, Sreraman; Zou, Changling; Jiang, Liang
2016-05-01
Quantum communication enables faithful quantum state transfer between different parties and protocols for cryptographic purposes. However, quantum communication over long distances (>1000km) remains challenging due to optical channel attenuation. This calls for investigation on developing novel encoding schemes that correct photon loss errors efficiently. In this talk, we introduce the generalization of multi-component Schrödinger cat states and propose to encode quantum information in these cat states for ultrafast quantum repeaters. We detail the quantum error correction procedures at each repeater station and characterize the performance of this novel encoding scheme given practical imperfections, such as coupling loss. A comparison with other quantum error correcting codes for bosonic modes will be discussed.
Hogsett, R.F.; Jha, M.C.
1991-12-01
Morgantown Energy Technology Center (METC) of DOE has sponsored, and continues to sponsor, programs for the development of technology and market strategies which will lead to the commercialization of processes for the production of coproducts from mild gasification of coal. It has been recognized by DOE and industry that mild gasification is a promising technology with potential to economically convert coal into marketable products, thereby increasing domestic coal utilization. In this process, coal is devolatilized under non- oxidizing conditions at mild temperature (900--1100{degrees}F) and pressure (1--15psig). Condensation of the vapor will yield a liquid product that can be upgraded to a petroleum substitute, and the remaining gas can provide the fuel for the process. The residual char can be burned in a power plant. Thus, in a long-term national scenario, implementation of this process will result in significant decrease of imported oil and increase in coal utilization.
1996-12-31
Char, the major co-product of mild coal gasification, represents about 70 percent of the total product yield. The only viable use for the char is in the production of formed coke. Early work to develop formed coke used char from a pilot plant sized mild gasification unit (MGU), which was based on commercial units of the COALITE plant in England. Formed coke was made at a bench-scale production level using MGU chars from different coals. An evolutionary formed coke development process over a two-year period resulted in formed coke production at bench-scale levels that met metallurgical industries` specifications. In an ASTM D5341 reactivity test by a certified lab, the coke tested CRI 30.4 and CSR 67.0 which is excellent. The standard is CRI < 32 and CSR > 55. In 1991, a continuous 1000 pounds per hour coal feed mild coal gasification pilot plant (CMGU) was completed. The gasification unit is a heated unique screw conveyor designed to continuously process plastic coal, vent volatiles generated by pyrolysis of coal, and convert the plastic coal to free flowing char. The screw reactor auxiliary components are basic solids materials handling equipment. The screw reactor will convert coal to char and volatile co-products at a rate greater than 1000 pounds per hour of coal feed. Formed coke from CMGU char is comparable to that from the MGU char. In pilot-plant test runs, up to 20 tons of foundry coke were produced. Three formed coke tests at commercial foundries were successful. In all of the cupola tests, the iron temperature and composition data indicated that the formed coke performed satisfactorily. No negative change in the way the cupola performed was noticed. The last 20-ton test was 100 percent CTC/DOE coke. With conventional coke in this cupola charging rates were 10 charges per hour. The formed coke charges were 11 to 12 charges per hour. This equates to a higher melt rate. A 10 percent increase in cupola production would be a major advantage. 13 figs., 13 tabs.
NASA Astrophysics Data System (ADS)
Osuna, J. L.; McDowell, N. G.; Shim, J. H.; Rahn, T.; Pockman, W.
