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Sample records for analog simulation

  1. Analog simulation of the Josephson effects

    International Nuclear Information System (INIS)

    Analog circuit techniques can be used to advantage to simulate the Josephson effects in a superconductor-insulator-superconductor tunnel junction. Details of an electronic Josephson simulator are presented, and the advantages of analog techniques over their digital counterparts for this application are discussed. The simulation of a Josephson microwave mixer is used as an example

  2. Superconducting circuit probe for analog quantum simulators

    Science.gov (United States)

    Du, Liang-Hui; You, J. Q.; Tian, Lin

    2015-07-01

    Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach and show that the spectrum of the resonator is directly related to the correlation function of the coupling operator between the resonator and the simulator. We then apply this scheme to a simulator of the transverse field Ising model implemented with superconducting qubits, where the resonance peaks in the resonator spectrum correspond to the frequencies of the elementary excitations. The effects of resonator damping, qubit decoherence, and resonator backaction are also discussed. This setup can be used to probe a broad range of many-body models.

  3. Analog and digital simulation of the radiocardiogram

    International Nuclear Information System (INIS)

    A mathematical model of the radiocardiogram has been developed to deal with the pulsatile component of the tracing. It is applicable to the bedside radiocardiogram, radionuclide angiocardiographic studies with the scintillation camera, or description of other tracer studies in the central circulation. The model consists of four heart chambers, each ejecting a fixed fraction of its contained tracer with each systole, and a lung delay function. Discrete-variable calculation of end-systolic and end-diastolic tracer content of the heart chambers and lung allowed development of simple, rapid programs for simulation by small digital computers. By this means, curve fitting and estimation of ejection fractions, end-diastolic volumes and mean lung delay may eventually be automated. A better understanding of the problems of extracting diagnostically useful information from such a multiparameter fit should result from study of these simulations. Families of characteristic curves were generated for several disorders where pattern recognition as well as parameter estimation is important. A small, light-weight, portable electronic analog simulator has been developed to permit the same simulation and trial-and-error parameter estimation at the bedside. It puts a real-time tracing onto the chart recorder used for actual radiocardiograms. Its design features are described. Some ideas unifying analog and digital modeling are expressed in differential equations. They provide a framework for future simulation of the radiocardiogram in the irregularly beating heart and an algorithm for potential extraction of detailed chamber-volume curves from the non-equilibrium portion of the radiocardiogram. (author)

  4. Spaceflight Sensorimotor Analogs: Simulating Acute and Adaptive Effects

    Science.gov (United States)

    Taylor, Laura C.; Harm, Deborah L.; Kozlovskaya, Inessa; Reschke, Millard F.; Wood, Scott J.

    2009-01-01

    Adaptive changes in sensorimotor function during spaceflight are reflected by spatial disorientation, motion sickness, gaze destabilization and decrements in balance, locomotion and eye-hand coordination that occur during and following transitions between different gravitational states. The purpose of this study was to conduct a meta-synthesis of data from spaceflight analogs to evaluate their effectiveness in simulating adaptive changes in sensorimotor function. METHODS. The analogs under review were categorized as either acute analogs used to simulate performance decrements accompanied with transient changes, or adaptive analogs used to drive sensorimotor learning to altered sensory feedback. The effectiveness of each analog was evaluated in terms of mechanisms of action, magnitude and time course of observed deficits compared to spaceflight data, and the effects of amplitude and exposure duration. RESULTS. Parabolic flight has been used extensively to examine effects of acute variation in gravitational loads, ranging from hypergravity to microgravity. More recently, galvanic vestibular stimulation has been used to elicit acute postural, locomotor and gaze dysfunction by disrupting vestibular afferents. Patient populations, e.g., with bilateral vestibular loss or cerebellar dysfunction, have been proposed to model acute sensorimotor dysfunction. Early research sponsored by NASA involved living onboard rotating rooms, which appeared to approximate the time course of adaptation and post-exposure recovery observed in astronauts following spaceflight. Exposure to different bed-rest paradigms (6 deg head down, dry immersion) result in similar motor deficits to that observed following spaceflight. Shorter adaptive analogs have incorporated virtual reality environments, visual distortion paradigms, exposure to conflicting tilt-translation cues, and exposure to 3Gx centrifugation. As with spaceflight, there is considerable variability in responses to most of the analogs

  5. A superconducting circuit probe for analog quantum simulators

    OpenAIRE

    Du, Liang-Hui; You, J. Q.; Tian, Lin

    2013-01-01

    Analog quantum simulators can be used to study quantum correlation in novel many-body systems by emulating the Hamiltonian of these systems. One essential question in quantum simulation is to probe the properties of an emulated many-body system. Here we present a circuit QED scheme for probing such properties by measuring the spectrum of a superconducting resonator coupled to a quantum simulator. We first study a general framework of this approach, and show that the spectrum of the resonator ...

  6. Dimensional analysis, similarity, analogy, and the simulation theory

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.A.

    1978-01-01

    Dimensional analysis, similarity, analogy, and cybernetics are shown to be four consecutive steps in application of the simulation theory. This paper introduces the classes of phenomena which follow the same formal mathematical equations as models of the natural laws and the interior sphere of restraints groups of phenomena in which one can introduce simplfied nondimensional mathematical equations. The simulation by similarity in a specific field of physics, by analogy in two or more different fields of physics, and by cybernetics in nature in two or more fields of mathematics, physics, biology, economics, politics, sociology, etc., appears as a unique theory which permits one to transport the results of experiments from the models, convenably selected to meet the conditions of researches, constructions, and measurements in the laboratories to the originals which are the primary objectives of the researches. Some interesting conclusions which cannot be avoided in the use of simplified nondimensional mathematical equations as models of natural laws are presented. Interesting limitations on the use of simulation theory based on assumed simplifications are recognized. This paper shows as necessary, in scientific research, that one write mathematical models of general laws which will be applied to nature in its entirety. The paper proposes the extent of the second law of thermodynamics as the generalized law of entropy to model life and its activities. This paper shows that the physical studies and philosophical interpretations of phenomena and natural laws cannot be separated in scientific work; they are interconnected and one cannot be put above the others.

  7. Simulation of the Laki volcanoe based upon analogs of winds

    Science.gov (United States)

    Balkanski, Yves; Menut, Laurent; Jourdain, Sylvie; Garnier, Emmanuel; Eschstruth, Celia; Vrac, Matthieu; Vautard, Robert; Yiou, Pascal

    2015-04-01

    Simulation of the Laki volcanoe based upon analogs of winds We used daily surface pressure measurements from 1783 over Europe to reconstruct a year of 3D wind fields based upon the closest analog found in the 6-hourly fields from the ECMWF ERAI re-analysis from 1979 to 2013. These fields are then used to nudge the LMDZORINCA global model with a full chemical scheme and a horizontal resolution of 1.29°x0.94° with 39 vertical layers to simulate the emissions of SO2 from the volcano emitting over several months from June to August 1783. Fields of SO2 and H2SO4 were analyzed over the whole year of 1783. We inject 81 Tg (S) over the period. In France, the Royal society of medicine (Société royale de médecine) had developed for the first time a network of persons that observed both climatic variables and morbidity. The network is composed of 150 contributors over France, and has a more scattered coverage for Italy, Austria, Germany the United States and Madagascar. The measurements reported three times a day include: temperature, air pressure, air humidity wind direction and a description of the sky. Within the CHEDAR (Climate and Health Data Rescue and Modelling) project an archive of daily observations of fogs over French meteorological stations was created and registers of deaths in main cities were compiled. These data indicate that increased mortality occurred from June to September 1783 immediately following the Laki eruption when compared to the average mortality over the period from 1774 to 1789. We quantified this increase over 23 cities in France. We provide a comparison of SO2 surface concentrations and draw the following conclusions: - The days when the first manifestations of the volcano are reported over Western and Northern Europe are extremely well captured by the construction of analogs of winds for 1783. - The sharp increase and the days of heavy fogs are correlated with decreases in visibility due to the advection of sulfur from the volcanic cloud

  8. Analog and Digital Simulations of Maxwellian Plasmas for Astrophysics

    International Nuclear Information System (INIS)

    Many astrophysical and laboratory plasmas possess Maxwell-Boltzmann (MB) electron energy distributions (EEDs). Interpreting or predicting the properties of these plasmas requires accurate knowledge of atomic processes such as radiative lifetimes, electron impact excitation and de-excitation, electron impact ionization, radiative recombination, dielectronic recombination, and charge transfer for thousands of levels or more. Plasma models cannot include all of the needed levels and atomic data. Hence approximations need to be made to make the models tractable. Here we report on an 'analog' technique we have developed for simulating a Maxwellian EED using an electron beam ion trap and review some recent results using this method. A subset of the atomic data needed for modeling Maxwellian plasmas relates to calculating the ionization balance. Accurate fractional abundance calculations for the different ionization stages of the various elements in the plasma are needed to reliably interpret or predict the properties of the gas. However, much of the atomic data needed for these calculations have not been generated using modern theoretical methods and are often highly suspect. Here we will also review our recent updating of the recommended atomic data for 'digital' computer simulations of MB plasmas in collisional ionization equilibrium (CIE), describe the changes relative to previously recommended CIE calculations, and discuss what further recombination and ionization data are needed to improve this latest set of recommended CIE calculations.

  9. Observations of Crew Dynamics during Mars Analog Simulations

    Science.gov (United States)

    Cusack, Stacy L.

    2010-01-01

    This presentation reviews the crew dynamics during two simulations of Mars Missions. Using an analog of a Mars habitat in two locations, Flashline Mars Arctic Research Station (FMARS) which is located on Devon Island at 75 deg North in the Canadian Arctic, and the Mars Desert Research Station (MDRS) which is located in the south of Utah, the presentation examines the crew dynamics in relation to the leadership style of the commander of the mission. The difference in the interaction of the two crews were shown to be related to the leadership style and the age group in the crew. As much as possible the habitats and environment was to resemble a Mars outpost. The difference between the International Space Station and a Mars missions is reviewed. The leadership styles are reviewed and the contrast between the FMARS and the MDRS leadership styles were related to crew productivity, and the personal interactions between the crew members. It became evident that leadership styles and interpersonal skill had more affect on mission success and crew dynamics than other characteristics.

  10. Market price simulator based on analog electrical circuit

    OpenAIRE

    Aki-Hiro Sato; Hideki Takayasu

    2001-01-01

    We constructed an analog electrical circuit which generates fluctuations in which probability density function has power law tails. In the circuit fluctuations with an arbitrary exponent of the power law can be obtained by adjusting the resistance. With this low cost circuit the random fluctuations which have the similar statistics to foreign exchang rates can be generated as fast as an expensive digital computer.

  11. Digital-Analog Quantum Simulation of Spin Models in Trapped Ions

    Science.gov (United States)

    Arrazola, Iñigo; Pedernales, Julen S.; Lamata, Lucas; Solano, Enrique

    2016-01-01

    We propose a method to simulate spin models in trapped ions using a digital-analog approach, consisting in a suitable gate decomposition in terms of analog blocks and digital steps. In this way, we show that the quantum dynamics of an enhanced variety of spin models could be implemented with substantially less number of gates than a fully digital approach. Typically, analog blocks are built of multipartite dynamics providing the complexity of the simulated model, while the digital steps are local operations bringing versatility to it. Finally, we describe a possible experimental implementation in trapped-ion technologies. PMID:27470970

  12. How do Analogizing and Mental Simulation Influence Team Dynamics in Innovative Product Design?

    DEFF Research Database (Denmark)

    Casakin, Hernan; Ball, Linden J.; Christensen, Bo T.;

    2015-01-01

    The aim of this study was to gain further insight into how analogical reasoning and mental simulation, two cognitive strategies, influence team dynamics in innovative product design. A particular emphasis was placed on exploring the association between these two strategies and team cohesion and...... was related to team cohesion and team collaboration, with mental simulation having an especially marked association with team collaboration. Within-domain analogizing was found to enhance team collaboration, but it did not influence team cohesion. Furthermore, all types of analogical purpose showed a...... similar association with team cohesion, whereas solution generation and function finding had a stronger association with team collaboration. We propose that analogizing and mental simulations are strategies that serve valuable functions in engendering enhanced cohesion and collaboration, which might be...

  13. Zero-Gravity Locomotion Simulators: New Ground-Based Analogs for Microgravity Exercise Simulation

    Science.gov (United States)

    Perusek, Gail P.; DeWitt, John K.; Cavanagh, Peter R.; Grodsinsky, Carlos M.; Gilkey, Kelly M.

    2007-01-01

    Maintaining health and fitness in crewmembers during space missions is essential for preserving performance for mission-critical tasks. NASA's Exercise Countermeasures Project (ECP) provides space exploration exercise hardware and monitoring requirements that lead to devices that are reliable, meet medical, vehicle, and habitat constraints, and use minimal vehicle and crew resources. ECP will also develop and validate efficient exercise prescriptions that minimize daily time needed for completion of exercise yet maximize performance for mission activities. In meeting these mission goals, NASA Glenn Research Center (Cleveland, OH, USA), in collaboration with the Cleveland Clinic (Cleveland, Ohio, USA), has developed a suite of zero-gravity locomotion simulators and associated technologies to address the need for ground-based test analog capability for simulating in-flight (microgravity) and surface (partial-gravity) exercise to advance the health and safety of astronaut crews and the next generation of space explorers. Various research areas can be explored. These include improving crew comfort during exercise, and understanding joint kinematics and muscle activation pattern differences relative to external loading mechanisms. In addition, exercise protocol and hardware optimization can be investigated, along with characterizing system dynamic response and the physiological demand associated with advanced exercise device concepts and performance of critical mission tasks for Exploration class missions. Three zero-gravity locomotion simulators are currently in use and the research focus for each will be presented. All of the devices are based on a supine subject suspension system, which simulates a reduced gravity environment by completely or partially offloading the weight of the exercising test subject s body. A platform for mounting treadmill is positioned perpendicularly to the test subject. The Cleveland Clinic Zero-g Locomotion Simulator (ZLS) utilizes a

  14. FDSAC-SPICE: fault diagnosis software for analog circuit based on SPICE simulation

    Science.gov (United States)

    Cao, Yiqin; Cen, Zhao-Hui; Wei, Jiao-Long

    2009-12-01

    This paper presents a novel fault diagnosis software (called FDSAC-SPICE) based on SPICE simulator for analog circuits. Four important techniques in AFDS-SPICE, including visual user-interface(VUI), component modeling and fault modeling (CMFM), fault injection and fault simulation (FIFS), fault dictionary and fault diagnosis (FDFD), greatly increase design-for-test and diagnosis efficiency of analog circuit by building a fault modeling-injection-simulationdiagnosis environment to get prior fault knowledge of target circuit. AFDS-SPICE also generates accurate fault coverage statistics that are tied to the circuit specifications. With employing a dictionary diagnosis method based on node-signalcharacters and regular BPNN algorithm, more accurate and effective diagnosis results are available for analog circuit with tolerance.

  15. A behavioral simulator for switched-capacitor sigma-delta modulator analog-to-digital converter

    International Nuclear Information System (INIS)

    In this paper, a PC-based simulator for state of the art oversampled switched-capacitor sigma-delta analog-to-digital converters is presented. The proposed simulator employs behavioral model of switched-capacitor integrator and non-linear quantizer to stimulate the system. The behavioral simulation of the integrator is also verified with SPICE. The simulator is fully integrated and standalone. It integrates an input netlist file interpreter, a behavioral simulator, a generic part library and a powerful post-processor to evaluate the SNR, SDR And TSNR. Both passive and active sensitivities can be investigated by the proposed simulator. The simulator is coded in C++, and is very fast

  16. Mars Analog Mission: Glacier Simulation AMADEE-15 by Austrian Space Forum

    Science.gov (United States)

    Groemer, Gernot; Losiak, Anna; Soucek, Alexander; Plank, Clemens; Zanardini, Laura; Sejkora, Nina; Sams, Sebastian

    2016-04-01

    Austrian Space Forum: The Austrian Space Forum (OeWF, Österreichisches Weltraum Forum) is a non-profit, citizen-science organization of aerospace specialists and enthusiasts. One of its specialisations is Mars analog research. Analog studies and analog instrument validation supported all planetary surface missions so far [1] and are considered as an effective tool to prepare for future missions to Mars [2,3,4,5,6,7]. Since 2006, OeWF has conducted 11 Mars analog field campaigns in diverse locations that represented: 1) average current Mars conditions (the Mars Desert Research Station (MDRS) in Utah in 2006 [8] and the Northern Sahara near Erfoud, Morocco in 2013 [9]); 2) the early and wet Mars (analog site of Rio Tinto Spain in 2011 [10]); and 3) subsurface exploration (Dachstein Ice Caves in 2012). During these campaigns, 68 experiments and major engineering tests were performed, whichwere mostly focused on astrobiology, robotics, human factors, geoscience and spacesuit operations. Major assets of OeWF include two advanced spacesuit simulators Aouda [11], an increasingly evolving Mission Support Center, a dedicated Remote Science Support team [12], and a growing set of Standard Operating Procedures defining major workflows within a mission team. The spacesuit simulators were operated by a total of 18 analog astronauts, who were selected and trained during a >6 month program. Total EVA time is nearly 600 hours, leading to a significant experience in analog field simulations. AMADEE-15: The mission took place between August 2nd and 14th 2015 at the Kaunertal Glacier in Tyrol, Austria. This glacier was selected as a study site because of its accessibility and high number of micro-landscapes analogous to those expected on Mars in locations where abundant water ice is present. As such it is considered a first-tier Mars analog [13]. The Base station was located at N 46.86320, E 10.71401 at 2800 masl, the highest reached location was on elevation of 2887 m. Eleven

  17. Analog simulation on enhanced ac Josephson effect for junction driven by pulse train current

    International Nuclear Information System (INIS)

    The enhanced ac Josephson effect is studied based on an analog simulation when the junction is driven by an rf-signal source. On the basis of the resistively shunted Josephson junction model driven by a pulse train current, larger rf-induced current step-heights in the current-voltage characteristics were obtained in comparison with those obtained by a monochromatic sinusoidal drive. This result is considered to be originated by the harmonics of the rf-signal. In addition, the maximum value of the step-height is independent on the step number. (orig.)

  18. The analog linear interpolation approach for Monte Carlo simulation of PGNAA: The CEARPGA code

    Science.gov (United States)

    Zhang, Wenchao; Gardner, Robin P.

    2004-01-01

    The analog linear interpolation approach (ALI) has been developed and implemented to eliminate the big weight problem in the Monte Carlo simulation code CEARPGA. The CEARPGA code was previously developed to generate elemental library spectra for using the Monte Carlo - library least-squares (MCLLS) approach in prompt gamma-ray neutron activation analysis (PGNAA). In addition, some other improvements to this code have been introduced, including (1) adopting the latest photon cross-section data, (2) using an improved detector response function, (3) adding the neutron activation backgrounds, (4) generating the individual natural background libraries, (5) adding the tracking of annihilation photons from pair production interactions outside of the detector and (6) adopting a general geometry package. The simulated result from the new CEARPGA code is compared with those calculated from the previous CEARPGA code and the MCNP code and experimental data. The new CEARPGA code is found to give the best result.

  19. Counterintuitive behavior of simulated network's conductance analogous to the Braess paradox

    Science.gov (United States)

    Toussaint, Sébastien; Logoteta, Demetrio; Pala, Marco; Bayot, Vincent; Hackens, Benoit

    Suppressing a channel from a two-terminal mesoscopic network defined in a two-dimensional electron system (2DES) can paradoxically increase its conductance. This counterintuitive behavior analogous to the Braess paradox is evidenced in by simulating the network's conductance (G) when progressively depleting one of its channels with a biased local probe. By means of 3D self-consistent Poisson-Schrödinger simulations based on the NEGF formalism we investigate the occurrence circumstances of this transport anomaly under the influence of a scanning tip. By simulating the current density and local density of states within the network in the coherent and ballistic transport regime, we can follow the modification of the electron flow when the anomaly occurs. This allows to get insights about the role of a simulated disordered potential within the 2DES and permit to evaluate the tip influence on the 2DES potential landscape. Interference phenomena between different network paths can be modified by simulating G under a magnetic field orthogonal to the 2DES. Different geometries and network congestion are also discussed. S.T. acknowledges support from the Belgian FRS-FNRS (FRIA).

  20. Simulation study for cloud detection with space lidars by use of analog detection photomultiplier tubes.

    Science.gov (United States)

    Liu, Zhaoyan; Sugimoto, Nobuo

    2002-03-20

    Output signal electrons from photomultiplier tubes (PMTs) have neither a Gaussian nor a Poisson distribution because of changes induced by multiplication when the number of input signal photons and dark electrons is fewer than approximately 100. Therefore the assumption of a Gaussian distribution of signal electrons cannot be used in simulations for space lidar observations with PMTs, for which the number of return signal photons is normally small. A theory is introduced for analog detection with PMTs that have Poisson-distributed secondary-electron emission at each dynode stage. The theory is validated by straightforward numerical simulations. It is shown that the multiplication in PMTs is a multiply stochastic Poisson process and that the distribution of output signal electrons can be interpreted basically as Neyman type A. Analysis by the threshold method of cloud detection with a space lidar shows considerable difference between a Gaussian approximation and the exact distribution. The result indicates that the threshold level must be optimized for the exact distribution. Return signals were simulated for a proposed space lidar, and cloud detection with the threshold method was demonstrated. PMID:11921806

  1. Creating analogs of thermal distributions from diabatic excitations in ion-trap-based quantum simulation

    Science.gov (United States)

    Lim, M. H.; Yoshimura, B. T.; Freericks, J. K.

    2016-04-01

    One broad goal of quantum simulation is to start a simple quantum system in its ground state and slowly evolve the Hamiltonian to a complex one, maintaining the ground state throughout the evolution (called adiabatic state preparation). This provides a natural setting to create a highly entangled and correlated quantum state if the final Hamiltonian supports such a ground state. In ion-trap-based quantum simulations, coherence times are too short to allow for such ground-state evolution for large chains, because the rapid evolution of the system creates excitations to higher energy states. Because the probability for this excitation depends exponentially on the excitation energy and because the thermal distribution also depends exponentially on the excitation energy, we investigate whether this so-called diabatic excitation can create the analog of a thermal distribution; as this could serve as an alternative for creating thermal states of complex quantum systems without requiring contact with a heat bath. In this work, we explore this relationship and determine situations, where diabatic excitation can approximately create thermal states.

  2. Modern approaches to the design of analog-digit integrated circuits based on multilevel simulation methods

    International Nuclear Information System (INIS)

    Modern methods for the design of analog and analog-digit integrated circuits have been analyzed. “Top-down” and “bottom-up” design methods are compared. The advantages of the “top-down” method in the rate of the development and verification of integrated circuits have been demonstrated

  3. Oligomerization of a Glucagon-like Peptide 1 Analog: Bridging Experiment and Simulations

    DEFF Research Database (Denmark)

    Frederiksen, Tine Maja; Sønderby, Pernille; Ryberg, Line A.;

    2015-01-01

    The glucagon-like peptide 1 (GLP-1) analog, liraglutide, is a GLP-1 agonist and is used in the treatment of type-2 diabetes mellitus and obesity. From a pharmaceutical perspective, it is important to know the oligomerization state of liraglutide with respect to stability. Compared to GLP-1...

  4. Spice Simulation of Neural Networks Multi-Layer Perception Four-Quadrant CMOS Analog Multiplier OTANNO

    International Nuclear Information System (INIS)

    In this paper, the OTTANNO version of four -quadrant CMOS analog multiplier circuit for artificial neural networks multi layer perception operation will be proposed. The proposed multiplier can be divided into two or three parts, which will be in the input, synapse and neuron. The percentage of silicon area saving is 95% with respect to that multiplier presented in (Chible,1997). A comparison between OTANNO and OTANPS is also presented. (author)

  5. Suited versus unsuited analog astronaut performance using the Aouda.X space suit simulator: the DELTA experiment of MARS2013.

    Science.gov (United States)

    Soucek, Alexander; Ostkamp, Lutz; Paternesi, Roberta

    2015-04-01

    Space suit simulators are used for extravehicular activities (EVAs) during Mars analog missions. Flight planning and EVA productivity require accurate time estimates of activities to be performed with such simulators, such as experiment execution or traverse walking. We present a benchmarking methodology for the Aouda.X space suit simulator of the Austrian Space Forum. By measuring and comparing the times needed to perform a set of 10 test activities with and without Aouda.X, an average time delay was derived in the form of a multiplicative factor. This statistical value (a second-over-second time ratio) is 1.30 and shows that operations in Aouda.X take on average a third longer than the same operations without the suit. We also show that activities predominantly requiring fine motor skills are associated with larger time delays (between 1.17 and 1.59) than those requiring short-distance locomotion or short-term muscle strain (between 1.10 and 1.16). The results of the DELTA experiment performed during the MARS2013 field mission increase analog mission planning reliability and thus EVA efficiency and productivity when using Aouda.X. PMID:25811713

  6. Simulation on a shaking table on soil-structure interaction using analog circuits; Shindodai to analog denshi kairo wo mochiita jiban to kozobutsu no doteki sogo sayo no shin simulation shuho

    Energy Technology Data Exchange (ETDEWEB)

    Konagai, K.

    1996-11-01

    This paper proposes a method to simulate a shaking table of soil-structure interaction using analog circuits. The method adds interactions in a time history in which an analog electronic circuit is reproduced, into waveforms of input into the shaking table, to incorporate effects of the interactions. Impulse response of the ground required for an experiment on the shaking table is approximated by a linear sum of three basic response functions. A circuit equivalent to a dynamic model which generates the basic response functions comprises an exponential function generating circuit and an inversion adding circuit. The shaking table experimenting system can simulate impulse response corresponding to forms of bases in a variety of grounds. A model of a ground structure would not use a ground model, but be arranged on the shaking table via a force sensor. The force sensor detects three components of the force, namely, translation, vertical motion and rotation. Its signal is inputted into a response generator, by which responses in three directions generated by force applied from the structure to its foundation are derived. The responses are added to seismic motion of the foundation. 4 refs., 6 figs.

  7. Accurate SPICE Modeling of Poly-silicon Resistor in 40nm CMOS Technology Process for Analog Circuit Simulation

    Directory of Open Access Journals (Sweden)

    Sun Lijie

    2015-01-01

    Full Text Available In this paper, the SPICE model of poly resistor is accurately developed based on silicon data. To describe the non-linear R-V trend, the new correlation in temperature and voltage is found in non-silicide poly-silicon resistor. A scalable model is developed on the temperature-dependent characteristics (TDC and the temperature-dependent voltage characteristics (TDVC from the R-V data. Besides, the parasitic capacitance between poly and substrate are extracted from real silicon structure in replacing conventional simulation data. The capacitance data are tested through using on-wafer charge-induced-injection error-free charge-based capacitance measurement (CIEF-CBCM technique which is driven by non-overlapping clock generation circuit. All modeling test structures are designed and fabricated through using 40nm CMOS technology process. The new SPICE model of poly-silicon resistor is more accurate to silicon for analog circuit simulation.

  8. Analog simulations of josephson junction in a microwave field. Devil's staircase, fractal dimension, and decay constants

    International Nuclear Information System (INIS)

    The RSJ model of the Josephson junction in the presence of a microwave field is studied using an analog computer, with special attention to the behavior of this system near or at the critical line, where the set of substeps forms a complete devil's staircase on the I-V characteristic. A value of fractal dimension D = 0.868 +/- 0.002 is determined from 240 substeps between the winding numbers W = 0 and W = 1. Four values of decay constants are determined. The results agree very well with the prediction obtained from the one-dimensional circle map. A self-similarity graph is shown confirming that the staircase is very near the critical line. Results confirm the universal and global character of D and decay constants on the critical line, as was suggested by Jensen et al

  9. Simulation analysis of analog IQ based LLRF control of RF cavity

    International Nuclear Information System (INIS)

    This paper presents the simulation work and results in Matlab Simulink for the analogue Inphase-Quadrature (IQ) based Low Level Radio Frequency (LLRF) control of RF cavity voltage. The RF cavity chosen here is the Radio Frequency Quadrupole (RFQ) cavity in our RIB project. All the subsystems in the IQ based RF control were modelled using the Simulink blocks/components. The envelope simulation was carried out using the IQ model of RF cavity. The PI controller was properly tuned to achieve good control performance in time. The simulation graphs showing the time evolution of the RF cavity voltage with a step change of the input reference signal is presented. The simulation graphs showing the control response time needed to correct a disturbance is presented. The simulation results showing Nichols plots of the control loop and the gain and phase margin values obtained from them are presented, which are good enough for stability considerations. (author)

  10. Aerodynamic noise prediction of a Horizontal Axis Wind Turbine using Improved Delayed Detached Eddy Simulation and acoustic analogy

    International Nuclear Information System (INIS)

    Highlights: • The noise predictions are performed by Ffowcs Williams and Hawkings method. • There is a direct relation between the radiated noise and the wind speed. • The tonal peaks in the sound spectra match with the blade passing frequency. • The quadrupole noises have negligible effect on the low frequency noises. - Abstract: This paper presents the results of the aerodynamic and aero-acoustic prediction of the flow field around the National Renewable Energy Laboratory Phase VI wind turbine. The Improved Delayed Detached Eddy Simulation turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is carried out using the Ffowcs Williams and Hawkings acoustic analogy. Simulations are performed for three different inflow conditions, U = 7, 10, 15 m/s. The capability of the Improved Delayed Detached Eddy Simulation turbulence model in massive separation is verified with available experimental data for pressure coefficient. The broadband noises of the turbulent boundary layers and the tonal noises due to the blade passing frequency are predicted via flow field noise simulation. The contribution of the thickness, loading and quadrupole noises are investigated, separately. The results indicated that there is a direct relation between the strength of the radiated noise and the wind speed. Furthermore, the effect of the receiver location on the Overall Sound Pressure Level is investigated

  11. Design and Simulation of Seido Buffer for Analog to Digital Converter (ADC) on Multichannel Analyzer (MCA) Application

    International Nuclear Information System (INIS)

    Most of our electronic equipment has buffer, thus this make buffer as one of importance in electronic gadget. This paper introduced Single Ended Input Differential Output (SEIDO) buffer to predict the bias at approximately 2.5 V. For this purpose, the input range between -1 mV to 4 V was implemented. The software used to cascade SEIDO buffer is called LTspice IV; an open source software developed by Linear Technology Incorporation. The component involve in this development was Operational Amplifier (OP AMP) AD826 from Analog Devices Incorporation, capacitor and resistor. Kirchhoffs Current Law and Kirchhoffs Voltage Law was applied to calculated voltage gain and biasing voltage. All design has been verified by LTspice IV. The result produced from simulation was between -0.3 V to 6.3 V with bias roughly at 2.5 V. These results prove that it was capable to drive Analog Digital Converter (ADC) that can subsequently apply for Multichannel Analyzer (MCA). (author)

  12. Development of an Analog System to Simulate Interface Formation During Fusion™ Casting

    Science.gov (United States)

    Di Ciano, Massimo; Weckman, D. C.; Wells, M. A.

    2016-04-01

    To improve casting and product yields of Fusion™ cast AA3003-core/AA4045-clad laminate ingots, a fundamental understanding of the wetting and interface formation process between the oxidized AA3003 cast surface and the AA4045 melt is required. In this study, a laboratory scale analog/immersion test was developed which mimics the wetting and interface formation process that occurs during Fusion™ casting. The effects of reheating and remelting of the AA3003 cast surface, the degree of surface oxidation present during initial contact of the two alloys, and the atmospheric conditions (air or argon) on interface formation when dipped into an AA4045 melt were examined. Results indicated that in an argon atmosphere, wetting and dissolution of the solid, oxidized AA3003 samples by liquid AA4045 occurred at temperatures both above and below the measured onset of AA3003 remelting. AA3003/AA4045 interfaces were similar to those produced during Fusion™ casting, with a thin layer of AA4045 forming an oxide-free, metallurgical interface to the AA3003 after immersion. The AA3003 surface oxides were not an impediment to wetting and bond formation. Mg surface segregation was observed on the oxidized AA3003 surfaces and may play a role to help penetrate the oxide layer. For tests conducted in air, wetting of the sample by AA4045 liquid was generally poor regardless of temperature.

  13. Simulating the swelling and deformation behaviour in soft tissues using a convective thermal analogy

    Directory of Open Access Journals (Sweden)

    Herzog Walter

    2002-12-01

    Full Text Available Abstract Background It is generally accepted that cartilage adaptation and degeneration are mechanically mediated. Investigating the swelling behaviour of cartilage is important because the stress and strain state of cartilage is associated with the swelling and deformation behaviour. It is well accepted that the swelling of soft tissues is associated with mechanical, chemical, and electrical events. Method The purpose of the present study was to implement the triphasic theory into a commercial finite element tool (ABAQUS to solve practical problems in cartilage mechanics. Because of the mathematical identity between thermal and mass diffusion processes, the triphasic model was transferred into a convective thermal diffusion process in the commercial finite element software. The problem was solved using an iterative procedure. Results The proposed approach was validated using the one-dimensional numerical solutions and the experimental results of confined compression of articular cartilage described in the literature. The time-history of the force response of a cartilage specimen in confined compression, which was subjected to swelling caused by a sudden change of saline concentration, was predicted using the proposed approach and compared with the published experimental data. Conclusion The advantage of the proposed thermal analogy technique over previous studies is that it accounts for the convective diffusion of ion concentrations and the Donnan osmotic pressure in the interstitial fluid.

  14. Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms. (orig.)

  15. Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, Tupac; Sabin, Carlos; Fuentes, Ivette [University of Nottingham, School of Mathematical Sciences, Nottingham (United Kingdom)

    2015-01-04

    We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms. (orig.)

  16. Laser spectroscopic real time measurements of methanogenic activity under simulated Martian subsurface analog conditions

    Science.gov (United States)

    Schirmack, Janosch; Böhm, Michael; Brauer, Chris; Löhmannsröben, Hans-Gerd; de Vera, Jean-Pierre; Möhlmann, Diedrich; Wagner, Dirk

    2014-08-01

    On Earth, chemolithoautothrophic and anaerobic microorganisms such as methanogenic archaea are regarded as model organisms for possible subsurface life on Mars. For this reason, the methanogenic strain Methanosarcina soligelidi (formerly called Methanosarcina spec. SMA-21), isolated from permafrost-affected soil in northeast Siberia, has been tested under Martian thermo-physical conditions. In previous studies under simulated Martian conditions, high survival rates of these microorganisms were observed. In our study we present a method to measure methane production as a first attempt to study metabolic activity of methanogenic archaea during simulated conditions approaching conditions of Mars-like environments. To determine methanogenic activity, a measurement technique which is capable to measure the produced methane concentration with high precision and with high temporal resolution is needed. Although there are several methods to detect methane, only a few fulfill all the needed requirements to work within simulated extraterrestrial environments. We have chosen laser spectroscopy, which is a non-destructive technique that measures the methane concentration without sample taking and also can be run continuously. In our simulation, we detected methane production at temperatures down to -5 °C, which would be found on Mars either temporarily in the shallow subsurface or continually in the deep subsurface. The pressure of 50 kPa which we used in our experiments, corresponds to the expected pressure in the Martian near subsurface. Our new device proved to be fully functional and the results indicate that the possible existence of methanogenic archaea in Martian subsurface habitats cannot be ruled out.

  17. Laser spectroscopic real time measurements of methanogenic activity under simulated Martian subsurface analog conditions

    OpenAIRE

    Schirmack, J.; Böhm, M.; Brauer, C.; Löhmannsröben, H.G.; de Vera, J.P.; Möhlmann, D.; Wagner, D

    2014-01-01

    On Earth, chemolithoautothrophic and anaerobic microorganisms such as methanogenic archaea are regarded as model organisms for possible subsurface life on Mars. For this reason, the methanogenic strain Methanosarcina soligelidi (formerly called Methanosarcina spec. SMA-21), isolated from permafrost-affected soil in northeast Siberia, has been tested under Martian thermo-physicalconditions. In previous studies under simulated Martian conditions, high survival rates of these microorganisms w...

  18. Analog Quantum Simulation of (1+1)D Lattice QED with Trapped Ions

    CERN Document Server

    Yang, Dayou; Johanning, Michael; Wunderlich, Christof; Zoller, Peter; Hauke, Philipp

    2016-01-01

    The prospect of quantum simulating lattice gauge theories opens exciting possibilities for understanding fundamental forms of matter. Here, we show that trapped ions represent a promising platform in this context when simultaneously exploiting internal pseudo-spins and external phonon vibrations. We illustrate our ideas with two complementary proposals for simulating lattice-regularized quantum electrodynamics (QED) in (1+1) space-time dimensions. The first scheme replaces the gauge fields by local vibrations with a high occupation number. By numerical finite-size scaling, we demonstrate that this model recovers Wilson's lattice gauge theory in a controlled way. Its implementation can be scaled up to tens of ions in an array of micro-traps. The second scheme represents the gauge fields by spins 1/2, and thus simulates a quantum link model. As we show, this allows the fermionic matter to be replaced by bosonic degrees of freedom, permitting small-scale implementations in a linear Paul trap. Both schemes work o...

  19. Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4

    Science.gov (United States)

    Durán-Riveroll, Lorena M.; Cembella, Allan D.; Band-Schmidt, Christine J.; Bustillos-Guzmán, José J.; Correa-Basurto, José

    2016-01-01

    Saxitoxin (STX) and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav), impeding passage of Na+ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs. PMID:27164145

  20. Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4

    Directory of Open Access Journals (Sweden)

    Lorena M. Durán-Riveroll

    2016-05-01

    Full Text Available Saxitoxin (STX and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav, impeding passage of Na+ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs.

  1. Docking Simulation of the Binding Interactions of Saxitoxin Analogs Produced by the Marine Dinoflagellate Gymnodinium catenatum to the Voltage-Gated Sodium Channel Nav1.4.

    Science.gov (United States)

    Durán-Riveroll, Lorena M; Cembella, Allan D; Band-Schmidt, Christine J; Bustillos-Guzmán, José J; Correa-Basurto, José

    2016-01-01

    Saxitoxin (STX) and its analogs are paralytic alkaloid neurotoxins that block the voltage-gated sodium channel pore (Nav), impeding passage of Na⁺ ions into the intracellular space, and thereby preventing the action potential in the peripheral nervous system and skeletal muscle. The marine dinoflagellate Gymnodinium catenatum produces an array of such toxins, including the recently discovered benzoyl analogs, for which the mammalian toxicities are essentially unknown. We subjected STX and its analogs to a theoretical docking simulation based upon two alternative tri-dimensional models of the Nav1.4 to find a relationship between the binding properties and the known mammalian toxicity of selected STX analogs. We inferred hypothetical toxicities for the benzoyl analogs from the modeled values. We demonstrate that these toxins exhibit different binding modes with similar free binding energies and that these alternative binding modes are equally probable. We propose that the principal binding that governs ligand recognition is mediated by electrostatic interactions. Our simulation constitutes the first in silico modeling study on benzoyl-type paralytic toxins and provides an approach towards a better understanding of the mode of action of STX and its analogs. PMID:27164145

  2. The Analogical Mind

    OpenAIRE

    Holyoak, Keith J.; Thagard, P.

    1997-01-01

    We examine the use of analogy in human thinking from the perspective of a multiconstraint theory, which postulates three basic types of constraints: similarity, structure and purpose. The operation of these constraints is apparent in both laboratory experiments on analogy and in naturalistic settings, including politics, psychotherapy, and scientific research. We sketch how the multiconstraint theory can be implemented in detailed computational simulations of the analogical human mind.

  3. Analysis and numerical simulation of a laboratory analog of radiatively induced cloud-top entrainment

    Science.gov (United States)

    Schmidt, Heiko; Kerstein, Alan R.; Wunsch, Scott; Nédélec, Renaud; Sayler, Ben J.

    2013-06-01

    Numerical simulations using the one-dimensional-turbulence (ODT) model are compared to water-tank measurements emulating convection and entrainment in stratiform clouds driven by cloud-top cooling. Measured dependences of the entrainment rate on Richardson number were numerically reproduced for water trials in which the initial stratification is due to temperature differences. For an additional set of trials where the initial stratification is obtained by adding dextrose to the lower layer of the tank, measured dependences of the entrainment rate on Richardson number were partially reproduced, and importantly, the model also captures the measured sensitivity of entrainment to molecular transport. Additional parameter variations suggest other dependences of the entrainment rate. Analysis suggests possible qualitative differences between laboratory and cloud entrainment behaviors that might be testable using ODT.

  4. A Closed Mars Analog Simulation: The Approach of Crew 5 At the Mars Desert Research Station

    Science.gov (United States)

    Clancey, William J.; Koga, Dennis (Technical Monitor)

    2002-01-01

    For twelve days in April 2002 we performed a closed simulation in the Mars Desert Research Station, isolated from other people, as on Mars, while performing systematic surface exploration and life support chores. Email provided our only means of contact; no phone or radio conversations were possible. All mission-related messages were mediated by a remote mission support team. This protocol enabled a systematic and controlled study of crew activities, scheduling, and use of space. The analysis presented here focuses on two questions: Where did the time go-why did people feel rushed and unable to complete their work? How can we measure and model productivity, to compare habitat designs, schedules, roles, and tools? Analysis suggests that a simple scheduling change-having lunch and dinner earlier, plus eliminating afternoon meetings-increased the available productive time by 41%.

  5. Analog design and simulation using OrCAD capture and PSpice

    CERN Document Server

    Fitzpatrick, Dennis

    2012-01-01

    Anyone involved in circuit design that needs the practical know-how it takes to design a successful circuit or product, will find this practical guide to using Capture-PSpice (written by a former Cadence PSpice expert for Europe) an essential book. The text delivers step-by-step guidance on using Capture-PSpice to help professionals produce reliable, effective designs. Readers will learn how to get up and running quickly and efficiently with industry standard software and in sufficient detail to enable building upon personal experience to avoid common errors and pit-falls. This book is of great benefit to professional electronics design engineers, advanced amateur electronics designers, electronic engineering students and academic staff looking for a book with a real-world design outlook. This book provides both a comprehensive user guide, and a detailed overview of simulation; each chapter has worked and ready to try sample designs and provides a wide range of to-do exercises; core skills are developed using...