2011-12-01
In the semi-arid Southwestern US, seasonal drought has strengthened in recent years due to both a decrease in winter precipitation and delayed onset of the summer monsoon. A process-based understanding of ecosystem response to increased drought stress is vital to predicting the long-term stability of semi-arid biomes. To understand the processes responsible for inter-annual and seasonal variability in net ecosystem carbon and water fluxes, we compared nearly continuous measurements of ecosystem scale respiration (R_e) from an eddy covariance system with the stable carbon and oxygen isotope signals in ecosystem respired CO_2 (delta^{13}C_r and delta^{18}O_r) measured continuously by a tunable diode laser spectrometer (TDL) sampling at various canopy heights at the same site. The study site, at Los Alamos National Laboratory, converted from pitilde{n}on juniper woodland to juniper woodland after over 90% of pitilde{n}ons died in 2002-2003 following multiple years of enhanced drought leaving a high necromass at the site. We analyzed the relationships between the Bowen ratio, delta^{18}O_r, daily and annual accumulated NEE, and delta^{13}C_r to understand the (de)coupling between the response of transpiration and respiration under varying degrees of drought stress. Additionally, we explored the variability in the lag and intensity of ecosystem response to precipitation pulses depending on antecedent conditions. The response of delta^{18}O_r was more consistent across years and seasons whereas variability in the contribution of autotrophic versus heterotrophic respiration appeared to cause differing responses of delta^{13}C_r to drought stress and precipitation pulses. This result was supported by the diurnal CO_2 and H_2O fluxes indicating nearly immediate transpirational water loss initiated by most precipitation pulses. Annual accumulated precipitation (versus pulse size) was a better indicator of delta^{13}C_ r response (i.e. relative contributions of autotrophic
NASA Astrophysics Data System (ADS)
Harrison, F. W.; Lin, B.; Ismail, S.; Nehrir, A. R.; Dobler, J. T.; Browell, E. V.; Kooi, S. A.; Campbell, J. F.; Obland, M. D.; Yang, M. M.; Meadows, B.
2014-12-01
This paper presents an overview of the methods for the retrieval of carbon dioxide (CO2) and oxygen (O2) column amounts and their associated path lengths measured by the Multi-Functional Fiber Laser Lidar (MFLL) and the ASCENDS CarbonHawk Experiment Simulator (ACES). MFLL and ACES are multi-frequency, Intensity-Modulated, Continuous-Wave (IM-CW) Lidar systems developed as proof-of-concept demonstrators for NASA's Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The National Research Council identified ASCENDS in 2007 as an important mid-term decadal survey mission to provide measurements critical to improved projections of the Earth's future climate. The ASCENDS measurement requirements have evolved significantly since first proposed by the NRC as has our understanding of the IM-CW measurement technique we propose for use by ASCENDS. To meet these requirements, both MFLL and ACES transmit wavelengths near 1.57 and 1.26 μm modulated with range-encoded signals to minimize bias from thin clouds in the CO2 and O2 column measurements while simultaneously measuring the path length to the surface and to intervening cloud layers. In preparation for the ASCENDS mission, the MFLL has been deployed on 13 airborne field campaigns since 2005, including the latest series of flights in August 2014. NASA also flew the ACES instrument as a technology demonstrator in 2014. In this paper we describe the current ASCENDS retrieval technique and present the accuracy and precision of the measurements obtained using this technique. We also present a reanalysis of the 2011 MFLL measurements and compare the results previously reported to the reanalysis. Reanalysis yields range precisions of less that one meter from an altitude of 12 kilometers from the CO2 offline channel with 1.6 watts of transmitted power.
Hatton, Matthew; Nankivell, Matthew; Lyn, Ethan; Falk, Stephen; Pugh, Cheryl; Navani, Neal; Stephens, Richard; Parmar, Mahesh
2011-11-01
Purpose: Recent clinical trials and meta-analyses have shown that both CHART (continuous hyperfractionated accelerated radiation therapy) and induction chemotherapy offer a survival advantage over conventional radical radiotherapy for patients with inoperable non-small cell-lung cancer (NSCLC). This multicenter randomized controlled trial (INCH) was set up to assess the value of giving induction chemotherapy before CHART. Methods and Materials: Patients with histologically confirmed, inoperable, Stage I-III NSCLC were randomized to induction chemotherapy (ICT) (three cycles of cisplatin-based chemotherapy followed by CHART) or CHART alone. Results: Forty-six patients were randomized (23 in each treatment arm) from 9 UK centers. As a result of poor accrual, the trial was closed in December 2007. Twenty-eight patients were male, 28 had squamous cell histology, 34 were Stage IIIA or IIIB, and all baseline characteristics were well balanced between the two treatment arms. Seventeen (74%) of the 23 ICT patients completed the three cycles of chemotherapy. All 42 (22 CHART + 20 ICT) patients who received CHART completed the prescribed treatment. Median survival was 17 months in the CHART arm and 25 months in the ICT arm (hazard ratio of 0.60 [95% CI 0.31-1.16], p = 0.127). Grade 3 or 4 adverse events (mainly fatigue, dysphagia, breathlessness, and anorexia) were reported for 13 (57%) CHART and 13 (65%) ICT patients. Conclusions: This small randomized trial indicates that ICT followed by CHART is feasible and well tolerated. Despite closing early because of poor accrual, and so failing to show clear evidence of a survival benefit for the additional chemotherapy, the results suggest that CHART, and ICT before CHART, remain important options for the treatment of inoperable NSCLC and deserve further study.
Continuous Advances in Technology for Continuing Adult Learning
ERIC Educational Resources Information Center
Demirdogen, R. Esra
2007-01-01
This paper is about a study carried out at a chemical production facility in Izmir, Turkey during 2005/6 using CNC Learning environment and Kolb cycle. The system has been tested with 12 chemists working in this factory. The training course was carried on in a web-based environment and also routine meetings with the instructors were held. The…
Clausal Continuations in Japanese
ERIC Educational Resources Information Center
Krekoski, Ross
2012-01-01
Recent studies illustrate cases of turn continuations that are not necessarily criterially dependent on clausal syntax (Couper-Kuhlen & Ono, 2007; Ford, Fox, & Thompson, 2002), advancing a more multidimensional construal of turn expansions, in general, which, as Auer (2007) put it, "is not a syntactic issue alone" (p. 651). This study further…
Picher, Maria M; Küpcü, Seta; Huang, Chun-Jen; Dostalek, Jakub; Pum, Dietmar; Sleytr, Uwe B; Ertl, Peter
2013-05-01
In the current work we have developed a lab-on-a-chip containing embedded amperometric sensors in four microreactors that can be addressed individually and that are coated with crystalline surface protein monolayers to provide a continuous, stable, reliable and accurate detection of blood glucose. It is envisioned that the microfluidic device will be used in a feedback loop mechanism to assess natural variations in blood glucose levels during hemodialysis to allow the individual adjustment of glucose. Reliable and accurate detection of blood glucose is accomplished by simultaneously performing (a) blood glucose measurements, (b) autocalibration routines, (c) mediator-interferences detection, and (d) background subtractions. The electrochemical detection of blood glucose variations in the absence of electrode fouling events is performed by integrating crystalline surface layer proteins (S-layer) that function as an efficient antifouling coating, a highly-oriented immobilization matrix for biomolecules and an effective molecular sieve with pore sizes of 4 to 5 nm. We demonstrate that the S-layer protein SbpA (from Lysinibacillus sphaericus CCM 2177) readily forms monomolecular lattice structures at the various microchip surfaces (e.g. glass, PDMS, platinum and gold) within 60 min, eliminating unspecific adsorption events in the presence of human serum albumin, human plasma and freshly-drawn blood samples. The highly isoporous SbpA-coating allows undisturbed diffusion of the mediator between the electrode surface, thus enabling bioelectrochemical measurements of glucose concentrations between 500 μM to 50 mM (calibration slope δI/δc of 8.7 nA mM(-1)). Final proof-of-concept implementing the four microfluidic microreactor design is demonstrated using freshly drawn blood. Accurate and drift-free assessment of blood glucose concentrations (6. 4 mM) is accomplished over 130 min at 37 °C using immobilized enzyme glucose oxidase by calculating the difference between
Continuous Problem of Function Continuity
ERIC Educational Resources Information Center
Jayakody, Gaya; Zazkis, Rina
2015-01-01
We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…
The Continuing Challenges of Leprosy
Scollard, D. M.; Adams, L. B.; Gillis, T. P.; Krahenbuhl, J. L.; Truman, R. W.; Williams, D. L.