  6. The Role of the Photogeologic Mapping in the Morocco 2013 Mars Analog Field Simulation (Austrian Space Forum)

    Science.gov (United States)

    Losiak, Anna; Orgel, Csilla; Moser, Linda; MacArthur, Jane; Gołębiowska, Izabela; Wittek, Steffen; Boyd, Andrea; Achorner, Isabella; Rampey, Mike; Bartenstein, Thomas; Jones, Natalie; Luger, Ulrich; Sans, Alejandra; Hettrich, Sebastian

    2013-04-01

    The MARS2013 mission: The Austrian Space Forum together with multiple scientific partners will conduct a Mars analog field simulation. The project takes place between 1st and 28th of February 2013 in the northern Sahara near Erfoud. During the simulation a field crew (consisting of suited analog astronauts and a support team) will conduct several experiments while being managed by the Mission Support Center (MSC) located in Innsbruck, Austria. The aim of the project is to advance preparation of the future human Mars missions by testing: 1) the mission design with regard to operational and engineering challenges (e.g., how to work efficiently with introduced time delay in communication between field team and MSC), 2) scientific instruments (e.g., rovers) and 3) human performance in conditions analogous to those that will be encountered on Mars. The Role of Geological Mapping: Remote Science Support team (RSS) is responsible for processing science data obtained in the field. The RSS is also in charge of preparing a set of maps to enable planning activities of the mission (including the development of traverses) [1, 2]. The usage of those maps will increase the time-cost efficiency of the entire mission. The RSS team members do not have any prior knowledge about the area where the simulation is taking place and the analysis is fully based on remote sensing satellite data (Landsat, GoogleEarth) and a digital elevation model (ASTER GDEM)from the orbital data. The maps design: The set of maps (covering area 5 km X 5 km centered on the Mission Base Camp) was designed to simplify the process of site selection for the daily traverse planning. Additionally, the maps will help to accommodate the need of the field crew for the increased autonomy in the decision making process, forced by the induced time delay between MSC and "Mars". The set of provided maps should allow the field team to orientate and navigate in the explored areas as well as make informed decisions about

  7. Aero-acoustics prediction of a vertical axis wind turbine using Large Eddy Simulation and acoustic analogy

    International Nuclear Information System (INIS)

    Operating wind turbines generate tonal and broadband noises affecting the living environment adversely; especially small wind turbines located in the vicinity of human living places. Therefore, it is important to determine the level of noise pollution of such type of wind turbine installation. The current study carries out numerical prediction for aerodynamic noise radiated from an H-Darrieus Vertical Axis Wind Turbine. Incompressible LES (Large Eddy Simulation) is conducted to obtain the instantaneous turbulent flow field. The noise predictions are performed by the Ffowcs Williams and Hawkings (FW–H) acoustic analogy formulation. Simulations are performed for five different tip-speed ratios. First, the mean torque coefficient is compared with the experimental data, and good agreement is observed. Then, the research focuses on the broadband noises of the turbulent boundary layers and the tonal noises due to blade passing frequency. The contribution of the thickness, loading and quadrupole noises are investigated, separately. The results indicate a direct relation between the strength of the radiated noise and the rotational speed. Furthermore, the effect of receiver distance on the OASPL (Overall Sound Pressure Level) is investigated. It is concluded that the OASPL varies with a logarithmic trend with the receiver distance as it was expected. - Highlights: • Large Eddy Simulation has been used to predict the turbulent flow field. • The Ffowcs Williams and Hawkings method was employed to predict radiated noise. • There is a direct relation between the radiated noise and the tip speed ratio. • The quadrupole noises have negligible effect on the tonal noises

  8. Binding Free Energies for Nicotine Analogs Inhibiting Cytochrome P450 2A6 by a Combined Use of Molecular Dynamics Simulations and QM/MM-PBSA Calculations

    OpenAIRE

    Lu, Haiting; Huang, Xiaoqin; AbdulHameed, Mohamed Diwan M.; Zhan, Chang-Guo

    2014-01-01

    Molecular dynamics (MD) simulations and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations have been perforemd to explore the dynamic behaviors of cytochrome P450 2A6 (CYP2A6) binding with nicotine analogs (that are typical inhibitors) and to calculate their binding free energies in combination with Poisson-Boltzmann surface area (PBSA) calculations. The combined MD simulations and QM/MM-PBSA calculations reveal that the most important structural parameters affecting the CYP2...

  9. The design and simulation of a titanium oxide memristor-based programmable analog filter in a simulation program with integrated circuit emphasis

    International Nuclear Information System (INIS)

    In many communication and signal routing applications, it is desirable to have a programmable analog filter. According to this practical demand, we consider the titanium oxide memristor, which is a kind of nano-scale electron device with low power dissipation and nonvolatile memory. Such characteristics could be suitable for designing the desired filter. However, both the non-analytical relation between the memristance and the charges that pass through it, and the changeable V—I characteristics in physical tests make it difficult to accurately set the memristance to the target value. In this paper, the conductive mechanism of the memristor is analyzed, a method of continuously programming the memristance is proposed and simulated in a simulation program with integrated circuit emphasis, and its feasibility and compatibility, both in simulations and physical realizations, are demonstrated. This method is then utilized in a first-order active filter as an example to show its applications in programmable filters. This work also provides a practical tool for utilizing memristors as resistance programmable devices. (interdisciplinary physics and related areas of science and technology)

  10. The design and simulation of a titanium oxide memristor-based programmable analog filter in a simulation program with integrated circuit emphasis

    Institute of Scientific and Technical Information of China (English)

    Tian Xiao-Bo; Xu Hui

    2013-01-01

    In many communication and signal routing applications,it is desirable to have a programmable analog filter.According to this practical demand,we consider the titanium oxide memristor,which is a kind of nano-scale electron device with low power dissipation and nonvolatile memory.Such characteristics could be suitable for designing the desired filter.However,both the non-analytical relation between the memristance and the charges that pass through it,and the changeable V-I characteristics in physical tests make it difficult to accurately set the memristance to the target value.In this paper,the conductive mechanism of the memristor is analyzed,a method of continuously programming the memristance is proposed and simulated in a simulation program with integrated circuit emphasis,and its feasibility and compatibility,both in simulations and physical realizations,are demonstrated.This method is then utilized in a first-order active filter as an example to show its applications in programmable filters.This work also provides a practical tool for utilizing memristors as resistance programmable devices.

  11. Optoelectronic analogs of self-programming neural nets - Architecture and methodologies for implementing fast stochastic learning by simulated annealing

    Science.gov (United States)

    Farhat, Nabil H.

    1987-01-01

    Self-organization and learning is a distinctive feature of neural nets and processors that sets them apart from conventional approaches to signal processing. It leads to self-programmability which alleviates the problem of programming complexity in artificial neural nets. In this paper architectures for partitioning an optoelectronic analog of a neural net into distinct layers with prescribed interconnectivity pattern to enable stochastic learning by simulated annealing in the context of a Boltzmann machine are presented. Stochastic learning is of interest because of its relevance to the role of noise in biological neural nets. Practical considerations and methodologies for appreciably accelerating stochastic learning in such a multilayered net are described. These include the use of parallel optical computing of the global energy of the net, the use of fast nonvolatile programmable spatial light modulators to realize fast plasticity, optical generation of random number arrays, and an adaptive noisy thresholding scheme that also makes stochastic learning more biologically plausible. The findings reported predict optoelectronic chips that can be used in the realization of optical learning machines.

  12. Direct reconstruction in CT-analogous pharmacokinetic diffuse fluorescence tomography: two-dimensional simulative and experimental validations

    Science.gov (United States)

    Wang, Xin; Zhang, Yanqi; Zhang, Limin; Li, Jiao; Zhou, Zhongxing; Zhao, Huijuan; Gao, Feng

    2016-04-01

    We present a generalized strategy for direct reconstruction in pharmacokinetic diffuse fluorescence tomography (DFT) with CT-analogous scanning mode, which can accomplish one-step reconstruction of the indocyanine-green pharmacokinetic-rate images within in vivo small animals by incorporating the compartmental kinetic model into an adaptive extended Kalman filtering scheme and using an instantaneous sampling dataset. This scheme, compared with the established indirect and direct methods, eliminates the interim error of the DFT inversion and relaxes the expensive requirement of the instrument for obtaining highly time-resolved date-sets of complete 360 deg projections. The scheme is validated by two-dimensional simulations for the two-compartment model and pilot phantom experiments for the one-compartment model, suggesting that the proposed method can estimate the compartmental concentrations and the pharmacokinetic-rates simultaneously with a fair quantitative and localization accuracy, and is well suitable for cost-effective and dense-sampling instrumentation based on the highly-sensitive photon counting technique.

  13. Analog model

    International Nuclear Information System (INIS)

    The invention relates to devices for modelling the space-dependent kinetics of a nuclear reactor. It can be advantageously used in studying the dynamics of the neutron field in the core to determine the effect of the control rods on the power distribution in the core, for training purposes. The proposed analog model of a nuclear reactor comprises operational amplifiers and a grid of resistors simulating neutron diffusion. Connected to the grid nodes are supply resistors modelling absorption and multiplication of neutrons. This is achieved by that, in the proposed model, all resistors through which power is supplied to the grid nodes are interconnected by their other leads and coupled to the output of the amplifier unit common for all nodes. Therewith, the amlifier unit models the transfer function of a ''point'' reactor. Connected to the input of this unit which includes two to four amplifiers are resistors for addition of signals with a grid node. Coupled to the grid nodes via additional resistors are voltage sources simulating reactivity

  14. Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

    Science.gov (United States)

    Tranter, W. H.; Turner, M. D.

    1977-01-01

    Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

  15. Modelling and simulation of tri-material gate stack gate all-around (TMGSGAA) MOSFET using Legendre Wavelets for analog/RF applications

    Science.gov (United States)

    Ramesh, R.; Bhattacharyya, A.

    2016-09-01

    In this work, a 2D modelling of tri-material gate stack gate all around (TMGSGAA) MOSFET considering quantum mechanical effects is developed and its analog/RF characteristics are simulated. A self-consistent solution of 2D Poisson-Schrödinger equation has been obtained using Legendre Wavelets. It provides accurate results by performing efficient computation using adaptive mesh obtained by multiresolution approach. The accuracy of the method has been verified with TCAD simulation results. A systematic, quantitative investigation of main figure of merit (FOMs) for the device is carried out to demonstrate its improved RF/analog performance. The results show an improvement in drain current, Ion/Ioff ratio, transconductance, fT and fmax providing superior RF performance under low-power operating conditions.

  16. Interferon Analogs

    NARCIS (Netherlands)

    Poelstra, Klaas; Prakash, Jai; Beljaars, Eleonora; Bansal, Ruchi

    2015-01-01

    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  17. Interferon Analogs

    NARCIS (Netherlands)

    Poelstra, Klaas; Prakash, Jai; Beljaars, Leonie; Bansal, Ruchi

    2010-01-01

    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  18. Analog circuits using FinFETs: benefits in speed-accuracy-power trade-off and simulation of parasitic effects

    Directory of Open Access Journals (Sweden)

    M. Fulde

    2007-06-01

    Full Text Available Multi-gate FET, e.g. FinFET devices are the most promising contenders to replace bulk FETs in sub-45 nm CMOS technologies due to their improved sub threshold and short channel behavior, associated with low leakage currents. The introduction of novel gate stack materials (e.g. metal gate, high-k dielectric and modified device architectures (e.g. fully depleted, undoped fins affect the analog device properties significantly. First measurements indicate enhanced intrinsic gain (gm/gDS and promising matching behavior of FinFETs. The resulting benefits regarding the speed-accuracy-power trade-off in analog circuit design will be shown in this work. Additionally novel device specific effects will be discussed. The hysteresis effect caused by charge trapping in high-k dielectrics or self-heating due to the high thermal resistor of the BOX isolation are possible challenges for analog design in these emerging technologies. To gain an early assessment of the impact of such parasitic effects SPICE based models are derived and applied in analog building blocks.

  19. Simulations

    CERN Document Server

    Ngada, N M

    2015-01-01

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  20. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  1. Clinical trial simulations in pediatric patients using realistic covariates: application to teduglutide, a glucagon-like peptide-2 analog in neonates and infants with short-bowel syndrome.

    Science.gov (United States)

    Mouksassi, M S; Marier, J F; Cyran, J; Vinks, A A

    2009-12-01

    Teduglutide, a synthetic glucagon-like peptide-2 (GLP-2) analog with activity relating to the regeneration, maintenance, and repair of the intestinal epithelium, is currently being evaluated for the treatment of short-bowel syndrome (SBS), Crohn's disease, and other gastrointestinal disorders. On the basis of promising results from teduglutide studies in adults with SBS and from studies in neonatal and juvenile animal models, a pediatric multiple-dose phase I clinical study was designed to determine the safety, efficacy, and pharmacokinetics of teduglutide in pediatric patients with SBS who have undergone resection for necrotizing enterocolitis, malrotation, or intestinal atresia. This report details the application of clinical trial simulations coupled with a novel approach using generalized additive modeling for location, scale, and shape (GAMLSS) that facilitates the simulation of demographic covariates specific to the targeted patient populations. The goal was to optimize phase I dosing strategies and the likelihood of achieving target exposure and therapeutic effect. PMID:19847163

  2. Electrical analogous in viscoelasticity

    Science.gov (United States)

    Ala, Guido; Di Paola, Mario; Francomano, Elisa; Li, Yan; Pinnola, Francesco P.

    2014-07-01

    In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical experiments based on finite difference time domain method shows that, for long time simulations, the correct time behavior can be obtained only with modal analysis. The use of electrical analogous in viscoelasticity can better reveal the real behavior of fractional hereditary materials.

  3. PC-based analog signal generator for simulated detector signals and arbitrary test waveforms for testing the nuclear instruments

    International Nuclear Information System (INIS)

    This work is performed in cooperation with IAEA-Vienna as a project, proposed as part of Agency's Co-ordinated Research Programme of Development of Computer-based Troubleshooting Tools and Instruments. A convenient way for testing and calibrating modern scientific equipment is to connect the test instruments to a personal computer to get additional feasibilities. This way, all settings for test, measurement and data acquisition functions are done by means of PC and are controlled by software drivers. This multifunctional spectrometric pulse generator is able to characterize different parts of high-resolution nuclear spectroscopy chain (preamplifier, amplifier, analog to digital converter, multichannel analyzer) as well as the whole chain. For this it generates periodic or random pulses with shape, time and amplitude specifications controlled by PC. Characteristics such as integral linearity, differential linearity, dead time, rate channel shifting and others will be easily determined. The block diagram of the multifunctional spectrometric generator is shown. The main sections are: PC-interface, control registers and command generation; PC-controlled periodic and random logic pulse oscillators; PC-controlled delay and width of periodic or random logic pulses; constant and ultra-linear ramp references for spectrometric pulse generation; generation of the tail and flat top pulses with PC-controlled amplitude and decay time; semi-gaussian pulse generation, polarity inverter and output amplifier. The specifications for generated signal correspond to: shape, time specifications and amplitude size. (author)

  4. Radiolysis of Amino Acids by Heavy and Energetic Cosmic Ray Analogs in Simulated Space Environments: $\\alpha$-Glycine Zwitterion Form

    CERN Document Server

    Portugal, Williamary; Boduch, Philippe; Rothard, Hermann; Andrade, Diana P P

    2014-01-01

    In this work, we studied the stability of the glycine molecule in the crystalline zwitterion form, known as {\\alpha}-glycine ($^{+}$NH$_{3}$CH$_{2}$COO$^{-}$) under action of heavy cosmic ray analogs. The experiments were conducted in a high vacuum chamber at heavy ions accelerator GANIL, in Caen, France. The samples were bombarded at two temperatures (14 K and 300 K) by $^{58}$Ni$^{11+}$ ions of 46 MeV until the final fluence of $10^{13}$ ions cm$^{-2}$. The chemical evolution of the sample was evaluated in-situ using Fourrier Transformed Infrared (FTIR) spectrometer. The bombardment at 14 K produced several daughter species such as OCN$^-$, CO, CO$_2$, and CN$^-$. The results also suggest the appearing of peptide bonds during irradiation but this must be confirmed by further experiments. The halflives of glycine in Interstellar Medium were estimated to be 7.8 $\\times 10^3$ years (300 K) and 2.8 $\\times 10^3$ years (14 K). In the Solar System the values were 8.4 $\\times 10^2$ years (300 K) and 3.6 $\\times 10...

  5. Computation of relative binding free energy for an inhibitor and its analogs binding with Erk kinase using thermodynamic integration MD simulation.

    Science.gov (United States)

    Wu, Kuan-Wei; Chen, Po-Chin; Wang, Jun; Sun, Ying-Chieh

    2012-10-01

    In the present study, we carried out thermodynamic integration molecular dynamics simulation for a pair of analogous inhibitors binding with Erk kinase to investigate how computation performs in reproducing the relative binding free energy. The computation with BCC-AM1 charges for ligands gave -1.1 kcal/mol, deviated from experimental value of -2.3 kcal/mol by 1.2 kcal/mol, in good agreement with experimental result. The error of computed value was estimated to be 0.5 kcal/mol. To obtain convergence, switching vdw interaction on and off required approximately 10 times more CPU time than switching charges. Residue-based contributions and hydrogen bonding were analyzed and discussed. Furthermore, subsequent simulation using RESP charge for ligand gave ΔΔG of -1.6 kcal/mol. The computed results are better than the result of -5.6 kcal/mol estimated using PBSA method in a previous study. Based on these results, we further carried out computations to predict ΔΔG for five new analogs, focusing on placing polar and nonpolar functional groups at the meta site of benzene ring shown in the Fig. 1, to see if these ligands have better binding affinity than the above ligands. The computations resulted that a ligand with polar -OH group has better binding affinity than the previous examined ligand by ~2.0 kcal/mol and two other ligands have better affinity by ~1.0 kcal/mol. The predicted better inhibitors of this kind should be of interest to experimentalist for future experimental enzyme and/or cell assays. PMID:22986633

  6. Binding free energies for nicotine analogs inhibiting cytochrome P450 2A6 by a combined use of molecular dynamics simulations and QM/MM-PBSA calculations.

    Science.gov (United States)

    Lu, Haiting; Huang, Xiaoqin; AbdulHameed, Mohamed Diwan M; Zhan, Chang-Guo

    2014-04-01

    Molecular dynamics (MD) simulations and hybrid quantum mechanical/molecular mechanical (QM/MM) calculations have been performed to explore the dynamic behaviors of cytochrome P450 2A6 (CYP2A6) binding with nicotine analogs (that are typical inhibitors) and to calculate their binding free energies in combination with Poisson-Boltzmann surface area (PBSA) calculations. The combined MD simulations and QM/MM-PBSA calculations reveal that the most important structural parameters affecting the CYP2A6-inhibitor binding affinity are two crucial internuclear distances, that is, the distance between the heme iron atom of CYP2A6 and the coordinating atom of the inhibitor, and the hydrogen-bonding distance between the N297 side chain of CYP2A6 and the pyridine nitrogen of the inhibitor. The combined MD simulations and QM/MM-PBSA calculations have led to dynamic CYP2A6-inhibitor binding structures that are consistent with the observed dynamic behaviors and structural features of CYP2A6-inhibitor binding, and led to the binding free energies that are in good agreement with the experimentally-derived binding free energies. The agreement between the calculated binding free energies and the experimentally-derived binding free energies suggests that the combined MD and QM/MM-PBSA approach may be used as a valuable tool to accurately predict the CYP2A6-inhibitor binding affinities in future computational design of new, potent and selective CYP2A6 inhibitors. PMID:24631364

  7. ''On-line'' analyses of simulated solar wind implantations of terrestrial analogs of lunar materials

    Energy Technology Data Exchange (ETDEWEB)

    Blanford, G.E.; Borgesen, P.; Maurette, M.; Moeller, W.; Monart, B.

    1986-03-30

    To help assess possible water reserves on the moon derived from the solar wind that could supply a lunar base, oligoclase, ilmenite, and simulated lunar glass have been irradiated with a beam of 2.5 keV/amu deuterium ions to simulate solar wind proton bombardment of lunar materials. For ilmenite and simulated lunar glass the areal density of deuterium D(phi) (D/cm/sup 2/) increases with the incident ion fluence phi until a critical reemission fluence is reached (phi = 3.3-3.5 x 10/sup 17/ D/cm/sup 2/). At this point deuterium begins to be lost from both targets until D(phi) reaches a saturation value D/sub s/ = 2-4 x 10/sup 17/ D/cm/sup 2/ at phi/sub s/ = 1-2 x 10/sup 18/ D/cm/sup 2/. Oligoclase begins losing deuterium when the beam is turned on; D(phi) never reaches a saturation value up to the limit of our experiment (phiapprox. =3 x 10/sup 18/ D/cm/sup 2/). There is a small yield of approx.10/sup -4/ D/sub 2/O/sup +//D/sub incident/ during the implantation. Thermal release patterns for D/sub 2/ in our targets do not correspond to those observed for H/sub 2/ in lunar soils, but the differences may be explainable after further experiments. Although ilmenite stores about twice as much deuterium as the other target materials, it is unknown whether this small enrichment factor will be sufficient to make it a potential source of lunar water.

  8. In Silico Exploration of 1,7-Diazacarbazole Analogs as Checkpoint Kinase 1 Inhibitors by Using 3D QSAR, Molecular Docking Study, and Molecular Dynamics Simulations.

    Science.gov (United States)

    Gao, Xiaodong; Han, Liping; Ren, Yujie

    2016-01-01

    Checkpoint kinase 1 (Chk1) is an important serine/threonine kinase with a self-protection function. The combination of Chk1 inhibitors and anti-cancer drugs can enhance the selectivity of tumor therapy. In this work, a set of 1,7-diazacarbazole analogs were identified as potent Chk1 inhibitors through a series of computer-aided drug design processes, including three-dimensional quantitative structure-activity relationship (3D-QSAR) modeling, molecular docking, and molecular dynamics simulations. The optimal QSAR models showed significant cross-validated correlation q² values (0.531, 0.726), fitted correlation r² coefficients (higher than 0.90), and standard error of prediction (less than 0.250). These results suggested that the developed models possess good predictive ability. Moreover, molecular docking and molecular dynamics simulations were applied to highlight the important interactions between the ligand and the Chk1 receptor protein. This study shows that hydrogen bonding and electrostatic forces are key interactions that confer bioactivity. PMID:27164065

  9. In Silico Exploration of 1,7-Diazacarbazole Analogs as Checkpoint Kinase 1 Inhibitors by Using 3D QSAR, Molecular Docking Study, and Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Xiaodong Gao

    2016-05-01

    Full Text Available Checkpoint kinase 1 (Chk1 is an important serine/threonine kinase with a self-protection function. The combination of Chk1 inhibitors and anti-cancer drugs can enhance the selectivity of tumor therapy. In this work, a set of 1,7-diazacarbazole analogs were identified as potent Chk1 inhibitors through a series of computer-aided drug design processes, including three-dimensional quantitative structure–activity relationship (3D-QSAR modeling, molecular docking, and molecular dynamics simulations. The optimal QSAR models showed significant cross-validated correlation q2 values (0.531, 0.726, fitted correlation r2 coefficients (higher than 0.90, and standard error of prediction (less than 0.250. These results suggested that the developed models possess good predictive ability. Moreover, molecular docking and molecular dynamics simulations were applied to highlight the important interactions between the ligand and the Chk1 receptor protein. This study shows that hydrogen bonding and electrostatic forces are key interactions that confer bioactivity.

  10. A Simulation Study to Explore Configuring the New SAT® Critical Reading Section without Analogy Items. Research Report No. 2004-2. ETS RR-04-01

    Science.gov (United States)

    Liu, Jinghua; Feigenbaum, Miriam; Cook, Linda

    2004-01-01

    This study explored possible configurations of the new SAT® critical reading section without analogy items. The item pool contained items from SAT verbal (SAT-V) sections of 14 previously administered SAT tests, calibrated using the three-parameter logistic IRT model. Multiple versions of several prototypes that do not contain analogy items were…

  11. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  12. From neural oscillations to reasoning ability: Simulating the effect of the theta-to-gamma cycle length ratio on individual scores in a figural analogy test.

    Science.gov (United States)

    Chuderski, Adam; Andrelczyk, Krzysztof

    2015-02-01

    Several existing computational models of working memory (WM) have predicted a positive relationship (later confirmed empirically) between WM capacity and the individual ratio of theta to gamma oscillatory band lengths. These models assume that each gamma cycle represents one WM object (e.g., a binding of its features), whereas the theta cycle integrates such objects into the maintained list. As WM capacity strongly predicts reasoning, it might be expected that this ratio also predicts performance in reasoning tasks. However, no computational model has yet explained how the differences in the theta-to-gamma ratio found among adult individuals might contribute to their scores on a reasoning test. Here, we propose a novel model of how WM capacity constraints figural analogical reasoning, aimed at explaining inter-individual differences in reasoning scores in terms of the characteristics of oscillatory patterns in the brain. In the model, the gamma cycle encodes the bindings between objects/features and the roles they play in the relations processed. Asynchrony between consecutive gamma cycles results from lateral inhibition between oscillating bindings. Computer simulations showed that achieving the highest WM capacity required reaching the optimal level of inhibition. When too strong, this inhibition eliminated some bindings from WM, whereas, when inhibition was too weak, the bindings became unstable and fell apart or became improperly grouped. The model aptly replicated several empirical effects and the distribution of individual scores, as well as the patterns of correlations found in the 100-people sample attempting the same reasoning task. Most importantly, the model's reasoning performance strongly depended on its theta-to-gamma ratio in same way as the performance of human participants depended on their WM capacity. The data suggest that proper regulation of oscillations in the theta and gamma bands may be crucial for both high WM capacity and effective complex

  13. Mars Analog Research and Technology Experiment (MARTE): A Simulated Mars Drilling Mission to Search for Subsurface Life at the Rio Tinto, Spain

    Science.gov (United States)

    Stoker, C. R.; Lemke, L. G.; Mandell, H.; McKay, D.; George, J.; Gomez-Elvira, J.; Amils, R.; Stevens, T.; Miller, D.

    2003-03-01

    MARTE is a Mars analog drilling experiment to search for subsurface life on Mars while also characterizing a sulfide-based subsurface biosphere. MARTE is among the first set of field experiments supported by the ASTEP program.

  14. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  15. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  16. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  17. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  18. Multilateral Collaborations in Analog Research

    Science.gov (United States)

    Cromwell, R. l.

    2016-01-01

    International collaborations in studies utilizing ground-based space flight analogs are an effective means for answering research questions common to participating agencies. These collaborations bring together worldwide experts to solve important space research questions. By collaborating unnecessary duplication of science is reduced, and the efficiency of analog use is improved. These studies also share resources among agencies for cost effective solutions to study implementation. Recently, NASA has engaged in collaborations with international partners at a variety of analog sites. The NASA Human Exploration Research Analog (HERA) is currently hosting investigator studies from NASA and from the German Space Agency (DLR). These isolation studies will answer questions in the areas of team cohesion, sleep and circadian rhythms, and neurobehavioral correlates to function. Planning for the next HERA campaign is underway as proposal selections are being made from the International Life Sciences Research Announcement (ILSRA). Studies selected from the ILSRA will be conducted across 4 HERA missions in 2017. NASA is planning collaborative studies with DLR at the :envihab facility in Cologne, Germany. Investigations were recently selected to study the effects of 0.5% CO2 exposure over 30 days of bed rest. These studies will help to determine the fidelity of this ground-based analog for studying the visual impairment intracranial pressure syndrome. NASA is also planning a multilateral collaboration at :envihab with DLR and the European Space Agency (ESA) to examine artificial gravity as a countermeasure to mitigate the effects of 60 days of bed rest. NASA is also considering collaborations with the Russian Institute for Biomedical Problems (IBMP) in studies that will utilize their Ground-based Experimental Facility (NEK). The NEK is comprised of 4 interconnected modules and a Martian surface simulator. This isolation analog can support 3 -10 crew members for long duration

  19. Insulin analogs and cancer

    Directory of Open Access Journals (Sweden)

    Laura eSciacca

    2012-02-01

    Full Text Available Today, insulin analogs are used in millions of diabetic patients. Insulin analogs have been developed to achieve more physiological insulin replacement in terms of time course of the effect. Modifications in the amino acid sequence of the insulin molecule change the pharmacokinetics and pharmacodynamics of the analogs in respect to human insulin. However, these changes can also modify the molecular and biological effects of the analogs. The rapid-acting insulin analogs, lispro, aspart and glulisine, have a rapid onset and shorter duration of action. The long-acting insulin analogs glargine and detemir have a protracted duration of action and a relatively smooth serum concentration profile. Insulin and its analogs may function as growth factors and therefore have a theoretical potential to promote tumor proliferation. A major question is whether analogs have an increased mitogenic activity in respect to insulin. These ligands can promote cell proliferation through many mechanisms like the prolonged stimulation of the insulin receptor, stimulation of the IGF-1 receptor (IGF-1R, prevalent activation of the ERK rather than the AKT intracellular post-receptor pathways. Studies on in vitro models indicate that short-acting analogs elicit molecular and biological effects that are similar to those of insulin. In contrast, long-acting analogs behave differently. Although not all data are homogeneous, both glargine and detemir have been found to have a decreased binding to IR but an increased binding to IGF-1R, a prevalent activation of the ERK pathway, and an increased mitogenic effect in respect to insulin. Recent retrospective epidemiological clinical studies have suggested that treatment with long-acting analogs (specifically glargine may increase the relative risk for cancer. Results are controversial and methodologically weak. Therefore prospective clinical studies are needed to evaluate the possible tumor growth-promoting effects of these insulin

  20. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  1. In Silico Exploration of 1,7-Diazacarbazole Analogs as Checkpoint Kinase 1 Inhibitors by Using 3D QSAR, Molecular Docking Study, and Molecular Dynamics Simulations

    OpenAIRE

    Xiaodong Gao; Liping Han; Yujie Ren

    2016-01-01

    Checkpoint kinase 1 (Chk1) is an important serine/threonine kinase with a self-protection function. The combination of Chk1 inhibitors and anti-cancer drugs can enhance the selectivity of tumor therapy. In this work, a set of 1,7-diazacarbazole analogs were identified as potent Chk1 inhibitors through a series of computer-aided drug design processes, including three-dimensional quantitative structure–activity relationship (3D-QSAR) modeling, molecular docking, and molecular dynamics simulatio...

  2. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations. PMID:24567476

  3. Implementing neural architectures using analog VLSI circuits

    OpenAIRE

    Maher, Mary Ann C.; DeWeerth, Stephen P.; Mahowald, Misha A.; Mead, Carver A.

    1989-01-01

    Analog very large-scale integrated (VLSI) technology can be used not only to study and simulate biological systems, but also to emulate them in designing artificial sensory systems. A methodology for building these systems in CMOS VLSI technology has been developed using analog micropower circuit elements that can be hierarchically combined. Using this methodology, experimental VLSI chips of visual and motor subsystems have been designed and fabricated. These chips exhibit behavior similar to...

  4. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  5. Analog pulse processor

    Science.gov (United States)

    Wessendorf, Kurt O.; Kemper, Dale A.

    2003-06-03

    A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.

  6. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    Science.gov (United States)

    Chopra, Sakshi; Gupta, Narendra Kumar; Tandan, Amrit; Dwivedi, Ravi; Gupta, Swati; Agarwal, Garima

    2016-01-01

    Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. Materials and Methods: The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. Results: A significant difference in the pressure produced using different impression materials was found (P zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. Conclusion: All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Clinical Implication: Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques. PMID:27041902

  7. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sakshi Chopra

    2016-01-01

    Full Text Available Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. Materials and Methods: The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. Results: A significant difference in the pressure produced using different impression materials was found (P < 0.001. Light body vinyl polysiloxane produced significantly lesser pressure than zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. Conclusion: All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Clinical Implication: Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  8. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320

  9. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  10. From snowball to moist greenhouse: the climatological evolution of Earth-analog planets simulated with a 3D climate system model

    Science.gov (United States)

    Wolf, Eric T.; Kopparapu, Ravi; Haqq-Misra, Jacob; Toon, Owen Brian

    2015-12-01

    The host star imposes a primary control on terrestrial planet climate. Both the spectral energy distribution and the main sequence lifetime vary as a function of stellar type. Here we present recent results from three-dimensional climate system models describing the evolutionary sequence of Earth-analog planets throughout their habitable lifetimes. Climatological evolution is traced from snowball to moist greenhouse, representing the conventional end-member states of the habitable zone. For Earth the habitable period would have been tantalizingly short, if not for geological and biological regulation of greenhouse gases. Without active carbon cycling, an early snowball could not have been broken until late in Earth’s history. Abrupt solar driven deglaciation would soon be followed by the onset of the water vapor greenhouse feedback and a moist greenhouse climate, leaving little over 1 billion years of habitable surface conditions. Around bluer stars, the habitable period for terrestrial planets is constricted further due to their reduced main sequence lifetimes and thus more rapid brightening. Planets with long-lived habitable periods are most likely found around stars redder than the Sun due to their more gradual brightening.

  11. Challenges in Analogical Reasoning

    CERN Document Server

    Lin, Shih-Yin

    2016-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.

  12. TV Analog Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...

  13. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  14. Synthesis of Paclitaxel Analogs

    OpenAIRE

    Xu, Zhibing

    2010-01-01

    Paclitaxel is one of the most successful anti-cancer drugs, particularly in the treatment of breast cancer and ovarian cancer. For the investigation of the interaction between paclitaxel and MD-2 protein, and development of new antagonists for lipopolysaccharide, several C10 A-nor-paclitaxel analogs have been synthesized and their biological activities have been evaluated. In order to reduce the myelosuppression effect of the paclitaxel, several C3â ² and C4 paclitaxel analogs have been synth...

  15. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  16. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  17. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  18. The analogic model ''RIC'' of thermal behaviour of mass concrete

    International Nuclear Information System (INIS)

    In order to study the thermal field and calorific flows in heat sources (i.e. mass concrete during setting) we have conceived, built and experimented with an analogical electric model. This model, named RIC, consists of resistors (R) and capacitors (C) in which nodes an electric current (I) has been injected. Several analogical constants were used for the mathematical approximation. Thus, this paper describes the analogical RIC model, simulating heat generation, boundary and initial conditions and concreting. (Author) 4 refs

  19. A Mechanical Analogy for Ohm's Law.

    Science.gov (United States)

    do Couto Tavares, Milton; And Others

    1991-01-01

    A mechanical analogy between the microscopic motion of a charged carrier in an ordinary resistor and the macroscopic motion of a ball falling along a slanted board covered with a lattice of nails is introduced. The Drude model is also introduced to include the case of inelastic collisions. Computer simulation of the motion is described. (KR)

  20. Crystal molecular dynamics simulations to speed up MM/PB(GB)SA evaluation of binding free energies of di-mannose deoxy analogs with P51G-m4-Cyanovirin-N.

    Science.gov (United States)

    Vorontsov, Ivan I; Miyashita, Osamu

    2011-04-30

    Complexes of two Cyanovirin-N (CVN) mutants, m4-CVN and P51G-m4-CVN, with deoxy di-mannose analogs were employed as models to generate conformational ensembles using explicit water Molecular Dynamics (MD) simulations in solution and in crystal environment. The results were utilized for evaluation of binding free energies with the molecular mechanics Poisson-Boltzmann (or Generalized Born) surface area, MM/PB(GB)SA, methods. The calculations provided the ranking of deoxy di-mannose ligands affinity in agreement with available qualitative experimental evidences. This confirms the importance of the hydrogen-bond network between di-mannose 3'- and 4'-hydroxyl groups and the protein binding site B(M) as a basis of the CVN activity as an effective HIV fusion inhibitor. Comparison of binding free energies averaged over snapshots from the solution and crystal simulations showed high promises in the use of the crystal matrix for acceleration of the conformational ensemble generation, the most time consuming step in MM/PB(GB)SA approach. Correlation between energy values based on solution versus crystal ensembles is 0.95 for both MM/PBSA and MM/GBSA methods. PMID:20949512

  1. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  2. Towards analogy in toponyms

    Czech Academy of Sciences Publication Activity Database

    Štěpán, Pavel

    Cluj : Mega, 2013 - (Felecan, O.), s. 379-383 ISBN 978-606-543-343-4. [Name and Naming /2./ Onomastics in Contemporary Public Space. Baia Mare (RO), 09.05.2013-11.05.2013] R&D Projects: GA ČR GPP406/12/P600 Institutional support: RVO:68378092 Keywords : onomastics * toponyms * analogy Subject RIV: AI - Linguistics

  3. Space flight nutrition research: platforms and analogs

    Science.gov (United States)

    Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.

    2002-01-01

    Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section.

  4. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  5. USW area analogs

    OpenAIRE

    Everett, Keith R.

    2005-01-01

    The purpose of this project is to investigate the feasibility of and methodology for the development of a set of environmental analogs of operational Undersea Warfare (USW) areas within fleet training areas. It is primarily a discussion of the identification of parameters that characterize the tactical USW environment, prioritization of these parameters, identification of existing databases that contain these parameters and an outline of the processes required to extract the desired data fro...

  6. ADSL Analog Front End

    OpenAIRE

    Stojković, Nino

    2006-01-01

    In this paper the Asymmetric Digital Subscriber Line (ADSL) analog front end (AFE) designs are described and compared. AFE is the part of ADSL modems most responsible for quality signal transmission over phone wires. It can be divided into the transmitting path (TX) circuitry, the receiving path (RX) circuitry and the hybrid network and transformer. The operations and realizations of each functional block are presented. There are the D/A converter, the filter and the line driver in the TX pat...

  7. Analog Signal Processing

    OpenAIRE

    Caloz, Christophe; Gupta, Shulabh; Zhang, Qingfeng; Nikfal, Babak

    2013-01-01

    Analog signal processing (ASP) is presented as a systematic approach to address future challenges in high speed and high frequency microwave applications. The general concept of ASP is explained with the help of examples emphasizing basic ASP effects, such as time spreading and compression, chirping and frequency discrimination. Phasers, which represent the core of ASP systems, are explained to be elements exhibiting a frequency-dependent group delay response, and hence a nonlinear phase resp...

  8. A Transiting Jupiter Analog

    CERN Document Server

    Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily

    2016-01-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...

  9. Experiments on Evolving Software Models of Analog Circuits

    Science.gov (United States)

    Lohn, Jason D.

    1999-01-01

    Analog circuits are of great importance in electronic system design since the world is fundamentally analog in nature. While the amount of digital design activity far outpaces that of analog design, most digital systems require analog modules for interfacing with the external world. It was recently estimated that approximately 60% of digital application- specific integrated circuit designs incorporated analog circuits. With challenging analog circuit design problems and few analog design engineers, there are economic reasons for automating the analog design process, especially time-to-market considerations. Techniques for analog circuit design automation began appearing about two decades ago. These methods incorporated heuristics [6], knowledge bases [1], simulated annealing [5], and other algorithms. Efforts using techniques from evolutionary computation began appearing over the last few years. These include the use of genetic algorithms to select electronic component values (for example, the resistance value of a resistor), to select circuit topologies, and to design amplifiers using a limited set of canned topologies [4]. A genetic programming-based analog circuit design system has been demonstrated in which the circuit sizes, component values, and the circuit topologies are determined automatically [3]. The genetic-algorithm systems typically represent circuit structures as vectors of parameters encoded in binary strings, while the genetic programming system manipulates tree data structures.

  10. Spiral structure in galaxies: analogies

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, R.C.

    1976-01-01

    The vortex analogy to galactic spiral structures is considered. Caution against carrying the analogy past its region of applicability is noted; and some experiments with vorticities are mentioned. (JFP)

  11. Natural Analogs for the Unsaturated Zone

    International Nuclear Information System (INIS)

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model

  12. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  13. The Age of Analog Networks

    OpenAIRE

    Mattiussi, Claudio; Swiss Federal Institute of Technology in Lausanne (EPFL); Marbach, Daniel; Swiss Federal Institute of Technology in Lausanne (EPFL); Dürr, Peter; Swiss Federal Institute of Technology in Lausanne (EPFL); Floreano, Dario; Swiss Federal Institute of Technology in Lausanne (EPFL)

    2008-01-01

    A large class of systems of biological and technological relevance can be described as analog networks, that is, collections of dynamical devices interconnected by links of varying strength. Some examples of analog networks are genetic regulatory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typically complex systems which include nonlinear feedback loops and possess temporal dynamics at different timescales. When tackled b...

  14. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  15. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  16. An analog electronic cochlea

    OpenAIRE

    Lyon, Richard F.; Mead, Carver

    1988-01-01

    An engineered system that hears, such as a speech recognizer, can be designed by modeling the cochlea, or inner ear, and higher levels of the auditory nervous system. To be useful in such a system, a model of the cochlea should incorporate a variety of known effects, such as an asymmetric low-pass/bandpass response at each output channel, a short ringing time, and active adaptation to a wide range of input signal levels. An analog electronic cochlea has been built in CMOS VLSI technolog...

  17. ON THE FREQUENCY OF JUPITER ANALOGS

    International Nuclear Information System (INIS)

    The Anglo-Australian Planet Search has now accumulated 12 years of radial-velocity data with long-term instrumental precision better than 3 m s-1. In this paper, we expand on earlier simulation work, to probe the frequency of near-circular, long-period gas-giant planets residing at orbital distances of 3-6 AU-the so-called Jupiter analogs. We present the first comprehensive analysis of the frequency of these objects based on radial-velocity data. We find that 3.3% of stars in our sample host Jupiter analogs; detailed, star-by-star simulations show that no more than 37% of stars host a giant planet between 3 and 6 AU.

  18. Reynolds analogy for the Rayleigh problem at various flow modes.

    Science.gov (United States)

    Abramov, A A; Butkovskii, A V

    2016-07-01

    The Reynolds analogy and the extended Reynolds analogy for the Rayleigh problem are considered. For a viscous incompressible fluid we derive the Reynolds analogy as a function of the Prandtl number and the Eckert number. We show that for any positive Eckert number, the Reynolds analogy as a function of the Prandtl number has a maximum. For a monatomic gas in the transitional flow regime, using the direct simulation Monte Carlo method, we investigate the extended Reynolds analogy, i.e., the relation between the shear stress and the energy flux transferred to the boundary surface, at different velocities and temperatures. We find that the extended Reynolds analogy for a rarefied monatomic gas flow with the temperature of the undisturbed gas equal to the surface temperature depends weakly on time and is close to 0.5. We show that at any fixed dimensionless time the extended Reynolds analogy depends on the plate velocity and temperature and undisturbed gas temperature mainly via the Eckert number. For Eckert numbers of the order of unity or less we generalize an extended Reynolds analogy. The generalized Reynolds analogy depends mainly only on dimensionless time for all considered Eckert numbers of the order of unity or less. PMID:27575220

  19. Non-analog Monte Carlo estimators for radiation momentum deposition

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, Jeffery D [Los Alamos National Laboratory; Hykes, Joshua M [Los Alamos National Laboratory

    2008-01-01

    The standard method for calculating radiation momentum deposition in Monte Carlo simulations is the analog estimator, which tallies the change in a particle's momentum at each interaction with the matter. Unfortunately, the analog estimator can suffer from large amounts of statistical error. In this paper, we present three new non-analog techniques for estimating momentum deposition. Specifically, we use absorption, collision, and track-length estimators to evaluate a simple integral expression for momentum deposition that does not contain terms that can cause large amounts of statistical error in the analog scheme. We compare our new non-analog estimators to the analog estimator with a set of test problems that encompass a wide range of material properties and both isotropic and anisotropic scattering. In nearly all cases, the new non-analog estimators outperform the analog estimator. The track-length estimator consistently yields the highest performance gains, improving upon the analog-estimator figure of merit by factors of up to two orders of magnitude.

  20. OpenModelica for Analog IC Design

    OpenAIRE

    Malo Cid, David

    2011-01-01

    Modelica is a language supported by Modelica Association. It is a non-proprietary, object-oriented, equation based language to conveniently model complex physical. OpenModelica is an open source environment for the Modelica language supported by Open Source Modelica Consortium (OSMC). The aim of this thesis is the development of a library of models and components for design and simulation of analog integrated circuits and an OMNotebook-based tutorial for an academic purpose as a design tool f...

  1. Vorticity in analog gravity

    Science.gov (United States)

    Cropp, Bethan; Liberati, Stefano; Turcati, Rodrigo

    2016-06-01

    In the analog gravity framework, the acoustic disturbances in a moving fluid can be described by an equation of motion identical to a relativistic scalar massless field propagating in curved space-time. This description is possible only when the fluid under consideration is barotropic, inviscid, and irrotational. In this case, the propagation of the perturbations is governed by an acoustic metric that depends algebrically on the local speed of sound, density, and the background flow velocity, the latter assumed to be vorticity-free. In this work we provide a straightforward extension in order to go beyond the irrotational constraint. Using a charged—relativistic and nonrelativistic—Bose–Einstein condensate as a physical system, we show that in the low-momentum limit and performing the eikonal approximation we can derive a d’Alembertian equation of motion for the charged phonons where the emergent acoustic metric depends on flow velocity in the presence of vorticity.

  2. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  3. Analogy-Based Expectation Equilibrium

    OpenAIRE

    Jehiel, P

    2001-01-01

    It is assumed that players bundle nodes in which other players must move into analogy classes, and players only have expectations about the average behavior in every class. A solution concept is proposed for multi-stage games with perfect information: at every node players choose best-responses to their analogy-based expectations, and expectations are correct on average over those various nodes pooled together into the same analogy classes. The approach is applied to a variety of games. It is...