2006-01-01
Leprosy is best understood as two conjoined diseases. The first is a chronic mycobacterial infection that elicits an extraordinary range of cellular immune responses in humans. The second is a peripheral neuropathy that is initiated by the infection and the accompanying immunological events. The infection is curable but not preventable, and leprosy remains a major global health problem, especially in the developing world, publicity to the contrary notwithstanding. Mycobacterium leprae remains noncultivable, and for over a century leprosy has presented major challenges in the fields of microbiology, pathology, immunology, and genetics; it continues to do so today. This review focuses on recent advances in our understanding of M. leprae and the host response to it, especially concerning molecular identification of M. leprae, knowledge of its genome, transcriptome, and proteome, its mechanisms of microbial resistance, and recognition of strains by variable-number tandem repeat analysis. Advances in experimental models include studies in gene knockout mice and the development of molecular techniques to explore the armadillo model. In clinical studies, notable progress has been made concerning the immunology and immunopathology of leprosy, the genetics of human resistance, mechanisms of nerve injury, and chemotherapy. In nearly all of these areas, however, leprosy remains poorly understood compared to other major bacterial diseases. PMID:16614253
Granato, Gregory E.
2006-01-01
The Kendall-Theil Robust Line software (KTRLine-version 1.0) is a Visual Basic program that may be used with the Microsoft Windows operating system to calculate parameters for robust, nonparametric estimates of linear-regression coefficients between two continuous variables. The KTRLine software was developed by the U.S. Geological Survey, in cooperation with the Federal Highway Administration, for use in stochastic data modeling with local, regional, and national hydrologic data sets to develop planning-level estimates of potential effects of highway runoff on the quality of receiving waters. The Kendall-Theil robust line was selected because this robust nonparametric method is resistant to the effects of outliers and nonnormality in residuals that commonly characterize hydrologic data sets. The slope of the line is calculated as the median of all possible pairwise slopes between points. The intercept is calculated so that the line will run through the median of input data. A single-line model or a multisegment model may be specified. The program was developed to provide regression equations with an error component for stochastic data generation because nonparametric multisegment regression tools are not available with the software that is commonly used to develop regression models. The Kendall-Theil robust line is a median line and, therefore, may underestimate total mass, volume, or loads unless the error component or a bias correction factor is incorporated into the estimate. Regression statistics such as the median error, the median absolute deviation, the prediction error sum of squares, the root mean square error, the confidence interval for the slope, and the bias correction factor for median estimates are calculated by use of nonparametric methods. These statistics, however, may be used to formulate estimates of mass, volume, or total loads. The program is used to read a two- or three-column tab-delimited input file with variable names in the first row and
Nishimura, R; Osonoi, T; Kanada, S; Jinnouchi, H; Sugio, K; Omiya, H; Ubukata, M; Sakai, S; Samukawa, Y
2015-08-01
The aim of the present study was to determine the effects of luseogliflozin on 24-h glucose levels, assessed by continuous glucose monitoring, and on pharmacodynamic variables measured throughout the day. In this double-blind, placebo-controlled, crossover study, 37 patients with type 2 diabetes mellitus inadequately controlled with diet and exercise were randomized into two groups. Patients in each group first received luseogliflozin then placebo for 7 days each, or vice versa. After 7 days of treatment, the mean 24-h glucose level was significantly lower with luseogliflozin than with placebo [mean (95% confidence interval) 145.9 (134.4-157.5) mg/dl vs 168.5 (156.9-180.0) mg/dl; p < 0.001]. The proportion of time spent with glucose levels ≥70 to ≤180 mg/dl was significantly greater with luseogliflozin than with placebo [median (interquartile range) 83.2 (67.7-96.5)% vs 71.9 (46.9-83.3)%; p < 0.001] without inducing hypoglycaemia. The decrease in glucose levels was accompanied by reductions in serum insulin levels throughout the day. PMID:25930989
Stratigraphy -- The Fall of Continuity.
ERIC Educational Resources Information Center
Byers, Charles W.
1982-01-01
Reviews advances in stratigraphy as illustrated in the current geological literature, discussing discontinuity and how the recognition of discontinuity in the stratigraphic record is changing views of Superposition and Original Lateral Continuity. (Author/JN)
Continuation of advanced crew procedures development techniques
NASA Technical Reports Server (NTRS)
Arbet, J. D.; Benbow, R. L.; Evans, M. E.; Mangiaracina, A. A.; Mcgavern, J. L.; Spangler, M. C.; Tatum, I. C.
1976-01-01
An operational computer program, the Procedures and Performance Program (PPP) which operates in conjunction with the Phase I Shuttle Procedures Simulator to provide a procedures recording and crew/vehicle performance monitoring capability was developed. A technical synopsis of each task resulting in the development of the Procedures and Performance Program is provided. Conclusions and recommendations for action leading to the improvements in production of crew procedures development and crew training support are included. The PPP provides real-time CRT displays and post-run hardcopy output of procedures, difference procedures, performance data, parametric analysis data, and training script/training status data. During post-run, the program is designed to support evaluation through the reconstruction of displays to any point in time. A permanent record of the simulation exercise can be obtained via hardcopy output of the display data and via transfer to the Generalized Documentation Processor (GDP). Reference procedures data may be transferred from the GDP to the PPP. Interface is provided with the all digital trajectory program, the Space Vehicle Dynamics Simulator (SVDS) to support initial procedures timeline development.
Drew, Yvette; Ledermann, Jonathan; Hall, Geoff; Rea, Daniel; Glasspool, Ros; Highley, Martin; Jayson, Gordon; Sludden, Julieann; Murray, James; Jamieson, David; Halford, Sarah; Acton, Gary; Backholer, Zoe; Mangano, Raffaella; Boddy, Alan; Curtin, Nicola; Plummer, Ruth
2016-01-01
Background: Rucaparib is an orally available potent selective small-molecule inhibitor of poly(ADP-ribose) polymerase (PARP) 1 and 2. Rucaparib induces synthetic lethality in cancer cells defective in the homologous recombination repair pathway including BRCA-1/2. We investigated the efficacy and safety of single-agent rucaparib in germline (g) BRCA mutation carriers with advanced breast and ovarian cancers. Methods: Phase II, open-label, multicentre trial of rucaparib in proven BRCA-1/2 mutation carriers with advanced breast and or ovarian cancer, WHO PS 0–1 and normal organ function. Intravenous (i.v.) and subsequently oral rucaparib were assessed, using a range of dosing schedules, to determine the safety, tolerability, dose-limiting toxic effects and pharmacodynamic (PD) and pharmacokinetic (PK) profiles. Results: Rucaparib was well tolerated in patients up to doses of 480 mg per day and is a potent inhibitor of PARP, with sustained inhibition ⩾24 h after single doses. The i.v. rucaparib (intermittent dosing schedule) resulted in an objective response rate (ORR) of only 2% but with 41% (18 out of 44) patients achieved stable disease for ⩾12 weeks and 3 patients maintaining disease stabilisation for >52 weeks. The ORR for oral rucaparib (across all six dose levels) was 15%. In the oral cohorts, 81% (22 out of 27) of the patients had ovarian cancer and 12 out of 13, who were dosed continuously, achieved RECIST complete response/partial response (CR/PR) or stable disease (SD) ⩾12 weeks, with a median duration of response of 179 days (range 84–567 days). Conclusions: Rucaparib is well tolerated and results in high levels of PARP inhibition in surrogate tissues even at the lowest dose levels. Rucaparib is active in gBRCA-mutant ovarian cancer and this activity correlates with platinum-free interval. The key lessons learned from this study is that continuous rucaparib dosing is required for optimal response, the recommended phase 2 dose (RP2D) for
Johnston, R.P.
1989-05-01
A variable-cycle diesel is examined for use in an unmanned long-endurance RPV. Engine-configuration studies are made and a possible installation arrangement developed. Installed performance projections are made, and a long endurance RPV mission fuel, installed engine weight and propeller performance estimates made along with several aircraft-installation drawings. It was found that the final engine configuration performed the specified mission with a total fuel and installed engine weight fraction of only 24% of the vehicle Take Off Gross Weight. The mission was evaluated at a cruise altitude of 65000 feet and an engine configuration suitable for use at 85000 feet was also investigated.