  4. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  5. Analog and digital signal processing

    Science.gov (United States)

    Baher, H.

    The techniques of signal processing in both the analog and digital domains are addressed in a fashion suitable for undergraduate courses in modern electrical engineering. The topics considered include: spectral analysis of continuous and discrete signals, analysis of continuous and discrete systems and networks using transform methods, design of analog and digital filters, digitization of analog signals, power spectrum estimation of stochastic signals, FFT algorithms, finite word-length effects in digital signal processes, linear estimation, and adaptive filtering.

  6. Analog circuit design optimization based on evolutionary algorithms

    OpenAIRE

    Barari, Mansour; Karimi, Hamid Reza; Razaghian, Farhad

    2014-01-01

    This paper investigates an evolutionary-based designing system for automated sizing of analog integrated circuits (ICs). Two evolutionary algorithms, genetic algorithm and PSO (Parswal particle swarm optimization) algorithm, are proposed to design analog ICs with practical user-defined specifications. On the basis of the combination of HSPICE and MATLAB, the system links circuit performances, evaluated through specific electrical simulation, to the optimization system in the MATLAB environmen...

  7. Analog Circuit Design Optimization Based on Evolutionary Algorithms

    OpenAIRE

    Mansour Barari; Hamid Reza Karimi; Farhad Razaghian

    2014-01-01

    This paper investigates an evolutionary-based designing system for automated sizing of analog integrated circuits (ICs). Two evolutionary algorithms, genetic algorithm and PSO (Parswal particle swarm optimization) algorithm, are proposed to design analog ICs with practical user-defined specifications. On the basis of the combination of HSPICE and MATLAB, the system links circuit performances, evaluated through specific electrical simulation, to the optimization system in the MATLAB environmen...

  8. Isolated transfer of analog signals

    Science.gov (United States)

    Bezdek, T.

    1974-01-01

    Technique transfers analog signal levels across high isolation boundary without circuit performance being affected by magnetizing reactance or leakage inductance. Transfers of analog information across isolated boundary are made by interrupting signal flow, with switch, in such a manner as to produce alternating signal which is applied to transformer.

  9. Drawing Analogies in Environmental Education

    Science.gov (United States)

    Affifi, Ramsey

    2014-01-01

    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  10. Analog elements for transuranic chemistries

    International Nuclear Information System (INIS)

    A chemical extraction technique for estimating the biologically available fraction of nonessential trace elements in soils has been developed. This procedure has been used in evaluating the uptake of naturally occurring transuranic analog elements from soils into several foodstuffs. The availability of the natural elements has been compared with the availability of their analog transuranics which have been derived from global fallout

  11. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  12. Analog Computation by DNA Strand Displacement Circuits.

    Science.gov (United States)

    Song, Tianqi; Garg, Sudhanshu; Mokhtar, Reem; Bui, Hieu; Reif, John

    2016-08-19

    DNA circuits have been widely used to develop biological computing devices because of their high programmability and versatility. Here, we propose an architecture for the systematic construction of DNA circuits for analog computation based on DNA strand displacement. The elementary gates in our architecture include addition, subtraction, and multiplication gates. The input and output of these gates are analog, which means that they are directly represented by the concentrations of the input and output DNA strands, respectively, without requiring a threshold for converting to Boolean signals. We provide detailed domain designs and kinetic simulations of the gates to demonstrate their expected performance. On the basis of these gates, we describe how DNA circuits to compute polynomial functions of inputs can be built. Using Taylor Series and Newton Iteration methods, functions beyond the scope of polynomials can also be computed by DNA circuits built upon our architecture. PMID:27363950

  13. Analog IC reliability in nanometer CMOS

    CERN Document Server

    Maricau, Elie

    2013-01-01

    This book focuses on modeling, simulation and analysis of analog circuit aging. First, all important nanometer CMOS physical effects resulting in circuit unreliability are reviewed. Then, transistor aging compact models for circuit simulation are discussed and several methods for efficient circuit reliability simulation are explained and compared. Ultimately, the impact of transistor aging on analog circuits is studied. Aging-resilient and aging-immune circuits are identified and the impact of technology scaling is discussed.   The models and simulation techniques described in the book are intended as an aid for device engineers, circuit designers and the EDA community to understand and to mitigate the impact of aging effects on nanometer CMOS ICs.   ·         Enables readers to understand long-term reliability of an integrated circuit; ·         Reviews CMOS unreliability effects, with focus on those that will emerge in future CMOS nodes; ·         Provides overview of models for...

  14. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  15. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  16. Analog Systems for Gravity Duals

    OpenAIRE

    Hossenfelder, S.

    2014-01-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore ...

  17. A Survey of Fast Analog Circuit Analysis Algorithm using SPICE

    Directory of Open Access Journals (Sweden)

    T.Murugajothi

    2014-01-01

    Full Text Available is paper presents a fast analog circuit analysis algorithm, fundamental circuit-based circuit analysis, for circuits being repeatedly modified and verified in product development. The algorithm reuses previous circuit simulation result on successive changed circuit analysis to achieve simulation operation reduction. The algorithm is implemented with SPICE simulator on linear and nonlinear circuit applications with the proposed device delta models. The experiments show that the algorithm increases the speed of the circuit simulation five to ten times over directly simulations under the same simulation accuracy

  18. A Survey of Fast Analog Circuit Analysis Algorithm using SPICE

    OpenAIRE

    T.Murugajothi

    2014-01-01

    is paper presents a fast analog circuit analysis algorithm, fundamental circuit-based circuit analysis, for circuits being repeatedly modified and verified in product development. The algorithm reuses previous circuit simulation result on successive changed circuit analysis to achieve simulation operation reduction. The algorithm is implemented with SPICE simulator on linear and nonlinear circuit applications with the proposed device delta models. The experiments show that t...

  19. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  20. Design of analog circuits through symbolic analysis

    CERN Document Server

    Fakhfakh, Mourad; V Fernández, Francisco

    2012-01-01

    Symbolic analyzers have the potential to offer knowledge to sophomores as well as practitioners of analog circuit design. Actually, they are an essential complement to numerical simulators, since they provide insight into circuit behavior which numerical analyzers do not provide. Symbolic analysis of electronic circuits addresses the generation of symbolic expressions for the parameters that describe the performance of linear and nonlinear circuits in three domains: DC, AC and time; some or all the circuit parameters can be kept as symbols. Due to the fact that these expressions remain va

  1. Performance of the Analog Moving Window Detector

    DEFF Research Database (Denmark)

    Hansen, V. Gregers

    1970-01-01

    A type of analog integrating moving window detector for use with a scanning pulse radar is examined. A performance analysis is carried out, which takes into account both the radiation pattern of the antenna and the dynamic character of the detection process due to the angular scanning of the...... antenna. An expression for the false alarm rate of the detector is first derived and evaluated numerically. The detection performance and angular accuracy are next determined in a direct Monte Carlo simulation of the detector on a digital computer for both no fading and pulse-to-pulse Rayleigh fading...

  2. A heat exchanger analogy of automotive paint ovens

    International Nuclear Information System (INIS)

    Computational prediction of vehicle temperatures in an automotive paint oven is essential to predict paint quality and manufacturability. The complex geometry of vehicles, varying scales in the flow, transient nature of the process, and the tightly coupled conjugate heat transfer render the numerical models computationally very expensive. Here, a novel, simplified model of the oven is developed using an analogy to a three-stream cross flow heat exchanger that transfers heat from air to a series of moving bodies and supporting carriers. The analogous heat exchanger equations are developed and solved numerically. Steady state Computational Fluid Dynamics (CFD) simulations are carried out to model the flow field and to extract the heat transfer coefficients around the body and carriers. The air temperature distribution from the CFD models is used as a boundary condition in the analogous model. Correction coefficients are used in the analogy to take care of various assumptions. These are determined from existing test data. The same corrections are used to predict air temperatures for a modified configuration of the oven and a different vehicle. The method can be used to conduct control volume analysis of ovens to determine energy efficiency, and to study new vehicle or oven designs. -- Highlights: • Analogy of an automotive paint oven as a three stream cross flow heat exchanger. • The three streams are vehicle bodies, carriers and hot air. • Convection coefficients and inlet air stream temperatures from steady CFD simulations. • Analogy useful for overall energy efficiency analysis of conveyor ovens in general

  3. Towards power centric analog design

    OpenAIRE

    Svensson, Christer

    2015-01-01

    Power consumption of analog systems is poorly understoodtoday, in contrast to the very well developed analysis of digitalpower consumption. We show that there is good opportunity todevelop also the analog power understanding to a similar levelas the digital. Such an understanding will have a large impact inthe design of future electronic systems, where low power consumptionwill be crucial. Eventually we may reach a power centricanalog design methodology.

  4. Efficient Analog Circuits for Boolean Satisfiability

    CERN Document Server

    Yin, Xunzhao; Varga, Melinda; Ercsey-Ravasz, Maria; Toroczkai, Zoltan; Hu, Xiaobo Sharon

    2016-01-01

    Efficient solutions to NP-complete problems would significantly benefit both science and industry. However, such problems are intractable on digital computers based on the von Neumann architecture, thus creating the need for alternative solutions to tackle such problems. Recently, a deterministic, continuous-time dynamical system (CTDS) was proposed (Nature Physics, 7(12), 966 (2011)) to solve a representative NP-complete problem, Boolean Satisfiability (SAT). This solver shows polynomial analog time-complexity on even the hardest benchmark $k$-SAT ($k \\geq 3$) formulas, but at an energy cost through exponentially driven auxiliary variables. With some modifications to the CTDS equations, here we present a novel analog hardware SAT solver, AC-SAT, implementing the CTDS. AC-SAT is intended to be used as a co-processor, and with its modular design can be readily extended to different problem sizes. The circuit is designed and simulated based on a 32nm CMOS technology. SPICE simulation results show speedup factor...

  5. Analog to digital control system replacement projects

    International Nuclear Information System (INIS)

    Problem Statement: Numerous Control Systems within Operating Nuclear Units are nearing or at the end of their useful life. These systems are typically Analog in design, installed and commissioned during original construction dates. Problems associated with these aging system which are plaging Nuclear Operators are Obsolescence, Inadequate Spares, Complexity in Troubleshooting large hardwired systems, Eroding Experience and Device Failures leading to safety and economic impacts. There are a number of factors to consider when attempting to justify a complete system replacement versus a component by component replacement. This presentation will look at some of these systems which have been chosen for replacement and discuss the rationale used to drive this digital upgrade decision. Specific project related concerns due to the digital technology such as Software Qualification shall be addressed. Also specific to hybrid main control rooms is the Human Factors requirements when replacing analog controllers and meters with Touch Screen based HMI. One aspect of the Nuclear Power Plants which traditionally differs from other industry is the requirement for Full Scope Simulator for training purposes. This presention will identify the importance of the full scope simulator and the role it plays in digital system replacements. Other topics to be discussed in proposed presentation include: - Probablistic Risk Assessment; - Stakeholder Involvement; - New Technology Benefits; - New Technology 'Traps'; - Security; - Phased Acceptance Testing. The proposed presentation shall be in a PowerPoint format

  6. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  7. Further on integrator circuit analogy for natural convection

    Energy Technology Data Exchange (ETDEWEB)

    Khane, Vaibhav [Nuclear Engineering, Missouri University of Science and Technology, 225 Fulton Hall, 300W. 13th St., Rolla, MO-65409 (United States); Usman, Shoaib, E-mail: usmans@mst.ed [Nuclear Engineering, Missouri University of Science and Technology, 225 Fulton Hall, 300W. 13th St., Rolla, MO-65409 (United States)

    2010-03-15

    This research is an extension of the previous work on the development of an integrator (RC) circuit analogy for natural convection. This analogy has been proven experimentally as well as by numerical simulations. Additional Rayleigh-Benard convection numerical simulations were performed to investigate DELTAT (temperature difference between source and sink) dependence of the thermal resistance of a natural convection system. Our results suggest that analogous to voltage dependent resistor (VDR) in electrical engineering, DELTAT dependent thermal resistance is observed in natural convection system. This DELTAT dependent thermal resistance leads to a variable time constant. Moreover, this research also suggests that for a natural convection system, in addition to the thermal capacitance a kinetic energy capacitance also exists. The relative contribution of kinetic energy capacitance depends on Rayleigh number. These results provide significant step forward towards development of a new inexpensive modeling and transient analysis tool for a natural convection system.

  8. Further on integrator circuit analogy for natural convection

    International Nuclear Information System (INIS)

    This research is an extension of the previous work on the development of an integrator (RC) circuit analogy for natural convection. This analogy has been proven experimentally as well as by numerical simulations. Additional Rayleigh-Benard convection numerical simulations were performed to investigate ΔT (temperature difference between source and sink) dependence of the thermal resistance of a natural convection system. Our results suggest that analogous to voltage dependent resistor (VDR) in electrical engineering, ΔT dependent thermal resistance is observed in natural convection system. This ΔT dependent thermal resistance leads to a variable time constant. Moreover, this research also suggests that for a natural convection system, in addition to the thermal capacitance a kinetic energy capacitance also exists. The relative contribution of kinetic energy capacitance depends on Rayleigh number. These results provide significant step forward towards development of a new inexpensive modeling and transient analysis tool for a natural convection system.

  9. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  10. Application handbook for analog IC

    International Nuclear Information System (INIS)

    This book consists of ten chapters, which are prolog on analog IC and digital, basic function of OP amp for operation, characteristic on direct current and interchange, Op amp and linear circuit, nonlinear arithmetic circuit, filter circuit, oscillation circuit and V-F converter, D-A converter, A-D converter on introduction eight bit and 12 bit, I C for power supply and switching regulator. Each chapter has the explanations of specific function of the programs, filter circuit, converters. So, this book is a application handbook for analog IC.

  11. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J;

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  12. Long-duration bed rest as an analog to microgravity.

    Science.gov (United States)

    Hargens, Alan R; Vico, Laurence

    2016-04-15

    Long-duration bed rest is widely employed to simulate the effects of microgravity on various physiological systems, especially for studies of bone, muscle, and the cardiovascular system. This microgravity analog is also extensively used to develop and test countermeasures to microgravity-altered adaptations to Earth gravity. Initial investigations of bone loss used horizontal bed rest with the view that this model represented the closest approximation to inactivity and minimization of hydrostatic effects, but all Earth-based analogs must contend with the constant force of gravity by adjustment of the G vector. Later concerns about the lack of similarity between headward fluid shifts in space and those with horizontal bed rest encouraged the use of 6 degree head-down tilt (HDT) bed rest as pioneered by Russian investigators. Headward fluid shifts in space may redistribute bone from the legs to the head. At present, HDT bed rest with normal volunteers is the most common analog for microgravity simulation and to test countermeasures for bone loss, muscle and cardiac atrophy, orthostatic intolerance, and reduced muscle strength/exercise capacity. Also, current physiologic countermeasures are focused on long-duration missions such as Mars, so in this review we emphasize HDT bed rest studies with durations of 30 days and longer. However, recent results suggest that the HDT bed rest analog is less representative as an analog for other important physiological problems of long-duration space flight such as fluid shifts, spinal dysfunction and radiation hazards. PMID:26893033

  13. Fuzzy classifier for fault diagnosis in analog electronic circuits.

    Science.gov (United States)

    Kumar, Ashwani; Singh, A P

    2013-11-01

    Many studies have presented different approaches for the fault diagnosis with fault models having ± 50% variation in the component values in analog electronic circuits. There is still a need of the approaches which provide the fault diagnosis with the variation in the component value below ± 50%. A new single and multiple fault diagnosis technique for soft faults in analog electronic circuit using fuzzy classifier has been proposed in this paper. This technique uses the simulation before test (SBT) approach by analyzing the frequency response of the analog circuit under faulty and fault free conditions. Three signature parameters peak gain, frequency and phase associated with peak gain, of the frequency response of the analog circuit are observed and extracted such that they give unique values for faulty and fault free configuration of the circuit. The single and double fault models with the component variations from ± 10% to ± 50% are considered. The fuzzy classifier along the classification of faults gives the estimated component value under faulty and faultfree conditions. The proposed method is validated using simulated data and the real time data for a benchmark analog circuit. The comparative analysis is also presented for both the validations. PMID:23849881

  14. Analog modelling of obduction processes

    Science.gov (United States)

    Agard, P.; Zuo, X.; Funiciello, F.; Bellahsen, N.; Faccenna, C.; Savva, D.

    2012-04-01

    Obduction corresponds to one of plate tectonics oddities, whereby dense, oceanic rocks (ophiolites) are presumably 'thrust' on top of light, continental ones, as for the short-lived, almost synchronous Peri-Arabic obduction (which took place along thousands of km from Turkey to Oman in c. 5-10 Ma). Analog modelling experiments were performed to study the mechanisms of obduction initiation and test various triggering hypotheses (i.e., plate acceleration, slab hitting the 660 km discontinuity, ridge subduction; Agard et al., 2007). The experimental setup comprises (1) an upper mantle, modelled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and (2) high-viscosity silicone plates (Rhodrosil Gomme with PDMS iron fillers to reproduce densities of continental or oceanic plates), located at the centre of the tank above the syrup to simulate the subducting and the overriding plates - and avoid friction on the sides of the tank. Convergence is simulated by pushing on a piston at one end of the model with velocities comparable to those of plate tectonics (i.e., in the range 1-10 cm/yr). The reference set-up includes, from one end to the other (~60 cm): (i) the piston, (ii) a continental margin containing a transition zone to the adjacent oceanic plate, (iii) a weakness zone with variable resistance and dip (W), (iv) an oceanic plate - with or without a spreading ridge, (v) a subduction zone (S) dipping away from the piston and (vi) an upper, active continental margin, below which the oceanic plate is being subducted at the start of the experiment (as is known to have been the case in Oman). Several configurations were tested and over thirty different parametric tests were performed. Special emphasis was placed on comparing different types of weakness zone (W) and the extent of mechanical coupling across them, particularly when plates were accelerated. Displacements, together with along-strike and across-strike internal deformation in all

  15. Classical wave-optics analogy of quantum information processing

    OpenAIRE

    Spreeuw, R. J. C.

    2001-01-01

    An analogous model system for quantum information processing is discussed, based on classical wave optics. The model system is applied to three examples that involve three qubits: ({\\em i}) three-particle Greenberger-Horne-Zeilinger entanglement, ({\\em ii}) quantum teleportation, and ({\\em iii}) a simple quantum error correction network. It is found that the model system can successfully simulate most features of entanglement, but fails to simulate quantum nonlocality. Investigations of how f...

  16. International Alligator Rivers Analog Project

    International Nuclear Information System (INIS)

    The Australian Nuclear Science and Technology Organization (ANSTO), the Japan Atomic Energy Research Institute, the Swedish Nuclear Power Inspectorate, the U.K. Department of the Environment, the US Nuclear Regulatory Commission (NRC), and the Power Reactor and Nuclear Fuel Development Corporation of Japan are participating under the aegis of the Nuclear Energy Agency in the International Alligator Rivers Analog Project. The project has a duration of 3 yr, starting in 1988. The project has grown out of a research program on uranium ore bodies as analogs of high-level waste (HLW) repositories undertaken by ANSTO supported by the NRC. A primary objective of the project is to develop an approach to radionuclide transport model validation that may be used by the participants to support assessments of the safety of radioactive waste repositories. The approach involves integrating mathematical and physical modeling with hydrological and geochemical field and laboratory investigations of the analog site. The Koongarra uranium ore body has been chosen as the analog site because it has a secondary ore body that has formed over the past million years as a result of leaching by groundwater flowing through fractures in the primary ore body

  17. Multichannel analog temperature sensing system

    International Nuclear Information System (INIS)

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

  18. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  19. Multichannel analog temperature sensing system

    Science.gov (United States)

    Gribble, R.

    1985-08-01

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer.

  20. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  1. A Computational Account of Children's Analogical Reasoning: Balancing Inhibitory Control in Working Memory and Relational Representation

    Science.gov (United States)

    Morrison, Robert G.; Doumas, Leonidas A. A.; Richland, Lindsey E.

    2011-01-01

    Theories accounting for the development of analogical reasoning tend to emphasize either the centrality of relational knowledge accretion or changes in information processing capability. Simulations in LISA (Hummel & Holyoak, 1997, 2003), a neurally inspired computer model of analogical reasoning, allow us to explore how these factors may…

  2. Low-power Analog VLSI Implementation of Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jiang-hong

    2009-01-01

    For applications requiring low-power, low-voltage and real-time, a novel analog VLSI implementation of continuous Marr wavelet transform based on CMOS log-domain integrator is proposed.Mart wavelet is approximated by a parameterized class of function and with Levenbery-Marquardt nonlinear least square method,the optimum parameters of this function are obtained.The circuits of implementating Mart wavelet transform are composed of analog filter whose impulse response is the required wavelet.The filter design is based on IFLF structure with CMOS log-domain integrators as the main building blocks.SPICE simulations indicate an excellent approximations of ideal wavelet.

  3. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  4. Hydraulic Analogy for Isentropic Flow Through a Nozzle

    Directory of Open Access Journals (Sweden)

    J. S. Rao

    1983-04-01

    Full Text Available Modelling aspects of isentropic compressible gas flow using hydraulic analogy are discussed. Subsonic and supersonic flows through a typical nozzle are simulated as free surface incompressible water flow in an equivalent 2-D model on a water table. The results are first compared for the well known classical analogy in order to estimate experimental errors. Correction factors for pressure and temperature, to account for non-ideal compressible gas flow are presented and the results obtained on the water table are modified and compared with gas dynamic solution. Within the experimental errors, it is shown that the hydraulic analogy can be used as an effective tool for the study of two dimensional isentropic flows of gases.

  5. Practice Utilization of Algorithms for Analog Filter Group Delay Optimization

    Directory of Open Access Journals (Sweden)

    K. Hajek

    2007-04-01

    Full Text Available This contribution deals with an application of three different algorithms which optimize a group delay of analog filters. One of them is a part of the professional circuit simulator Micro Cap 7 and the others two original algorithms are developed in the MATLAB environment. An all-pass network is used to optimize the group delay of an arbitrary analog filter. Introduced algorithms look for an optimal order and optimal coefficients of an all-pass network transfer function. Theoretical foundations are introduced and all algorithms are tested using the optimization of testing analog filter. The optimization is always run three times because the second, third and fourth-order all-pass network is used. An equalization of the original group delay is a main objective of these optimizations. All outputs of all algorithms are critically evaluated and also described.

  6. Analog Circuit Design Optimization Based on Evolutionary Algorithms

    Directory of Open Access Journals (Sweden)

    Mansour Barari

    2014-01-01

    Full Text Available This paper investigates an evolutionary-based designing system for automated sizing of analog integrated circuits (ICs. Two evolutionary algorithms, genetic algorithm and PSO (Parswal particle swarm optimization algorithm, are proposed to design analog ICs with practical user-defined specifications. On the basis of the combination of HSPICE and MATLAB, the system links circuit performances, evaluated through specific electrical simulation, to the optimization system in the MATLAB environment, for the selected topology. The system has been tested by typical and hard-to-design cases, such as complex analog blocks with stringent design requirements. The results show that the design specifications are closely met. Comparisons with available methods like genetic algorithms show that the proposed algorithm offers important advantages in terms of optimization quality and robustness. Moreover, the algorithm is shown to be efficient.

  7. Analog computing using graphene-based metalines.

    Science.gov (United States)

    AbdollahRamezani, Sajjad; Arik, Kamalodin; Khavasi, Amin; Kavehvash, Zahra

    2015-11-15

    We introduce the new concept of "metalines" for manipulating the amplitude and phase profile of an incident wave locally and independently. Thanks to the highly confined graphene plasmons, a transmit-array of graphene-based metalines is used to realize analog computing on an ultra-compact, integrable, and planar platform. By employing the general concepts of spatial Fourier transformation, a well-designed structure of such meta-transmit-array, combined with graded index (GRIN) lenses, can perform two mathematical operations, i.e., differentiation and integration, with high efficiency. The presented configuration is about 60 times shorter than the recent structure proposed by Silva et al. [Science343, 160 (2014)SCIEAS0036-807510.1126/science.1242818]; moreover, our simulated output responses are in better agreement with the desired analytical results. These findings may lead to remarkable achievements in light-based plasmonic signal processors at nanoscale, instead of their bulky conventional dielectric lens-based counterparts. PMID:26565844

  8. Analog gravity from field theory normal modes?

    CERN Document Server

    Barcelo, C; Visser, M; Barcelo, Carlos; Liberati, Stefano; Visser, Matt

    2001-01-01

    We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the large number of ``analog models'' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is something more fundamental going on. Indeed, linearization of a classical field theory (a field theoretic ``normal mode analysis'') results in fluctuations whose propagation is governed by a Lorentzian-signature curved spacetime ``effective metric''. For a single scalar field, this procedure results in a unique effective metric, which is quite sufficient for simulating kinematic aspects of general relativity (up to and including Hawking radiation). Quantizing the linearized fluctuations, the one-loop effective action contains a term proportional to the Einstein--Hilbert action, suggesting that while classical physics is respo...

  9. Synaptic dynamics in analog VLSI.

    Science.gov (United States)

    Bartolozzi, Chiara; Indiveri, Giacomo

    2007-10-01

    Synapses are crucial elements for computation and information transfer in both real and artificial neural systems. Recent experimental findings and theoretical models of pulse-based neural networks suggest that synaptic dynamics can play a crucial role for learning neural codes and encoding spatiotemporal spike patterns. Within the context of hardware implementations of pulse-based neural networks, several analog VLSI circuits modeling synaptic functionality have been proposed. We present an overview of previously proposed circuits and describe a novel analog VLSI synaptic circuit suitable for integration in large VLSI spike-based neural systems. The circuit proposed is based on a computational model that fits the real postsynaptic currents with exponentials. We present experimental data showing how the circuit exhibits realistic dynamics and show how it can be connected to additional modules for implementing a wide range of synaptic properties. PMID:17716003

  10. Mechanical Analogies of Fractional Elements

    Institute of Scientific and Technical Information of China (English)

    HU Kai-Xin; ZHU Ke-Qin

    2009-01-01

    A Fractional element model describes a special kind of viscoelastic material.Its stress is proportional to the fractional-order derivative of strain. Physically the mechanical analogies of fractional elements can be represented by spring-dashpot fractal networks. We introduce a constitutive operator in the constitutive equations of viscoelastic materials.To derive constitutive operators for spring-dashpot fractal networks, we use Heaviside operational calculus, which provides explicit answers not otherwise obtainable simply.Then the series-parallel formulas for the constitutive operator are derived. Using these formulas, a constitutive equation of fractional element with 1/2-order derivative is obtained.Finally we find the way to derive the constitutive equations with other fractional-order derivatives and their mechanical analogies.

  11. Bottomed analog of Z+(4433)

    International Nuclear Information System (INIS)

    The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV

  12. Analog Nonvolatile Computer Memory Circuits

    Science.gov (United States)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  13. A Global Analog of Cheshire Charge

    OpenAIRE

    McGraw, Patrick

    1994-01-01

    It is shown that a model with a spontaneously broken global symmetry can support defects analogous to Alice strings, and a process analogous to Cheshire charge exchange can take place. A possible realization in superfluid He-3 is pointed out.

  14. Overview of the Human Exploration Research Analog (HERA)

    Science.gov (United States)

    Neigut, J.

    2015-01-01

    In 2013, the Human Research Program at NASA began developing a new confinement analog specifically for conducting research to investigate the effects of confinement on the human system. The HERA (Human Exploration Research Analog) habitat has been used for both 7 and 14 day missions to date to examine and mitigate exploration risks to enable safe, reliable and productive human space exploration. This presentation will describe how the Flight Analogs Project developed the HERA facility and the infrastructure to suit investigator requirements for confinement research and in the process developed a new approach to analog utilization and a new state of the art analog facility. Details regarding HERA operations will be discussed including specifics on the mission simulation utilized for the current 14-day campaign, the specifics of the facility (total volume, overall size, hardware), and the capabilities available to researchers. The overall operational philosophy, mission fidelity including timeline, schedule pressures and cadence, and development and implementation of mission stressors will be presented. Research conducted to date in the HERA has addressed risks associated with behavioral health and performance, human physiology, as well as human factors. This presentation will conclude with a discussion of future research plans for the HERA, including infrastructure improvements and additional research capabilities planned for the upcoming 30-day missions in 2016.

  15. Atheism and Analogy: Aquinas Against the Atheists

    OpenAIRE

    Linford, Daniel J.

    2014-01-01

    In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

  16. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  17. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  18. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  19. Classical analogy of Fano resonances

    International Nuclear Information System (INIS)

    We present an analogy of Fano resonances in quantum interference to classical resonances in the harmonic oscillator system. It has a manifestation as a coupled behaviour of two effective oscillators associated with propagating and evanescent waves. We illustrate this point by considering a classical system of two coupled oscillators and interfering electron waves in a quasi-one-dimensional narrow constriction with a quantum dot. Our approach provides a novel insight into Fano resonance physics and provides a helpful view in teaching Fano resonances

  20. Macroscopic acousto-mechanical analogy of a microbubble

    CERN Document Server

    Chaline, Jennifer; Mehrem, Ahmed; Bouakaz, Ayache; Santos, Serge Dos; Sánchez-Morcillo, Víctor J

    2015-01-01

    Microbubbles, either in the form of free gas bubbles surrounded by a fluid or encapsulated bubbles used currently as contrast agents for medical echography, exhibit complex dynamics under specific acoustic excitations. Nonetheless, considering their micron size and the complexity of their interaction phenomenon with ultrasound waves, expensive and complex experiments and/or simulations are required for their analysis. The behavior of a microbubble along its equator can be linked to a system of coupled oscillators. In this study, the oscillatory behavior of a microbubble has been investigated through an acousto-mechanical analogy based on a ring-shaped chain of coupled pendula. Observation of parametric vibration modes of the pendula ring excited at frequencies between $1$ and $5$ Hz is presented. Simulations have been carried out and show mode mixing phenomena. The relevance of the analogy between a microbubble and the macroscopic acousto-mechanical setup is discussed and suggested as an alternative way to in...

  1. Interstellar and Planetary Analogs in the Laboratory

    Science.gov (United States)

    Salama, Farid

    2013-01-01

    We present and discuss the unique capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to investigate the interaction of ionizing radiation (UV, charged particles) with molecular species (neutral molecules, radicals and ions) and carbonaceous grains in the Solar System and in the Interstellar Medium (ISM). COSmIC stands for Cosmic Simulation Chamber, a laboratory chamber where interstellar and planetary analogs are generated, processed and analyzed. It is composed of a pulsed discharge nozzle (PDN) expansion that generates a free jet supersonic expansion in a plasma cavity coupled to two ultrahigh-sensitivity, complementary in situ diagnostics: a cavity ring down spectroscopy (CRDS) system for photonic detection and a Reflectron time-of-flight mass spectrometer (ReTOF-MS) for mass detection. This setup allows the study of molecules, ions and solids under the low temperature and high vacuum conditions that are required to simulate some interstellar, circumstellar and planetary physical environments providing new fundamental insights on the molecular level into the processes that are critical to the chemistry in the ISM, circumstellar and planet forming regions, and on icy objects in the Solar System. Recent laboratory results that were obtained using COSmIC will be discussed, in particular the progress that have been achieved in monitoring in the laboratory the formation of solid particles from their gas-phase molecular precursors in environments as varied as circumstellar outflow and planetary atmospheres.

  2. The MARS2013 Mars analog mission.

    Science.gov (United States)

    Groemer, Gernot; Soucek, Alexander; Frischauf, Norbert; Stumptner, Willibald; Ragonig, Christoph; Sams, Sebastian; Bartenstein, Thomas; Häuplik-Meusburger, Sandra; Petrova, Polina; Evetts, Simon; Sivenesan, Chan; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Foresta, Luca; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Stadler, Andrea; Stummer, Florian; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Turetschek, Thomas; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    We report on the MARS2013 mission, a 4-week Mars analog field test in the northern Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated martian surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near real time, providing planning input for the management of a complex system of field assets; two advanced space suit simulators, four robotic vehicles, an emergency shelter, and a stationary sensor platform in a realistic work flow were coordinated by a Flight Control Team. A dedicated flight planning group, external control centers for rover tele-operations, and a biomedical monitoring team supported the field operations. A 10 min satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, tele-science, exploration, and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission architecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational work flows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations. PMID:24823799

  3. Approaches to synthetic platelet analogs.

    Science.gov (United States)

    Modery-Pawlowski, Christa L; Tian, Lewis L; Pan, Victor; McCrae, Keith R; Mitragotri, Samir; Sen Gupta, Anirban

    2013-01-01

    Platelet transfusion is routinely used for treating bleeding complications in patients with hematologic or oncologic clotting disorders, chemo/radiotherapy-induced myelosuppression, trauma and surgery. Currently, these transfusions mostly use allogeneic platelet concentrates, while products like lyophilized platelets, cold-stored platelets and infusible platelet membranes are under investigation. These natural platelet-based products pose considerable risks of contamination, resulting in short shelf-life (3-5 days). Recent advances in pathogen reduction technologies have increased shelf-life to ~7 days. Furthermore, natural platelets are short in supply and also cause several biological side effects. Hence, there is significant clinical interest in platelet-mimetic synthetic analogs that can allow long storage-life and minimum side effects. Accordingly, several designs have been studied which decorate synthetic particles with motifs that promote platelet-mimetic adhesion or aggregation. Recent refinement in this design involves combining the adhesion and aggregation functionalities on a single particle platform. Further refinement is being focused on constructing particles that also mimic natural platelet's shape, size and elasticity, to influence margination and wall-interaction. The optimum design of a synthetic platelet analog would require efficient integration of platelet's physico-mechanical properties and biological functionalities. We present a comprehensive review of these approaches and provide our opinion regarding the future directions of this research. PMID:23092864

  4. Analog computation with dynamical systems

    Science.gov (United States)

    Siegelmann, Hava T.; Fishman, Shmuel

    1998-09-01

    Physical systems exhibit various levels of complexity: their long term dynamics may converge to fixed points or exhibit complex chaotic behavior. This paper presents a theory that enables to interpret natural processes as special purpose analog computers. Since physical systems are naturally described in continuous time, a definition of computational complexity for continuous time systems is required. In analogy with the classical discrete theory we develop fundamentals of computational complexity for dynamical systems, discrete or continuous in time, on the basis of an intrinsic time scale of the system. Dissipative dynamical systems are classified into the computational complexity classes P d, Co-RP d, NP d and EXP d, corresponding to their standard counterparts, according to the complexity of their long term behavior. The complexity of chaotic attractors relative to regular ones leads to the conjecture P d ≠ NP d. Continuous time flows have been proven useful in solving various practical problems. Our theory provides the tools for an algorithmic analysis of such flows. As an example we analyze the continuous Hopfield network.

  5. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  6. An Optimized Device Sizing of Analog Circuits using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    K. Duraiswamy

    2012-01-01

    Full Text Available Problem statement: Day by day more and more products rely on analog circuits to improve the speed and reduce the power consumption(Products rely on analog circuits to improve the speed and reduce the power consumption day by day more and more.. For the VLSI implementation analog circuit design plays an important role. This analog circuit synthesis might be the most challenging and time-consumed task, because it does not only consist of topology and layout synthesis but also of component sizing. Approach: A Particle Swarm Optimization (PSO technique for the optimal design of analog circuits. Analog signal processing finds many applications and widely uses OpAmp based amplifiers, mixers, comparators. and filters. Results: A two-stage opamp (Miller Operational Trans-conductance Amplifier (OTA is considered for the synthesis that satisfies certain design specifications. Performance has been evaluated with the Simulation Program with Integrated Circuit Emphasis (SPICE circuit simulator until optimal sizes of the transistors are found. Conclusion: The output of the simulation for the two-stage opamp shows that the PSO technique is an accurate and promising approach in determining the device sizes in an analog circuit.

  7. Analog Design for Digital Deployment of a Serious Leadership Game

    Science.gov (United States)

    Maxwell, Nicholas; Lang, Tristan; Herman, Jeffrey L.; Phares, Richard

    2012-01-01

    This paper presents the design, development, and user testing of a leadership development simulation. The authors share lessons learned from using a design process for a board game to allow for quick and inexpensive revision cycles during the development of a serious leadership development game. The goal of this leadership simulation is to accelerate the development of leadership capacity in high-potential mid-level managers (GS-15 level) in a federal government agency. Simulation design included a mixed-method needs analysis, using both quantitative and qualitative approaches to determine organizational leadership needs. Eight design iterations were conducted, including three user testing phases. Three re-design iterations followed initial development, enabling game testing as part of comprehensive instructional events. Subsequent design, development and testing processes targeted digital application to a computer- and tablet-based environment. Recommendations include pros and cons of development and learner testing of an initial analog simulation prior to full digital simulation development.

  8. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

    2006-10-01

    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy. PMID:17263066

  9. QCD analogy for quantum gravity

    Science.gov (United States)

    Holdom, Bob; Ren, Jing

    2016-06-01

    Quadratic gravity presents us with a renormalizable, asymptotically free theory of quantum gravity. When its couplings grow strong at some scale, as in QCD, then this strong scale sets the Planck mass. QCD has a gluon that does not appear in the physical spectrum. Quadratic gravity has a spin-2 ghost that we conjecture does not appear in the physical spectrum. We discuss how the QCD analogy leads to this conjecture and to the possible emergence of general relativity. Certain aspects of the QCD path integral and its measure are also similar for quadratic gravity. With the addition of the Einstein-Hilbert term, quadratic gravity has a dimensionful parameter that seems to control a quantum phase transition and the size of a mass gap in the strong phase.

  10. Analysis of analogies used by science teachers

    Science.gov (United States)

    Dagher, Zoubeida R.

    Science teachers use analogies that display a rich variety of form and content. An account of science teacher analogies that relies solely on systems of analysis imported from other fields of inquiry tends to obscure the unique features of these analogies as they operate within classroom discourse. This study examines teachers' analogies in context and highlights some of their special characteristics. The purpose of this analysis is to increase our understanding of how analogies operate in naturalistic instructional settings and to generate new research questions about science teaching and learning in view of the broader dimensions of the curriculum.Science isa very human activity. It involves human actors and judgements, rivalries and antagonisms, mysteries and surprises, the creative use of metaphor and analogy. It is fallible, often uncertain, and sometimes creatively ambiguous [Lemke, 1990, p. 134].Received: 1 June 1993; Revised: 29 November 1993;

  11. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems. PMID:25784574

  12. Analog circuit design scalable analog circuit design, high speed D/A converters, RF power amplifiers

    CERN Document Server

    Huijsing, Johan

    2007-01-01

    Preface. Part I: Scalable Analog Circuit Design. Introduction. Scalable High-Speed Analog Circuit Design; M. Vertregt, P. Scholtens. Scalable High Resolution Mixed Mode Circuit Design; R.J. Brewer. Scalable 'High Voltages' Integrated Circuit Design for XDSL Type of Applications; D. Rossi. Scalability of Wire-Line Analog Front-Ends; K. Bult. Reusable IP Analog Circuit Design; J. Hauptmann, A. Wiesbauer, H. Weinberger. Process Migration Tools for Analog and Digital Circuits; K. Francken, G. Gielen. Part II: High-Speed D/A Converters. Introduction. Introduction to High-Speed Digital-to-Analog Con

  13. Xampling: Compressed Sensing of Analog Signals

    OpenAIRE

    Mishali, Moshe; Eldar, Yonina C.

    2011-01-01

    Xampling generalizes compressed sensing (CS) to reduced-rate sampling of analog signals. A unified framework is introduced for low rate sampling and processing of signals lying in a union of subspaces. Xampling consists of two main blocks: Analog compression that narrows down the input bandwidth prior to sampling with commercial devices followed by a nonlinear algorithm that detects the input subspace prior to conventional signal processing. A variety of analog CS applications are reviewed wi...

  14. Analog to Digital Conversion in Physical Measurements

    OpenAIRE

    Kapitaniak, T.; Zyczkowski, K.; Feudel, U.; Grebogi, C.

    1999-01-01

    There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output of the device. We analyze the Bernoulli shift and the tent map which are realized in specific analog/digital converters. Furthermore, we d...

  15. Robust hyperchaotic synchronization via analog transmission line

    Science.gov (United States)

    Sadoudi, S.; Tanougast, C.

    2016-02-01

    In this paper, a novel experimental chaotic synchronization technique via analog transmission is discussed. We demonstrate through Field-Programmable Gate Array (FPGA) implementation design the robust synchronization of two embedded hyperchaotic Lorenz generators interconnected with an analog transmission line. The basic idea of this work consists in combining a numerical generation of chaos and transmitting it with an analog signal. The numerical chaos allows to overcome the callback parameter mismatch problem and the analog transmission offers robust data security. As application, this technique can be applied to all families of chaotic systems including time-delayed chaotic systems.

  16. Formation Law of Teaching and Researching through Competition of Enterprise Competition Simulation based on Analogy Education%相似教育的“企业竞争模拟”以赛事促教研的形成规律

    Institute of Scientific and Technical Information of China (English)

    文理; 李姚矿; 方晓; 朱云鹃; 尚广海; 单永强

    2013-01-01

    In view of the formation of Enterprise Competition Simulation Competition among the uni-versities in Anhui Province ,and based on the theory of analogy education and the teaching theory of constructivism ,the simulation teaching methods with the game thinking adopted by university teach-ers are discussed ,which generates an evolution law of “teaching through competing - researching through teaching -leaning through researching” .This law can improve the overall quality of teaching , make full use of the research capacities of the teachers ,and enhance the entrepreneurial abilities of the students .The study is valuable for the teachers of management class and business class who are en-gaged in simulation teaching .%文章以安徽地区高校企业竞争模拟大赛的形成为背景,基于相似教育理论和建构主义(Constructiv-ism)教学理论,探讨了高校教师应用具有博弈思维的模拟教学方法形成“以赛促教---以教促研---以研促学”演变规律,发现该规律可以提高整体的教学质量,即既可以发挥教师的研究能力,也可以提升学生的创业能力;并以此供从事模拟教学的管理类和商科类教师参考。

  17. Low-power design techniques and CAD tools for analog and RF integrated circuits

    CERN Document Server

    Wambacq, Piet

    2007-01-01

    List of Figures. List of Tables. Contributing Authors. Introduction. 1. Motivation, context and objectives; G. Gielen, et al. 2. Analysis and simulation of RF subsystems; J. Roychowdhury. 3. FAST: an efficient high-level dataflow simulator of mixed-signal front-ends of digital telecom transceivers; G. Vandersteen, et al. 4. Efficient high-level simulation of analog telecom frontends; P. Vanassche, et al. 5. High-level power estimation of analog front-end blocks; E. Lauwers, G. Gielen. 6. Models and Analysis Techniques for Systematic Design and Verification of Frequency Synthesizers; B

  18. A Novel Method of Solving Linear Programs with an Analog Circuit

    OpenAIRE

    Vichik, Sergey; Borrelli, Francesco

    2013-01-01

    We present the design of an analog circuit which solves linear programming (LP) problems. In particular, the steady-state circuit voltages are the components of the LP optimal solution. The paper shows how to construct the circuit and provides a proof of equivalence between the circuit and the LP problem. The proposed method is used to implement a LP-based Model Predictive Controller by using an analog circuit. Simulative and experimental results show the effectiveness of the proposed approach.

  19. Precision BiCMOS successive approximation analog-to-digital converter with low power consumption

    International Nuclear Information System (INIS)

    An IP block of a successive approximation analog-to-digital converter (ADC) with low power consumption has been developed as a part of an application-specific integrated circuit (ASIC) for an intellectual flow meter. The advantages of the application of the modified “top-down” design method to the design of the chip have been demonstrated. The results of the simulation, verification, and test of the analog-to-digital converter are presented

  20. Novel Analog For Muscle Deconditioning

    Science.gov (United States)

    Ploutz-Snyder, Lori; Ryder, Jeff; Buxton, Roxanne; Redd. Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle; Fiedler, James; Ploutz-Snyder, Robert; Bloomberg, Jacob

    2011-01-01

    Existing models (such as bed rest) of muscle deconditioning are cumbersome and expensive. We propose a new model utilizing a weighted suit to manipulate strength, power, or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre-and postflightastronaut performance data for the same tasks. Splineregression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/BW of 79 J/kg, isokineticknee extension (KE)/BW of 6 Nm/kg, and KE torque/BW of 1.9 Nm/kg.Conclusions: Laboratory manipulation of relative strength has promise as an appropriate analog for spaceflight-induced loss of muscle function, for predicting occupational task performance and establishing operationally relevant strength thresholds.

  1. An Analog Computer for Electronic Engineering Education

    Science.gov (United States)

    Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

    2011-01-01

    This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

  2. Analogical Processes and College Developmental Reading

    Science.gov (United States)

    Paulson, Eric J.

    2014-01-01

    Although a solid body of research concerning the role of analogies in reading processes has emerged at a variety of age groups and reading proficiencies, few of those studies have focused on analogy use by readers enrolled in college developmental reading courses. The current study explores whether 232 students enrolled in mandatory (by placement…

  3. Several Forms of Fuzzy Analogical Reasoning

    OpenAIRE

    Bouchon-Meunier, B; Delechamp, J.; Marsala, C.; Rifqi, M.

    1997-01-01

    We present a general framework representing analogy, on the basis of a link between variables and measures of comparison between values of variables. This analogical scheme is proven to represent a common description of several forms of reasoning used in fuzzy control or in the management of knowledge-based systems, such as deductive reasoning, inductive reasoning or prototypical reasoning, gradual reasoning.

  4. A physical analogy to fuzzy clustering

    DEFF Research Database (Denmark)

    Jantzen, Jan

    2004-01-01

    This tutorial paper provides an interpretation of the membership assignment in the fuzzy clustering algorithm fuzzy c-means. The membership of a data point to several clusters is shown to be analogous to the gravitational forces between bodies of mass. This provides an alternative way to explain...... the algorithm to students. The analogy suggests a possible extension of the fuzzy membership assignment equation....

  5. Novel Gemini vitamin D3 analogs

    DEFF Research Database (Denmark)

    Okamoto, Ryoko; Gery, Sigal; Kuwayama, Yoshio;

    2014-01-01

    We have synthesized 39 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] analogs having two side chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anticancer activity. One of thes...

  6. Young Children's Analogical Reasoning in Science Domains

    Science.gov (United States)

    Haglund, Jesper; Jeppsson, Fredrik; Andersson, Johanna

    2012-01-01

    This exploratory study in a classroom setting investigates first graders' (age 7-8 years, N = 25) ability to perform analogical reasoning and create their own analogies for two irreversible natural phenomena: mixing and heat transfer. We found that the children who contributed actively to a full-class discussion were consistently successful at…

  7. Analogies in high school Brazilian chemistry textbooks

    Directory of Open Access Journals (Sweden)

    Rosária Justi

    2000-05-01

    Full Text Available This paper presents and discusses an analysis of the analogies presented by Brazilian chemistry textbooks for the medium level. The main aim of the analysis is to discuss whether such analogies can be said good teaching models. From the results, some aspects concerning with teachers' role are discussed. Finally, some new research questions are emphasised.

  8. Play with Language: Overextensions as Analogies.

    Science.gov (United States)

    Hudson, Judith; Nelson, Katherine

    1984-01-01

    Defines criteria to identify children's language overextensions and investigates how young children in the early stages of language acquisition rename objects analogically during a standardized play situation. Results indicate that analogic extensions are well within the capabilities of children from one year, eight months to two years, four…

  9. System-level techniques for analog performance enhancement

    CERN Document Server

    Song, Bang-Sup

    2016-01-01

    This book shows readers to avoid common mistakes in circuit design, and presents classic circuit concepts and design approaches from the transistor to the system levels. The discussion is geared to be accessible and optimized for practical designers who want to learn to create circuits without simulations. Topic by topic, the author guides designers to learn the classic analog design skills by understanding the basic electronics principles correctly, and further prepares them to feel confident in designing high-performance, state-of-the art CMOS analog systems. This book combines and presents all in-depth necessary information to perform various design tasks so that readers can grasp essential material, without reading through the entire book. This top-down approach helps readers to build practical design expertise quickly, starting from their understanding of electronics fundamentals. .

  10. PARADIGM UNIFORMITY AND ANALOGY: THE CAPITALISTIC VERSUS MILITARISTIC DEBATE

    Directory of Open Access Journals (Sweden)

    David Eddington

    2006-12-01

    Full Text Available In American English, /t/ in capitalistic is generally flapped while in militaristic it is not due to the influence of capi[ɾ]al and mili[tʰ]ary. This is called Paradigm Uniformity or PU (Steriade, 2000. Riehl (2003 presents evidence to refute PU which when reanalyzed supports PU. PU is thought to work in tandem with a rule of allophonic distribution, the nature of which is debated. An approach is suggested that eliminates the need for the rule versus PU dichotomy; allophonic distribution is carried out by analogy to stored items in the mental lexicon. Therefore, the influence of the pronunciation of capital on capitalistic is determined in the same way as the pronunciation of /t/ in monomorphemic words such as Mediterranean is. A number of analogical computer simulations provide evidence to support this notion.

  11. A neurocomputer based on an analog-digital hybrid architecture

    Science.gov (United States)

    Moopenn, A.; Thakoor, A. P.; Duong, T.; Khanna, S. K.

    1987-01-01

    A novel analog-digital hybrid architecture based on the utilization of high density digital random access memories for the storage of the synaptic weights of a neural network, and high speed analog hardware to perform neural computation is described. An electronic neurocomputer based on such an architecture is ideally suited for investigating the dynamics, associative recall properties, and computational capabilities of neural networks and provides significant speed improvement in comparison to conventional software based neural network simulations. As a demonstration of the feasibility of the hybrid architectural concept, a prototype breadboard hybrid neurocomputer system with 32 neurons has been designed and fabricated with off-the-shelf hardware components. The performance of the breadboard system has been tested for variety of applications including associative memory and combinatorial problem solving such as Graph Coloring, and is discussed in this paper.

  12. Computational approaches to analogical reasoning current trends

    CERN Document Server

    Richard, Gilles

    2014-01-01

    Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

  13. Analog regulation of metabolic demand

    Directory of Open Access Journals (Sweden)

    Muskhelishvili Georgi

    2011-03-01

    Full Text Available Abstract Background The 3D structure of the chromosome of the model organism Escherichia coli is one key component of its gene regulatory machinery. This type of regulation mediated by topological transitions of the chromosomal DNA can be thought of as an analog control, complementing the digital control, i.e. the network of regulation mediated by dedicated transcription factors. It is known that alterations in the superhelical density of chromosomal DNA lead to a rich pattern of differential expressed genes. Using a network approach, we analyze these expression changes for wild type E. coli and mutants lacking nucleoid associated proteins (NAPs from a metabolic and transcriptional regulatory network perspective. Results We find a significantly higher correspondence between gene expression and metabolism for the wild type expression changes compared to mutants in NAPs, indicating that supercoiling induces meaningful metabolic adjustments. As soon as the underlying regulatory machinery is impeded (as for the NAP mutants, this coherence between expression changes and the metabolic network is substantially reduced. This effect is even more pronounced, when we compute a wild type metabolic flux distribution using flux balance analysis and restrict our analysis to active reactions. Furthermore, we are able to show that the regulatory control exhibited by DNA supercoiling is not mediated by the transcriptional regulatory network (TRN, as the consistency of the expression changes with the TRN logic of activation and suppression is strongly reduced in the wild type in comparison to the mutants. Conclusions So far, the rich patterns of gene expression changes induced by alterations of the superhelical density of chromosomal DNA have been difficult to interpret. Here we characterize the effective networks formed by supercoiling-induced gene expression changes mapped onto reconstructions of E. coli's metabolic and transcriptional regulatory network. Our

  14. Advances in Analog Circuit Design 2015

    CERN Document Server

    Baschirotto, Andrea; Harpe, Pieter

    2016-01-01

    This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

  15. Fostering Multilateral Involvement in Analog Research

    Science.gov (United States)

    Cromwell, Ronita L.

    2015-01-01

    International collaboration in space flight research is an effective means for conducting investigations and utilizing limited resources to the fullest extent. Through these multilateral collaborations mutual research questions can be investigated and resources contributed by each international partner to maximize the scientific benefits to all parties. Recently the international partners embraced this approach to initiate collaborations in ground-based space flight analog environments. In 2011, the International Analog Research Working Group was established, and later named the International Human Space Flight Analog Research Coordination Group (HANA). Among the goals of this working group are to 1) establish a framework to coordinate research campaigns, as appropriate, to minimize duplication of effort and enhance synergy; 2) define what analogs are best to use for collaborative interests; and 3) facilitate interaction between discipline experts in order to have the full benefit of international expertise. To accomplish these goals, HANA is currently engaged in developing international research campaigns in ground-based analogs. Plans are being made for an international solicitation for proposals to address research of common interest to all international partners. This solicitation with identify an analog environment that will best accommodate the types of investigations requested. Once selected, studies will be integrated into a campaign and implemented at the analog site. Through these combined efforts, research beneficial to all partners will be conducted efficiently to further address human risks of space exploration.

  16. Analogies: Explanatory Tools in Web-Based Science Instruction

    Science.gov (United States)

    Glynn, Shawn M.; Taasoobshirazi, Gita; Fowler, Shawn

    2007-01-01

    This article helps designers of Web-based science instruction construct analogies that are as effective as those used in classrooms by exemplary science teachers. First, the authors explain what analogies are, how analogies foster learning, and what form analogies should take. Second, they discuss science teachers' use of analogies. Third, they…

  17. The Search for Subsurface Life on Mars: Results from the MARTE Analog Drill Experiment in Rio Tinto, Spain

    Science.gov (United States)

    Stoker, C. R.; Lemke, L. G.; Cannon, H.; Glass, B.; Dunagan, S.; Zavaleta, J.; Miller, D.; Gomez-Elvira, J.

    2006-03-01

    The Mars Analog Research and Technology (MARTE) experiment has developed an automated drilling system on a simulated Mars lander platform including drilling, sample handling, core analysis and down-hole instruments relevant to searching for life in the Martian subsurface.

  18. Photonic analog computing with integrated silicon waveguides

    CERN Document Server

    Dong, Jianji; Zheng, Aoleng; Zhang, Xinliang

    2014-01-01

    The spectra of silicon integrated waveguides are tailored to process analog computing (i.e.,differential and integral) in optical domain with huge bandwidth.With the theory of signal and system, we design some silicon integrated devices to implement photonic differentiator and optical differential equation solver. The basic principle is to tailor the spectra of silicon integrated waveguides to meet the requirements of analog computing circuits. These analog photonic integrated circuits are very promising in future computing systems with high speed, low cost, and compact size. We also plan to employ these basic computing units in more complex computing modules.

  19. A reconfigurable analog baseband circuit for WLAN, WCDMA, and Bluetooth

    Energy Technology Data Exchange (ETDEWEB)

    Tong Tao; Chi Baoyong; Wang Ziqiang; Zhang Ying; Jiang Hanjun; Wang Zhihua, E-mail: tongt05@gmail.co [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2010-05-15

    A reconfigurable analog baseband circuit for WLAN, WCDMA, and Bluetooth in 0.35 {mu}m CMOS is presented. The circuit consists of two variable gain amplifiers (VGA) in cascade and a G{sub m}-C elliptic low-pass filter (LPF). The filter-order and the cut-off frequency of the LPF can be reconfigured to satisfy the requirements of various applications. In order to achieve the optimum power consumption, the bandwidth of the VGAs can also be dynamically reconfigured and some G{sub m} cells can be cut off in the given application. Simulation results show that the analog baseband circuit consumes 16.8 mW for WLAN, 8.9 mW for WCDMA and only 6.5 mW for Bluetooth, all with a 3 V power supply. The analog baseband circuit could provide -10 to +40 dB variable gain, third-order low pass filtering with 1 MHz cut-off frequency for Bluetooth, fourth-order low pass filtering with 2.2 MHz cut-off frequency for WCDMA, and fifth-order low pass filtering with 11 MHz cut-off frequency for WLAN, respectively. (semiconductor integrated circuits)

  20. A reconfigurable analog baseband circuit for WLAN, WCDMA, and Bluetooth

    International Nuclear Information System (INIS)

    A reconfigurable analog baseband circuit for WLAN, WCDMA, and Bluetooth in 0.35 μm CMOS is presented. The circuit consists of two variable gain amplifiers (VGA) in cascade and a Gm-C elliptic low-pass filter (LPF). The filter-order and the cut-off frequency of the LPF can be reconfigured to satisfy the requirements of various applications. In order to achieve the optimum power consumption, the bandwidth of the VGAs can also be dynamically reconfigured and some Gm cells can be cut off in the given application. Simulation results show that the analog baseband circuit consumes 16.8 mW for WLAN, 8.9 mW for WCDMA and only 6.5 mW for Bluetooth, all with a 3 V power supply. The analog baseband circuit could provide -10 to +40 dB variable gain, third-order low pass filtering with 1 MHz cut-off frequency for Bluetooth, fourth-order low pass filtering with 2.2 MHz cut-off frequency for WCDMA, and fifth-order low pass filtering with 11 MHz cut-off frequency for WLAN, respectively. (semiconductor integrated circuits)

  1. Photoresistance analog multiplier has wide range

    Science.gov (United States)

    Hartenstein, R. G.

    1965-01-01

    Photoactivated bridge facilitates equal performance of analog multipliers over a wide frequency range. The multiplier operates from direct current to an upper frequency limited by either the light source or the closed-loop amplifier.

  2. The Analog (Computer) As a Physiology Adjunct.

    Science.gov (United States)

    Stewart, Peter A.

    1979-01-01

    Defines and discusses the analog computer and its use in a physiology laboratory. Includes two examples: (1) The Respiratory Control Function and (2) CO-Two Control in the Respiratory System. Presents diagrams and mathematical models. (MA)

  3. An Electrical Analog Computer for Poets

    Science.gov (United States)

    Bruels, Mark C.

    1972-01-01

    Nonphysics majors are presented with a direct current experiment beyond Ohms law and series and parallel laws. This involves construction of an analog computer from common rheostats and student-assembled voltmeters. (Author/TS)

  4. Optical analog-to-digital converter

    Science.gov (United States)

    Vawter, G. Allen; Raring, James; Skogen, Erik J.

    2009-07-21

    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  5. Modern analog filter analysis and design a practical approach

    CERN Document Server

    Raut, R

    2011-01-01

    Starting from the fundamentals, the present book describes methods of designing analog electronic filters and illustrates these methods by providing numerical and circuit simulation programs. The subject matters comprise many concepts and techniques that are not available in other text books on the market. To name a few - principle of transposition and its application in directly realizing current mode filters from well known voltage mode filters; an insight into the technological aspect of integrated circuit components used to implement an integrated circuit filter; a careful blending of basi

  6. Autonomous Traffic Signal Control Model with Neural Network Analogy

    CERN Document Server

    Ohira, T

    1997-01-01

    We propose here an autonomous traffic signal control model based on analogy with neural networks. In this model, the length of cycle time period of traffic lights at each signal is autonomously adapted. We find a self-organizing collective behavior of such a model through simulation on a one-dimensional lattice model road: traffic congestion is greatly diffused when traffic signals have such autonomous adaptability with suitably tuned parameters. We also find that effectiveness of the system emerges through interactions between units and shows a threshold transition as a function of proportion of adaptive signals in the model.

  7. Analog simulation of Weyl particles with cold atoms

    Science.gov (United States)

    Rabinovic, Mihail; Suchet, Daniel; Reimann, Thomas; Kretzschmar, Norman; Sievers, Franz; Salomon, Christophe; Lau, Jonathan; Lobo, Carlos; Goulko, Olga; Chevy, Frederic

    2016-05-01

    The high degree of control of the properties of ultracold gases offers the possibility to study experimentally unconventional many-body systems. An example is given by massless relativistic Weyl fermions, which are of particular interest in high energy and condensed matter physics, where they emerge in the form of low energy excitations of exotic compounds like TaAs. The particular case of harmonically trapped Weyl particles can be mimicked by a laser-cooled cloud of 6Li trapped in a magnetic quadrupole potential. The non-separability of this particular potential enables a quasi-thermalization of the single particle distribution function even in the absence of interactions. Surprisingly, the dynamics features an effective decoupling between the strong trapping axis and the weak trapping plane. We studied both, numerically and experimentally, the relaxation of the excited cloud towards its equilibrium distribution, mapping this dynamics directly to the case of non-interaction massless particles in a harmonic potential.

  8. Pigeons, Rats, and Humans Show Analogous Misinformation

    OpenAIRE

    Garry, Maryanne; Harper, David N

    2009-01-01

    In three experiments, we show that pigeons, rats and humans can be influenced by misleading postevent information in ways analogous to findings in the human memory distortion literature. We used a delayed matching to sample analog of the eyewitness testimony procedure from Loftus et al.(1978), and varied the length of the delay between event and exposure to post event information(PEI). We also varied the nature of PEI so that it was consistent with the event information, inconsistent, or neut...

  9. Analog VLSI model of binaural hearing

    OpenAIRE

    Mead, Carver A.; Arreguit, Xavier; Lazzaro, John

    1991-01-01

    The stereausis model of biological auditory processing was proposed as a representation that encodes both binaural and spectral information in a unified framework. We describe a working analog VLSI chip that implements this model of early auditory processing in the brain. The chip is a 100 000-transistor integrated circuit that computes the stereausis representation in real time, using continuous-time analog processing. The chip receives two audio inputs, representing sou...

  10. Analogical Learning and Automated Rule Constructions

    Institute of Scientific and Technical Information of China (English)

    周哈阳

    1991-01-01

    This paper describes some experiments of analogical learning and automated rule construction.The present investigation focuses on knowledge acquisition,learning by analyogy,and knowledge retention.The developed system initially learns from scratch,gradually acquires knowledge from its environment through trial-and-error interaction,incrementally augments its knowledge base,and analogically solves new tasks in a more efficient and direct manner.

  11. AMiBA Wideband Analog Correlator

    CERN Document Server

    Li, Chao-Te; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P T P; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Wu, Jiun-Huei Proty

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  12. AMiBA Wideband Analog Correlator

    OpenAIRE

    Li, Chao-Te; Kubo, Derek Y.; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; P. T. P. Ho; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting c...

  13. AMiBA Wideband Analog Correlator

    Science.gov (United States)

    Li, Chao-Te; Kubo, Derek Y.; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P. T. P.; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B.; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Proty Wu, Jiun-Huei

    2010-06-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband intermediate frequency distribution, back-end signal processing, and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  14. Low Power Analog Design in Scaled Technologies

    CERN Document Server

    Baschirotto, A; Cocciolo, G; D’Amico, S; De Matteis, M; Delizia, P

    2009-01-01

    In this paper an overview on the main issues in analog IC design in scaled CMOS technology is presented. Decreasing the length of MOS channel and the gate oxide has led to undoubted advantages in terms of chip area, speed and power consumption (mainly exploited in the digital parts). Besides, some drawbacks are introduced in term of power leakage and reliability. Moreover, the scaled technology lower supply voltage requirement has led analog designers to find new circuital solution to guarantee the required performance.

  15. A review of EBMT using proportional analogies

    OpenAIRE

    Somers, Harold; Dandapat, Sandipan; Naskar, Sudip Kumar

    2009-01-01

    Some years ago a number of papers reported an experimental implementation of Example Based Machine Translation (EBMT) using Proportional Analogy. This approach, a type of analogical learning, was attractive because of its simplicity; and the papers reported considerable success with the method. This paper reviews what we believe to be the totality of research reported using this method, as an introduction to our own experiments in this framework, reported in a companion paper. We report first...

  16. Automated Integrated Analog Filter Design Issues

    OpenAIRE

    Karolis Kiela; Romualdas Navickas

    2015-01-01

    An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is t...

  17. On the gravitational analog of electromagnetic induction

    International Nuclear Information System (INIS)

    Discussed are some aspects of the analogy between stationary gravitational and electromagnetic fields, in particular, the gravitational analog of the electromagnetic induction phenomenon. The point is that the field of forces influencing the test particle in the strict system of reference is similar to the field of forces influencing a charged particle in the stationary electromagnetic field. The effect proceeds from the equation of motion of a spinning extended body

  18. On the computational complexity of binary and analog symmetric hopfield nets

    Science.gov (United States)

    Sima; Orponen; Antti-Poika

    2000-12-01

    We investigate the computational properties of finite binary- and analog-state discrete-time symmetric Hopfield nets. For binary networks, we obtain a simulation of convergent asymmetric networks by symmetric networks with only a linear increase in network size and computation time. Then we analyze the convergence time of Hopfield nets in terms of the length of their bit representations. Here we construct an analog symmetric network whose convergence time exceeds the convergence time of any binary Hopfield net with the same representation length. Further, we prove that the MIN ENERGY problem for analog Hopfield nets is NP-hard and provide a polynomial time approximation algorithm for this problem in the case of binary nets. Finally, we show that symmetric analog nets with an external clock are computationally Turing universal. PMID:11112262

  19. An Analog Gamma Correction Scheme for High Dynamic Range CMOS Logarithmic Image Sensors

    Directory of Open Access Journals (Sweden)

    Yuan Cao

    2014-12-01

    Full Text Available In this paper, a novel analog gamma correction scheme with a logarithmic image sensor dedicated to minimize the quantization noise of the high dynamic applications is presented. The proposed implementation exploits a non-linear voltage-controlled-oscillator (VCO based analog-to-digital converter (ADC to perform the gamma correction during the analog-to-digital conversion. As a result, the quantization noise does not increase while the same high dynamic range of logarithmic image sensor is preserved. Moreover, by combining the gamma correction with the analog-to-digital conversion, the silicon area and overall power consumption can be greatly reduced. The proposed gamma correction scheme is validated by the reported simulation results and the experimental results measured for our designed test structure, which is fabricated with 0.35 μm standard complementary-metal-oxide-semiconductor (CMOS process.

  20. An analog gamma correction scheme for high dynamic range CMOS logarithmic image sensors.

    Science.gov (United States)

    Cao, Yuan; Pan, Xiaofang; Zhao, Xiaojin; Wu, Huisi

    2014-01-01

    In this paper, a novel analog gamma correction scheme with a logarithmic image sensor dedicated to minimize the quantization noise of the high dynamic applications is presented. The proposed implementation exploits a non-linear voltage-controlled-oscillator (VCO) based analog-to-digital converter (ADC) to perform the gamma correction during the analog-to-digital conversion. As a result, the quantization noise does not increase while the same high dynamic range of logarithmic image sensor is preserved. Moreover, by combining the gamma correction with the analog-to-digital conversion, the silicon area and overall power consumption can be greatly reduced. The proposed gamma correction scheme is validated by the reported simulation results and the experimental results measured for our designed test structure, which is fabricated with 0.35 μm standard complementary-metal-oxide-semiconductor (CMOS) process. PMID:25517692

  1. Human performance profiles for planetary analog extra-vehicular activities: 120 day and 30 day analog missions

    Science.gov (United States)

    Swarmer, Tiffany M.

    Understanding performance factors for future planetary missions is critical for ensuring safe and successful planetary extra-vehicular activities (EVAs). The goal of this study was to gain operational knowledge of analog EVAs and develop biometric profiles for specific EVA types. Data was collected for a 120 and 30 day analog planetary exploration simulation focusing on EVA type, pre and post EVA conditions, and performance ratings. From this five main types of EVAs were performed: maintenance, science, survey/exploratory, public relations, and emergency. Each EVA type has unique characteristics and performance ratings showing specific factors in chronological components, environmental conditions, and EVA systems that have an impact on performance. Pre and post biometrics were collected to heart rate, blood pressure, and SpO2. Additional data about issues and specific EVA difficulties provide some EVA trends illustrating how tasks and suit comfort can negatively affect performance ratings. Performance decreases were noted for 1st quarter and 3rd quarter EVAs, survey/exploratory type EVAs, and EVAs requiring increased fine and gross motor function. Stress during the simulation is typically higher before the EVA and decreases once the crew has returned to the habitat. Stress also decreases as the simulation nears the end with the 3rd and 4th quarters showing a decrease in stress levels. Operational components and studies have numerous variable and components that effect overall performance, by increasing the knowledge available we may be able to better prepare future crews for the extreme environments and exploration of another planet.

  2. Optical domain analog to digital conversion methods and apparatus

    Science.gov (United States)

    Vawter, Gregory A

    2014-05-13

    Methods and apparatus for optical analog to digital conversion are disclosed. An optical signal is converted by mapping the optical analog signal onto a wavelength modulated optical beam, passing the mapped beam through interferometers to generate analog bit representation signals, and converting the analog bit representation signals into an optical digital signal. A photodiode receives an optical analog signal, a wavelength modulated laser coupled to the photodiode maps the optical analog signal to a wavelength modulated optical beam, interferometers produce an analog bit representation signal from the mapped wavelength modulated optical beam, and sample and threshold circuits corresponding to the interferometers produce a digital bit signal from the analog bit representation signal.

  3. Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End

    Science.gov (United States)

    Prokop, Norman; Krasowski, Michael

    2013-01-01

    This innovation is capable of correlating two analog signals by using an analog-based signal conditioning front end to hard-limit the analog signals through adaptive thresholding into a binary bit stream, then performing the correlation using a Hamming "similarity" calculator function embedded in a one-bit digital correlator (OBDC). By converting the analog signal into a bit stream, the calculation of the correlation function is simplified, and less hardware resources are needed. This binary representation allows the hardware to move from a DSP where instructions are performed serially, into digital logic where calculations can be performed in parallel, greatly speeding up calculations.

  4. 1 alpha,25-dihydroxyvitamin D3 analogs featuring aromatic and heteroaromatic rings: design, synthesis, and preliminary biological testing.

    Science.gov (United States)

    Posner, G H; Li, Z; White, M C; Vinader, V; Takeuchi, K; Guggino, S E; Dolan, P; Kensler, T W

    1995-10-27

    Aromatic compounds 2a-c, analogs of 1 alpha, 25-dihydroxyvitamin (calcitriol, 1), and heteroaromatic compounds 4a-c and 5a-c, analogs of 19-nor-1 alpha, 25-dihydroxyvitamin D3 (3), were designed to simulate the topology of their biologically potent parent compounds while avoiding previtamin D equilibrium. Convergent and facile total syntheses of the analogs (+)-2b, (+)-2c, (-)-4b, and (-)-5b were achieved via carbonyl addition of regiospecifically formed organolithium nucleophiles to the enantiomerically pure C,D-ring ketone (+)-17, characteristic of natural calcitriol (1). Likewise, hybrid analogs 20a-c were prepared to determine whether incorporation of a known potentiating side chain would lead to increased biological activity. Preliminary in vitro biological testing showed that aromatic analogs (+)-2b, (+)-2c, and 20a-c as well as heteroaromatic analogs (-)-4b and (-)-5b have very low affinities for the calf thymus vitamin D receptor but considerable antiproliferative activities in murine keratinocytes at micromolar concentration. No biological advantage was observed in this keratinocyte assay for the doubly modified hybrid analogs 20a-c over the singly modified parent (+)-2b. Analog (+)-2b, but surprisingly not the corresponding analog 20b differing from (+)-2b only in the side chain, showed considerable activity in nongenomic opening of calcium channels in rat osteosarcoma cells. PMID:7473581

  5. Principles for Integrating Mars Analog Science, Operations, and Technology Research

    Science.gov (United States)

    Clancey, William J.

    2003-01-01

    During the Apollo program, the scientific community and NASA used terrestrial analog sites for understanding planetary features and for training astronauts to be scientists. Human factors studies (Harrison, Clearwater, & McKay 1991; Stuster 1996) have focused on the effects of isolation in extreme environments. More recently, with the advent of wireless computing, we have prototyped advanced EVA technologies for navigation, scheduling, and science data logging (Clancey 2002b; Clancey et al., in press). Combining these interests in a single expedition enables tremendous synergy and authenticity, as pioneered by Pascal Lee's Haughton-Mars Project (Lee 2001; Clancey 2000a) and the Mars Society s research stations on a crater rim on Devon Island in the High Canadian Arctic (Clancey 2000b; 2001b) and the Morrison Formation of southeast Utah (Clancey 2002a). Based on this experience, the following principles are proposed for conducting an integrated science, operations, and technology research program at analog sites: 1) Authentic work; 2) PI-based projects; 3) Unencumbered baseline studies; 4) Closed simulations; and 5) Observation and documentation. Following these principles, we have been integrating field science, operations research, and technology development at analog sites on Devon Island and in Utah over the past five years. Analytic methods include work practice simulation (Clancey 2002c; Sierhuis et a]., 2000a;b), by which the interaction of human behavior, facilities, geography, tools, and procedures are formalized in computer models. These models are then converted into the runtime EVA system we call mobile agents (Clancey 2002b; Clancey et al., in press). Furthermore, we have found that the Apollo Lunar Surface Journal (Jones, 1999) provides a vast repository or understanding astronaut and CapCom interactions, serving as a baseline for Mars operations and quickly highlighting opportunities for computer automation (Clancey, in press).

  6. The future of vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Carlien eLeyssens

    2014-04-01

    Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

  7. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Directory of Open Access Journals (Sweden)

    Troco K. Mihali

    2010-07-01

    Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

  8. Analog forecasting with dynamics-adapted kernels

    Science.gov (United States)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

    Analog forecasting is a nonparametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from kernel methods developed in harmonic analysis and machine learning and state-space reconstruction for dynamical systems. A key ingredient of our approach is to replace single-analog forecasting with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve forecast skill, including Takens’ delay-coordinate maps (to recover information in the initial data lost through partial observations) and a directional dependence on the dynamical vector field generating the data. Mathematically, our approach is closely related to kernel methods for out-of-sample extension of functions, and we discuss alternative strategies based on the Nyström method and the multiscale Laplacian pyramids technique. We illustrate these techniques in applications to forecasting in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale forecasting in the North Pacific sector of a comprehensive climate model. We find that forecasts based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.

  9. Dual Metal Gate and Conventional MOSFET at Sub nm for Analog Application

    Directory of Open Access Journals (Sweden)

    Sonal Aggarwal

    2012-03-01

    Full Text Available The use of nanometer CMOS technologies (below 90nm however brings along significant challenges for circuit design (both analog and digital. By reducing the dimensions of transistors many physical phenomenon like gate leakage, drain induced barrier lowering and many more effects comes into picture.Reducing the feature size in the technology of device with the addition of ever more interconnect layers, the density of the digital as well as analog circuit will increase while intrinsic gate switching delay is reduced . We have simulated conventional and DMG MOSFET at 30nm scale using Silvaco TAD tool and obtained result. A two dimensional device simulation was carried out and observed that DMG MOSFET has a low leakage current as compared to conventional MOSFET and find suitable application in analog circuits.

  10. Dual Metal Gate and Conventional MOSFET at Sub nm for Analog Application

    Directory of Open Access Journals (Sweden)

    Sonal Aggarwal

    2012-02-01

    Full Text Available The use of nanometer CMOS technologies (below 90nm however brings along significant challenges for circuit design (both analog and digital. By reducing the dimensions of transistors many physical phenomenon like gate leakage, drain induced barrier lowering and many more effects comes into picture.Reducing the feature size in the technology of device with the addition of ever more interconnect layers, the density of the digital as well as analog circuit will increase while intrinsic gate switching delay is reduced . We have simulated conventional and DMG MOSFET at 30nm scale using Silvaco TAD tool and obtained result. A two dimensional device simulation was carried out and observed that DMG MOSFET has a low leakage current as compared to conventional MOSFET and find suitable application in analog circuits.

  11. Analogical reasoning for reliability analysis based on generic data

    Energy Technology Data Exchange (ETDEWEB)

    Kozin, Igor O

    1996-10-01

    The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects.

  12. Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

    Science.gov (United States)

    Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

    2014-01-01

    The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

  13. Analog Forecasting with Dynamics-Adapted Kernels

    CERN Document Server

    Zhao, Zhizhen

    2014-01-01

    Analog forecasting is a non-parametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from state-space reconstruction for dynamical systems and kernel methods developed in harmonic analysis and machine learning. The first improvement is to augment the dimension of the initial data using Takens' delay-coordinate maps to recover information in the initial data lost through partial observations. Then, instead of using Euclidean distances between the states, weighted ensembles of analogs are constructed according to similarity kernels in delay-coordinate space, featuring an explicit dependence on the dynamical vector field generating the data. The eigenvalues and eigenfunctions ...

  14. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  15. Analog pipeline readout for ATLAS calorimetry

    International Nuclear Information System (INIS)

    This paper presents the design and prototype testing of an analog pipeline readout module suitable for readout of the LAr calorimetry at the large hadron collider. The design has been driven by the readout requirements of the ATLAS electromagnetic liquid argon calorimeter and the ATLAS trigger design parameters. The results indicate that an analog pipeline readout system meeting the ATLAS requirements can be built using our modules. The SCA-chip employed has resolution approaching 13-bits (using the full range of the SCA) and can achieve a 16-bit dynamic range using a dual-range scheme. The module is based on switched capacitor array chips. A brief description of the design of the pipeline controller development, that will enable the SCA readout system to run as a deadtimeless analog RAM, is also given. (orig.)

  16. On Lovelock analogs of the Riemann tensor

    Energy Technology Data Exchange (ETDEWEB)

    Camanho, Xian O. [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, Golm (Germany); Dadhich, Naresh [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); Inter-University Centre for Astronomy and Astrophysics, Pune (India)

    2016-03-15

    It is possible to define an analog of the Riemann tensor for Nth order Lovelock gravity, its characterizing property being that the trace of its Bianchi derivative yields the corresponding analog of the Einstein tensor. Interestingly there exist two parallel but distinct such analogs and the main purpose of this note is to reconcile both formulations. In addition we will introduce a simple tensor identity and use it to show that any pure Lovelock vacuum in odd d = 2N + 1 dimensions is Lovelock flat, i.e. any vacuum solution of the theory has vanishing Lovelock-Riemann tensor. Further, in the presence of cosmological constant it is the Lovelock-Weyl tensor that vanishes. (orig.)

  17. Biosynthesis of amphetamine analogs in plants.

    Science.gov (United States)

    Hagel, Jillian M; Krizevski, Raz; Marsolais, Frédéric; Lewinsohn, Efraim; Facchini, Peter J

    2012-07-01

    Amphetamine analogs are produced by plants in the genus Ephedra and by Catha edulis, and include the widely used decongestants and appetite suppressants pseudoephedrine and ephedrine. A combination of yeast (Candida utilis or Saccharomyces cerevisiae) fermentation and subsequent chemical modification is used for the commercial production of these compounds. The availability of certain plant biosynthetic genes would facilitate the engineering of yeast strains capable of de novo pseudoephedrine and ephedrine biosynthesis. Chemical synthesis has yielded amphetamine analogs with myriad functional group substitutions and diverse pharmacological properties. The isolation of enzymes with the serendipitous capacity to accept novel substrates could allow the production of substituted amphetamines in synthetic biosystems. Here, we review the biology, biochemistry and biotechnological potential of amphetamine analogs in plants. PMID:22502775

  18. Landauer Bound for Analog Computing Systems

    CERN Document Server

    Diamantini, M Cristina; Trugenberger, Carlo A

    2016-01-01

    By establishing a relation between information erasure and continuous phase transitions we generalise the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  19. Doing mathematics convention, subject, calculation, analogy

    CERN Document Server

    Krieger, Martin H

    2003-01-01

    This book discusses some ways of doing mathematical work and the subject matter that is being worked upon and created. It argues that the conventions we adopt, the subject areas we delimit, what we can prove and calculate about the physical world, and the analogies that work for mathematicians - all depend on mathematics, what will work out and what won't. And the mathematics, as it is done, is shaped and supported, or not, by convention, subject matter, calculation, and analogy. The cases studied include the central limit theorem of statistics, the sound of the shape of a drum, the connection

  20. Associative Pattern Recognition In Analog VLSI Circuits

    Science.gov (United States)

    Tawel, Raoul

    1995-01-01

    Winner-take-all circuit selects best-match stored pattern. Prototype cascadable very-large-scale integrated (VLSI) circuit chips built and tested to demonstrate concept of electronic associative pattern recognition. Based on low-power, sub-threshold analog complementary oxide/semiconductor (CMOS) VLSI circuitry, each chip can store 128 sets (vectors) of 16 analog values (vector components), vectors representing known patterns as diverse as spectra, histograms, graphs, or brightnesses of pixels in images. Chips exploit parallel nature of vector quantization architecture to implement highly parallel processing in relatively simple computational cells. Through collective action, cells classify input pattern in fraction of microsecond while consuming power of few microwatts.

  1. One higher dimensional analog of jet schemes

    OpenAIRE

    Yuen, Cornelia

    2006-01-01

    We develop the theory of truncated wedge schemes, a higher dimensional analog of jet schemes. We prove some basic properties and give an irreducibility criterion for truncated wedge schemes of a locally complete intersection variety analogous to Musta\\c{t}\\v{a}'s for jet schemes. We show that the reduced subscheme structure of a truncated wedge scheme of any monomial scheme is itself a monomial scheme in a natural way by explicitly describing generators of each of the minimal primes of any tr...

  2. Discrete analog computing with rotor-routers.

    Science.gov (United States)

    Propp, James

    2010-09-01

    Rotor-routing is a procedure for routing tokens through a network that can implement certain kinds of computation. These computations are inherently asynchronous (the order in which tokens are routed makes no difference) and distributed (information is spread throughout the system). It is also possible to efficiently check that a computation has been carried out correctly in less time than the computation itself required, provided one has a certificate that can itself be computed by the rotor-router network. Rotor-router networks can be viewed as both discrete analogs of continuous linear systems and deterministic analogs of stochastic processes. PMID:20887076

  3. Analog circuit design for communication SOC

    CERN Document Server

    Tu, Steve Hung-Lung

    2012-01-01

    This e-book provides several state-of-the-art analog circuit design techniques. It presents both empirical and theoretical materials for system-on-a-chip (SOC) circuit design. Fundamental communication concepts are used to explain a variety of topics including data conversion (ADC, DAC, S-? oversampling data converters), clock data recovery, phase-locked loops for system timing synthesis, supply voltage regulation, power amplifier design, and mixer design. This is an excellent reference book for both circuit designers and researchers who are interested in the field of design of analog communic

  4. Unbiased estimators of coincidence and correlation in non-analogous Monte Carlo particle transport

    International Nuclear Information System (INIS)

    Highlights: • The history splitting method was developed for non-Boltzmann Monte Carlo estimators. • The method allows variance reduction for pulse-height and higher moment estimators. • It works in highly multiplicative problems but Russian roulette has to be replaced. • Estimation of higher moments allows the simulation of neutron noise measurements. • Biased sampling of fission helps the effective simulation of neutron noise methods. - Abstract: The conventional non-analogous Monte Carlo methods are optimized to preserve the mean value of the distributions. Therefore, they are not suited to non-Boltzmann problems such as the estimation of coincidences or correlations. This paper presents a general method called history splitting for the non-analogous estimation of such quantities. The basic principle of the method is that a non-analogous particle history can be interpreted as a collection of analogous histories with different weights according to the probability of their realization. Calculations with a simple Monte Carlo program for a pulse-height-type estimator prove that the method is feasible and provides unbiased estimation. Different variance reduction techniques have been tried with the method and Russian roulette turned out to be ineffective in high multiplicity systems. An alternative history control method is applied instead. Simulation results of an auto-correlation (Rossi-α) measurement show that even the reconstruction of the higher moments is possible with the history splitting method, which makes the simulation of neutron noise measurements feasible

  5. Performance Analysis of Various Readout Circuits for Monitoring Quality of Water Using Analog Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Pawan Whig

    2012-10-01

    Full Text Available This paper presents a comparative performance study of various analog integrated circuits (namely CC-II, DVCC, CDBA and CDTA used with ISFET for monitoring the quality of water. The use of these active components makes the implementation simple and attractive. The functionality of the circuits are tested using Tanner simulator version 15 for a 70nm CMOS process model also the transfer functions realization for each is done on MATLAB R2011a version, the Very high speed integrated circuit Hardware description language(VHDL code for all scheme is simulated on Xilinx ISE 10.1 and various simulation results are obtained and its is found that DVCC is most stable and consume maximum power whereas CC-II is the least stable and consumes minimum power amongst all the four deployed analog IC’s. Detailed simulation results are included in the paper to give insight into the research work carried out.

  6. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog filte

  7. Impact of Time-interleaved Analog-to-Digital Converter Mismatch on Digital Receivers

    OpenAIRE

    Soudan, Michael; Farrell, Ronan

    2008-01-01

    This paper presents the impact that gain, offset and timing mismatch in time-interleaved analog-to-digital converter (TIADC) have on digital receiver systems. An analysis of the mismatch errors shows the dependency of the different errors from the spectrum of the input signal. A discrete-time TIADC model is derived allowing to simulate the mismatch effects of the individual ADCs. Finally, simulations results present the performance degradation that can be expected by the usage of non-id...

  8. The GMO-Nanotech (Dis)Analogy?

    Science.gov (United States)

    Sandler, Ronald; Kay, W. D.

    2006-01-01

    The genetically-modified-organism (GMO) experience has been prominent in motivating science, industry, and regulatory communities to address the social and ethical dimensions of nanotechnology. However, there are some significant problems with the GMO-nanotech analogy. First, it overstates the likelihood of a GMO-like backlash against…

  9. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  10. A high-speed analog neural processor

    NARCIS (Netherlands)

    Masa, Peter; Hoen, Klaas; Wallinga, Hans

    1994-01-01

    Targeted at high-energy physics research applications, our special-purpose analog neural processor can classify up to 70 dimensional vectors within 50 nanoseconds. The decision-making process of the implemented feedforward neural network enables this type of computation to tolerate weight discretiza

  11. Analog Optical Computing Primitives in Silicon Photonics

    CERN Document Server

    Jiang, Yunshan; Jalali, Bahram

    2015-01-01

    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  12. Analog optical computing primitives in silicon photonics

    Science.gov (United States)

    Jiang, Yunshan; DeVore, Peter T. S.; Jalali, Bahram

    2016-03-01

    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  13. Biological Analogs for Language Contact Situations

    Science.gov (United States)

    Seliger, Herbert W.

    1977-01-01

    This article proposes that language contact can be best understood if the entire range of such situations from second language learning to evolution of dialects and creoles is studied within a framework analogical to the symbiosis of living organisms. Language contact is viewed in terms of dynamic evolutionary stages. (CHK)

  14. Formal analogies in physics teacher education

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio

    2012-01-01

    . Despite the relevance of the subject, formal analogies are rarely systematically approached in physics education. In order to discuss this issue with pre-service physics teachers, we planned a lecture and designed a questionnaire with the goal of encouraging them to think about some “coincidences” in well...

  15. Plasma analog of particle-pair production

    International Nuclear Information System (INIS)

    It is shown that the plasma axial shear flow instability satisfies the Klein-Gordon equation. The plasma instability is then shown to be analogous to spontaneous particle-pair production when a potential energy is present that is greater than twice the particle rest mass energy. Stability criteria can be inferred based on field theoretical conservation laws. (UK)

  16. Radiation Behavior of Analog Neural Network Chip

    Science.gov (United States)

    Langenbacher, H.; Zee, F.; Daud, T.; Thakoor, A.

    1996-01-01

    A neural network experiment conducted for the Space Technology Research Vehicle (STRV-1) 1-b launched in June 1994. Identical sets of analog feed-forward neural network chips was used to study and compare the effects of space and ground radiation on the chips. Three failure mechanisms are noted.