NASA Astrophysics Data System (ADS)
Marullo, S.; Santoleri, R.; Malanotte-Rizzoli, P.; Bergamasco, A.
1999-04-01
A ten-year dataset of AVHRR-SST (Sea Surface Temperature) with 18 km space resolution and weekly frequency has been analyzed in the Eastern Mediterranean. In Part I of the present study, we examined the seasonal variability of the basin and we defined the time and space scales of the monthly climatologies of the sea surface temperature distributions. A detailed and quantitative comparison was also carried out between the SST distribution of September 1987 and the surface temperature map of the corresponding hydrological survey of the POEM (Physical Oceanography of the Eastern Mediterranean) Programme. In this second part, we extend the analysis to examine and quantify the interannual variabilities. We summarize our results as follows. The analysis reveals the presence of an interannual cycle in the Ionian basin in the decade 1983-1992. The climatological pattern of the isotherms oscillates between two main states corresponding to the winter (zonal) and the summer (meridional) distributions. The apparent interannual cycle appears in the SST distribution only in winter and only in the Ionian basin, while the Levantine basin shows only fluctuations around the climatology. Thus, the interannual signal in our dataset is present but is much less important than the seasonal one. To confirm and quantify the above conclusions, we evaluate the Empirical Orthogonal Function of the SST time series. Gradient EOF's modes show the presence of a very strong yearly signal explaining 60% of the variance and a less intense seasonal signal that account for 16% of the variance. No interannual variability is represented by EOF gradient modes even though it can be observed in the increasing trend of the time varying amplitude of the first EOF mode. To observe the interannual variability signal, a seasonal temperature cycle was subtracted from each image instead of the ensemble (spatial) mean. A new EOF mode that accounts for 20% of the variance emerges between the first and second
Competitive Strategy in Continuing Education.
ERIC Educational Resources Information Center
Baden, Clifford
1987-01-01
Reviews strategic variables available to those planning continuing education marketing programs. Discusses generic competitive strategies: (1) overall cost leadership, (2) differentiation, and (3) specialization. Mentions several potential problems. (CH)
Ikeda, Osama Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki; Takamori, Hiroshi; Kanemitsu, Keiichiro; Baba, Hideo
2007-09-15
Purpose. The purpose of this study was to compare intrahepatic and pancreatic perfusion on fusion images using a combined single-photon emission computed tomography (SPECT)/CT system and to evaluate the efficacy of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in the treatment of advanced pancreatic carcinoma. Materials and Methods. CTAI was performed in 33 patients (22 men, 11 women; age range, 35-77 years; mean age, 60 years) with stage IV pancreatic cancer with liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. In all patients we obtained fusion images using a combined SPECT/CT system. Pancreatic perfusion on fusion images was classified as perfusion presence or as perfusion absent in the pancreatic cancer. Using WHO criteria we recorded the tumor response after 3 months on multislice helical CT scans. Treatment effects were evaluated based on the pancreatic cancer, liver metastasis, and factors such as intrahepatic and pancreatic perfusion on fusion images. For statistical analysis we used the chi-square test; survival was evaluated by the Kaplan Meier method (log-rank test). Results. On fusion images, pancreatic and intrahepatic perfusion was recorded as hot spot and as homogeneous distribution, respectively, in 18 patients (55%) and as cold spot and heterogeneous distribution, respectively, in 15 (45%). Patients with hot spot in the pancreatic tumor and homogeneous distribution in the liver manifested better treatment results (p < 0.05 and p < 0.01, respectively). Patients with hot spot both in the pancreatic cancer and in the liver survived longer than those with cold spot in the pancreatic cancer and heterogeneous distribution in the liver (median {+-} SD, 16.0 {+-} 3.7 vs. 8.0 {+-} 1.4 months; p < 0.05). Conclusions. We conclude that in patients with advanced
Latent Variable Interaction Modeling.
ERIC Educational Resources Information Center
Schumacker, Randall E.