  17. Bootstrapped Low-Voltage Analog Switches

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1999-01-01

    Novel low-voltage constant-impedance analog switch circuits are proposed. The switch element is a single MOSFET, and constant-impedance operation is obtained using simple circuits to adjust the gate and bulk voltages relative to the switched signal. Low-voltage (1-volt) operation is made feasible...

  18. A Low Power High Bandwidth Four Quadrant Analog Multiplier in 32 NM CNFET Technology

    Directory of Open Access Journals (Sweden)

    Ishit Makwana

    2012-04-01

    Full Text Available Carbon Nano tube Field Effect Transistor (CNFET is a promising new technology that overcomes several limitations of traditional silicon integrated circuit technology. In recent years, the potential of CNFET for analog circuit applications has been explored. This paper proposes a novel four quadrant analog multiplier design using CNFETs. The simulation based on 32nm CNFET technology shows that the proposed multiplier has very low harmonic distortion (<0.45%, large input range (±400mV, large bandwidth (~50GHz and low power consumption (~247µW, while operating at a supply voltage of ±0.9V.

  19. LINEARITY AND ANALOG PERFORMANCE ANALYSIS OF DOUBLE GATE TUNNEL FET: EFFECT OF TEMPERATURE AND GATE STACK

    Directory of Open Access Journals (Sweden)

    RAKHI NARANG

    2011-10-01

    Full Text Available The linearity and analog performance of a Silicon Double Gate Tunnel Field Effect Transistor (DG-TFETis investigated and the impact of elevated temperature on the device performance degradation has beenstudied. The impact on the device performance due to the rise in temperature and a gate stack (GSarchitecture has also been investigated for the case of Silicon DG-MOSFET and a comparison with DGTFETis made. The parameters governing the analog performance and linearity have been studied, andhigh frequency simulations are carried out to determine the cut-off frequency of the device and itstemperature dependence.

  20. LINEARITY AND ANALOG PERFORMANCE ANALYSIS OF DOUBLE GATE TUNNEL FET: EFFECT OF TEMPERATURE AND GATE STACK

    Directory of Open Access Journals (Sweden)

    Rakhi Narang

    2011-09-01

    Full Text Available The linearity and analog performance of a Silicon Double Gate Tunnel Field Effect Transistor (DG-TFETis investigated and the impact of elevated temperature on the device performance degradation has been studied. The impact on the device performance due to the rise in temperature and a gate stack (GSarchitecture has also been investigated for the case of Silicon DG-MOSFET and a comparison with DGTFET is made. The parameters governing the analog performance and linearity have been studied, and high frequency simulations are carried out to determine the cut-off frequency of the device and its temperature dependence.

  1. A Low Power High Bandwidth Four Quadrant Analog Multiplier in 32 NM CNFET Technology

    Directory of Open Access Journals (Sweden)

    Vitrag Sheth

    2012-05-01

    Full Text Available Carbon Nanotube Field Effect Transistor (CNFET is a promising new technology that overcomes several limitations of traditional silicon integrated circuit technology. In recent years, the potential of CNFET for analog circuit applications has been explored. This paper proposes a novel four quadrant analog multiplier design using CNFETs. The simulation based on 32nm CNFET technology shows that the proposed multiplier has very low harmonic distortion (<0.45%, large input range (±400mV, large bandwidth (~50GHz and low power consumption (~247µW, while operating at a supply voltage of ±0.9V.

  2. A Novel Analog-to-digital conversion Technique using nonlinear duty-cycle modulation

    Directory of Open Access Journals (Sweden)

    Jean Mbihi

    2012-06-01

    Full Text Available A new type of analog-to-digital conversion technique is presented in this paper. The interfacing hardware is a very simple nonlinear circuit with 1-bit modulated output. As a implication, behind the hardware simplicity retained is hidden a dreadful nonlinear duty-cycle modulation ratio. However, the overall nonlinear behavior embeds a sufficiently wide linear range, for a rigorous digital reconstitution of the analog input signal using a standard linear filter. Simulation and experimental results obtained using a well tested prototyping system, show the feasibility and good quality of the proposed conversion technique.

  3. Multimode lasers as analogs of complex biological systems (a survey)

    Science.gov (United States)

    Danilov, O. B.; Rosanov, N. N.; Solov'ev, N. A.; Soms, L. N.

    2016-04-01

    Simulating the activity of complex biological systems, in particular, the human brain, is a topical problem the solution of which is necessary both for understanding their functioning and for developing new classes of computational system based on operating principles of the brain. Some features and analogies that can be found in the operation of laser systems and brain and used for developing new generation computational systems are discussed. The appropriateness of such analogies is justified by the fact that both laser systems and the brain are open (interacting with the environment) dissipative spatially distributed nonlinear systems. Therefore, laser optical systems and, in particular, systems with dissipative optical solitons offer an opportunity to experimentally and theoretically model some important cognitive brain functions. One of particularities of the brain operation is the ability to manipulate images. Proceeding from this, in this work, problems related to generation and amplification with laser of spatial structures (images), as well as to amplification of signals coming to it from outside are discussed.

  4. Analog VLSI-based modeling of the primate oculomotor system.

    Science.gov (United States)

    Horiuchi, T K; Koch, C

    1999-01-01

    One way to understand a neurobiological system is by building a simulacrum that replicates its behavior in real time using similar constraints. Analog very large-scale integrated (VLSI) electronic circuit technology provides such an enabling technology. We here describe a neuromorphic system that is part of a long-term effort to understand the primate oculomotor system. It requires both fast sensory processing and fast motor control to interact with the world. A one-dimensional hardware model of the primate eye has been built that simulates the physical dynamics of the biological system. It is driven by two different analog VLSI chips, one mimicking cortical visual processing for target selection and tracking and another modeling brain stem circuits that drive the eye muscles. Our oculomotor plant demonstrates both smooth pursuit movements, driven by a retinal velocity error signal, and saccadic eye movements, controlled by retinal position error, and can reproduce several behavioral, stimulation, lesion, and adaptation experiments performed on primates. PMID:9950732

  5. The Acoustic Black Hole Is Not Merely An Analogy

    CERN Document Server

    Ge, Xian-Hui; Tian, Yu; Wu, Xiao-Ning; Zhang, Yun-Long

    2015-01-01

    With the attempt to find the holographic description of the usual acoustic black hole in fluid, we construct an acoustic black hole formed in the $d$-dimensional fluid located at the timelike cutoff surface of an neutral black brane in asymptotically AdS$_{d+1}$ spacetime, the bulk gravitational dual of the acoustic black hole is presented at first order of the hydrodynamic fluctuation. Moreover, the Hawking-like temperature of the acoustic black hole horizon is showed to be connected to the Hawking temperature of the real AdS black brane in the bulk, and the duality between the phonon propagating in the acoustic black hole and the sound channel quasinormal mode is analyzed. We thus point out that, the acoustic black hole in fluid, which was originally proposed as an analogous model to simulate Hawking radiation of the real black hole, is not merely an analogy, it can indeed be used to describe specific properties of the real black hole, in the spirits of the fluid/gravity duality.

  6. Interfacing the Analog Camera with FPGA Board for Real-time Video Acquisition

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    2014-03-01

    Full Text Available Advances in FPGA technology have dramatically increased the use of FPGAs for computer vision applications. The primary task for development of such FPGAs based systems is the interfacing of the analog camera with FPGA board. This paper describes the design and implementation of camera interface module required for connecting analog camera with Xilinx ML510 (Virtex–5 FXT FPGA board having no video input port. Digilent VDEC1 video daughter card is used for digitizing the analog video into digital form. The necessary control logics for video acquisition and video display are designed using VHDL and Verilog, simulated in ModelSim, and synthesized using Xilinx ISE 12.1. Designed and implemented interfaces provide the real-time video acquisition and display.

  7. An Analog Correlator for Ultra-Wideband Receivers

    Directory of Open Access Journals (Sweden)

    Tu Chunjiang

    2005-01-01

    Full Text Available We present a new analog circuit exhibiting high bandwidth and low distortion, specially designed for signal correlation in an ultra-wideband receiver front end. The ultra-wideband short impulse signals are correlated with a local pulse template by the correlator. A comparator then samples the output for signal detection. A typical Gilbert mixer core is adopted for multiplication of broadband signals up to . As a result of synchronization of the received signal and the local template, the output voltage level after integration and sampling can reach up to , which is sufficient for detection by the comparator. The circuit dissipates about from double voltage supplies of and using SiGe BiCMOS technology. Simulation results are presented to show the feasibility of this circuit design for use in ultra-wideband receivers.

  8. Optical-spectrum-encoded analog-to-digital converter

    Institute of Scientific and Technical Information of China (English)

    LIAO Xiao-jun; YANG Ya-pei

    2007-01-01

    A novel optical-spectrum-encoded (OSE) analog-to-digital converter (ADC) is proposed in this letter. To simply exemplify the conversion idea, a 5-bit device structure consisted of Fabry-Perot interferometers (FPI) is analyzed and numerically simulated. The dependence of peak-transmission wavelength on modulation voltage in an electro-optical FPI and the dependence of transmitted power on incident light wavelength in an FPI are discussed and utilized to implement OSEADC.A linearly tunable mode-locked laser, as a voltage-wavelength transformer and a sampler, and chirped grating FPIs, as an encoder array, can be used to obtain much greater sampling rate and bit-resolution.

  9. Electronic Circuit Analog of Synthetic Genetic Networks: Revisited

    CERN Document Server

    Hellen, Edward H

    2016-01-01

    Electronic circuits are useful tools for studying potential dynamical behaviors of synthetic genetic networks. The circuit models are complementary to numerical simulations of the networks, especially providing a framework for verification of dynamical behaviors in the presence of intrinsic and extrinsic noise of the electrical systems. Here we present an improved version of our previous design of an electronic analog of genetic networks that includes the 3-gene Repressilator and we show conversions between model parameters and real circuit component values to mimic the numerical results in experiments. Important features of the circuit design include the incorporation of chemical kinetics representing Hill function inhibition, quorum sensing coupling, and additive noise. Especially, we make a circuit design for a systematic change of initial conditions in experiment, which is critically important for studies of dynamical systems' behavior, particularly, when it shows multistability. This improved electronic ...

  10. Characterization of the Dosepix detector with XRF and analog testpulses

    Science.gov (United States)

    Ritter, I.; Anton, G.; Ballabriga Sune, R.; Bisello, F.; Campbell, M.; Gabor, T.; Llopart Cudie, X.; Wölfel, S.; Wong, W. S.; Michel, T.

    2014-05-01

    Dosepix is a hybrid pixel detector based on the technology of the Medipix and Timepix detectors. The Dosepix detector has a matrix of 16 × 16 square pixels, with the sensor segmented into rows of small (55 μm) and big (220 μm) pixels. In addition to photon counting, the Dosepix detector has a time over threshold mode which permits energy resolved measurements. In this contribution, we present results of the characterization of the Dosepix detector regarding energy calibration and energy resolution. We calibrated the detectors with X-ray fluorescence (XRF) and analog testpulses. We determined a conversion factor from testpulse amplitude to energy. This work aims to develop a calibration method of the Dosepix detector without the need for radiation. In addition, Monte Carlo simulations with ROSI were carried out to compare energy deposition spectra reconstructed with the radiation-based calibration and with testpulse-based calibration.

  11. Asymmetric bilayer graphene nanoribbon MOSFETs for analog and digital electronics

    Science.gov (United States)

    Dinarvand, A.; Ahmadi, V.; Darvish, Gh.

    2016-05-01

    In this paper, a new structure was proposed for bilayer graphene nanoribbon field-effect transistor (BGNFET) mainly to enhance the electrical characteristics in analog and digital applications. The proposed device uses two metallic gates on the top and bottom of a bilayer graphene nanoribbon, which is surrounded by SiO2 and connected to heavily doped source/drain contacts. Electrical properties of the proposed device were explored using fully self-consistent solution of Poisson and Schrödinger equations based on the nonequilibrium Green's function (NEGF) formalism. Significant improvements in the electrical behavior was seen in the simulation results for gates asymmetrically biased. The comparison with graphene nanoribbon FET showed that the proposed structure benefited from higher intrinsic voltage gain and cut-off frequency and improved switching characteristics such as delay and Ion/Ioff ratio.

  12. Optimal neural computations require analog processors

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1998-12-31

    This paper discusses some of the limitations of hardware implementations of neural networks. The authors start by presenting neural structures and their biological inspirations, while mentioning the simplifications leading to artificial neural networks. Further, the focus will be on hardware imposed constraints. They will present recent results for three different alternatives of parallel implementations of neural networks: digital circuits, threshold gate circuits, and analog circuits. The area and the delay will be related to the neurons` fan-in and to the precision of their synaptic weights. The main conclusion is that hardware-efficient solutions require analog computations, and suggests the following two alternatives: (i) cope with the limitations imposed by silicon, by speeding up the computation of the elementary silicon neurons; (2) investigate solutions which would allow the use of the third dimension (e.g. using optical interconnections).

  13. Observing spin optodynamical analog of cavity optomechanics

    Science.gov (United States)

    Gerber, Justin; Kohler, Jonathan; Spethmann, Nicolas; Schreppler, Sydney; Stamper-Kurn, Dan

    2016-05-01

    Cavity Optomechanics has been realized in many diverse systems and led to many interesting results such as ponderomotive squeezing of light, beyond-SQL measurement sensitivity, and squeezing of mechanical oscillators. Optical cavities also allow sensitive measurements of the spin of an atomic ensemble. It has been proposed to utilize this sensitivity to realize an analog of optomechanics by measuring the precession of small excitations of a spin-oscillator around a transverse magnetic field. I will present our recent work in which we realize optomechanical analogs in our system such as cavity-assisted cooling and amplification and optical spring shifts. In addition, the presence of a high-energy `ground state' of the spin oscillator allows the realization of an effective negative mass oscillator which is demonstrated by an inverted sideband asymmetry. In our ongoing work we attempt to realize coherent quantum noise cancelation by coupling spin oscillation with mechanical oscillation.

  14. High resolution tomography using analog coding

    International Nuclear Information System (INIS)

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  15. An analogy strategy for transformation optics

    International Nuclear Information System (INIS)

    We introduce an analogy strategy to design transformation optical devices. Based on the similarities between field lines in different physical systems, the trajectories of light can be intuitively determined to curve in a gentle manner, and the resulting materials are isotropic and nonmagnetic. Furthermore, the physical meaning of the analogue problems plays a key role in the removal of dielectric singularities. We illustrate this approach by creating two designs of carpet cloak and a collimating lens as representative examples in two- and three-dimensional spaces, respectively. The analogy strategy not only reveals the intimate connections between different physical disciplines, such as optics, fluid mechanics and electrostatics, but also provides a heuristic pathway to designing advanced photonic systems

  16. Analog data transmission via fiber optics

    International Nuclear Information System (INIS)

    In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particulary susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

  17. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum...... and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS. The article describes the principles of HAPS...... and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing....

  18. Analog fault diagnosis by inverse problem technique

    KAUST Repository

    Ahmed, Rania F.

    2011-12-01

    A novel algorithm for detecting soft faults in linear analog circuits based on the inverse problem concept is proposed. The proposed approach utilizes optimization techniques with the aid of sensitivity analysis. The main contribution of this work is to apply the inverse problem technique to estimate the actual parameter values of the tested circuit and so, to detect and diagnose single fault in analog circuits. The validation of the algorithm is illustrated through applying it to Sallen-Key second order band pass filter and the results show that the detecting percentage efficiency was 100% and also, the maximum error percentage of estimating the parameter values is 0.7%. This technique can be applied to any other linear circuit and it also can be extended to be applied to non-linear circuits. © 2011 IEEE.

  19. Electromagnetotoroid Structures and their Hydrodynamic Analogs

    CERN Document Server

    Pinheiro, Mario J

    2012-01-01

    We introduce the concept of an electromagnetotoroid in astrophysics, and explore its role in polar jets. This model represents the onset of Abraham's force driven by some external source, for example, the infall of gas towards a star. The Abraham's force term is analogous to the Magnus force, and thus represents the formation of electromagnetic vortex structures in the fabric of space-time. In principle, the proposed toroidal field structure can also provide force spaceship propulsion.

  20. Interference Alignment with Analog Channel State Feedback

    OpenAIRE

    Ayach, Omar El; Heath Jr, Robert W.

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement often comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback ...

  1. Pyrrolidine nucleotide analogs with a tunable conformation

    Czech Academy of Sciences Publication Activity Database

    Poštová Slavětínská, Lenka; Rejman, Dominik; Pohl, Radek

    2014-01-01

    Roč. 10, Aug 22 (2014), s. 1967-1980. ISSN 1860-5397 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : conformation * NMR * nucleic acids * nucleotide analog * phosphonic acid * pseudorotation * pyrrolidine Subject RIV: CC - Organic Chemistry Impact factor: 2.762, year: 2014 http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-10-205

  2. Quantum Electric Circuits Analogous to Ballistic Conductors

    OpenAIRE

    Dragoman, Daniela

    2007-01-01

    The conductance steps in a constricted two-dimensional electron gas and the minimum conductivity in graphene are related to a new uncertainty relation between electric charge and conductance in a quantized electric circuit that mimics the electric transport in mesoscopic systems. This uncertainty relation makes specific use of the discreteness of electric charge. Quantum electric circuits analogous to both constricted two-dimensional electron gas and graphene are introduced. In the latter cas...

  3. The 2012 Moon and Mars Analog Mission

    Science.gov (United States)

    Graham, Lee

    2014-01-01

    The 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were completed on Mauna Kea volcano in Hawaii in July 2012. The investigations were conducted on the southeast flank of the Mauna Kea volcano at an elevation of approximately 11,500 ft. This area is known as "Apollo Valley" and is in an adjacent valley to the Very Large Baseline Array dish antenna.

  4. SOI design analog, memory and digital techniques

    CERN Document Server

    Marshall, Andrew

    2007-01-01

    Preface. Acknowledgements. 1. Overview. 2. SOI Materials. 3. Components. 4. SOI Modeling. 5. Layout for SOI. 6. Static SOI Design. 7. Dynamic SOI Design. 8. SOI SRAMs. 9. SOI DRAMs. 10. SOI Analog Design. 11. Global Design Issues. 12. Low Power Design. 13. SOI in Development. Appendix 1: Internet Sites (issue 1.0). Appendix 2: Trade Mark / Technology Information (issue 1.0). Index. About the Authors.

  5. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    OpenAIRE

    Shi Ke; Arlin G. Cameron; Wei Wang

    2012-01-01

    Two kinds of fluorescent hyaluronan (HA) analogs, one serving as normal imaging agent and the other used as a biosensitive contrast agent, were developed for the investigation of HA uptake and degradation. Our approach of developing HA imaging agents depends on labeling HA with varying molar percentages of a near-infrared (NIR) dye. At low labeling ratios, the hyaluronan uptake can be directly imaged while at high labeling ratios, the fluorescent signal is quenched and signal generation occur...

  6. Survey of Evaluated Isobaric Analog States

    Energy Technology Data Exchange (ETDEWEB)

    MacCormick, M., E-mail: maccorm@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud, 91406 Orsay CEDEX (France); Audi, G. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS/IN2P3, Université Paris-Sud, Bât. 108, F-91405 Orsay Campus (France)

    2014-06-15

    Isobaric analog states (IAS) can be used to estimate the masses of members belonging to the same isospin multiplet. Experimental and estimated IAS have been used frequently within the Atomic Mass Evaluation (AME) in the past, but the associated set of evaluated masses have been published for the first time in AME2012 and NUBASE2012. In this paper the current trends of the isobaric multiplet mass equation (IMME) coefficients are shown. The T = 2 multiplet is used as a detailed illustration.

  7. The exoplanets analogy to the Multiverse

    OpenAIRE

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct evidence for exopla...

  8. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  9. Synthesis and Biological Evaluation of Paclitaxel Analogs

    OpenAIRE

    Baloglu, Erkan

    2001-01-01

    The complex natural product paclitaxel (Taxol®), first isolated from Taxus brevifolia, is a member of a large family of taxane diterpenoids. Paclitaxel is extensively used for the treatment of solid tumors, particularly those of the breasts and ovaries. In order to obtain additional information about the mechanism of action of paclitaxel and the environment of the paclitaxel-binding site, several fluorescent analogs of paclitaxel were synthesized, and thei...

  10. An introduction to analog and digital communications

    CERN Document Server

    Haykin, Simon

    2012-01-01

    The second edition of this accessible book provides readers with an introductory treatment of communication theory as applied to the transmission of information-bearing signals. While it covers analog communications, the emphasis is placed on digital technology. It begins by presenting the functional blocks that constitute the transmitter and receiver of a communication system. Readers will next learn about electrical noise and then progress to multiplexing and multiple access techniques.

  11. Controller implementation using analog reconfigurable hardware (FPAA)

    OpenAIRE

    Fonseca, Paulo Jorge Rodrigues da

    2015-01-01

    This Thesis has the main target to make a research about FPAA/dpASPs devices and technologies applied to control systems. These devices provide easy way to emulate analog circuits that can be reconfigurable by programming tools from manufactures and in case of dpASPs are able to be dynamically reconfigurable on the fly. It is described different kinds of technologies commercially available and also academic projects from researcher groups. These technologies are very recent and...

  12. Difficulties in constructing Bose analogs to supergravity

    International Nuclear Information System (INIS)

    An alternative to the usual fermionic supersymmetry transformations is discussed, namely bosonic ones in which the particle helicities are changed by an integral multiple of h/2π. No matter how such transformations are carried out, it appears that the road to a local supersymmtric analog to supergravity is closed, either because no gauge field of the required rank to couple with the supercurrent exists, or because the non-interacting action is already locally invariant, and hence the supercurrent vanishes identically. (Auth.)

  13. Priming Analogical Reasoning with False Memories

    OpenAIRE

    Howe, M. L.; Garner, S. R.; Threadgold, E.; Ball, L. J.

    2015-01-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false mem...

  14. Analog "neuronal" networks in early vision

    OpenAIRE

    Koch, C; Marroquin, J; Yuille, A.

    1986-01-01

    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be "solved" by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the...

  15. Analog controllers using digital stochastic logic

    OpenAIRE

    Quero Reboul, José Manuel; S. L. Toral; García Ortega, Juan de la Cruz; García Franquelo, Leopoldo

    1999-01-01

    Stochastic logic is based on digital processing of a random pulse stream, where the information is codified as the probability of a high level in a finite sequence. The probability of the pulse stream codifies a continuous time variable. Subsequently, this pulse stream can be digitally processed to perform analog operations. In this paper we propose a stochastic approach to the digital implementation of complex controllers. This is approach allows for the realization of the controllers, and A...

  16. Analog gravity from field theory normal modes?

    OpenAIRE

    Barcelo, Carlos; Liberati, Stefano; Visser, Matt

    2001-01-01

    We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the large number of ``analog models'' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is something more fundamental going on. Indeed, linearization of a classical field theory (a field theoretic ...

  17. Backtracking quantum trajectories with analog feedback

    Science.gov (United States)

    de Lange*, G.; Ristè*, D.; Tiggelman, M. J.; Eichler, C.; Tornberg, L.; Johansson, G.; Wallraff, A.; Schouten, R. N.; Dicarlo, L.

    2014-03-01

    Circuit quantum electrodynamics offers a nearly ideal platform for the fundamental study of continuous quantum measurement. A nondemolition measurement of a superconducting qubit can be performed via homodyne detection of microwave transmission through a dispersively coupled cavity. By boosting the homodyne signal with a nearly noiseless phase-sensitive parametric amplifier, we experimentally show that a form of measurement backaction, consisting of stochastic quantum phase kicks on the measured qubit, is highly correlated with the fluctuations in the continuous homodyne record. We demonstrate a real-time analog feedback scheme that counteracts these phase kicks and thereby reduces measurement-induced dephasing. We develop a numerical optimization technique to overcome the bandwidth limitations of the amplification chain and provide a theoretical model for the optimization result. A quantum efficiency of 50% is extracted for the complete analog feedback loop. Finally, we discuss the integration of this analog feedback technique to improve performance in our recent demonstration of entanglement by dispersive parity measurement. *equal contribution. Research funded by NWO and the EU projects SOLID and SCALEQIT.

  18. ANALOG SIGNAL PROCESSING SOLUTION FOR IMAGE ALIGNMENT

    Directory of Open Access Journals (Sweden)

    Nihar Athreyas

    2014-11-01

    Full Text Available Imaging and Image sensors is a field that is continuously evolving. There are new products coming into the market every day. Some of these have very severe Size, Weight and Power constraints whereas other devices have to handle very high computational loads. Some require both these conditions to be met simultaneously. Current imaging architectures and digital image processing solutions will not be able to meet these ever increasing demands. There is a need to develop novel imaging architectures and image processing solutions to address these requirements. In this work we propose analog signal processing as a solution to this problem. The analog processor is not suggested as a replacement to a digital processor but it will be used as an augmentation device which works in parallel with the digital processor, making the system faster and more efficient. In order to show the merits of analog processing the highly computational Normalized Cross Correlation algorithm is implemented. We propose two novel modifications to the algorithm and a new imaging architecture which, significantly reduces the computation time.

  19. Theory of analogous force on number sets

    International Nuclear Information System (INIS)

    A general statistical thermodynamic theory that considers given sequences of x-integers to play the role of particles of known type in an isolated elastic system is proposed. By also considering some explicit discrete probability distributions px for natural numbers, we claim that they lead to a better understanding of probabilistic laws associated with number theory. Sequences of numbers are treated as the size measure of finite sets. By considering px to describe complex phenomena, the theory leads to derive a distinct analogous force fx on number sets proportional to (∂px/∂x)T at an analogous system temperature T. In particular, this yields to an understanding of the uneven distribution of integers of random sets in terms of analogous scale invariance and a screened inverse square force acting on the significant digits. The theory also allows to establish recursion relations to predict sequences of Fibonacci numbers and to give an answer to the interesting theoretical question of the appearance of the Benford's law in Fibonacci numbers. A possible relevance to prime numbers is also analyzed. (author)

  20. Analog "neuronal" networks in early vision.

    Science.gov (United States)

    Koch, C; Marroquin, J; Yuille, A

    1986-01-01

    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be "solved" by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the cost function is nonquadratic, raising the question of designing efficient algorithms for computing the optimal solution. Recently, Hopfield and Tank [Hopfield, J. J. & Tank, D. W. (1985) Biol. Cybern. 52, 141-152] have shown that networks of nonlinear analog "neurons" can be effective in computing the solution of optimization problems. We show how these networks can be generalized to solve the nonconvex energy functionals of early vision. We illustrate this approach by implementing a specific analog network, solving the problem of reconstructing a smooth surface from sparse data while preserving its discontinuities. These results suggest a novel computational strategy for solving early vision problems in both biological and real-time artificial vision systems. PMID:3459172

  1. Analog ``Neuronal'' Networks in Early Vision

    Science.gov (United States)

    Koch, Christof; Marroquin, Jose; Yuille, Alan

    1986-06-01

    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be ``solved'' by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the cost function is nonquadratic, raising the question of designing efficient algorithms for computing the optimal solution. Recently, Hopfield and Tank [Hopfield, J. J. & Tank, D. W. (1985) Biol. Cybern. 52, 141-152] have shown that networks of nonlinear analog ``neurons'' can be effective in computing the solution of optimization problems. We show how these networks can be generalized to solve the nonconvex energy functionals of early vision. We illustrate this approach by implementing a specific analog network, solving the problem of reconstructing a smooth surface from sparse data while preserving its discontinuities. These results suggest a novel computational strategy for solving early vision problems in both biological and real-time artificial vision systems.

  2. Radiolabeled somatostatin analogs: Biodistribution and pharmacokinetics

    International Nuclear Information System (INIS)

    Different somatostatin analogs labeled with iodine-123 or indium-111 are currently used for the scintigraphic in vivo detection of somatostatin receptor expression by neuroendocrine tumors. The general features of the biodistribution of iodine-123-Tyr3-octreotide are the rapid clearance from the circulation and the predominantly hepatobiliary excretion. This pathway of excretion leads to a considerable amount of activity in the bowels and thus may compromise the diagnostic reliability of somatostatin receptor scintigraphy in gastroentereopancreatic tumors. In contrast, up to 85% of the applied dose of indium-111 labeled pentreotide is cleared from the circulation via the kidneys. High receptor density and affinity as well as the small molecular size of the labeled somatostatin analogs are most likely responsible for the observed rapid tumor visualization within a few hours after intravenous application of the radiopharmaceuticals. Continuous treatment with somatostatin analogs changes the biodistribution of indium-111 pentetreotide, but the diagnostic reliability of somatostatin receptor scintigraphy is not necessarily compromised under these therapeutic conditions. (orig./MG)

  3. Automated Generation of Cross-Domain Analogies via Evolutionary Computation

    CERN Document Server

    Baydin, Atilim Gunes; Ontanon, Santiago

    2012-01-01

    Analogy plays an important role in creativity, and is extensively used in science as well as art. In this paper we introduce a technique for the automated generation of cross-domain analogies based on a novel evolutionary algorithm (EA). Unlike existing work in computational analogy-making restricted to creating analogies between two given cases, our approach, for a given case, is capable of creating an analogy along with the novel analogous case itself. Our algorithm is based on the concept of "memes", which are units of culture, or knowledge, undergoing variation and selection under a fitness measure, and represents evolving pieces of knowledge as semantic networks. Using a fitness function based on Gentner's structure mapping theory of analogies, we demonstrate the feasibility of spontaneously generating semantic networks that are analogous to a given base network.

  4. Influences of Stocking Salmon Carcass Analogs on Salmonids in Yakima River Tributaries, 2001-2002 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Pearsons, Todd N.; Johnson, Christopher L. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-04-01

    The benefits that marine derived nutrients from adult salmon carcasses provide to juvenile salmonids are increasingly being recognized. Current estimates suggest that only 6-7% of marine-derived nitrogen and phosphorus that were historically available to salmonids in the Pacific Northwest are currently available. Food limitation may be a major constraint limiting the restoration of salmonids. A variety of methods have been proposed to offset this nutrient deficit including: allowing greater salmon spawning escapement, stocking hatchery salmon carcasses, and stocking inorganic nutrients. Unfortunately, each of these methods has some ecological or socio-economic shortcoming. We intend to overcome many of these shortcomings by making and evaluating a pathogen free product that simulates a salmon carcass (analog). Abundant sources of marine derived nutrients are available such as fish offal from commercial fishing and salmon carcasses from hatcheries. However, a method for recycling these nutrients into a pathogen free analog that degrades at a similar rate as a natural salmon carcass has never been developed. We endeavored to (1) develop a salmon carcass analog that will increase the food available to salmonids, (2) determine the pathways that salmonids use to acquire food from analogs, and (3) determine the benefits to salmonids and the potential for application to salmonid restoration. We used a before-after-control-impact-paired design in six tributaries of the upper Yakima basin to determine the utility of stocking carcass analogs. Our preliminary results suggest that the introduction of carcass analogs into food-limited streams can be used to restore food pathways previously provided by anadromous salmon. The analogs probably reproduced both of the major food pathways that salmon carcasses produce: direct consumption and food chain enhancement. Trout and salmon fed directly on the carcass analogs during the late summer and presumably benefited from the increased

  5. High-stage analog accumulator for TDI CMOS image sensors

    Science.gov (United States)

    Jianxin, Li; Fujun, Huang; Yong, Zong; Jing, Gao

    2016-02-01

    The impact of the parasitic phenomenon on the performance of the analog accumulator in TDI CMOS image sensor is analyzed and resolved. A 128-stage optimized accumulator based on 0.18-μm one-poly four-metal 3.3 V CMOS technology is designed and simulated. A charge injection effect from the top plate sampling is employed to compensate the un-eliminated parasitics based on the accumulator with a decoupling switch, and then a calibration circuit is designed to restrain the mismatch and Process, Voltage and Temperature (PVT) variations. The post layout simulation indicates that the improved SNR of the accumulator upgrades from 17.835 to 21.067 dB, while an ideal value is 21.072 dB. In addition, the linearity of the accumulator is 99.62%. The simulation results of two extreme cases and Monte Carlo show that the mismatch and PVT variations are restrained by the calibration circuit. Furthermore, it is promising to design a higher stage accumulator based on the proposed structure. Project supported by the National Natural Science Foundation of China (Nos. 61404090, 61434004).

  6. NMR analog of Bell's inequalities violation test

    Energy Technology Data Exchange (ETDEWEB)

    Souza, A M; Oliveira, I S; Sarthour, R S [Centro Brasileiro de Pesquisas FIsicas, Rua Dr Xavier Sigaud 150, Rio de Janeiro 22290-180, RJ (Brazil); Magalhaes, A; Teles, J; Azevedo, E R de; Bonagamba, T J [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, PO Box 369, Sao Carlos 13560-970, SP (Brazil)], E-mail: amsouza@cbpf.br

    2008-03-15

    In this paper, we present an analog of Bell's inequalities violation test for N qubits to be performed in a nuclear magnetic resonance (NMR) quantum computer. This can be used to simulate or predict the results for different Bell's inequality tests, with distinct configurations and a larger number of qubits. To demonstrate our scheme, we implemented a simulation of the violation of the Clauser, Horne, Shimony and Holt (CHSH) inequality using a two-qubit NMR system and compared the results to those of a photon experiment. The experimental results are well described by the quantum mechanics theory and a local realistic hidden variables model (LRHVM) that was specifically developed for NMR. That is why we refer to this experiment as a simulation of Bell's inequality violation. Our result shows explicitly how the two theories can be compatible with each other due to the detection loophole. In the last part of this work, we discuss the possibility of testing some fundamental features of quantum mechanics using NMR with highly polarized spins, where a strong discrepancy between quantum mechanics and hidden variables models can be expected.

  7. Bolometer Simulation Using SPICE

    Science.gov (United States)

    Jones, Hollis H.; Aslam, Shahid; Lakew, Brook

    2004-01-01

    A general model is presented that assimilates the thermal and electrical properties of the bolometer - this block model demonstrates the Electro-Thermal Feedback (ETF) effect on the bolometers performance. This methodology is used to construct a SPICE model that by way of analogy combines the thermal and electrical phenomena into one simulation session. The resulting circuit diagram is presented and discussed.

  8. Functional DNA: Teaching Infinite Series through Genetic Analogy

    Science.gov (United States)

    Kowalski, R. Travis

    2011-01-01

    This article presents an extended analogy that connects infinite sequences and series to the science of genetics, by identifying power series as "DNA for a function." This analogy allows standard topics such as convergence tests or Taylor approximations to be recast in a "forensic" light as mathematical analogs of genetic concepts such as DNA…

  9. Analog implementation of radix-2, 16-FFT processor for OFDM receivers: non-linearity behaviours and system performance analysis

    Science.gov (United States)

    Mokhtarian, N.; Hodtani, G. A.

    2015-12-01

    Analog implementations of decoders have been widely studied by considering circuit complexity, as well as power and speed, and their integration with other analog blocks is an extension of analog decoding research. In the front-end blocks of orthogonal frequency-division multiplexing (OFDM) systems, combination of an analog fast Fourier transform (FFT) with an analog decoder is suitable. In this article, the implementation of a 16-symbol FFT processor based on analog complementary metal-oxide-semiconductor current mirrors within circuit and system levels is presented, and the FFT is implemented using a butterfly diagram, where each node is implemented using analog circuits. Implementation details include consideration of effects of transistor mismatch and inherent noises and effects of circuit non-linearity in OFDM system performance. It is shown that not only can transistor inherent noises be measured but also transistor mismatch can be applied as an input-referred noise source that can be used in system- and circuit-level studies. Simulations of a radix-2, 16-symbol FFT show that proposed circuits consume very low power, and impacts of noise, mismatch and non-linearity for each node of this processor are very small.

  10. Stable carbon isotope fractionation by methanogens growing on different Mars regolith analogs

    Science.gov (United States)

    Sinha, Navita; Kral, Timothy A.

    2015-07-01

    In order to characterize stable carbon (13C/12C) isotope fractionation of metabolically produced methane by methanogens in martian settings, Methanothermobacter wolfeii, Methanosarcina barkeri, and Methanobacterium formicicum were cultured on four different Mars regolith analogs - JSC Mars-1, Artificial Mars Simulant, montmorillonite, and Mojave Mars Simulant - and also in their growth supporting media. These chemoautotrophic methanogens utilize CO2 for their carbon source and H2 for their energy source. When compared to the carbon isotope signature of methane when grown on their respective growth media, M. wolfeii and M. barkeri demonstrated variability in carbon isotope fractionation values during methanogenesis on the Mars analogs, while M. formicicum showed subtle or negligible difference in carbon isotope fractionation values. Interestingly, M. wolfeii and M. barkeri have shown relatively consistent enriched values of 12C on montmorillonite, a kind of clay found on Mars, compared to other Mars regolith analogs. In general, M. barkeri showed large carbon isotope fractionation compared to M. wolfeii and M. formicicum during methanognesis on various kinds of analogs. Stable carbon isotope fractionation is one of the techniques used to infer different origins, environments, and pathways of methanogensis. The results obtained in this novel research can provide clues to determine ambiguous sources of methane on Mars.

  11. An optimized analog to digital converter for WLAN analog front end

    International Nuclear Information System (INIS)

    A 10 bit 80 MSPS analog to digital converter optimized for WLAN analog front end is presented. In contrast to conventional 1.5 bit pipeline architecture, four optimized multi-bit multiply digital to analog converter stages are implemented. An on-chip low-noise reference buffer is proposed for SoC integration purposes, and a wide-bandwidth wide swing sample and hold amplifier is also presented for achieving a good dynamic range. The converter was fabricated in 0.18 μm 1P6M CMOS technology, and the core area occupies approximately 0.85 mm2. Measured results show that with an 11 MHz input signal, it provides a 9.4 bit effective number of bits and a 72 dBc spurious frequency dynamic range when sampled at 80 MHz. (semiconductor integrated circuits)

  12. Graveoline Analogs Exhibiting Selective Acetylcholinesterase Inhibitory Activity as Potential Lead Compounds for the Treatment of Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Zeng Li

    2016-01-01

    Full Text Available This study designed and synthesized a series of new graveoline analogs on the basis of the structural characteristics of acetylcholinesterase (AChE dual-site inhibitors. The activity of these analogs was also evaluated. Results showed that the synthesized graveoline analogs displayed stronger inhibitory activity against AChE and higher selectivity than butyrylcholine esterase (BuChE (Selectivity Index from 45 to 486. When the two sites in the graveoline parent ring substituting phenyl and amino terminal had six chemical bonds (n = 3 and the terminal amino was piperidine, compound 5c showed the best activity. Furthermore, the mechanism of action and binding mode were explored by enzyme kinetic simulation, molecular docking, and thioflavin T-based fluorometric assay. Cytotoxicity assay showed that the low concentration of the analogs did not affect the viability of the neurocyte SH-SY5Y.

  13. Historical financial analogies of the current crisis

    OpenAIRE

    Andrada-Félix, Julián; Fernández Rodríguez, Fernando; Sosvilla Rivero, Simón Javier

    2011-01-01

    Este trabajo intenta arrojar luz sobre las analogías históricas de la crisis actual. Para ello se compara la distribución de los rendimientos del Índice Dow Jones Industrial Average durante un período de 769 días (del 15 de septiembre de 2008, la quiebra de Lehman Brothers, hasta septiembre de 2011), con todas las distribuciones históricas posibles de rendimientos calculados con una ventana móvil de 769 días desde el 2 de enero de 1900 al 12 de septiembre de 2008. Mediante el uso de un contra...

  14. High fluid intelligence and analogical reasoning

    OpenAIRE

    Preusse, Franziska

    2011-01-01

    Hitherto, previous studies on the cerebral correlates of fluid intelligence (fluIQ) used tasks that did not exclusively demand fluIQ, or were restricted to participants of average fluIQ (ave-fluIQ) solving intelligence test items of varying difficulty, thus not allowing assumptions on interindividual differences in fluIQ. Geometric analogical reasoning (GAR) demands fluIQ very purely and thus is an eligible approach for research on interindividual differences in fluIQ. In a first study, we ...

  15. An optical analog of quantum optomechanics

    CERN Document Server

    Rodríguez-Lara, B M

    2014-01-01

    We present a two-dimensional array of nearest-neighbor coupled waveguides that is the optical analog of a quantum optomechanical system. We show that the quantum model predicts the appearance of effective column isolation, diagonal-coupling and other non-trivial couplings in the two-dimensional photonic lattice under a standard approximation from ion-trap cavity electrodynamics. We provide an approximate impulse function for the case of effective column isolation and compare it with exact numerical propagation in the photonic lattice.

  16. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. PMID:21982934

  17. Analogy perception applied to seven tests of word comprehension

    CERN Document Server

    Turney, Peter D

    2011-01-01

    It has been argued that analogy is the core of cognition. In AI research, algorithms for analogy are often limited by the need for hand-coded high-level representations as input. An alternative approach is to use high-level perception, in which high-level representations are automatically generated from raw data. Analogy perception is the process of recognizing analogies using high-level perception. We present PairClass, an algorithm for analogy perception that recognizes lexical proportional analogies using representations that are automatically generated from a large corpus of raw textual data. A proportional analogy is an analogy of the form A:B::C:D, meaning "A is to B as C is to D". A lexical proportional analogy is a proportional analogy with words, such as carpenter:wood::mason:stone. PairClass represents the semantic relations between two words using a high-dimensional feature vector, in which the elements are based on frequencies of patterns in the corpus. PairClass recognizes analogies by applying s...

  18. Investigation of detonation velocity in heterogeneous explosive system using the reactive Burgers' analog

    Science.gov (United States)

    Di Labbio, G.; Kiyanda, C. B.; Mi, X.; Higgins, A. J.; Nikiforakis, N.; Ng, H. D.

    2016-06-01

    In this study, the applicability of the Chapman-Jouguet (CJ) criterion is tested numerically for heterogeneous explosive media using a simple detonation analog. The analog system consists of a reactive Burgers' equation coupled with an Arrhenius type reaction wave, and the heterogeneity of the explosive media is mimicked using a discrete energy source approach. The governing equation is solved using a second order, finite-volume approach and the average propagation velocity of the discrete detonation is determined by tracking the leading shock front. Consistent with previous studies, the averaged velocity of the leading shock front from the unsteady numerical simulations is also found to be in good agreement with the velocity of a CJ detonation in a uniform medium wherein the energy source is spatially homogenized. These simulations have thus implications for whether the CJ criterion is valid to predict the detonation velocity in heterogeneous explosive media.

  19. Analog domain adaptive equalizer for low power 40 Gbps DP-QPSK receivers

    Indian Academy of Sciences (India)

    Nandakumar Nambath; Pawan Kumar Moyade; Allmin Ansari; Shalabh Gupta

    2014-04-01

    Electrical domain equalization of chromatic and polarization mode dispersion is attractive in coherent optical communication links. Digital coherent receivers used for this purpose are based on high speed ADCs followed by DSP, which dissipate excessive amount of power and are very costly to implement. We propose analog coherent receiver to drastically reduce the power consumption, size and cost. An adaptive feed forward equalizer for 40 Gbps dual polarization quadrature phase shift keying (DP-QPSK) systems, which processes signals in analog domain itself, is demonstrated using circuit and system simulations. The equalizer, designed in 90 nm CMOS technology, consumes 450 mW of power and occupies 1.8 mm × 1.1 mm chip area. System simulations are used to show that blind equalization is also possible when this approach is used in decision directed mode.

  20. X-ray Emission from Early Universe Analog Galaxies

    Science.gov (United States)

    Brorby, Matthew; Kaaret, Philip; Prestwich, Andrea H.; Mirabel, I. Felix; Feng, Hua

    2016-01-01

    Around 300,000 years after the Big Bang, the Universe had cooled enough to combine and form neutral atoms. This signified the beginning of a time known as the Dark Ages. Neutral matter began to fall into the dark matter gravitational wells that were seeded after the initial moments of the Big Bang. As the first stars and galaxies formed within these gravitational wells, the surrounding baryonic matter was heated and started to ionize. The source of energetic photons that heated and reionized the early Universe remains uncertain. Early galaxies had low metallicity and recent population synthesis calculations suggest that the number and luminosity of high-mass X-ray binaries are enhanced in star-forming galaxies with low metallicity, offering a potentially important and previously overlooked source of heating and reionization. Here we examine two types of local galaxies that have been shown to be good analogs to the early galaxies in the Universe: Blue compact dwarf galaxies (BCDs) and Lyman Break Analogs (LBAs).A BCD is defined by its blue optical colors, low metallicities, and physically small size. This makes BCDs the best available local analogs for early star formation. We analyzed data from a sample of 25 metal-poor BCDs and compared our results with those of near-solar metallicity galaxies. Using a Bayesian approach, we showed that the X-ray luminosity function for the low-metallicity BCDs is significantly elevated relative to the XLF for near-solar metallicity galaxies.Larger, gas-rich galaxies may have formed shortly after these first galaxies. These larger galaxies would be similar in their properties to the high-redshift Lyman break galaxies (LBGs). LBAs provide the best local comparison to the LBGs. We studied a sample of 10 LBAs in order to measure the relation between star formation rate and X-ray luminosity for these galaxies. We found that for LBAs with intermediate sub-solar metallicities, there is enhanced X-ray emission relative to the expected

  1. Comparison between analog and digital filters

    Directory of Open Access Journals (Sweden)

    Zoltan Erdei

    2010-12-01

    Full Text Available Digital signal processing(DSP is one of the most powerful technologies and will model science and engineering in the 21st century. Revolutionary changes have already been made in different areas of research such as communications, medical imaging, radar and sonar technology, high fidelity audio signal reproducing etc. Each of these fields developed a different signal processing technology with its own algorithms, mathematics and technology, Digital filters are used in two general directions: to separate mixed signals and to restore signals that were compromised in different modes. The objective of this paper is to compare some basic digital filters versus analog filters such as low-pass, high-pass, band-pass filters. Scientists and engineers comprehend that, in comparison with analog filters, digital filters can process the same signal in real-time with broader flexibility. This understanding is considered important to instill incentive for engineers to become interested in the field of DSP. The analysis of the results will be made using dedicated libraries in MATLAB and Simulink software, such as the Signal Processing Toolbox.

  2. Beryllium Abundances of Solar-Analog Stars

    CERN Document Server

    Takeda, Yoichi; Honda, Satoshi; Kawanomoto, Satoshi; Ando, Hiroyasu; Sakurai, Takashi

    2011-01-01

    An extensive beryllium abundance analysis was conducted for 118 solar analogs (along with 87 FGK standard stars) by applying the spectrum synthesis technique to the near-UV region comprising the Be II line at 3131.066 A, in an attempt to investigate whether Be suffers any depletion such as the case of Li showing a large diversity. We found that, while most of these Sun-like stars are superficially similar in terms of their A(Be) (Be abundances) around the solar value within ~ +/- 0.2dex, 4 out of 118 samples turned out strikingly Be-deficient (by more than ~2 dex) and these 4 stars belong to the group of lowest v_e sin i (projected rotation velocity). Moreover, even for the other majority showing an apparent similarity in Be, we can recognize a tendency that A(Be) gradually increases with an increase in v_e sin i. These observational facts suggest that any solar analog star (including the Sun) generally suffers some kind of Be depletion during their lives, where the rotational velocity (or the angular momentu...

  3. Isolation and characterization of soybean NBS analogs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Isolation of plant resistance genes is greatly helpful to crop resistance breeding and the insight of resistance mechanism. The cloned plant resistance genes are classified into four classes according to their putative structural domain, of which the majority possesses nucleotide-binding site (NBS) domain that consists of P-loop, kinase2a and kinase3a. The conservation of this domain affords the potential possibility of cloning the plant resistance genes, which is homology-based cloning technique. In the present study, the degenerate oligonucleotide primers were designed according to the tobacco N and Arabidopsis RPS2, and 358 clones were isolated from the genomic DNA of resistance soybean cultivar Kefeng1, resistant to soybean mosaic virus, and 4 open-reading NBS analogs were finally characterized and designated as KNBS1, KNBS2, KNBS3 and KNBS4. Southern hybridization suggested that they were present with multicopy in the soybean genome; KNBS4 was mapped to F linkage group and KNBS2 co-located J linkage group with the SCAR marker of Rsa resistant to soybean mosaic virus by RFLP analysis. Northern analysis suggested that KNBS2- related sequence was low and constitutively expressed in the root, stem and leaves of soybean. The detailed characterization of NBS analogs is very helpful to ultimately cloning the soybean resistance gene.

  4. AFEII Analog Front End Board Design Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Rubinov, Paul; /Fermilab

    2005-04-01

    This document describes the design of the 2nd iteration of the Analog Front End Board (AFEII), which has the function of receiving charge signals from the Central Fiber Tracker (CFT) and providing digital hit pattern and charge amplitude information from those charge signals. This second iteration is intended to address limitations of the current AFE (referred to as AFEI in this document). These limitations become increasingly deleterious to the performance of the Central Fiber Tracker as instantaneous luminosity increases. The limitations are inherent in the design of the key front end chips on the AFEI board (the SVXIIe and the SIFT) and the architecture of the board itself. The key limitations of the AFEI are: (1) SVX saturation; (2) Discriminator to analog readout cross talk; (3) Tick to tick pedestal variation; and (4) Channel to channel pedestal variation. The new version of the AFE board, AFEII, addresses these limitations by use of a new chip, the TriP-t and by architectural changes, while retaining the well understood and desirable features of the AFEI board.

  5. The exoplanets analogy to the Multiverse

    CERN Document Server

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct evidence for exoplanets that appeared since the 90s. We argue that the fine-tuning of Earth to life (and not only the fine-tuning of life to Earth) could predict with certainty the existence of exoplanets decades or even centuries before that direct evidence. Several other predictions can be made by studying only the Earth and the Sun, without any information about stars. The analogy also shows that theories that defend that the Earth is the unique existing planet and that, at the same time, is fine-tuned to life by pure chance (or pure phy...

  6. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    Directory of Open Access Journals (Sweden)

    Shi Ke

    2012-02-01

    Full Text Available Two kinds of fluorescent hyaluronan (HA analogs, one serving as normal imaging agent and the other used as a biosensitive contrast agent, were developed for the investigation of HA uptake and degradation. Our approach of developing HA imaging agents depends on labeling HA with varying molar percentages of a near-infrared (NIR dye. At low labeling ratios, the hyaluronan uptake can be directly imaged while at high labeling ratios, the fluorescent signal is quenched and signal generation occurs only after degradation. It is found that the conjugate containing 1%–2% NIR dye can be used as a normal optical imaging agent, while bioactivable imaging agents are formed at 6% to 17% dye loading. It was determined that the conjugation of dye to HA with different loading percentages does not impact HA biodegradation by hyaluronidase (Hyal. The feasibility of using these two NIR fluorescent hyaluronan analogs for HA investigation was evaluated in vivo with optical imaging. The data demonstrates that the 1% dye loaded fluorescent HA can be used to monitor the behavior of HA and its fragments, whereas bioactivatable HA imaging agent (17% dye in HA is more suitable for detecting HA fragments.

  7. Palytoxin and Analogs: Biological and Ecological Effects

    Directory of Open Access Journals (Sweden)

    Vítor Ramos

    2010-06-01

    Full Text Available Palytoxin (PTX is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems.

  8. Four channel analog router for spectroscopy applications

    International Nuclear Information System (INIS)

    A four input analog multiplexer/router has been developed in order to acquire spectral data from four different detector systems on first-come-first-sort basis. The circuit is incorporated in a single width NIM module and is fully compatible with the HPD 4K MCA developed in the Health Physics Division. The analog router accepts output from upto 4 detectors after these are passed through individual preamplifiers and linear amplifiers. The router generates signal for the channel whose input crosses set LLD limits first and simultaneously disables other inputs. The selected input is then passed to the ADC for further processing. The processed signal generates a channel dependent two bit address along with normal digital outputs of the ADC. The channel dependent two bit address is directly used to store the event in one of the four 1k segment of the HPD 4K MCA. The multiplexer is re-enabled to accept next input on priority basis. One such unit has already been commissioned to acquire data from four solid state detectors used for spectrometry. The paper discusses hardware of the router, its linearity resolution cross-talk between the channels and other performance characteristics. (author). 3 figs

  9. Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

    Directory of Open Access Journals (Sweden)

    Ricardo Costa

    2013-01-01

    Full Text Available Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT scans, magnetic resonance imaging (MRI, and positron emission tomography (PET/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU.

  10. Operational Lessons Learned from NASA Analog Missions

    Science.gov (United States)

    Arnold, Larissa S.

    2010-01-01

    vehicle and system capabilities are required to support the activities? How will the crew and the Earth-based mission control team interact? During the initial phases of manned planetary exploration, one challenge in particular is virtually the same as during the Apollo program: How can scientific return be maximized during a relatively short surface mission? Today, NASA is investigating solutions to these challenges by conducting analog missions. These Earth-based missions possess characteristics that are analogous to missions on the Moon or Mars. These missions are excellent for testing operational concepts, and the design, configuration, and functionality of spacesuits, robots, rovers, and habitats. Analog mission crews test specific techniques and procedures for surface field geology, biological sample collection, and planetary protection. The process of actually working an analog mission reveals a myriad of small details, which either contribute to or impede efficient operations, many of which would never have been thought about otherwise. It also helps to define the suite of tools, containers, and other small equipment that surface explorers will use. This paper focuses on how analog missions have addressed selected operational considerations for future planetary missions.

  11. Time and Frequency Domain Investigation of Selected Memristor Based Analog Circuits

    OpenAIRE

    Dongale, T. D.; Gaikwad, P. K.; Kamat, R. K.

    2016-01-01

    In this paper we investigate few memristor based analog circuits namely the phase shift oscillator, integrator and differentiator which have been explored numerously using the traditional lumped components. We use LTspice-IV platform for simulation of the above said circuits. The investigation resorts to the nonlinear dopent drift model of memristor and the window function portrayed in the literature for nonlinearity realization. The results of our investigations depict good agreement with th...

  12. An Ohm's law analogy for the effective diffusivity of composite media

    Science.gov (United States)

    Alvarez-Ramirez, J.; Valdes-Parada, F. J.; Ibarra-Valdez, C.

    2016-04-01

    The aim of this work is to obtain an equation for the effective diffusivity of permeable composite media based on an analogy with Ohm's law of electricity. Here, particles are transported across a composite medium, which is seen as an arrangement of series and parallel resistances. Comparison with simulations of Brownian particles traveling through the successive walls of the medium showed good agreement for moderate inclusion-to-continuous medium diffusivity ratio.

  13. Gating of the Mitochondrial Permeability Transition Pore by Long Chain Fatty Acyl Analogs in Vivo*

    OpenAIRE

    Samovski, Dmitri; Kalderon, Bella; Yehuda-Shnaidman, Einav; Bar-Tana, Jacob

    2009-01-01

    The role played by long chain fatty acids (LCFA) in promoting energy expenditure is confounded by their dual function as substrates for oxidation and as putative classic uncouplers of mitochondrial oxidative phosphorylation. LCFA analogs of the MEDICA (MEthyl-substituted DICarboxylic Acids) series are neither esterified into lipids nor β-oxidized and may thus simulate the uncoupling activity of natural LCFA in vivo, independently of their substrate role. Treatment of rats or cell lines with M...

  14. Parallel analog VLSI architectures for computation of heading direction and time-to-contact

    OpenAIRE

    Indiveri, Giacomo; Kramer, Jörg; Koch, Christof

    1996-01-01

    We describe two parallel analog VLSI architectures that integrate optical flow data obtained from arrays of elementary velocity sensors to estimate heading direction and time-to-contact. For heading direction computation, we performed simulations to evaluate the most important qualitative properties of the optical flow field and determine the best functional operators for the implementation of the architecture. For time-to-contact we exploited the divergence theorem to integrate data from ...

  15. An analog VLSI real time optical character recognition system based on a neural architecture

    International Nuclear Information System (INIS)

    In this paper a real time Optical Character Recognition system is presented: it is based on a feature extraction module and a neural network classifier which have been designed and fabricated in analog VLSI technology. Experimental results validate the circuit functionality. The results obtained from a validation based on a mixed approach (i.e., an approach based on both experimental and simulation results) confirm the soundness and reliability of the system

  16. Implementation of a Simulated Annealing algorithm for Matlab

    OpenAIRE

    Moins, Stephane

    2002-01-01

    In this report we describe an adaptive simulated annealing method for sizing the devices in analog circuits. The motivation for use an adaptive simulated annealing method for analog circuit design are to increase the efficiency of the design circuit. To demonstrate the functionality and the performance of the approach, an operational transconductance amplifier is simulated. The circuit is modeled with symbolic equations that are derived automatically by a simulator.

  17. Investigation of flip-flop effects in a linear analog comparator-with-hysteresis circuit

    International Nuclear Information System (INIS)

    The impact of the positive feedback loop on analog single event transient (ASET) shapes was investigated for a comparator- with-hysteresis circuit. Simulation based on previous developed ASET simulation tool is used to model the impact of the power supply voltage, the input voltage level and the injected energy. Simulation results show that these kinds of circuits are sensitive to flip-flop effects. This phenomenon occurs if the input voltage is in the hysteresis band range. In this case, simulations show that the ASET can latch the output into a non-desired state by changing the state of the circuit on his transfer characteristic curves. Laser experiments were conducted and show that the simulation outputs are in agreement with the experimental collected data. (authors)

  18. Four-gate transistor analog multiplier circuit

    Science.gov (United States)

    Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)

    2011-01-01

    A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.

  19. READ - Remote Analog ASIC Design System

    Directory of Open Access Journals (Sweden)

    Michael E. Auer

    2006-11-01

    Full Text Available The scope of this work is to present a solution to implement a remote electronic laboratory for testing and designing analog ASICs (ispPAC10. The application allows users to create circuit schematics, upload the design to the device and perform measurements. The software used for designing circuits is the PAC-Designer and it runs on a Citrix server. The signals are generated and the responses are acquired by a data acquisition board controlled by LabView. The virtual instruments interact with some ActiveX controls specially designed to look like real oscilloscope and function generator devices and represent the user interface of the lab. These ActiveX give users the control over the LabView VIs and the access to its facilities in order to perform electronic exercises.

  20. Analog Electronic Filters Theory, Design and Synthesis

    CERN Document Server

    Dimopoulos, Hercules G

    2012-01-01

    Filters are essential subsystems in a huge variety of electronic systems. Filter applications are innumerable; they are used for noise reduction, demodulation, signal detection, multiplexing, sampling, sound and speech processing, transmission line equalization and image processing, to name just a few. In practice, no electronic system can exist without filters. They can be found in everything from power supplies to mobile phones and hard disk drives and from loudspeakers and MP3 players to home cinema systems and broadband Internet connections. This textbook introduces basic concepts and methods and the associated mathematical and computational tools employed in electronic filter theory, synthesis and design.  This book can be used as an integral part of undergraduate courses on analog electronic filters. Includes numerous, solved examples, applied examples and exercises for each chapter. Includes detailed coverage of active and passive filters in an independent but correlated manner. Emphasizes real filter...

  1. Simple analogs of the toxin callicarpone.

    Science.gov (United States)

    McChesney, J D; Kabra, P M; Fraher, P

    1979-09-01

    Callicarpone, a component 10 times as toxic to fish as rotenone, has been isolated from the leaves of Callicarpa candicans. It is reasonable to assume that callicarpone will act as an insecticidal agent as does rotenone. Therefore, the structure-activity relationship of callicarpone was examined by synthesizing a series of compounds having certain of its structural features. Those compounds were tested for insecticidal and antimicrobial activities. A study of synthetic analogs elucidated the functional group chemistry of callicarpone so that a synthesis might be undertaken. Piperitone oxide showed approximately 1/100th the activity of rotenone against Daphnia magna. 1-(alpha-Hydroxyisopropyl)-3-oxocyclohexene oxide showed activity against myobacterium while 2,3,4,6,7,8-hexahydronaphthalene-1,4-dione showed inhibitory activity against the mycobacterium and two yeasts. PMID:501532

  2. Test signal generation for analog circuits

    Science.gov (United States)

    Burdiek, B.; Mathis, W.

    2003-05-01

    In this paper a new test signal generation approach for general analog circuits based on the variational calculus and modern control theory methods is presented. The computed transient test signals also called test stimuli are optimal with respect to the detection of a given fault set by means of a predefined merit functional representing a fault detection criterion. The test signal generation problem of finding optimal test stimuli detecting all faults form the fault set is formulated as an optimal control problem. The solution of the optimal control problem representing the test stimuli is computed using an optimization procedure. The optimization procedure is based on the necessary conditions for optimality like the maximum principle of Pontryagin and adjoint circuit equations.

  3. Test signal generation for analog circuits

    Directory of Open Access Journals (Sweden)

    B. Burdiek

    2003-01-01

    Full Text Available In this paper a new test signal generation approach for general analog circuits based on the variational calculus and modern control theory methods is presented. The computed transient test signals also called test stimuli are optimal with respect to the detection of a given fault set by means of a predefined merit functional representing a fault detection criterion. The test signal generation problem of finding optimal test stimuli detecting all faults form the fault set is formulated as an optimal control problem. The solution of the optimal control problem representing the test stimuli is computed using an optimization procedure. The optimization procedure is based on the necessary conditions for optimality like the maximum principle of Pontryagin and adjoint circuit equations.

  4. Integrated Circuits for Analog Signal Processing

    CERN Document Server

    2013-01-01

      This book presents theory, design methods and novel applications for integrated circuits for analog signal processing.  The discussion covers a wide variety of active devices, active elements and amplifiers, working in voltage mode, current mode and mixed mode.  This includes voltage operational amplifiers, current operational amplifiers, operational transconductance amplifiers, operational transresistance amplifiers, current conveyors, current differencing transconductance amplifiers, etc.  Design methods and challenges posed by nanometer technology are discussed and applications described, including signal amplification, filtering, data acquisition systems such as neural recording, sensor conditioning such as biomedical implants, actuator conditioning, noise generators, oscillators, mixers, etc.   Presents analysis and synthesis methods to generate all circuit topologies from which the designer can select the best one for the desired application; Includes design guidelines for active devices/elements...

  5. On analog implementations of discrete neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.; Moore, K.R.

    1998-12-01

    The paper will show that in order to obtain minimum size neural networks (i.e., size-optimal) for implementing any Boolean function, the nonlinear activation function of the neutrons has to be the identity function. The authors shall shortly present many results dealing with the approximation capabilities of neural networks, and detail several bounds on the size of threshold gate circuits. Based on a constructive solution for Kolmogorov`s superpositions they will show that implementing Boolean functions can be done using neurons having an identity nonlinear function. It follows that size-optimal solutions can be obtained only using analog circuitry. Conclusions, and several comments on the required precision are ending the paper.

  6. Hamilton analogy and ultracold neutron optics

    International Nuclear Information System (INIS)

    An optics of ultracold neutrons (UCN) is discussed, starting with the Hamilton analogy between the trajectories of particles in potential fields and trajectories of light beams in the nonuniform refraction index media. However, for the optics of UCN the geometrical optics approximation is not sufficient and the wave properties should be taken into account. Because of very low energy of UCN its motion is substantially influenced by the interaction of the magnetic moment with external magnetic fields. The first calculations of the focusing action of magnetic fields on neutron beams are performed. A peculiar feature of the UCN is a neccessity in taking into account the Earth gravitational field. The practical formulation of the UCN optics is achieved by introducing the coordinate and velocity dependent refraction index and solving the Hamilton-Jacobi equation for the concrete problem. In certain cases is is possible to employ the well-known geometrical optics results, properly extending them to the case of nonuniform refraction index

  7. Analogy between fluid cavitation and fracture mechanics

    Science.gov (United States)

    Hendricks, R. C.; Mullen, R. L.; Braun, M. J.

    1983-01-01

    When the stresses imposed on a fluid are sufficiently large, rupture or cavitation can occur. Such conditions can exist in many two-phase flow applications, such as the choked flows, which can occur in seals and bearings. Nonspherical bubbles with large aspect ratios have been observed in fluids under rapid acceleration and high shear fields. These bubbles are geometrically similar to fracture surface patterns (Griffith crack model) existing in solids. Analogies between crack growth in solid and fluid cavitation are proposed and supported by analysis and observation (photographs). Healing phenomena (void condensation), well accepted in fluid mechanics, have been observed in some polymers and hypothesized in solid mechanics. By drawing on the strengths of the theories of solid mechanics and cavitation, a more complete unified theory can be developed.

  8. Analog VLSI neural network integrated circuits

    Science.gov (United States)

    Kub, F. J.; Moon, K. K.; Just, E. A.

    1991-01-01

    Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit.

  9. Analog computing using reflective plasmonic metasurfaces

    CERN Document Server

    Pors, Anders; Bozhevolnyi, Sergey I

    2016-01-01

    Motivated by the recent renewed interest in compact analog computing using light and metasurfaces (Silva, A. et al., Science 2014, 343, 160-163), we suggest a practical approach to its realization that involves reflective metasurfaces consisting of arrayed gold nanobricks atop a subwavelength-thin dielectric spacer and optically-thick gold film, a configuration that supports gap-surface plasmon resonances. Using well established numerical routines, we demonstrate that these metasurfaces enable independent control of the light phase and amplitude, and design differentiator and integrator metasurfaces featuring realistic system parameters. Proof-of-principle experiments are reported along with the successful realization of a high-quality poor-man's integrator metasurface operating at the wavelength of 800 nm.

  10. Design, synthesis and antimicrobial evaluation of novel carbendazim dithioate analogs

    DEFF Research Database (Denmark)

    Zahran, Magdy A H; Osman, Amany M A; Wahed, Rania A.;

    2015-01-01

    A novel series of carbendazim dithioate analogs was synthesized by the reaction of 2-aminobenzimdazole with CS2 and different alkyl halide in one pot reaction. All the chemical structure of carbendazim analogs were elucidated with all the spectroscopical tools IR, 1H, 13C NMR and mass......-spectroscopy. All the synthesized carbendazim analogs were screened for their in vitro antimicrobial activity against different Gram-positive (Staphylococcus aureus and Micrococcus luteus), Gram-negative (Escherichia coli and Klebsiella pneumonia) bacteria, fungi (Fusarium solani and Fusarium oxysporu) and in vivo...... against soil dehydrogenase activity. Among the carbendazim dithioates, some analogs were the most effective analogs against all the Gram-negative and positive-bacteria. While the most of them showed slight activities against Fusarium solani and Fusarium oxysporum. One of these analogs seemed to be more...

  11. 23rd workshop on Advances in Analog Circuit Design

    CERN Document Server

    Baschirotto, Andrea; Makinwa, Kofi

    2015-01-01

    This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

  12. Property-Based Monitoring of Analog and Mixed-Signal Systems

    Science.gov (United States)

    Havlicek, John; Little, Scott; Maler, Oded; Nickovic, Dejan

    In the recent past, there has been a steady growth of the market for consumer embedded devices such as cell phones, GPS and portable multimedia systems. In embedded systems, digital, analog and software components are combined on a single chip, resulting in increasingly complex designs that introduce richer functionality on smaller devices. As a consequence, the potential insertion of errors into a design becomes higher, yielding an increasing need for automated analog and mixed-signal validation tools. In the purely digital setting, formal verification based on properties expressed in industrial specification languages such as PSL and SVA is nowadays successfully integrated in the design flow. On the other hand, the validation of analog and mixed-signal systems still largely depends on simulation-based, ad-hoc methods. In this tutorial, we consider some ingredients of the standard verification methodology that can be successfully exported from digital to analog and mixed-signal setting, in particular property-based monitoring techniques. Property-based monitoring is a lighter approach to the formal verification, where the system is seen as a "black-box" that generates sets of traces, whose correctness is checked against a property, that is its high-level specification. Although incomplete, monitoring is effectively used to catch faults in systems, without guaranteeing their full correctness.

  13. Photometry’s Bright Future: Detecting Solar System Analogs with Future Space Telescopes

    Science.gov (United States)

    Hippke, Michael; Angerhausen, Daniel

    2015-09-01

    Time-series transit photometry from the Kepler space telescope has allowed for the discovery of thousands of exoplanets. We explore the potential of yet improved future missions such as PLATO 2.0 in detecting solar system analogs. We use real-world solar data and end-to-end simulations to explore the stellar and instrumental noise properties. By injecting and retrieving planets, rings, and moons of our own solar system, we show that the discovery of Venus and Earth analogs transiting G dwarfs like our Sun is feasible at high signal-to-noise ratio after collecting 6 yr of data, but Mars and Mercury analogs will be difficult to detect owing to stellar noise. In the best cases, Saturn’s rings and Jupiter’s moons will be detectable even in single-transit observations. Through the high number (>1 billion) of observed stars by PLATO 2.0, it will become possible to detect thousands of single-transit events by cold gas giants, analogs to our Jupiter, Saturn, Uranus, and Neptune. Our own solar system aside, we also show, through signal injection and retrieval, that PLATO 2.0 class photometry will allow for the secure detection of exomoons transiting quiet M dwarfs. This is the first study analyzing in depth the potential of future missions and the ultimate limits of photometry, using realistic case examples.

  14. CMOS DESIGN OF A MULTI_INPUT ANALOG MULTIPLIER AND DIVIDER CIRCUIT

    OpenAIRE

    SAATLO, Ali NADERI

    2014-01-01

    This paper proposes a CMOS current-mode multi_input analog multiplier and divider circuit based on a new method. Exponential and logarithmic functions are employed to realize the circuit which is used in neural network and fuzzy integrated systems. The major advantages of this multiplier are ability of having multi_input signals, and low Total Harmonic Distortion (THD). The circuit is designed and simulated using MATLAB software and HSPICE simulator by level 49 parameters (BSIM3v3) in 0.35μm ...

  15. A Bilateral Frontoparietal Network Underlies Visuospatial Analogical Reasoning

    OpenAIRE

    Watson, Christine E.; Chatterjee, Anjan

    2011-01-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analo...

  16. Analog circuit design a tutorial guide to applications and solutions

    CERN Document Server

    Williams, Jim

    2011-01-01

    * Covers the fundamentals of linear/analog circuit and system design to guide engineers with their design challenges. * Based on the Application Notes of Linear Technology, the foremost designer of high performance analog products, readers will gain practical insights into design techniques and practice. * Broad range of topics, including power management tutorials, switching regulator design, linear regulator design, data conversion, signal conditioning, and high frequency/RF design. * Contributors include the leading lights in analog design, Robert Dobkin, Jim Willia

  17. Configurable analog-digital conversion using the neural engineering framework

    OpenAIRE

    Christian G Mayr; Partzsch, Johannes; Noack, Marko; Schüffny, Rene

    2014-01-01

    Efficient Analog-Digital Converters (ADC) are one of the mainstays of mixed-signal integrated circuit design. Besides the conventional ADCs used in mainstream ICs, there have been various attempts in the past to utilize neuromorphic networks to accomplish an efficient crossing between analog and digital domains, i.e., to build neurally inspired ADCs. Generally, these have suffered from the same problems as conventional ADCs, that is they require high-precision, handcrafted analog circuits and...

  18. An asynchronous spike event coding scheme for programmable analog arrays

    OpenAIRE

    Gouveia, L.C.; Koickal, T.; Hamilton, A.

    2008-01-01

    This paper presents a spike event coding scheme for the communication of analog signals in programmable analog arrays. In the scheme presented here no events are transmitted when the signals are constant leading to low power dissipation and traffic reduction in analog arrays. The design process and the implementation of the scheme in a programmable array context are explained. The validation of the presented scheme is performed using a speech signal. Finally, we demonstrate how the event code...

  19. A Novel cooked extruded lentils analog: physical and chemical properties

    OpenAIRE

    Abu-Ghoush, Mahmoud; Alavi, Sajid; Al-Shathri, Abdulaziz

    2014-01-01

    Developing an extruded lentil analog is our aim. Lentil analog with six formulations were produced using a pilot-scale single (SS) and twin screw (TS) extruders. Texture analysis of lentil analogs prepared for consumption revealed that the products formulated with 60:40 and 70:30 soy: wheat ratios exhibited a significantly higher hardness, adhesiveness and lower springiness as compared to all other treatments. Differential Scanning Calorimeter (DSC) results indicated that all starches in dry ...

  20. Analogies between classical statistical mechanics and quantum mechanics

    International Nuclear Information System (INIS)

    Some analogies between nonequilibrium classical statistical mechanics and quantum mechanics, at the level of the Liouville equation and at the kinetic level, are commented on. A theorem, related to the Vlasov equation applied to a plasma, is proved. The theorem presents an analogy with Ehrenfest's theorem of quantum mechanics. An analogy between the plasma kinetic theory and Bohm's quantum theory with 'hidden variables' is also shown. (Author)

  1. Effects of Two Types of Information on Malingering of Closed Head Injury on the MMPI-2: An Analog Investigation.

    Science.gov (United States)

    Lamb, David G.; And Others

    1994-01-01

    The impact of detailed information on closed head injury (CHI) and Minnesota Multiphasic Personality Inventory-2 (MMPI-2) validity scales on malingering psychological symptoms of CHI on the MMPI-2 was studied in an analog experiment with 270 undergraduates. Results suggest the impact of such coaching on simulation of CHI. (SLD)

  2. Searching for Organics During the Robotic Mars Analog Rio Tinto Drilling Experiment: Ground Truth and Contamination Issues

    Science.gov (United States)

    Bonaccorsi, R.; Stoker, C. R.; Marte Project Science Team

    2007-03-01

    The Mars Analog Rio Tinto Experiment (MARTE) performed a simulation of a Mars drilling experiment at the Rio Tinto (Spain). Ground-truth and contamination issues during the distribution of bulk organics and their CN isotopic composition in hematite and go

  3. Novel C-1 Substituted Cocaine Analogs Unlike Cocaine or Benztropine

    OpenAIRE

    Reith, Maarten E.A.; Ali, Solav; Hashim, Audrey; Sheikh, Imran S.; Theddu, Naresh; Gaddiraju, Narendra V.; Mehrotra, Suneet; Schmitt, Kyle C.; Murray, Thomas F.; Sershen, Henry; Unterwald, Ellen M.; Davis, Franklin A.

    2012-01-01

    Despite a wealth of information on cocaine-like compounds, there is no information on cocaine analogs with substitutions at C-1. Here, we report on (R)-(−)-cocaine analogs with various C-1 substituents: methyl (2), ethyl (3), n-propyl (4), n-pentyl (5), and phenyl (6). Analog 2 was equipotent to cocaine as an inhibitor of the dopamine transporter (DAT), whereas 3 and 6 were 3- and 10-fold more potent, respectively. None of the analogs, however, stimulated mouse locomotor activity, in contrast...

  4. Practical approach to programmable analog circuits with memristors

    CERN Document Server

    Pershin, Yuriy V

    2009-01-01

    We suggest an approach to use memristors (resistors with memory) in programmable analog circuits. Our idea consists in a circuit design in which low voltages are applied to memristors during their operation as analog circuit elements and high voltages are used to program the memristor's states. This way, as it was demonstrated in recent experiments, the state of memristors does not essentially change during analog mode operation. As an example of our approach, we have built several programmable analog circuits demonstrating memristor-based programming of threshold, gain and frequency.

  5. Experiments of analog states on Lead 206 and 207

    International Nuclear Information System (INIS)

    This research thesis aims at verifying hypotheses according to which the spread of analog states decreases as much as nuclei are far from a double magic nucleus, under some conditions. Therefore, analog states of lead 207 and 208 have been studied by proton scattering on targets in lead 206 and 207. Some theoretical aspects of analog states of isobaric spin are presented. An experimental method of determination of excitation functions is described. Results obtained for analog states in bismuth 207-208 are discussed. Results obtained on four steady lead isotopes in different laboratories are compared

  6. Analog solar system model relates celestial bodies spatially

    Science.gov (United States)

    Baerg, H. R.

    1966-01-01

    Portable analog planetarium indicates the relative time and space angular locations of the sun and planets. Distance measuring scales, angular direction indicators, and typical probe trajectories are included.

  7. CRC handbook of neurohypophyseal hormone analogs. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Jost, K.; Lebl, M.; Brtnik, F.

    1987-01-01

    This book is discussed in two parts. The Part 1 discusses the: Prohormones and Hormonogens of Neuro-hypophyseal Hormones, Analogs with Inhibitory properties. Analogs with Dissociated and/or High activities. Introduction. Uterotonic Activity. Galactogogic Activity. Pressor Activity. Antidiuretic Activity. References. Part 2 discusses the Other Important Activities. CNS Activities. Corticotropin- and ..beta..-Entriuretic Action. Natriferic Action. References. Practical Use in Human and Veterinary Medicine. Introduction. Methyloxytocin. Deamino-Oxytocin. Cargutocin. Glypressin. Octapressin. Desmopressin. Analogs Clinically Tried But Not Introduced into Production and Routine Clinical Practice. References. Tables of Analogs and Index.

  8. Analog-digital converters for industrial applications including an introduction to digital-analog converters

    CERN Document Server

    Ohnhäuser, Frank

    2015-01-01

    This book offers students and those new to the topic of analog-to-digital converters (ADCs) a broad introduction, before going into details of the state-of-the-art design techniques for SAR and DS converters, including the latest research topics, which are valuable for IC design engineers as well as users of ADCs in applications. The book then addresses important topics, such as correct connectivity of ADCs in an application, the verification, characterization and testing of ADCs that ensure high-quality end products. Analog-to-digital converters are the central element in any data processing system and regulation loops such as modems or electrical motor drives. They significantly affect the performance and resolution of a system or end product. System development engineers need to be familiar with the performance parameters of the converters and understand the advantages and disadvantages of the various architectures. Integrated circuit development engineers have to overcome the problem of achieving high per...

  9. Planning the electron traffic in semiconductor networks: A mesoscopic analog of the Braess paradox encountered in road networks

    International Nuclear Information System (INIS)

    By combining quantum simulations of electron transport and scanning-gate microscopy, we have shown that the current transmitted through a semiconductor two-path rectangular network in the ballistic and coherent regimes of transport can be paradoxically degraded by adding a third path to the network. This is analogous to the Braess paradox occurring in classical networks. Simulations reported here enlighten the role played by congestion in the network

  10. Planning the electron traffic in semiconductor networks: A mesoscopic analog of the Braess paradox encountered in road networks

    Science.gov (United States)

    Huant, S.; Baltazar, S.; Liu, P.; Sellier, H.; Hackens, B.; Martins, F.; Bayot, V.; Wallart, X.; Desplanque, L.; Pala, M. G.

    2013-12-01

    By combining quantum simulations of electron transport and scanning-gate microscopy, we have shown that the current transmitted through a semiconductor two-path rectangular network in the ballistic and coherent regimes of transport can be paradoxically degraded by adding a third path to the network. This is analogous to the Braess paradox occurring in classical networks. Simulations reported here enlighten the role played by congestion in the network.

  11. Planning the electron traffic in semiconductor networks: A mesoscopic analog of the Braess paradox encountered in road networks

    Energy Technology Data Exchange (ETDEWEB)

    Huant, S.; Liu, P.; Sellier, H. [Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble (France); Baltazar, S. [IMEP-LAHC, Grenoble INP, Minatec, BP 257, F-38016 Grenoble, France and Departamento de Fısica, Universidad de Santiago de Chile, Santiago 9170124 (Chile); Hackens, B.; Martins, F. [Université Catholique de Louvain, IMCN/NAPS, Louvain-la-Neuve (Belgium); Bayot, V. [Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble, France and Université Catholique de Louvain, IMCN/NAPS, Louvain-la-Neuve (Belgium); Wallart, X.; Desplanque, L. [IEMN, UMR CNRS 8520, UST Lille, BP 60069, F-59652 Villeneuve d' Ascq (France); Pala, M. G. [IMEP-LAHC, Grenoble INP, Minatec, BP 257, F-38016 Grenoble (France)

    2013-12-04

    By combining quantum simulations of electron transport and scanning-gate microscopy, we have shown that the current transmitted through a semiconductor two-path rectangular network in the ballistic and coherent regimes of transport can be paradoxically degraded by adding a third path to the network. This is analogous to the Braess paradox occurring in classical networks. Simulations reported here enlighten the role played by congestion in the network.

  12. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    OpenAIRE

    van de Plassche, R.J.

    1992-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog filtering of input signals before they are applied to an A/D converter are defined. In the case of a D/A converter the amount of filtering of the repetitive signal bands around multiples of the sampling...

  13. Physicochemical analog for modeling superimposed and coded memories

    Science.gov (United States)

    Ensanian, Minas

    1992-07-01

    The mammalian brain is distinguished by a life-time of memories being stored within the same general region of physicochemical space, and having two extraordinary features. First, memories to varying degrees are superimposed, as well as coded. Second, instantaneous recall of past events can often be affected by relatively simple, and seemingly unrelated sensory clues. For the purposes of attempting to mathematically model such complex behavior, and for gaining additional insights, it would be highly advantageous to be able to simulate or mimic similar behavior in a nonbiological entity where some analogical parameters of interest can reasonably be controlled. It has recently been discovered that in nonlinear accumulative metal fatigue memories (related to mechanical deformation) can be superimposed and coded in the crystal lattice, and that memory, that is, the total number of stress cycles can be recalled (determined) by scanning not the surfaces but the `edges' of the objects. The new scanning technique known as electrotopography (ETG) now makes the state space modeling of metallic networks possible. The author provides an overview of the new field and outlines the areas that are of immediate interest to the science of artificial neural networks.

  14. Thermal desorption of circumstellar and cometary ice analogs

    CERN Document Server

    Martín-Doménech, Rafael; Bueno, Juan; Goesmann, Fred

    2014-01-01

    Thermal annealing of interstellar ices takes place in several stages of star formation. Knowledge of this process comes from a combination of astronomical observations and laboratory simulations under astrophysically relevant conditions. For the first time we present the results of temperature programmed desorption (TPD) experiments with pre-cometary ice analogs composed of up to five molecular components: H2 O, CO, CO2, CH3 OH, and NH3 . The experiments were performed with an ultra-high vacuum chamber. A gas line with a novel design allows the controlled preparation of mixtures with up to five molecular components. Volatiles desorbing to the gas phase were monitored using a quadrupole mass spectrometer, while changes in the ice structure and composition were studied by means of infrared spectroscopy. The TPD curves of water ice containing CO, CO2, CH3 OH, and NH3 present desorption peaks at temperatures near those observed in pure ice experiments, volcano desorption peaks after water ice crystallization, and...

  15. Analog front-end prototype electronics for the LHAASO WCDA

    Science.gov (United States)

    Cong, Ma; Lei, Zhao; Yu-Xiang, Guo; Jian-Feng, Liu; Shu-Bin, Liu; Qi, An

    2016-01-01

    In the readout electronics of the Water Cerenkov Detector Array (WCDA) in the Large High Altitude Air Shower Observatory (LHAASO) experiment, both high-resolution charge and time measurement are required over a dynamic range from 1 photoelectron (P.E.) to 4000 P.E. The Analog Front-end (AFE) circuit is one of the crucial parts in the readout electronics. We designed and optimized a prototype of the AFE through parameter calculation and circuit simulation, and conducted initial electronics tests on this prototype to evaluate its performance. Test results indicate that the charge resolution is better than 1%@4000 P.E. and remains better than 10%@1 P.E., and the time resolution is better than 0.5 ns RMS, which is better than the application requirements. Supported by Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-N27), National Natural Science Foundation of China (11175174) and CAS Center for Excellence in Particle Physics (CCEPP)

  16. Atomistic study of macroscopic analogs to short-chain molecules

    Science.gov (United States)

    Welch, Kyle J.; Kilmer, Clayton S. G.; Corwin, Eric I.

    2015-02-01

    We use a bath of chaotic surface waves in water to mechanically and macroscopically mimic the thermal behavior of a short articulated chain with only nearest-neighbor interactions. The chaotic waves provide isotropic and random agitation to which a temperature can be ascribed, allowing the chain to passively explore its degrees of freedom in analogy to thermal motion. We track the chain in real time and infer end-to-end potentials using Boltzmann statistics. We extrapolate our results, by using Monte Carlo simulations of self-avoiding polymers, to lengths not accessible in our system. In the long-chain limit we demonstrate universal scaling of the statistical parameters of all chains in agreement with well-known predictions for self-avoiding walks. However, we find that the behavior of chains below a characteristic length scale fundamentally differs. We find that short chains have much greater compressional stiffness than would be expected. However, chains rapidly soften as length increases to meet with expected scalings.

  17. A column-based two-stage analog-to-digital converter for uncooled microbolometer arrays

    Science.gov (United States)

    Toprak, Alperen; Tepegoz, Murat; Akin, Tayfun

    2009-05-01

    This paper presents a column-based, two-stage, 12-bit analog-to-digital converter structure designed for uncooled microbolometer arrays. On-chip analog-to-digital converters prevent the degradation of sensitive analog output by external noise sources as well as providing a more integrated functionality. Despite these advantages, the area and power constraints limit the usage of high performance converters. This paper presents a new structure that provides a balance between area, power, and performance. The structure is composed of two stages: a tracking ADC stage running at each column during integration and a successive approximation ADC stage which is shared by a number of columns depending on the array size and operation frequency. The tracking ADC operates during the integration time, while the second ADC starts after the integration is completed. The converter includes self-calibration to lower the effect of process variations and digital correction mechanisms to eliminate the need for low-offset comparators. The simulations and theoretical calculations based on the simulation results show that the total power dissipation of the proposed structure will be approximately 73.7 mW and 88.4 mW on a 320x240 array operating at 60 Hz and 384x288 array operating at 50 Hz, respectively.

  18. Evaluating The Global Inventory of Planetary Analog Environments on Earth: An Ontological Approach

    Science.gov (United States)

    Conrad, P. G.

    2010-12-01

    Introduction: Field sites on Earth are routinely used to simulate planetary environments so that we can try to understand the evidence of processes such as sedimentary deposition, weathering, evolution of habitable environments, and behavior of spacecraft and instrumentation prior to selection of mission architectures, payload investigations and landing sites for in situ exploration of other planets. The rapid evolution of astrobiology science drivers for space exploration as well as increasing capability to explore planetary surfaces in situ has led to a proliferation of declarations that various Earth environments are analogs for less accessible planetary environments. We have not yet progressed to standardized measures of analog fidelity, and the analog value of field sites can be variable de-pending upon a variety of factors. Here we present a method of evaluating the fidelity and hence utility of analog environments by using an ontological approach to evaluating how well the analogs work. The use of ontologies as specification constructs is now quite common in artificial intelligence, systems engineering, business development and various informatics systems. We borrow from these developments just as they derive from the original use of ontology in philosophy, where it was meant as a systematic approach to describing the fundamental elements that define “being,” or existence [1]. An ontology is a framework for the specification of a concept or domain of interest. The knowledge regarding that domain, eg., inventory of objects, hierarchical classes, relationships and functions is what describes and defines the domain as a declarative formalism [2]. In the case of planetary environments, one can define a list of fundamen-tal attributes without which the domain (environment) in question must be defined (classified) otherwise. In particu-lar this is problematic when looking at ancient environments because of their alteration over time. In other words, their

  19. Geostatistical inspired metamodeling and optimization of nanoscale analog circuits

    Science.gov (United States)

    Okobiah, Oghenekarho

    The current trend towards miniaturization of modern consumer electronic devices significantly affects their design. The demand for efficient all-in-one appliances leads to smaller, yet more complex and powerful nanoelectronic devices. The increasing complexity in the design of such nanoscale Analog/Mixed-Signal Systems-on-Chip (AMS-SoCs) presents difficult challenges to designers. One promising design method used to mitigate the burden of this design effort is the use of metamodeling (surrogate) modeling techniques. Their use significantly reduces the time for computer simulation and design space exploration and optimization. This dissertation addresses several issues of metamodeling based nanoelectronic based AMS design exploration. A surrogate modeling technique which uses geostatistical based Kriging prediction methods in creating metamodels is proposed. Kriging prediction techniques take into account the correlation effects between input parameters for performance point prediction. We propose the use of Kriging to utilize this property for the accurate modeling of process variation effects of designs in the deep nanometer region. Different Kriging methods have been explored for this work such as simple and ordinary Kriging. We also propose another metamodeling technique Kriging-Bootstrapped Neural Network that combines the accuracy and process variation awareness of Kriging with artificial neural network models for ultra-fast and accurate process aware metamodeling design. The proposed methodologies combine Kriging metamodels with selected algorithms for ultra-fast layout optimization. The selected algorithms explored are: Gravitational Search Algorithm (GSA), Simulated Annealing Optimization (SAO), and Ant Colony Optimization (ACO). Experimental results demonstrate that the proposed Kriging metamodel based methodologies can perform the optimizations with minimal computational burden compared to traditional (SPICE-based) design flows.