2002-01-01
Used simulation to study two different approaches to latent variable interaction modeling with continuous observed variables: (1) a LISREL 8.30 program and (2) data analysis through PRELIS2 and SIMPLIS programs. Results show that parameter estimation was similar but standard errors were different. Discusses differences in ease of implementation.…
Roman, Nicholas O.; Shepherd, Wes; Mukhopadhyay, Nitai; Hugo, Geoffrey D.; Weiss, Elisabeth
2012-08-01
Purpose: To evaluate implanted markers as a surrogate for tumor-based setup during image-guided lung cancer radiotherapy with audiovisual biofeedback. Methods and Materials: Seven patients with locally advanced non-small-cell lung cancer were implanted bronchoscopically with gold coils. Markers, tumor, and a reference bony structure (vertebra) were contoured for all 10 phases of the four-dimensional respiration-correlated fan-beam computed tomography and weekly four-dimensional cone-beam computed tomography. Results: The systematic/random interfractional marker-to-tumor centroid displacements were 2/3, 2/2, and 3/3 mm in the x (lateral), y (anterior-posterior), and z (superior-inferior) directions, respectively. The systematic/random interfractional marker-to-bone displacements were 2/3, 2/3, and 2/3 mm in the x, y, and z directions, respectively. The systematic/random tumor-to-bone displacements were 2/3, 2/4, and 4/4 mm in the x, y, and z directions, respectively. All displacements changed significantly over time (p < 0.0001). Conclusions: Although marker-based image guidance may decrease the risk for geometric miss compared with bony anatomy-based positioning, the observed displacements between markers and tumor centroids indicate the need for repeated soft tissue imaging, particularly in situations with large tumor volume change and large initial marker-to-tumor centroid distance.
Matsumoto, Shigeyuki; Yoshida, Takuya; Murata, Hiroko; Harada, Shusaku; Fujita, Naoko; Nakamura, Shota; Yamamoto, Yasuhiko; Watanabe, Takuo; Yonekura, Hideto; Yamamoto, Hiroshi; Ohkubo, Tadayasu; Kobayashi, Yuji
2008-11-25
Diabetes is defined by chronic hyperglycemia due to deficiency in insulin action. It has been found that the amount of advanced glycation end products (AGE) from the Maillard reaction between proteins and sugar molecules increases in blood of diabetic patients and furthermore that AGE binding to their cell surface receptor (RAGE) triggers both macrovascular and microvascular impairments to cause diabetic complications. Due to the clinical significance of the vascular complications, RAGE is currently a focus as an attractive target for drug discovery of candidates which interfere with AGE-RAGE binding to prevent the subsequent intracellular signaling related to pathogenical effects. Here, we determined the three-dimensional structure of the recombinant AGE-binding domain by using multidimensional heteronuclear NMR spectroscopy and showed that the domain assumes a structure similar to those of other immunoglobulin V-type domains. The site-directed mutagenesis studies identified the basic amino acids which play a key role in the AGE binding activities. Our results obtained from this study provide new insight into AGE-RAGE interaction. PMID:19032093
Liu, Xu; Yoon, Sunhee; Batchelor, Bill; Abdel-Wahab, Ahmed
2013-06-01
Vinyl chloride (VC) poses a threat to humans and environment due to its toxicity and carcinogenicity. In this study, an advanced reduction process (ARP) that combines sulfite with UV light was developed to destroy VC. The degradation of VC followed pseudo-first-order decay kinetics and the effects of several experimental factors on the degradation rate constant were investigated. The largest rate constant was observed at pH9, but complete dechlorination was obtained at pH11. Higher sulfite dose and light intensity were found to increase the rate constant linearly. The rate constant had a little drop when the initial VC concentration was below 1.5mg/L and then was approximately constant between 1.5mg/L and 3.1mg/L. A degradation mechanism was proposed to describe reactions between VC and the reactive species that were produced by the photolysis of sulfite. A kinetic model that described major reactions in the system was developed and was able to explain the dependence of the rate constant on the experimental factors examined. This study may provide a new treatment technology for the removal of a variety of halogenated contaminants. PMID:23570912
NASA Astrophysics Data System (ADS)
Tegze, György; Bansel, Gurvinder; Tóth, Gyula I.; Pusztai, Tamás; Fan, Zhongyun; Gránásy, László
2009-03-01
We present an efficient method to solve numerically the equations of dissipative dynamics of the binary phase-field crystal model proposed by Elder et al. [K.R. Elder, M. Katakowski, M. Haataja, M. Grant, Phys. Rev. B 75 (2007) 064107] characterized by variable coefficients. Using the operator splitting method, the problem has been decomposed into sub-problems that can be solved more efficiently. A combination of non-trivial splitting with spectral semi-implicit solution leads to sets of algebraic equations of diagonal matrix form. Extensive testing of the method has been carried out to find the optimum balance among errors associated with time integration, spatial discretization, and splitting. We show that our method speeds up the computations by orders of magnitude relative to the conventional explicit finite difference scheme, while the costs of the pointwise implicit solution per timestep remains low. Also we show that due to its numerical dissipation, finite differencing can not compete with spectral differencing in terms of accuracy. In addition, we demonstrate that our method can efficiently be parallelized for distributed memory systems, where an excellent scalability with the number of CPUs is observed.