  20. Analog gradient beamformer for a wireless ultrasound scanner

    Science.gov (United States)

    Di Ianni, Tommaso; Hemmsen, Martin Christian; Bagge, Jan; Jensen, Henrik; Vardi, Nitsan; Jensen, Jørgen Arendt

    2016-04-01

    This paper presents a novel beamformer architecture for a low-cost receiver front-end, and investigates if the image quality can be maintained. The system is oriented to the development of a hand-held wireless ultrasound probe based on Synthetic Aperture Sequential Beamforming, and has the advantage of effectively reducing circuit complexity and power dissipation. The array of transducers is divided into sub-apertures, in which the signals from the single channels are aligned through a network of cascaded gradient delays, and summed in the analog domain before A/D conversion. The delay values are quantized to simplify the shifting unit, and a single A/D converter is needed for each sub-aperture yielding a compact, low-power architecture that can be integrated in a single chip. A simulation study was performed using a 3:75MHz convex array, and the point spread function (PSF) for different configurations was evaluated in terms of lateral full-width-at-half-maximum (FWHM) and -20 dB cystic resolution (CR). Several setups were simulated varying the sub-aperture size N and the quantization step, and design constraints were obtained comparing the PSF to that of an ideal non-quantized system. The PSF is shown for N = 32 with a quantization step of 12 ns. For this configuration, the FWHM is degraded by 0.25% and the CR is 8.70% lower compared to the ideal situation. The results demonstrate that the gradient beamformer provides an adequate image quality, and open the way to a fully-integrated chip for a compact, low-cost, wireless ultrasound probe.

  1. Applying analog integrated circuits for HERO protection

    Science.gov (United States)

    Willis, Kenneth E.; Blachowski, Thomas J.

    1994-01-01

    One of the most efficient methods for protecting electro-explosive devices (EED's) from HERO and ESD is to shield the EED in a conducting shell (Faraday cage). Electrical energy is transferred to the bridge by means of a magnetic coupling which passes through a portion of the conducting shell that is made from a magnetically permeable but electrically conducting material. This technique was perfected by ML Aviation, a U.K. company, in the early 80's, and was called a Radio Frequency Attenuation Connector (RFAC). It is now in wide use in the U.K. Previously, the disadvantage of RFAC over more conventional methods was its relatively high cost, largely driven by a thick film hybrid circuit used to switch the primary of the transformer. Recently, through a licensing agreement, this technology has been transferred to the U.S. and significant cost reductions and performance improvements have been achieved by the introduction of analog integrated circuits. An integrated circuit performs the following functions: (1) Chops the DC input to a signal suitable for driving the primary of the transformer; (2) Verifies the input voltage is above a threshold; (3) Verifies the input voltage is valid for a pre set time before enabling the device; (4) Provides thermal protection of the circuit; and (5) Provides an external input for independent logic level enabling of the power transfer mechanism. This paper describes the new RFAC product and its applications.

  2. Analogy between solar flares and aurora

    International Nuclear Information System (INIS)

    Complete text of publication follows. Making an analogy between solar flares and magnetospheric substorms, we can conjecture that quasi-separatrix layer (QSL) reconnection may very well occur in the latter. Indeed, the geometry of the Earth magnetosphere can possibly make the appearance of real 3D null points impossible in the magneto-tail when it is stretched anti sunward. This does not preclude the development of Harris-type current sheet with a guide field in the tail, i.e. of 2D null points with an azimuthally guide field, as often reported in global models of the magnetosphere. But solar models teach us that the latter configurations can correspond to a hyperbolic flux tube (HFT), hence to QSLs when the system is viewed globally. assuming that substorms correspond, on large scales, to the formation of a fully 3D twisted flux rope rooted in the ionosphere (and not a 2D plasmoid), we can transpose the solar Cartesian 3D model of Demoulin et al. (1996) to the Earth spherical geometry, replacing the solar photosphere by the ionosphere and the solar corona by the magnetosphere.

  3. Vitamin E Analogs as Radiation Response Modifiers

    Directory of Open Access Journals (Sweden)

    Pankaj K. Singh

    2015-01-01

    Full Text Available The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine.

  4. Natural CO2 Analogs for Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott H. Stevens; B. Scott Tye

    2005-07-31

    The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.

  5. JNT multiplexer and analog input processor

    International Nuclear Information System (INIS)

    This paper discusses the design, implementation, and performance of a working model of the Multiplexer-Analog Input Processor (AIP) System for the transmission and measurements of Johnson Noise Power Thermometer sensor information. The goal of this study was to determine the practical circuit limitations, investigate the circuit/component degradations due to radiation, develop an interference cancellation technique, and evaluate the measurements accuracy as a function of temperature, radition, and interference levels. By using a Fast Fourier Transform (FFT) for spectral estimation, the tuned-circuit parameters of the JNT Preamplifiers can be measured and the temperature computed from the power integrated over a limited bandwidth, thereby greatly reducing the system bandwidth requirements and the amplifier noise contamination. Preliminary measurements show that the temperature measurement can be made to ±10K for temperatures below 1000 K and ±1% above 1000K, for approximately 1 second of integration time. Multiple interfering signals, down to negative Signal-to-Interference Ratios (SIR), are eliminated with no significant degradation in the temperature measured. The AIP also adaptively monitors and extracts an estimate of the Preamplifier's noise contribution, eliminating this error from the overall JNT noise power measurement

  6. Natural Analog Studies at Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment

  7. Natural Analog Studies at Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  8. Radiolabeled somatostatin analogs in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, M.L.; Kolan, H.; Li, J.; Wiaderkiewicz, R.; Pallela, V.R.; Duggaraju, R.; Schally, A.V

    1997-01-01

    Vapreotide (RC-160), a somatostatin analog, was labeled with {sup 99m}Tc by a direct method and also by using CPTA [1,4,8,11-tetraazacyclotetradecane] as a bifunctional chelating agent. The labeled compounds were evaluated in nude mice bearing experimental human prostate cancers. In these studies, {sup 111}In-DTPA-D-Phe-Octreotide ({sup 111}In-DTPA-octreotide) served as a standard and {sup 99m}Tc-oxytocin as a receptor-non-specific control. {sup 99m}Tc-octreotide was also used. The 24 htumor uptake of {sup 99m}Tc-RC-160 was nearly 400% higher, (p < 0.05), than that of {sup 111}In-DTPA-octreotide and diminished upon receptor blocking. In all tissues except the kidneys, the uptake of {sup 99m}Tc-RC-160 was also higher than that of {sup 111}In-DTPA-octreotide. The uptake of {sup 99m}Tc-RC-160 was influenced by the amount of peptide injected and the best tumor/muscle and tumor/blood ratios were obtained when only one {mu}g of the peptide (200 Ci/mmol) was administered.

  9. Analog gravity from Bose-Einstein condensates

    CERN Document Server

    Barcelo, C; Visser, M; Barcelo, Carlos; Liberati, Stefano; Visser, Matt

    2001-01-01

    We analyze prospects for the use of Bose-Einstein condensates as condensed-matter systems suitable for generating a generic ``effective metric'', and for mimicking kinematic aspects of general relativity. We extend the analysis due to Garay et al, [gr-qc/0002015, gr-qc/0005131]. Taking a long term view, we ask what the ultimate limits of such a system might be. To this end, we consider a very general version of the nonlinear Schrodinger equation (with a 3-tensor position-dependent mass and arbitrary nonlinearity). Such equations can be used for example in discussing Bose-Einstein condensates in heterogeneous and highly nonlinear systems. We demonstrate that at low momenta linearized excitations of the phase of the condensate wavefunction obey a (3+1)-dimensional d'Alembertian equation coupling to a (3+1)-dimensional Lorentzian-signature ``effective metric'' that is generic, and depends algebraically on the background field. Thus at low momenta this system serves as an analog for the curved spacetime of genera...

  10. Use of analogies by novice and experienced design engineers

    DEFF Research Database (Denmark)

    Ahmed, Saeema; Christensen, Bo T.

    2008-01-01

    This paper describes a study to understand the use of analogies by design engineers with different levels of experience. Protocol analyses of twelve design engineers have been analysed to understand the functions and reasoning of the analogies. The protocols are real world data from the aerospace...

  11. Molecular interactions between (--epigallocatechin gallate analogs and pancreatic lipase.

    Directory of Open Access Journals (Sweden)

    Shihui Wang

    Full Text Available The molecular interactions between pancreatic lipase (PL and four tea polyphenols (EGCG analogs, like (--epigallocatechin gallate (EGCG, (--gallocatechin gallate (GCG, (--epicatechin gallate (ECG, and (--epigallocatechin (EC, were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.

  12. Analysis of Attention and Analogical Reasoning in Children of Poverty

    Science.gov (United States)

    Weatherholt, Tara N.; Harris, Ruby C.; Burns, Barbara M.; Clement, Catherine

    2006-01-01

    This study examined the relationship between specific attentional aspects of processing capacity and analogical reasoning in children from low-income families. 77 children aged 48-77 (M = 56.7) months were assessed on an analogical reasoning task (matrices subtest of the Kaufman Brief Intelligence Test) and on computerized attention tasks designed…

  13. Recombinant DNA technology in the treatment of diabetes: insulin analogs.

    Science.gov (United States)

    Vajo, Z; Fawcett, J; Duckworth, W C

    2001-10-01

    After more than half a century of treating diabetics with animal insulins, recombinant DNA technologies and advanced protein chemistry made human insulin preparations available in the early 1980s. As the next step, over the last decade, insulin analogs were constructed by changing the structure of the native protein with the goal of improving the therapeutic properties of it, because the pharmacokinetic characteristics of rapid-, intermediate-, and long-acting preparations of human insulin make it almost impossible to achieve sustained normoglycemia. The first clinically available insulin analog, lispro, confirmed the hopes by showing that improved glycemic control can be achieved without an increase in hypoglycemic events. Two new insulin analogs, insulin glargine and insulin aspart, have recently been approved for clinical use in the United States, and several other analogs are being intensively tested. Thus, it appears that a rapid acceleration of basic and clinical research in this arena will be seen, which will have direct significance to both patients and their physicians. The introduction of new short-acting analogs and the development of the first truly long-acting analogs and the development of analogs with increased stability, less variability, and perhaps selective action, will help to develop more individualized treatment strategies targeted to specific patient characteristics and to achieve further improvements in glycemic control. Data on the currently available and tested analogs, as well as data on those currently being developed, are reviewed. PMID:11588149

  14. Using Self-Generated Analogies in Teaching of Thermodynamics

    Science.gov (United States)

    Haglund, Jesper; Jeppsson, Fredrik

    2012-01-01

    Using self-generated analogies has been proposed as a method in a constructivist tradition for students to learn about a new subject, by use of what they previously know. We report on a group exercise on using self-generated analogies to make sense of two thermodynamic processes, reversible adiabatic expansion and free adiabatic expansion of an…

  15. Magic Bullets, Slate, and Stradivarius: Analogies, Research, and Policy Making.

    Science.gov (United States)

    Baker, Keith

    1998-01-01

    Considering how important analogies are to human thinking, it is surprising how little attention educators and educational researchers give them. Valid research results can lead to false conclusions if viewed through the mental filter of a faulty analogy. This article examines two policy problems (prison literacy/recidivism rates and vanishing…

  16. Young Children's Analogical Problem Solving: Gaining Insights from Video Displays

    Science.gov (United States)

    Chen, Zhe; Siegler, Robert S.

    2013-01-01

    This study examined how toddlers gain insights from source video displays and use the insights to solve analogous problems. Two- to 2.5-year-olds viewed a source video illustrating a problem-solving strategy and then attempted to solve analogous problems. Older but not younger toddlers extracted the problem-solving strategy depicted in the video…

  17. Analogical Reasoning in the Classroom: Insights from Cognitive Science

    Science.gov (United States)

    Vendetti, Michael S.; Matlen, Bryan J.; Richland, Lindsey E.; Bunge, Silvia A.

    2015-01-01

    Applying knowledge from one context to another is a notoriously difficult problem, both for children and adults, but lies at the heart of educational endeavors. Analogical reasoning is a cognitive underpinning of the ability to notice and draw similarities across contexts. Reasoning by analogy is especially challenging for students, who must…

  18. Exploring the Impacts of Analogies on Computer Hardware

    Science.gov (United States)

    Dincer, Serkan

    2011-01-01

    In the last few decades, analogy, which is considered as a special case for reasoning, has attracted a great deal of attention from cognitive scientists. Although analogy was rarely applied in previous decades, now it is often considered by educators and researchers as a strategy to provide creative solutions and poetic writing (Paris & Glynn,…

  19. Novel analog switching circuit for van der Pauw measurements

    OpenAIRE

    David, T.; Molchadsky, I.; Somechi, A.; Rosenbaum, R.

    2005-01-01

    A simple electronic circuit is described using four common and very inexpensive analog multiplexer/demultiplexer chips. These analog switches are used to select eight different wiring configurations to a van der Pauw sample. Several interfacing schemes to a PC are suggested. The van der Pauw resistivity and Hall voltage expressions are also summarized.

  20. Soft Fault Diagnosis for Analog Circuits Based on Slope Fault Feature and BP Neural Networks

    Institute of Scientific and Technical Information of China (English)

    HU Mei; WANG Hong; HU Geng; YANG Shiyuan

    2007-01-01

    Fault diagnosis is very important for development and maintenance of safe and reliable electronic circuits and systems. This paper describes an approach of soft fault diagnosis for analog circuits based on slope fault feature and back propagation neural networks (BPNN). The reported approach uses the voltage relation function between two nodes as fault features; and for linear analog circuits, the voltage relation function is a linear function, thus the slope is invariant as fault feature. Therefore, a unified fault feature for both hard fault (open or short fault) and soft fault (parametric fault) is extracted. Unlike other NN-based diagnosis methods which utilize node voltages or frequency response as fault features, the reported BPNN is trained by the extracted feature vectors, the slope features are calculated by just simulating once for each component, and the trained BPNN can achieve all the soft faults diagnosis of the component. Experiments show that our approach is promising.

  1. Low power Analog Digital Converter for a silicon photomultiplier readout ASIC

    International Nuclear Information System (INIS)

    We present an ADC designed in the UMC 0.18um CMOS technology. It will be used in the SiPM analog front-end ''KLauS' developed for the analog hadronic calorimeter at ILD. Key parameter in this application is an extremely low power consumption of the front-end electronics. For quantization of the energy depositions, a 10-bit ADC resolution is required. For calibration purposes, a 12-bit quantization is used. A successive approximation register split capacitor array structure is chosen to minimize the DC power consumption. A peak sensing block is used to minimize the required sampling rate. We present design details and simulation results of the ADC, as well as the peak sensing track and hold circuit

  2. Chromatography under critical conditions: An analogy between functionalized and partially cyclic polymers.

    Science.gov (United States)

    Gorbunov, Alexei A; Vakhrushev, Andrey V

    2016-07-22

    An analogy is established between functionalized polymers and partially cyclic macromolecules (PCMs) in the liquid chromatography at critical conditions (LCCC). Application of the functionalized chain analogy (FCA) for prediction of the behavior of complex multi-cyclic PCMs in the LCCC mode is demonstrated. By using FCA, we discuss possibilities of LCCC to separate multi-cyclic PCMs by the number of cycles, and with respect to molecular topology. FCA is also extended to describe PCMs with specifically adsorbing groups; this results in a simplified theory of LCCC of functionalized PCMs. By simulating chromatograms of heterogeneous functionalized PCMs at the conditions of LCCC, we show possible dramatic effects of functional groups on the topological separation of PCMs: even the retention order of components may change to opposite. PMID:27324625

  3. Characterization and Modeling of Nonfilamentary Ta/TaOx/TiO2/Ti Analog Synaptic Device

    Science.gov (United States)

    Wang, Yu-Fen; Lin, Yen-Chuan; Wang, I.-Ting; Lin, Tzu-Ping; Hou, Tuo-Hung

    2015-05-01

    A two-terminal analog synaptic device that precisely emulates biological synaptic features is expected to be a critical component for future hardware-based neuromorphic computing. Typical synaptic devices based on filamentary resistive switching face severe limitations on the implementation of concurrent inhibitory and excitatory synapses with low conductance and state fluctuation. For overcoming these limitations, we propose a Ta/TaOx/TiO2/Ti device with superior analog synaptic features. A physical simulation based on the homogeneous (nonfilamentary) barrier modulation induced by oxygen ion migration accurately reproduces various DC and AC evolutions of synaptic states, including the spike-timing-dependent plasticity and paired-pulse facilitation. Furthermore, a physics-based compact model for facilitating circuit-level design is proposed on the basis of the general definition of memristor devices. This comprehensive experimental and theoretical study of the promising electronic synapse can facilitate realizing large-scale neuromorphic systems.

  4. An analog data processor for chart records using a multielement photodetector.

    Science.gov (United States)

    Minami, S; Tsutsui, S; Onoda, H

    1969-06-01

    The apparatus, which is capable of computing the convolution integrals of electrically programmed functions and graphical data in the form of recorder traces, is described. The recorder trace is scanned by means of an optical scanner involving a multielement photodiode array. The signals from the scan head, which correspond to trace positions on the chart, are processed with analog circuits so arranged that the weighted moving average is accomplished. The over-all accuracy of the system, including the long-term drift of analog computing electronics, is better than 0.5%. To demonstrate the performance, spectroscopic data provided with conventional ir spectrophotometers are processed. This simple processor can also be utilized as a function generator or an instrument simulator. PMID:20072408

  5. The design, fabrication, and test of a new VLSI hybrid analog-digital neural processing element

    Science.gov (United States)

    Deyong, Mark R.; Findley, Randall L.; Fields, Chris

    1992-01-01

    A hybrid analog-digital neural processing element with the time-dependent behavior of biological neurons has been developed. The hybrid processing element is designed for VLSI implementation and offers the best attributes of both analog and digital computation. Custom VLSI layout reduces the layout area of the processing element, which in turn increases the expected network density. The hybrid processing element operates at the nanosecond time scale, which enables it to produce real-time solutions to complex spatiotemporal problems found in high-speed signal processing applications. VLSI prototype chips have been designed, fabricated, and tested with encouraging results. Systems utilizing the time-dependent behavior of the hybrid processing element have been simulated and are currently in the fabrication process. Future applications are also discussed.

  6. Space Station Habitability Recommendations Based on a Systematic Comparative Analysis of Analogous Conditions

    Science.gov (United States)

    Stuster, Jack W.

    1986-01-01

    Conditions analogous to the proposed NASA Space Station are systematically analyzed in order to extrapolate design guidelines and recommendations concerning habitability and crew productivity. Analogous environments studied included Skylab, Sealab, Tektite, submarines, Antarctic stations and oil drilling platforms, among others. These analogues were compared and rated for size and composition of group, social organization, preparedness for mission, duration of tour, types of tasks, physical and psychological isolation, personal motivation, perceived risk, and quality of habitat and life support conditions. One-hundred design recommendations concerning, sleep, clothing, exercise, medical support, personal hygiene, food preparation, group interaction, habitat aesthetics, outside communications, recreational opportunities, privacy and personal space, waste disposal, onboard training, simulation and task preparation, and behavioral and physiological requirements associated with a microgravity environment, are provided.

  7. Low power Analog Digital Converter for a silicon photomultiplier readout ASIC

    Science.gov (United States)

    Briggl, K.; Chen, H.; Shen, W.; Schultz-Coulon, H. C.

    2015-04-01

    We present an ADC designed in the UMC 0.18um CMOS technology. It will be used in the SiPM analog front-end ``KLauS" developed for the analog hadronic calorimeter at ILD. Key parameter in this application is an extremely low power consumption of the front-end electronics. For quantization of the energy depositions, a 10-bit ADC resolution is required. For calibration purposes, a 12-bit quantization is used. A successive approximation register split capacitor array structure is chosen to minimize the DC power consumption. A peak sensing block is used to minimize the required sampling rate. We present design details and simulation results of the ADC, as well as the peak sensing track & hold circuit.

  8. Low Voltage Analog Circuit Design Based on the Flipped Voltage Follower

    Directory of Open Access Journals (Sweden)

    Neeraj Yadav

    2012-03-01

    Full Text Available The desire for portability of electronics equipment generated a need for low power system in battery products like hearing aids, implantable cardiac pacemakers, cell phones and hand held multimedia terminals. Low voltage analog circuit design differs considerably from those of high voltage analog circuit design. This paper present the basic cell knows as “flipped voltage follower” for low voltage/ low power operation. The detailed classification of basic topologies derived from the FVF cell is presented and there is a low voltage current mirror based on FVF cell has been presented. All the Circuit has been simulated using Hspice tool 0.18µm CMOS Technology. Different quality factors such as frequency response, power consumption are considered. A compression also made between previous current mirror and new designed current mirror. The layout of the current mirror has been also designed using Cadence tool.

  9. Nonpeptide somatostatin analogs: recent advances in its application and research

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Along with its wide anatomical distribution, somatostatin (SST) acts on multiple targets via a family of 5 receptors to produce a broad spectrum of biological effects. Therefore, a variety of peptide analogs have been produced and are widely used in clinical treatment. However, because of their flaws in the structure of peptide, the clinical efficacy is limited. In this review, we summarize the structure, pharmacological effects and the potential clinical value of non-peptide SST analogs. We focus on the research and development of non-peptide SST analogs since 1998, and discuss the problems and potential prospects for non-peptide SST analogs. We believe that as more non-peptide somatostatin analogs are successfully developed, the extensive clinical application of SSTs will contribute a great deal to medical science.

  10. Scattering Properties of Lunar Dust Analogs

    Science.gov (United States)

    Davis, S.; Marshall, J.; Richard, D.; Adler, D.; Adler, B.

    2013-01-01

    A number of space missions are planned to explore the lunar exosphere which may contain a small population of dust particles. The objective of this paper is to present preliminary results from scattering experiments on a suspension of lunar simulants to support one such mission. The intensity of the light scattered from a lunar simulant is measured with a commercial version of the spectrometer used in the forthcoming LADEE mission. Physical properties of the lunar simulant are described along with two similarly-sized reference microspheres. We confirm that micron-sized particles tend to form agglomerates rather than remaining isolated entities and that certain general characteristic of the target particles can be predicted from intensity measurements alone. These results can be used directly to assess general features of the lunar exosphere from LADEE instrument data. Further analysis of particle properties from such remote sensing data will require measurements of polarization signatures.

  11. NASA HRP Immunology Discipline - Use of Terrestrial Analogs

    Science.gov (United States)

    Crucian, Brian

    2014-01-01

    Due to the cost and operational constraints, as well as technical implementation limitations, it is desirous to perform relevant space physiology investigations first in terrestrial 'space analogs'. This is particularly true for initial investigations, which may then provide appropriate focus for subsequent flight investigations, or for mechanistic investigations that simply cannot be performed during spaceflight. Appropriate analog choice is extremely important. There are a wide variety of terrestrial space analogs, each relevant to a particular physiological discipline (or disciplines) and each with a particular fidelity (or lack thereof) to spaceflight, and each with unique operational constraints. The HRP Immunology Discipline is tasked with managing the HRP Risk concerning clinical risk for Astronaut crews related to spaceflight-associated immune dysregulation. Such dysregulation has been documented to occur during spaceflight, and found to persist for the duration of a 6-month ISS mission. Studies continue to characterize the onorbit phenomenon, but it generally consists of diminished immunocyte function, dysregulated cytokine profiles, and persistent herpesvirus reactivation. Causes are thought to synergistically include microgravity, psychological or physiological stress, radiation, and/or circadian misalignment. An appropriate terrestrial analog for immune dysregulation would replicate as many of these influences as possible. Such analogs may include clinostat or bioreactor cell culture (microgravity), hindlimb suspension (stress, fluid shifts, hypokinesis), or human deployment to remote or extreme environments (isolation, stress, circadian). Also, the laboratory setting may be used as an analog, or to augment analogs, such as sleep deprivation/misalignment or human centrifugation to replicate gravitational stress. As an appropriate example of a NASA Disciplines use of Terrestrial space analogs, this talk will discuss spaceflight associated immune

  12. Feasibility Study of a Lunar Analog Bed Rest Model

    Science.gov (United States)

    Cromwell, Ronita L.; Platts, Steven H.; Yarbough, Patrice; Buccello-Stout, Regina

    2010-01-01

    The purpose of this study was to determine the feasibility of using a 9.5deg head-up tilt bed rest model to simulate the effects of the 1/6 g load to the human body that exists on the lunar surface. The lunar analog bed rest model utilized a modified hospital bed. The modifications included mounting the mattress on a sled that rolled on bearings to provide freedom of movement. The weight of the sled was off-loaded using a counterweight system to insure that 1/6 body weight was applied along the long axis (z-axis) of the body. Force was verified through use of a force plate mounted at the foot of the bed. A seating assembly was added to the bed to permit periods of sitting. Subjects alternated between standing and sitting positions throughout the day. A total of 35% of the day was spent in the standing position and 65% was spent sitting. In an effort to achieve physiologic fluid shifts expected for a 1/6 G environment, subjects wore compression stockings and performed unloaded foot and ankle exercises. Eight subjects (3 females and 5 males) participated in this study. Subjects spent 13 days in the pre-bed rest phase, 6 days in bed rest and 3 days post bed rest. Subjects consumed a standardized diet throughout the study. To determine feasibility, measures of subject comfort, force and plasma volume were collected. Subject comfort was assessed using a Likert scale. Subjects were asked to assess level of comfort (0-100) for 11 body regions and provide an overall rating. Results indicated minimal to no discomfort as most subjects reported scores of zero. Force measures were performed for each standing position and were validated against subject s calculated 1/6 body weight (r(sup 2) = 0.993). The carbon monoxide rebreathing technique was used to assess plasma volume during pre-bed rest and on the last day of bed rest. Plasma volume results indicated a significant decrease (p = 0.001) from pre to post bed rest values. Subjects lost on average 8.3% (sd = 6.1%) during the

  13. Remote Sensing and Quantization of Analog Sensors

    Science.gov (United States)

    Strauss, Karl F.

    2011-01-01

    This method enables sensing and quantization of analog strain gauges. By manufacturing a piezoelectric sensor stack in parallel (physical) with a piezoelectric actuator stack, the capacitance of the sensor stack varies in exact proportion to the exertion applied by the actuator stack. This, in turn, varies the output frequency of the local sensor oscillator. The output, F(sub out), is fed to a phase detector, which is driven by a stable reference, F(sub ref). The output of the phase detector is a square waveform, D(sub out), whose duty cycle, t(sub W), varies in exact proportion according to whether F(sub out) is higher or lower than F(sub ref). In this design, should F(sub out) be precisely equal to F(sub ref), then the waveform has an exact 50/50 duty cycle. The waveform, D(sub out), is of generally very low frequency suitable for safe transmission over long distances without corruption. The active portion of the waveform, t(sub W), gates a remotely located counter, which is driven by a stable oscillator (source) of such frequency as to give sufficient digitization of t(sub W) to the resolution required by the application. The advantage to this scheme is that it negates the most-common, present method of sending either very low level signals (viz. direct output from the sensors) across great distances (anything over one-half meter) or the need to transmit widely varying higher frequencies over significant distances thereby eliminating interference [both in terms of beat frequency generation and in-situ EMI (electromagnetic interference)] caused by ineffective shielding. It also results in a significant reduction in shielding mass.

  14. BOOK REVIEW: An Analog Electronics Companion

    Science.gov (United States)

    Hamilton, Scott

    2003-09-01

    The expression 'Analog electronics' here means the sum of a vast quantity of scientific and technical knowledge and topics. By the same token, the electronic analogue and circuit designer should also have a vast cultural and scientific know-how. The aim of this book is to be a guide for neophytes as well as a useful 'travelling companion' for the mature designer confronted with such a vast world. In my opinion it successfully meets these intentions. The subjects are treated in a concise, clear and self-contained fashion, always helped by a broad exhaustive bibliography, and cover all the necessary aspects for electronic design, such as: the essential elements of mathematical analysis, trigonometry and logarithms to reach Fourier and Laplace transforms and differential equations; physics phenomena and laws from electrostatics and electrodynamics up to Maxwell equations and electronic noise; the fundamental elements of electronic circuit theory and their methods of analysis up to the theory of feedback and control systems; an analysis of the electrical characteristics of the main passive and active electronic components. The above mentioned points take up about half of the text. The remaining topics deal with circuit applications often faced by the electronic designer. In the second part, circuit analysis is treated analytically as well as by the use of CAD, and Pspice software is provided on a CD which illustrates examples. The list of topics treated is long and ranges from operational amplifier circuits to rectifier circuits as well as current feedback amplifiers and high frequency transformers. The book closes by mentioning chaos theory. Daniele Marioli

  15. De Analogía a Digitalia

    Directory of Open Access Journals (Sweden)

    Dr. Xaime Fandiño Alonso

    2001-01-01

    ía, creatividad y contenidos.ABSTRACTThe transition towards binary-based technology has unleashed dramatic changes that in the last decade have affected the different stages involved in an audiovisual production: from scripting and creating a project, through the various technological procedures of the actual production process to its final distribution.The remains of the analogical era are finally sinking under a seemingly unstoppable wave of constantly evolving new digital environments.The new hardware devices used in this field are mainly prototypes. An ever evolving market, the constant arising of new competitors, newborn joint-ventures and a myriad of related facts force technology providers to keep a pace of constant updating in a mad race of fierce competition.The old system which implied one machine for each process is increasingly becoming a memory of the past. Today new devices are being launched at such a speed that the old technological approach which dealt with mechanical appliances like magnetoscopes, closed platforms and linear recording are already bound for extinction.It’s only natural then that the sacred cows of the industry fear for their position. Big and small are elusive concepts in this new audiovisual frenzy. Its almost daily routine to read about big audiovisual corporations announcing mergers, buy-outs or the acquisition of a stake in new and small creativity and development firms built from scratch by young entrepreneurs out of the blue.The digital era is drawing a heavy curtain that luckily leaves behind an analogical era in which the ownership of the costly means of production was the most important card in the game. The artist could only exercise its art if access to the professional team and technical equipment required for an audiovisual work was granted by its proprietors.Today, digital means new systems with far more productive environments which besides are user-friendly and cost only a small fraction of the old hardware.Right now, with

  16. Education and Public Outreach and Engagement at NASA's Analog Missions in 2012

    Science.gov (United States)

    Watkins, Wendy L.; Janoiko, Barbara A.; Mahoney, Erin; Hermann, Nicole B.

    2013-01-01

    each activity into the mission timeline. In 2012, the AES Analog Missions Project performed three distinct missions - NASA Extreme Environment Mission Operations (NEEMO), which simulated a mission to an asteroid using an undersea laboratory; In-Situ Resource Utilization (ISRU) Field Test, which simulated a robotic mission to the moon searching and drilling for water; and Research and Technology Studies (RATS) integrated tests, which also simulated a mission to an asteroid. This paper will discuss the education and public engagement that occurred during these missions.

  17. Simulations of the Cardiovascular System Using the Cardiovascular Simulation Toolbox

    OpenAIRE

    Ortiz-León, Gabriela; Vílchez-Monge, Marta; Montero-Rodríguez, Juan J.

    2014-01-01

    In the present document, six mathematical models of the cardiovascular system are studied and implemented in MATLAB R2013a using an updated version of the Cardiovascular Simulation Toolbox proposed by O. Barnea at the Tel-Aviv University. All the mathematical models are based on electrical lumped-parameter analogies. The results of the simulations are compared with a list of expected hemodynamic parameters and contrasted with laboratory values.

  18. UV IRRADIATION OF AROMATIC NITROGEN HETEROCYCLES IN INTERSTELLAR ICE ANALOGS

    Science.gov (United States)

    Elsila, J. E.; Bernstein, M. P.; Sanford, S. A.

    2005-01-01

    Here, we present information on the properties of the ANH quinoline frozen in interstellar water-ice analogs. Quinoline is a two-ring compound structurally analogous to the PAH naphthalene. In this work, binary mixtures of water and quinoline were frozen to create interstellar ice analogs, which were then subjected to ultraviolet photolysis. We will present the infrared spectra of the resulting ices at various temperatures, as well as chromatographic analysis of the residues remaining upon warm-up of these ices to room temperature.

  19. Synthesis and biological activity of nifuroxazide and analogs. II.

    Science.gov (United States)

    Tavares, L C; Chisté, J J; Santos, M G; Penna, T C

    1999-09-01

    Nifuroxazyde and six analogs were synthesized by varying the substitute from the para-position of the benzenic ring and the heteroatom of the heterocyclic ring. The MIC of seven resultant compounds was determined by serial dilutions, testing the ATCC 25923 strain of Staphylococcus aureus. A significant increase in the anti-microbial activity of thyophenic analogs, as compared with furanic and pyrrholic analogs, was observed. In addition, unlike the cyano and hydroxyl groups, the acetyl group promoted anti-microbial activity. PMID:10622109

  20. Superconducting sigma-delta analog-to-digital converter

    International Nuclear Information System (INIS)

    This patent describes a superconducting sigma-delta analog-to-digital converter for converting an analog input signal to a digital output signal. It comprises a superconducting inductor to which the analog input signal is applied to produce an inductor current; a Josephson junction connected in series with the superconducting inductor and through which the inductor current flows; a pulse generator adding sampling current pulses to the inductor current to produce a total current flowing through the Josephson junction; and output means generating from the voltage pulses the digital output signal

  1. Braneworld physics from the analog-gravity perspective

    CERN Document Server

    Barcelo, C; Barcelo, Carlos; Campos, Antonio

    2003-01-01

    We study Randall-Sundrum brane models from the viewpoint of condensed matter/quantum optics. Following the idea of analog gravity we obtain effective metrics in fluid and Bose-Einstein-condensate systems mimicking those in the brane framework. We see that the effect of warp factors in the bulk geometry translates into finite-size of the analog systems. We stress that many open questions in braneworld physics can benefit from the understanding of critical phenomena of surfaces in finite analog systems.

  2. Airframe Noise Prediction by Acoustic Analogy: Revisited

    Science.gov (United States)

    Farassat, F.; Casper, Jay H.; Tinetti, A.; Dunn, M. H.

    2006-01-01

    The present work follows a recent survey of airframe noise prediction methodologies. In that survey, Lighthill s acoustic analogy was identified as the most prominent analytical basis for current approaches to airframe noise research. Within this approach, a problem is typically modeled with the Ffowcs Williams and Hawkings (FW-H) equation, for which a geometry-independent solution is obtained by means of the use of the free-space Green function (FSGF). Nonetheless, the aeroacoustic literature would suggest some interest in the use of tailored or exact Green s function (EGF) for aerodynamic noise problems involving solid boundaries, in particular, for trailing edge (TE) noise. A study of possible applications of EGF for prediction of broadband noise from turbulent flow over an airfoil surface and the TE is, therefore, the primary topic of the present work. Typically, the applications of EGF in the literature have been limited to TE noise prediction at low Mach numbers assuming that the normal derivative of the pressure vanishes on the airfoil surface. To extend the application of EGF to higher Mach numbers, the uniqueness of the solution of the wave equation when either the Dirichlet or the Neumann boundary condition (BC) is specified on a deformable surface in motion. The solution of Lighthill s equation with either the Dirichlet or the Neumann BC is given for such a surface using EGFs. These solutions involve both surface and volume integrals just like the solution of FW-H equation using FSGF. Insight drawn from this analysis is evoked to discuss the potential application of EGF to broadband noise prediction. It appears that the use of a EGF offers distinct advantages for predicting TE noise of an airfoil when the normal pressure gradient vanishes on the airfoil surface. It is argued that such an approach may also apply to an airfoil in motion. However, for the prediction of broadband noise not directly associated with a trailing edge, the use of EGF does not

  3. Back-propagation operation for analog neural network hardware with synapse components having hysteresis characteristics.

    Science.gov (United States)

    Ueda, Michihito; Nishitani, Yu; Kaneko, Yukihiro; Omote, Atsushi

    2014-01-01

    To realize an analog artificial neural network hardware, the circuit element for synapse function is important because the number of synapse elements is much larger than that of neuron elements. One of the candidates for this synapse element is a ferroelectric memristor. This device functions as a voltage controllable variable resistor, which can be applied to a synapse weight. However, its conductance shows hysteresis characteristics and dispersion to the input voltage. Therefore, the conductance values vary according to the history of the height and the width of the applied pulse voltage. Due to the difficulty of controlling the accurate conductance, it is not easy to apply the back-propagation learning algorithm to the neural network hardware having memristor synapses. To solve this problem, we proposed and simulated a learning operation procedure as follows. Employing a weight perturbation technique, we derived the error change. When the error reduced, the next pulse voltage was updated according to the back-propagation learning algorithm. If the error increased the amplitude of the next voltage pulse was set in such way as to cause similar memristor conductance but in the opposite voltage scanning direction. By this operation, we could eliminate the hysteresis and confirmed that the simulation of the learning operation converged. We also adopted conductance dispersion numerically in the simulation. We examined the probability that the error decreased to a designated value within a predetermined loop number. The ferroelectric has the characteristics that the magnitude of polarization does not become smaller when voltages having the same polarity are applied. These characteristics greatly improved the probability even if the learning rate was small, if the magnitude of the dispersion is adequate. Because the dispersion of analog circuit elements is inevitable, this learning operation procedure is useful for analog neural network hardware. PMID:25393715

  4. Back-propagation operation for analog neural network hardware with synapse components having hysteresis characteristics.

    Directory of Open Access Journals (Sweden)

    Michihito Ueda

    Full Text Available To realize an analog artificial neural network hardware, the circuit element for synapse function is important because the number of synapse elements is much larger than that of neuron elements. One of the candidates for this synapse element is a ferroelectric memristor. This device functions as a voltage controllable variable resistor, which can be applied to a synapse weight. However, its conductance shows hysteresis characteristics and dispersion to the input voltage. Therefore, the conductance values vary according to the history of the height and the width of the applied pulse voltage. Due to the difficulty of controlling the accurate conductance, it is not easy to apply the back-propagation learning algorithm to the neural network hardware having memristor synapses. To solve this problem, we proposed and simulated a learning operation procedure as follows. Employing a weight perturbation technique, we derived the error change. When the error reduced, the next pulse voltage was updated according to the back-propagation learning algorithm. If the error increased the amplitude of the next voltage pulse was set in such way as to cause similar memristor conductance but in the opposite voltage scanning direction. By this operation, we could eliminate the hysteresis and confirmed that the simulation of the learning operation converged. We also adopted conductance dispersion numerically in the simulation. We examined the probability that the error decreased to a designated value within a predetermined loop number. The ferroelectric has the characteristics that the magnitude of polarization does not become smaller when voltages having the same polarity are applied. These characteristics greatly improved the probability even if the learning rate was small, if the magnitude of the dispersion is adequate. Because the dispersion of analog circuit elements is inevitable, this learning operation procedure is useful for analog neural network hardware.

  5. Study of archaeological analogs for the validation of nuclear glass long-term behavior models

    International Nuclear Information System (INIS)

    Fractured archaeological glass blocks collected from a shipwreck discovered in the Mediterranean Sea near Embiez Island (Var) were investigated because of their morphological analogy with vitrified nuclear waste and of a known and stable environment. These glasses are fractured due to a fast cooling after they were melted (like nuclear glass) and have been altered for 1800 years in seawater. This work results in the development and the validation of a geochemical model able to simulate the alteration of a fractured archaeological glass block over 1800 years. The kinetics associated with the different mechanisms (interdiffusion and dissolution) and the thermodynamic parameters of the model were determined by leaching experiments. The model implemented in HYTEC software was used to simulate crack alteration over 1800 years. The consistency between simulated alteration thicknesses and measured data on glass blocks validate the capacity of the model to predict long-term alteration. This model is able to account for the results from the characterization of crack network and its state of alteration. The cracks in the border zone are the most altered due to a fast renewal of the leaching solution, whereas internal cracks are thin because of complex interactions between glass alteration and transport of elements in solution (influence of initial crack aperture and of the crack sealing). The lowest alteration thicknesses, as well as their variability, can be explained. The analog behavior of archaeological and nuclear glasses from leaching experiments makes possible the transposition of the model to nuclear glass in geological repository. (author)

  6. Pathological Deformations of Brain Vascular System Modelling Using Analogous Eletromagnetic Systems

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2004-01-01

    Full Text Available The contribution deals with the modelling and simulation of human brain haemodynamics using analogous electromagnetic systems characteristic especially propagation properties of distributed parameters circuits. The cascade connection of analogical transmission line elements represents the vascular tree both from the point of the parameters and the topology as well. In the paper there are presented simulation examples of the healthy cerebral system mainly in the big arteries in comparing with the pathologically changed ones. The various degrees of stenosis are considered for the simulations of blood pressure and blood flow velocity and the results are compared with the healthy arteries. According to the last investigations the pathological deformations of brain arteries are th most frequently reasons of deaths in the world. The stenoses or aneurysms change the physical properties of arteries and they follow insufficient vascularisation of the brain. These computer-aided non-invasive methods together with the non-invasive experimental techniques represent a helpful tool both for the diagnostics and the treatment of vascular pathological deformations.