NASA Technical Reports Server (NTRS)
Kopasakis, George; Connolly, Joseph W.; Cheng, Larry
2015-01-01
This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.
Continuous Progress Schools See the "Whole Child"
ERIC Educational Resources Information Center
Mack, Jamie
2008-01-01
It has been called many names: Continuous Progress Format, Advancement Based on Competency (ABC), Continuous Progress Schools, and Continuous Progress Education. The idea of "Continuous Progress" refers to academic and developmental growth of students in a multi-age program. Students learn new materials as they are ready, regardless of their age,…
Advanced microwave processing concepts
Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.
1997-04-01
The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymeric materials. The variable frequency microwave furnace, whose initial conception and design was funded by the AIM Materials Program, allows the authors, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of various thermoset resins will be studied because it holds the potential of in-situ curing of continuous-fiber composites for strong, lightweight components or in-situ curing of adhesives, including metal-to-metal. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.
Advanced microwave processing concepts
Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.
1995-05-01
The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymer composites. The variable frequency microwave furnace, whose initial conception and design was funded by the AIC Materials Program, will allow us, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of thermoset resins will be studied because it hold the potential of in-situ curing of continuous-fiber composites for strong, lightweight components. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.
Hydromechanical Advanced Coal Excavator
NASA Technical Reports Server (NTRS)
Estus, Jay M.; Summers, David
1990-01-01
Water-jet cutting reduces coal dust and its hazards. Advanced mining system utilizes full-face, hydromechanical, continuous miner. Coal excavator uses high-pressure water-jet lances, one in each of cutting heads and one in movable lance, to make cuts across top, bottom and middle height, respectively, of coal face. Wedge-shaped cutting heads advance into lower and upper cuts in turn, thereby breaking coal toward middle cut. Thrust cylinders and walking pads advance excavator toward coal face.
Godsil, E.C.; Robinson, E.Y.
1963-07-16
A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)
Connecting the Dots: Rediscovering Continuity
ERIC Educational Resources Information Center
Camenga, Kristin A.; Yates, Rebekah B. Johnson
2014-01-01
The topic of continuity is typically not introduced until calculus and then reexamined in real analysis. Recognizing the connections between secondary school mathematics and the advanced mathematics studied at the college level allows teachers to better identify mathematical concepts in student ideas, motivate students by piquing their curiosity,…
ERIC Educational Resources Information Center
Coughlin, Kevin B.
2013-01-01
This study is intended to provide researchers with empirically derived guidelines for conducting factor analytic studies in research contexts that include dichotomous and continuous levels of measurement. This study is based on the hypotheses that ordinary least squares (OLS) factor analysis will yield more accurate parameter estimates than…
ERIC Educational Resources Information Center
Chou, Chun-Mei; Hsiao, His-Chi; Shen, Chien-Hua; Chen, Su-Chang
2010-01-01
This study aims to analyze the correlation (N = 335) among technological and vocational school teachers' perceived organizational innovative climate, computer self-efficacy, and continuous use of e-teaching in Taiwan. Teachers' perceived organizational innovative climate includes five factors, namely, job autonomy, innovative leadership, resource…