  7. A Simple Hydraulic Analog Model of Oxidative Phosphorylation.

    Science.gov (United States)

    Willis, Wayne T; Jackman, Matthew R; Messer, Jeffrey I; Kuzmiak-Glancy, Sarah; Glancy, Brian

    2016-06-01

    Mitochondrial oxidative phosphorylation is the primary source of cellular energy transduction in mammals. This energy conversion involves dozens of enzymatic reactions, energetic intermediates, and the dynamic interactions among them. With the goal of providing greater insight into the complex thermodynamics and kinetics ("thermokinetics") of mitochondrial energy transduction, a simple hydraulic analog model of oxidative phosphorylation is presented. In the hydraulic model, water tanks represent the forward and back "pressures" exerted by thermodynamic driving forces: the matrix redox potential (ΔGredox), the electrochemical potential for protons across the mitochondrial inner membrane (ΔGH), and the free energy of adenosine 5'-triphosphate (ATP) (ΔGATP). Net water flow proceeds from tanks with higher water pressure to tanks with lower pressure through "enzyme pipes" whose diameters represent the conductances (effective activities) of the proteins that catalyze the energy transfer. These enzyme pipes include the reactions of dehydrogenase enzymes, the electron transport chain (ETC), and the combined action of ATP synthase plus the ATP-adenosine 5'-diphosphate exchanger that spans the inner membrane. In addition, reactive oxygen species production is included in the model as a leak that is driven out of the ETC pipe by high pressure (high ΔGredox) and a proton leak dependent on the ΔGH for both its driving force and the conductance of the leak pathway. Model water pressures and flows are shown to simulate thermodynamic forces and metabolic fluxes that have been experimentally observed in mammalian skeletal muscle in response to acute exercise, chronic endurance training, and reduced substrate availability, as well as account for the thermokinetic behavior of mitochondria from fast- and slow-twitch skeletal muscle and the metabolic capacitance of the creatine kinase reaction. PMID:26807634

  8. Viscoelastic silicone oils in analog modeling - a rheological benchmark

    Science.gov (United States)

    Rudolf, Michael; Boutelier, David; Rosenau, Matthias; Schreurs, Guido; Oncken, Onno

    2016-04-01

    Tectonic analog models frequently use silicone oils to simulate viscous flow in the lower crust and mantle. Precise knowledge of the model rheology is required to ensure dynamic similarity with the prototype. We assessed the rheological properties of various silicone oils using rotational and oscillatory tests. Resulting viscosities are in the range of 2 - 3 ×104 Pa s with a transition from Newtonian viscous to power-law, shear-thinning, around shear rates of 10‑2 to 10‑1 s‑1. Maxwell relaxation times are in the range of 10‑1 s. Comparing the rheological properties of chemically similar silicone oils from different laboratories shows that they differ from laboratory to laboratory. Furthermore, we characterized the temperature dependency of viscosity and aging effects. The samples show a reduction in zero-shear viscosity over time. This stabilizes at a certain value over several months. The dynamic moduli decrease as well, but other viscoelastic constants, such as the Maxwell relaxation time, are not affected by aging. We conclude that the aging is mainly controlled by the storage conditions and that a silicone shows no further aging when it has equilibrated with the ambient laboratory conditions. We consider all these differences as minor compared to the much larger uncertainties for estimating the lithosphere rheology. Nevertheless, it is important that the rheological properties of the experimental materials are monitored during an experimental series that spans over several weeks to months. Additionally, the viscoelastic properties may be scaled using dimensionless parameters (Deborah number) and show a dynamically similar change from Newtonian to power-law flow, like the natural prototype. In consequence, the viscoelasticity of these silicone oils is able to mimic the change in deformation mechanism from diffusion to dislocation creep.

  9. Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

    CERN Document Server

    Gavilan, L; Simionovici, A; Lemaire, J L; Sabri, T; Foy, E; Yagoubi, S; Henning, T; Salomon, D; Martinez-Criado, G

    2016-01-01

    Protoplanetary disks, interstellar clouds, and active galactic nuclei, contain X-ray dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Our goal is to study the effects of hard X-rays on cosmic dust analogs via in-situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments, and provide an upper limit on the effect of hard X-rays on dust grain structure. We prepared enstatite nanograins, analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy and high-resolution transmission electron microscopy before irradiation. Powder samples were prepared i...

  10. A flexible analog memory address list manager/controller for PHENIX

    International Nuclear Information System (INIS)

    A programmable analog memory address list manager/controller has been developed for use with all analog memory-based detector subsystems of PHENIX. The unit provides simultaneous read/write control, cell write-over protection for both a Level-1 trigger decision delay and digitization latency, and re-ordering of AMU addresses following conversion, at a beam crossing rate of 112 ns. Addresses are handled such that up to 5 Level-1 events can be maintained in the AMU without write-over. Data tagging is implemented for handling overlapping and shared beam event data packets. Full usage in all PHENIX analog memory-based detector sub-systems is accomplished by the use of detector-specific programmable parameters -- the number of data samples per Level-1 trigger valid and the swnple spacing. Architectural candidates for the system are discussed with emphasis on implementation implications. Details of the design are presented including design simulations, timing information, and test results from a full implementation using programmable logic devices

  11. Fault Diagnosis of Mixed-Signal Analog Circuit using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar Narula

    2015-06-01

    Full Text Available This paper presents parametric fault diagnosis in mixed-signal analog circuit using artificial neural networks. Single parametric faults are considered in this study. A benchmark R2R digital to analog converter circuit has been used as an example circuit for experimental validations. The input test pattern required for testing are reduced to optimum value using sensitivity analysis of the circuit under test. The effect of component tolerances has also been taken care of by performing the Monte-Carlo analysis. In this study parametric fault models are defined for the R2R network of the digital to analog converter. The input test patterns are applied to the circuit under test and the output responses are measured for each fault model covering all the Monte-Carlo runs. The classification of the parametric faults is done using artificial neural networks. The fault diagnosis system is developed in LabVIEW environment in the form of a virtual instrument. The artificial neural network is designed using MATLAB and finally embedded in the virtual instrument. The fault diagnosis is validated with simulated data and with the actual data acquired from the circuit hardware.

  12. Digitally programmable analog building blocks for the implementation of artificial neural networks.

    Science.gov (United States)

    Almeida, A P; Franca, J E

    1996-01-01

    This paper describes the design, experimental characterization and behavior modeling of a homogeneous set of building blocks necessary to construct in analog hardware feed-forward artificial neural networks. A novel synapse architecture is proposed using a quasi-passive D/A (digital-to-analog) converter followed by a four-quadrant analog-digital multiplier, its main advantages are 1) increased signal input range; 2) improved area/weight resolution ratio; 3) on-chip refreshing of the weight value; and 4) serial loading the weight bits. The neurons are built using MOS (metal-oxide semiconductor) transistors operating in the saturation region and exploiting the inherent quadratic characteristics. Experimental results obtained from a demonstration prototype chip realized in a 1.2 mum double-poly, double-metal CMOS (complimentary MOS) technology show good agreement with the design specifications. A simple application of the proposed building blocks is illustrated based on the mixed-signal simulation of the corresponding behavior models constructed from the experimental characterization data. PMID:18255602

  13. MAPPING EARTH ANALOGS FROM PHOTOMETRIC VARIABILITY: SPIN-ORBIT TOMOGRAPHY FOR PLANETS IN INCLINED ORBITS

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yuka [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Kawahara, Hajime, E-mail: yuka.fujii@utap.phys.s.u-tokyo.ac.jp [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan)

    2012-08-20

    Aiming at obtaining detailed information on the surface environment of Earth analogs, Kawahara and Fujii proposed an inversion technique of annual scattered light curves named spin-orbit tomography (SOT), which enables us to sketch a two-dimensional albedo map from annual variation of the disk-integrated scattered light, and demonstrated the method with a planet in a face-on orbit. We extend it to be applicable to general geometric configurations, including low-obliquity planets like the Earth in inclined orbits. We simulate light curves of the Earth in an inclined orbit in three photometric bands (0.4-0.5 {mu}m, 0.6-0.7 {mu}m, and 0.8-0.9 {mu}m) and show that the distribution of clouds, snow, and continents is retrieved with the aid of the SOT. We also demonstrate the SOT by applying it to an upright Earth, a tidally locked Earth, and Earth analogs with ancient continental configurations. The inversion is model independent in the sense that we do not assume specific albedo models when mapping the surface, and hence applicable in principle to any kind of inhomogeneity. This method can potentially serve as a unique tool to investigate the exohabitats/exoclimes of Earth analogs.

  14. Gating of the mitochondrial permeability transition pore by long chain fatty acyl analogs in vivo.

    Science.gov (United States)

    Samovski, Dmitri; Kalderon, Bella; Yehuda-Shnaidman, Einav; Bar-Tana, Jacob

    2010-03-01

    The role played by long chain fatty acids (LCFA) in promoting energy expenditure is confounded by their dual function as substrates for oxidation and as putative classic uncouplers of mitochondrial oxidative phosphorylation. LCFA analogs of the MEDICA (MEthyl-substituted DICarboxylic Acids) series are neither esterified into lipids nor beta-oxidized and may thus simulate the uncoupling activity of natural LCFA in vivo, independently of their substrate role. Treatment of rats or cell lines with MEDICA analogs results in low conductance gating of the mitochondrial permeability transition pore (PTP), with 10-40% decrease in the inner mitochondrial membrane potential. PTP gating by MEDICA analogs is accounted for by inhibition of Raf1 expression and kinase activity, resulting in suppression of the MAPK/RSK1 and the adenylate cyclase/PKA transduction pathways. Suppression of RSK1 and PKA results in a decrease in phosphorylation of their respective downstream targets, Bad(Ser-112) and Bad(Ser-155). Decrease in Bad(Ser-112, Ser-155) phosphorylation results in increased binding of Bad to mitochondrial Bcl2 with concomitant displacement of Bax, followed by PTP gating induced by free mitochondrial Bax. Low conductance PTP gating by LCFA/MEDICA may account for their thyromimetic calorigenic activity in vivo. PMID:20037159

  15. Direct Digital Demultiplexing of Analog TDM Signals for Cable Reduction in Ultrasound Imaging Catheters.

    Science.gov (United States)

    Carpenter, Thomas M; Rashid, M Wasequr; Ghovanloo, Maysam; Cowell, David M J; Freear, Steven; Degertekin, F Levent

    2016-08-01

    In real-time catheter-based 3-D ultrasound imaging applications, gathering data from the transducer arrays is difficult, as there is a restriction on cable count due to the diameter of the catheter. Although area and power hungry multiplexing circuits integrated at the catheter tip are used in some applications, these are unsuitable for use in small sized catheters for applications, such as intracardiac imaging. Furthermore, the length requirement for catheters and limited power available to on-chip cable drivers leads to limited signal strength at the receiver end. In this paper, an alternative approach using analog time-division multiplexing (TDM) is presented, which addresses the cable restrictions of ultrasound catheters. A novel digital demultiplexing technique is also described, which allows for a reduction in the number of analog signal processing stages required. The TDM and digital demultiplexing schemes are demonstrated for an intracardiac imaging system that would operate in the 4- to 11-MHz range. A TDM integrated circuit (IC) with an 8:1 multiplexer is interfaced with a fast analog-to-digital converter (ADC) through a microcoaxial catheter cable bundle, and processed with a field-programmable gate array register-transfer level simulation. Input signals to the TDM IC are recovered with -40-dB crosstalk between the channels on the same microcoax, showing the feasibility of this system for ultrasound imaging applications. PMID:27116738

  16. General Reynolds Analogy for Blunt-nosed Bodies in Hypersonic Flows

    CERN Document Server

    Chen, Xing-Xing; Yu, Yong-Liang

    2015-01-01

    In this paper, the relation between skin friction and heat transfer along windward sides of blunt-nosed bodies in hypersonic flows is investigated. The self-similar boundary layer analysis is accepted to figure out the distribution of the ratio of skin friction to heat transfer coefficients along the wall. It is theoretically obtained that the ratio depends linearly on the local slope angle of the wall surface, and an explicit analogy expression is presented for circular cylinders, although the linear distribution is also found for other nose shapes and even in gas flows with chemical reactions. Furthermore, based on the theoretical modelling of the second order shear and heat transfer terms in Burnett equations, a modified analogy is derived in the near continuum regime by considering the rarefied gas effects. And a bridge function is also constructed to describe the nonlinear analogy in the transition flow regime. At last, the direct simulation Monte Carlo method is used to validate the theoretical results....

  17. Analog and radio-frequency performance analysis of silicon-nanotube MOSFETs

    Science.gov (United States)

    Tiwari, Pramod Kumar; Kumar, Mukesh; Sakru Naik, Ramavathu; Krishna Saramekala, Gopi

    2016-06-01

    This work presents a comparative study of the influence of various parameters on the analog and RF properties of silicon-nanotube MOSFETs and nanowire-based gate-all-around (GAA) MOSFETs. The important analog and RF performance parameters of SiNT FETs and GAA MOSFETs, namely drain current (I d), transconductance to drain current ratio (g m/I d), I on/I off, the cut-off frequency (f T) and the maximum frequency of oscillation (f MAX) are evaluated with the help of Y- and H-parameters which are obtained from a 3-D device simulator, ATLAS™. It is found that the silicon-nanotube MOSFETs have far more superior analog and RF characteristics (g m/I d, f T and f MAX) compared to the nanowire-based gate-all-around GAA MOSFETs. The silicon-nanotube MOSFET shows an improvement of ∼2.5 and 3 times in the case of f T and f MAX values respectively compared with the nanowire-based gate-all-around (GAA) MOSFET. Project supported by the Defence Research and Development Organisation (DRDO), Ministry of Defence, Govt. of India (No. CC/TM/ERIPR/GIA/1516/020).

  18. 22nd Workshop on Advances in Analog Circuit Design

    CERN Document Server

    Makinwa, Kofi; Harpe, Pieter

    2014-01-01

    This book is based on the 18 tutorials presented during the 22nd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including frequency reference, power management for systems-on-chip, and smart wireless interfaces.  This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of frequency reference, power management for systems-on-chip, and smart wireless interfaces.

  19. Zwittermicin A: Synthesis of Analogs and Structure-Activity Studies

    OpenAIRE

    Rogers, Evan W.; Dalisay, Doralyn S.; Molinski, Tadeusz F.

    2010-01-01

    Analogs and diastereomers of the natural product zwittermicin A were prepared. SAR studies of these compounds reveal the antifungal activity to be dependent singularly upon the natural constitution and configuration.

  20. FXR agonist activity of conformationally constrained analogs of GW 4064

    Energy Technology Data Exchange (ETDEWEB)

    Akwabi-Ameyaw, Adwoa; Bass, Jonathan Y.; Caldwell, Richard D.; Caravella, Justin A.; Chen, Lihong; Creech, Katrina L.; Deaton, David N.; Madauss, Kevin P.; Marr, Harry B.; McFadyen, Robert B.; Miller, Aaron B.; Navas, III, Frank; Parks, Derek J.; Spearing, Paul K.; Todd, Dan; Williams, Shawn P.; Wisely, G. Bruce; (GSKNC)

    2010-09-27

    Two series of conformationally constrained analogs of the FXR agonist GW 4064 1 were prepared. Replacement of the metabolically labile stilbene with either benzothiophene or naphthalene rings led to the identification of potent full agonists 2a and 2g.

  1. Energy Harvesting Using an Analog Circuit under Multimodal Vibration

    Directory of Open Access Journals (Sweden)

    Shigeru Shimose

    2013-01-01

    Full Text Available The efficiency of harvesting energy from a vibrating structure using a piezoelectric transducer and a simple analog circuit is investigated experimentally. This analog circuit was originally invented for a synchronized switch damping on inductor (SSDI technique, which enhances the damping of mechanical vibration. In this study, the circuit is used to implement a synchronized switch harvesting on inductor (SSHI technique. A multiple degree of freedom (MDOF structure is excited by single sinusoidal forces at its resonant frequencies and by random forces. The piezoelectric transducer converts this mechanical energy into electrical energy which is harvested using a standard rectifier bridge circuit with and without our analog circuit. Experimental results show that our analog circuit makes it possible to harvest twice as much energy under both single sinusoidal and random vibration excitations.

  2. Project Birdseye Aerial Photograph Collection: Digital and Analog Materials

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection consists of both analog and digital aerial photographs from Arctic areas in and around Baffin Bay, the Labrador Sea, the Arctic Ocean, the Beaufort...

  3. Analog and digital signal analysis from basics to applications

    CERN Document Server

    Cohen Tenoudji, Frédéric

    2016-01-01

    This book provides comprehensive, graduate-level treatment of analog and digital signal analysis suitable for course use and self-guided learning. This expert text guides the reader from the basics of signal theory through a range of application tools for use in acoustic analysis, geophysics, and data compression. Each concept is introduced and explained step by step, and the necessary mathematical formulae are integrated in an accessible and intuitive way. The first part of the book explores how analog systems and signals form the basics of signal analysis. This section covers Fourier series and integral transforms of analog signals, Laplace and Hilbert transforms, the main analog filter classes, and signal modulations. Part II covers digital signals, demonstrating their key advantages. It presents z and Fourier transforms, digital filtering, inverse filters, deconvolution, and parametric modeling for deterministic signals. Wavelet decomposition and reconstruction of non-stationary signals are also discussed...

  4. A Uniform Approach to Analogies, Synonyms, Antonyms, and Associations

    CERN Document Server

    Turney, Peter D

    2008-01-01

    Recognizing analogies, synonyms, antonyms, and associations appear to be four distinct tasks, requiring distinct NLP algorithms. In the past, the four tasks have been treated independently, using a wide variety of algorithms. These four semantic classes, however, are a tiny sample of the full range of semantic phenomena, and we cannot afford to create ad hoc algorithms for each semantic phenomenon; we need to seek a unified approach. We propose to subsume a broad range of phenomena under analogies. To limit the scope of this paper, we restrict our attention to the subsumption of synonyms, antonyms, and associations. We introduce a supervised corpus-based machine learning algorithm for classifying analogous word pairs, and we show that it can solve multiple-choice SAT analogy questions, TOEFL synonym questions, ESL synonym-antonym questions, and similar-associated-both questions from cognitive psychology.

  5. Reference-Free CMOS Pipeline Analog-to-Digital Converters

    CERN Document Server

    Figueiredo, Michael; Evans, Guiomar

    2013-01-01

    This book shows that digitally assisted analog-to-digital converters are not the only way to cope with poor analog performance caused by technology scaling. It describes various analog design techniques that enhance the area and power efficiency without employing any type of digital calibration circuitry. These techniques consist of self-biasing for PVT enhancement, inverter-based design for improved speed/power ratio, gain-of-two obtained by voltage sum instead of charge redistribution, and current-mode reference shifting instead of voltage reference shifting. Together, these techniques allow enhancing the area and power efficiency of the main building blocks of a multiplying digital-to-analog converter (MDAC) based stage, namely, the flash quantizer, the amplifier, and the switched capacitor network of the MDAC. Complementing the theoretical analyses of the various techniques, a power efficient operational transconductance amplifier is implemented and experimentally characterized. Furthermore, a medium-low ...

  6. Parameter estimation of analog circuits based on the fractional wavelet method

    Science.gov (United States)

    Yong, Deng; He, Zhang

    2015-03-01

    Aiming at the problem of parameter estimation in analog circuits, a new approach is proposed. The approach is based on the fractional wavelet to derive the Volterra series model of the circuit under test (CUT). By the gradient search algorithm used in the Volterra model, the unknown parameters in the CUT are estimated and the Volterra model is identified. The simulations show that the parameter estimation results of the proposed method in the paper are better than those of other parameter estimation methods. Project supported by the Key Research Project of Sichuan Provincial Department of Education, China (No. 13ZA0186).

  7. Digital Operation of Microelectronic Circuits Analogous to Protein Hydrogen Bonding Networks

    Directory of Open Access Journals (Sweden)

    Elitsa Gieva

    2012-12-01

    Full Text Available Two hydrogen bonding networks with water molecules and branching residues extracted from β-lactamase protein are investigated and their proton transfer characteristics are studied by creating analogous electrical circuits consisting of block-elements. The block-elements and their proton transfer are described by polynomials that are coded in Matlab and in Verilog-A for use in the Spectre simulator of Cadence IC design system. DC and digital pulse analyses are performed to demonstrate that some circuit outputs behave as repeaters while other - behave as inverters. The results also showed that the HBN circuits might behave as a D-latch and a demultiplexer.

  8. Analog-to-digital conversion with a SQUID: Conditions for a countable pulse train

    International Nuclear Information System (INIS)

    A superconducting loop containing a Josephson junction develops voltage pulses when it admits and expels magnetic flux quanta, and thus may be used as an A/D converter. We here develop and discuss several conditions which must be satisfied for the generation by the SQUID of an unambiguously countable pulse train, from which the analog signal can be faithfully reconstructed. These conditions can be satisfied over a broad range of realizable values of inductance and resistance. The capacitance, however, must be carefully controlled. The results of simulations are also presented, illustrating the various ways in which the pulse trains are affected

  9. Radiolysis of H2O:CO2 ices by heavy energetic cosmic ray analogs

    OpenAIRE

    Pilling, S.; Duarte, E. Seperuelo; Domaracka, A.; Rothard, H.; Boduch, P.; da Silveira, E. F.

    2010-01-01

    An experimental study on the interaction of heavy, highly charged, and energetic ions (52 MeV Ni^13+) with pure H2O, pure CO2 and mixed H2O:CO2 astrophysical ice analogs is presented. This analysis aims to simulate the chemical and the physicochemical interactions induced by heavy cosmic rays inside dense and cold astrophysical environments such as molecular clouds or protostellar clouds. The measurements were performed at the heavy ion accelerator GANIL (Grand Accelerateur National d'Ions Lo...

  10. Formation of unsaturated hydrocarbons in interstellar ice analogs by cosmic rays

    OpenAIRE

    Pilling, S.; Andrade, D. P. P; da Silveira, E. F.; Rothard, H.; Domaracka, A.; Boduch, P.

    2012-01-01

    The formation of double and triple C-C bonds from the processing of pure c-C6H12 (cyclohexane) and mixed H2O:NH3:c-C6H12 (1:0.3:0.7) ices by highly-charged, and energetic ions (219 MeV O^{7+} and 632 MeV Ni^{24+}) is studied. The experiments simulate the physical chemistry induced by medium-mass and heavy-ion cosmic rays in interstellar ices analogs. The measurements were performed inside a high vacuum chamber at the heavy-ion accelerator GANIL (Grand Accel\\'erat\\'eur National d'Ions Lourds) ...

  11. Interaction of Rupture Zones of Adjacent Anchor Plates in an Analogical Medium

    Directory of Open Access Journals (Sweden)

    H. Abbad

    2013-12-01

    Full Text Available In this paper, an experimental study which required the design and implementation of a model containing plastic granules powder to simulate a natural environment, is presented. The latter is subjected to the removal of "anchor plates." For each test, several digital photographs are taken to materialize different deformed configurations during the pullout process. These photos processed in couples by the 7D software (image correlation giving the evolution of the displacement field and plane strain analogical environment. Particular attention is paid to the discussion of the interference of rupture zones of neighboring anchors by reducing the axis between plates.

  12. Wideband precision analog telemetry link using digital techniques

    International Nuclear Information System (INIS)

    A highly linear Wideband Analog Fiber Optic Link is described which samples at a 1 MHz rate with 10-bit accuracy and transmits and receives by means of a high speed PDM code. Aliasing and sampling effects are fully suppressed and a nearly Gaussian pulse response is attained with a 2 μsec risetime. Analog signals are recovered with very low distortion and d.c. drift and a S/N ratio of better than 52 db

  13. Energy Harvesting Using an Analog Circuit under Multimodal Vibration

    OpenAIRE

    Shigeru Shimose; Kanjuro Makihara; Junjiro Onoda

    2013-01-01

    The efficiency of harvesting energy from a vibrating structure using a piezoelectric transducer and a simple analog circuit is investigated experimentally. This analog circuit was originally invented for a synchronized switch damping on inductor (SSDI) technique, which enhances the damping of mechanical vibration. In this study, the circuit is used to implement a synchronized switch harvesting on inductor (SSHI) technique. A multiple degree of freedom (MDOF) structure is excited by single sin...

  14. Direct (under) Sampling vs. Analog Downconversion for BPM Electroncs

    CERN Document Server

    Wendt, M

    2014-01-01

    Digital signal processing by means of undersampling the analog signal has become a popular method for acquiring beam position monitor signals. This presentation discusses the technique and its principle limitations, presents today’s technical limits (e.g. in terms of performance of available ADCs), and provides an outlook for the future. It will also try to compare the technique with more tradition analog downmixing and signal processing methods

  15. Extending west's analogy royce, mead, and american philosophy

    OpenAIRE

    Claudio Marcelo Viale

    2008-01-01

    In The American Evasion of Philosophy Cornell West makes a comparison between the developments of European and classical American philosophies. Within West’s analogy, however, two important American figures are missing: Josiah Royce and George H. Mead. In the context of this framework, this article attempts to extend West’s analogy, speculating on the possible roles of Royce and Mead within it. The argumentation is developed in two parts: on the one hand, I show how secondary literature that ...

  16. Synthetic analogs of anoplin show improved antimicrobial activities

    DEFF Research Database (Denmark)

    Munk, Jens; Uggerhøj, Lars Erik; Poulsen, Tanja Juul;

    2013-01-01

    We present the antimicrobial and hemolytic activities of the decapeptide anoplin and 19 analogs thereof tested against methicillin-resistant Staphylococcus aureus ATCC 33591 (MRSA), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), vancomycin-resistant Enterococcus faecium (ATCC...... that increasing the charge and/or hydrophobicity improves antimicrobial activity and increases hemolytic activity. For each strain tested, we identify at least six anoplin analogs with an improved therapeutic index compared with anoplin, the only exception being Enterococcus faecium, against which only...

  17. Presence of organophosphorus pesticide oxygen analogs in air samples

    OpenAIRE

    Armstrong, Jenna L.; Fenske, Richard A; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-01-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and lab...

  18. Analogies between light optics and charged-particle optics

    OpenAIRE

    Khan, Sameen Ahmed

    2002-01-01

    The close analogy between geometrical optics and the classical theories of charged-particle beam optics have been known for a very long time. In recent years, quantum theories of charged-particle beam optics have been presented with the very expected feature of wavelength-dependent effects. With the current development of non-traditional prescriptions of Helmholtz and Maxwell optics respectively, accompanied with the wavelength-dependent effects, it is seen that the analogy between the two sy...

  19. Performance report for Stanford/SLAC Microstore Analog Memory Unit

    International Nuclear Information System (INIS)

    Tests of a newly developed Analog Memory Unit (AMU) are described. The device contains 256 analog storage cells consisting of pass transistors, a storage capacitor and a differential read out buffer. By addressing the storage cells sequentially, the shape of the signal present at the input can be recorded in time. Fast response and good amplitude resolution were the design goals for the development. Measurements on individual devices will be presented and the status of hybridized subsystems containing eight AMUs discussed

  20. Analog Genetic Encoding for the Evolution of Circuits and Networks

    OpenAIRE

    Mattiussi, Claudio; Floreano, Dario

    2007-01-01

    This paper describes a new kind of genetic representation called analog genetic encoding (AGE). The representation is aimed at the evolutionary synthesis and reverse engineering of circuits and networks such as analog electronic circuits, neural networks, and genetic regulatory networks. AGE permits the simultaneous evolution of the topology and sizing of the networks. The establishment of the links between the devices that form the network is based on an implicit definition of the interactio...

  1. Benefit of Analog, Programmable and Digital Hearing Aids

    Directory of Open Access Journals (Sweden)

    Jamileh Fatahi

    2006-12-01

    Full Text Available Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impaired persons. Materials and Methods: This cross-sectional study was performed on 90 persons with mild to severe sensorineural hearing loss dividing into three groups: 43 subjects were fitted with digital, 15 with programmable, 32 with analog hearing aids. After pure tone audiometry, Abbreviated profile of hearing aid benefit (APHAB was completed before and one month after using hearing aids to determine the benefit of them. Results: Global APHAB mean scores for digital, programmable and analog hearing aids were 49.05, 33.19 and 39.53, respectively. Ease of Communication subscale mean scores were 53.46 for digitals, 37.66 for programmables and 39.09 for analogs. Background noise subscale mean scores for digital programmable and analog hearing aids were 46.36, 25.53 and 35.31, respectively. Global and also both subscale mean scores showed significant difference between digital hearing aids and programmable and analog ones. There was no significant difference between reverberation subscale mean scores of three groups. Conclusion: It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are.

  2. Comparing Analog and Digital Hearing Aids in Reducing Hearing Disability

    OpenAIRE

    Ghassem Mohammad Khani; Mohammad Hassan Khalesi; Soghrat Faghih Zadeh; Bahieh Kohansal; Zahra Jafari

    2004-01-01

    Objective: Comparing analog and digital hearing aids reducing disability caused by hearing deficiency among moderate to severe sensorineural hearing-impaired persons. Method and Material: This descriptive-analytic study was carried out on two groups of subjects participated in this study in some audiology clinics of hearing aid since May 2002 to October 2003. Twenty subjects wore analog hearing aids and twenty one subjects wore digital hearing aids. In this study , no subject had previous mid...

  3. Benefit of Analog, Programmable and Digital Hearing Aids

    OpenAIRE

    Jamileh Fatahi; Mansoureh Adel Ghahraman; Azadeh Ebrahimi; Faranak Ehsani; Samaneh Pourhadi

    2006-01-01

    Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impair...

  4. Deficits in analogical reasoning in adolescents with traumatic brain injury

    OpenAIRE

    Krawczyk, Daniel C.; Gerri Hanten; Elisabeth A. Wilde; Levin, Harvey S.

    2010-01-01

    Individuals with traumatic brain injury (TBI) exhibit deficits in executive control, which may impact their reasoning abilities. Analogical reasoning requires working memory and inhibitory abilities. In this study, we tested adolescents with moderate to severe TBI and typically-developing (TD) controls on a set of picture analogy problems. Three factors were varied: complexity (number of relations in the problems), distraction (distractor item present or absent), and animacy (living or non-li...

  5. Deficits in Analogical Reasoning in Adolescents with Traumatic Brain Injury

    OpenAIRE

    Krawczyk, Daniel C.; Hanten, Gerri; Elisabeth A. Wilde; Li, Xiaoqi; Schnelle, Kathleen P.; Merkley, Tricia L.; Vasquez, Ana C.; Cook, Lori G.; McClelland, Michelle; Chapman, Sandra B.; Levin, Harvey S.

    2010-01-01

    Individuals with traumatic brain injury (TBI) exhibit deficits in executive control, which may impact their reasoning abilities. Analogical reasoning requires working memory and inhibitory abilities. In this study, we tested adolescents with moderate to severe TBI and typically developing (TD) controls on a set of picture analogy problems. Three factors were varied: complexity (number of relations in the problems), distraction (distractor item present or absent), and animacy (living or non-li...

  6. Fluorinated Analogs of Malachite Green: Synthesis and Toxicity

    Directory of Open Access Journals (Sweden)

    Bahram Parvin

    2008-04-01

    Full Text Available A series of fluorinated analogs of malachite green (MG have been synthesizedand their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell lineexamined. The toxicity profiles were found to be different for these two species. Twoanalogs, one with 2,4-difluoro substitution and the other with 2-fluoro substitution seem tobe the most promising analogs because they showed the lowest toxicity to the human cells.

  7. Hydroacoustic characterization of a marine propeller through the Acoustic Analogy

    OpenAIRE

    Ianniello, Sandro; Muscari, Roberto; Di Mascio, Andrea

    2011-01-01

    This paper deals with the use of the Acoustic Analogy for the prediction of the underwater noise generated by a marine propeller. Different configurations are treated in order to demonstrate the potentiality of such a numerical approach and to analyze the role played by the different noise sources. Unlike analogous aeronautical propellers, it will be shown that the evaluation of the nonlinear quadrupole sources is relevant regardless of the blade rotational speed. On the contrary, the linear ...

  8. The parbelos, a parabolic analog of the arbelos

    OpenAIRE

    Sondow, Jonathan

    2012-01-01

    The arbelos is a classical geometric shape bounded by three mutually tangent semicircles with collinear diameters. We introduce a parabolic analog, the parbelos. After a review of the parabola, we use theorems of Archimedes and Lambert to demonstrate seven properties of the parbelos, drawing analogies to similar properties of the arbelos, some of which may be new. The seventh constructs a parbelos directly from an arbelos via a locus. Along the way we mention the Universal Parabolic Constant ...

  9. Understanding Young Exoplanet Analogs with WISE

    Science.gov (United States)

    Rice, Emily

    We propose to tackle outstanding questions about the fundamental properties of young brown dwarfs, which are atmospheric analogs to massive gas giant exoplanets, using public archive data from the Wide-field Infrared Survey Explorer (WISE) combined with our extensive dataset of optical and near-infrared observations, including spectra, proper motions, and parallaxes. Using WISE data we will construct color-color diagrams, color- magnitude diagrams, and spectral energy distributions for our sample of candidate young brown dwarfs. We will fully characterize the spectral properties of the candidates and evaluate their membership in nearby young moving groups in order to obtain independent age estimates. The practical outcomes of this project will allow the research community to use observed colors and spectra to reliably constrain the properties - including effective temperature, gravity, and dust/cloud properties - of both brown dwarfs and gas giant exoplanets. We will also search for new young brown dwarfs in the WISE archive using colors and proper motions. The expanded sample of young brown dwarfs will be used to create a self-contained feedback loop to identify and address the shortcomings of cool atmosphere models and low-mass evolutionary tracks, both of which are already being used to infer the properties of massive exoplanets. Disentangling the effects of physical parameters on the observed properties of young brown dwarfs is directly relevant to studies of exoplanets. Direct observations of exoplanets are currently very limited, and young brown dwarfs are the laboratories in which we can solve existing problems before the onslaught of new observations from instruments capable of directly imaging exoplanets, including the Gemini Planet Imager, Project 1640 at the Palomar Observatory, SPHERE on the VLT, and the James Webb Space Telescope. This project addresses the goal of the NASA Science Mission Directorate to discover how the universe works; in particular

  10. Cartographic distortions make dielectric spacetime analog models imperfect mimickers

    Science.gov (United States)

    Fathi, Mohsen; Thompson, Robert T.

    2016-06-01

    It is commonly assumed that if the optical metric of a dielectric medium is identical to the metric of a vacuum space-time then light propagation through the dielectric mimics light propagation in the vacuum. However, just as the curved surface of the Earth cannot be mapped into a flat plane without distortion of some surface features, so too is it impossible to project the behavior of light from the vacuum into a dielectric analog residing in Minkowski space-time without introducing distortions. We study the covariance properties of dielectric analog space-times and the kinematics of a congruence of light in the analog, and show how certain features can be faithfully emulated in the analog depending on the choice of projection, but that not all features can be simultaneously emulated without distortion. These findings indicate conceptual weaknesses in the idea of using analog space-times as a basis for transformation optics, and we show that a certain formulation of transformation optics closely related to analog space-times resolves these issues.

  11. A Postcolonial Feminist Critique of Harem Analogies in Psychological Science

    Directory of Open Access Journals (Sweden)

    Natasha Bharj

    2015-08-01

    Full Text Available Since the 1930s, psychologists have used the term harem as an analogy for social relations among animals. In doing so they draw upon gendered and racial stereotypes located in the history of colonialism. We present an experimental study on the harem analogy as a means of confronting and challenging colonial undercurrents in psychological science. We investigated whether the use of this colonialist image in studies of animal societies could subtly affect thinking about Middle Eastern Muslim people. Two-hundred and forty-nine participants read about animal societies; in the experimental condition these were described as “harems” and accompanied by the analogy of harems in Middle Eastern Muslim societies. In the two control conditions, animal societies were either described as “groups” or “harems”, with no mention of the analogy. In the experimental condition, participants falsely remembered descriptions of Muslim people of the Middle East as applying to animals. This finding replicates the “resistance is futile” effect (Blanchette & Dunbar, 2002; Perrott, Gentner, & Bodenhausen, 2005 by which false remembering of analogical statements as previously seen literal descriptions is taken as suggestive of analogical mapping between two disparate concepts. As such, the study contributes to debate between feminist and evolutionary psychology about the value-neutrality of psychology, and to postcolonial critique of the partiality of mainstream psychological accounts of the universality of nature and society.

  12. An assessment of reference exposure in analogic and digital mammographic units

    Science.gov (United States)

    Tilly, J. G.; Miguel, C.; Schelin, H. R.; Porto, L. E.; Paschuk, S.; Denyak, V.; Kmiecik, C.

    2014-11-01

    In this study, the incident air kerma (Ki,a), half-value layer (HVL), output and voltage accuracy for 28 mammography services were evaluated. All mammographs had high frequency rectification, a focus-film distance greater than 60 cm, automatic exposure control, a Mo-Mo anode-filter combination, and compression system. Twenty-three evaluations were made of analogic imaging systems and 21 of digital imaging systems, two of which were full field digital mammography units. The Ki,a was measured in the beam radiation with a 6 cm3 ionization chamber, calibrated for a mammography range of energy. A standard American College of Radiology mammographic phantom simulated a skull caudal incidence. The average, minimum, and maximum Ki,a values were 10.13 mGy, 3.92 mGy, and 30.41 mGy, respectively. However, when the analogic and digital systems are analyzed separately in two subsets, the values were 8.13 mGy, 3.92 mGy, and 11.78 mGy for the analogic systems and 12.33 mGy, 5.21 mGy, and 30.41 mGy for the digital systems, respectively. The results show that the Ki,a values found in digital systems were higher than those in analogic systems, highlighting the differences between these acquisition systems. All HVL values, measured in the primary beam at 28 kV were found between 0.33 mm Al and 0.43 mm Al. Although the manufacture time of the equipment was approximately 146 months (~12 years) prior, the variation in output was between 0.071 mGy/mAs and 0.164 mGy/mAs for the entire sample.

  13. Diffenrent affinity of the two forms of human cytosolic thymidine kinase towards pyrimidine analogs

    DEFF Research Database (Denmark)

    Munch-Petersen, B.; Tyrsted, Gerda; Cloos, Lisbeth;

    1995-01-01

    Biokemi, thymidine kinase 1, cytosolic, regulation, ATP activation, azidothymidine, nucleoside analog......Biokemi, thymidine kinase 1, cytosolic, regulation, ATP activation, azidothymidine, nucleoside analog...

  14. Efficient and accurate statistical analog yield optimization and variation-aware circuit sizing based on computational intelligence techniques

    OpenAIRE

    Liu, Bo; Fernández, Francisco V.; Gielen, Georges

    2011-01-01

    In nanometer complementary metal-oxide-semiconductor technologies, worst-case design methods and response-surface-based yield optimization methods face challenges in accuracy. Monte-Carlo (MC) simulation is general and accurate for yield estimation, but its efficiency is not high enough to make MC-based analog yield optimization, which requires many yield estimations, practical. In this paper, techniques inspired by computational intelligence are used to speed up yield optimization without sa...

  15. Electrical Evolution of a Dust Plume from a Low Energy Lunar Impact: A Model Analog to LCROSS

    Science.gov (United States)

    Farrell, W. M.; Stubbs, T. J.; Jackson, T. L.; Colaprete, A.; Heldmann, J. L.; Schultz, P. H.; Killen, R. M.; Delory, G. T.; Halekas, J. S.; Marshall, J. R.; Zimmerman, M. I.; Collier, M. R.; Vondrak, R. R.

    2011-01-01

    A Monte Carlo test particle model was developed that simulates the charge evolution of micron and sub-micron sized dust grains ejected upon low-energy impact of a moderate-size object onto a lunar polar crater floor. Our analog is the LCROSS impact into Cabeus crater. Our primary objective is to model grain discharging as the plume propagates upwards from shadowed crater into sunlight.

  16. Analogy Between Temporally and Spatially Evolving Wakes: Two-Point Velocity Correlations

    Science.gov (United States)

    Ewing, Dan

    1998-11-01

    There has been a long tradition of approximating temporally evolving homogeneous flows, such as decaying isotropic turbulence, using spatially evolving flows in wind tunnels. More recently, researchers who perform Direct Numerical Simulations have examined temporally evolving flows that are analogous to spatially evolving flows. For example, Moser et al. (J. Fluid Mech., 367, 255-289, 1998) performed simulations of temporally evolving wakes whose velocity deficit grow with time, as opposed to space. It is argued that this flow is analogous to a spatially evolving flow in the small-deficit limit if both are viewed from a reference frame moving with the free stream and the downstream position and time are related by x = U_∞ t. It is straightforward to show that the first-order single-point equations for the two flows have self-similar solutions that can be related by using transformation. It is shown here that the first order governing equations for the two-point velocity correlations in the spatially evolving wake also have similarity solutions that can be related to similarity solutions in the temporally evolving wake (Ewing, Ph.D. Dissertation, 1995) using this transformation. However, it seems the similarity solutions for the more general two-point, two-time correlations in the two flows can not be related with this transformation. The differences between the cases are discussed.

  17. Synthesis and bioactivity of 2',3'-benzoabscisic acid analogs.

    Science.gov (United States)

    Han, Xiaoqiang; Wan, Chuan; Li, Xiuyun; Li, Hong; Yang, Dongyan; Du, Shijie; Xiao, Yumei; Qin, Zhaohai

    2015-06-01

    2',3'-Benzoabscisic acid 4a is significantly more active than (±)-ABA and can be potentially used as a plant growth regulator for agriculture. In this study, six 4a analogs were designed and synthesized. Bioassay showed that 4a displayed greater activity than (±)-ABA and the six analogs produced less inhibition than 4a itself. Specially, some analogs displayed markedly different activities to different physiological and biochemical process, which were largely different from ABA and 4a. Compared to (±)-ABA, 4b and 4c were more effective germination inhibitors for lettuce, but less effective inhibitors for rice elongation. Five-membered analog 5 was higher or slightly weaker in inhibiting Arabidopsis seed germination and rice elongation, respectively, but at least 10 times less effective than (±)-ABA in lettuce seed germination. Dual acid 6 and alkyne acid 20 nearly produced no inhibitory activity for Arabidopsis seed germination, but displayed excellent activity in inhibiting rice seedling growth. The preference of the analogs to different physiology process indicated that they might provide a strategy to develop novel ABA agonists or antagonist and be used as probe to investigate the function of different ABA receptors. PMID:25913114

  18. Pharmacokinetic and radiosensitizing properties of phenylalanine analogs of 2-nitroimidazole

    International Nuclear Information System (INIS)

    In the authors efforts to improve the pharmacokinetic properties of 2-nitroimidazoles to develop a superior radiosensitizer than misonidazole, they have synthesized new phenylalanine analogs to minimize the enzymatic hydrolysis of the amide bond between the amino function of 2-nitroimidazole-1-ethylamine (NEA) and carboxylic group of phenylalanine. Two major metabolites, NEA and its acetylated derivative, were identified in plasma tumor and brain tissues after the administration of the phenylalanine analogs with a free amino function, in B16 melanoma bearing C57 mice. The enzymatic hydrolysis of the peptide bond was significantly reduced in analogs containing an α-methyl function in the ethylamine side chain. Since the metabolites were more toxic than the parent compounds, the LD/sub 50/ values were directly related to the ease of hydrolysis of the amide bond. The L-amino acid analogs were found to be less toxic than the D-isomers. These agents were potent radiosensitizers against hypoxic Chinese hamster (V-79) cells producing enhancement ratio of 2.0 to 2.4 at concentrations between 0.25 and 1.0 mM. These results suggest that the pharmacokinetics of the amino acid analogs can be conveniently manipulated by creating steric hindrance to provide therapeutically effective radiosensitizers

  19. Simultaneous manipulation of propositional and analog codes in picture memory.

    Science.gov (United States)

    Talasli, U

    1990-04-01

    Revealing a picture as a whole or as momentarily displayed strips presumably manipulated the propositional coding of the picture. Analog manipulation employed superimposition of a grid pattern. Effectiveness of simultaneous manipulations was tested via recognition with three foil categories, each of which presumably tapped the analog or propositional codes mainly, or both of them in detection. While figural units' perspective reversals should presumably be detected via the analog code, their locational displacements should be detected via the propositional code. Foils with novel item substitution should be detected by both codes. On the basis of such presumptions about encoding and recognition manipulations, certain predictions were made for scan and grid effects in "reversal," "displacement," and "novelty" foil categories. Full confirmation of these predictions was then taken as evidence that both analog and propositional codes do exist. Once such evidence was established, other issues were tackled, showing that target detection involves the propositional code only, while foil detection involves both codes. Further, recognition hypermnesia, where performance improves with repeated testing, was obtained only when both codes were attenuated. Data suggested that subjects might be switching from analog to propositional codes when both codes were strong, thereby preventing hypermnesia. PMID:2342839

  20. The Acoustic Analogy and Alternative Theories for Jet Noise Prediction

    Science.gov (United States)

    Morris, Philip J.; Farassat, F.; Morris, Philip J.

    2002-01-01

    This paper describes several methods for the prediction of jet noise. All but one of the noise prediction schemes are based on Lighthill's or Lilley's acoustic analogy while the other is the jet noise generation model recently proposed by Tam and Auriault. In all the approaches some assumptions must be made concerning the statistical properties of the turbulent sources. In each case the characteristic scales of the turbulence are obtained from a solution of the Reynolds-averaged Navier Stokes equation using a k-epsilon turbulence model. It is shown that, for the same level of empiricism, Tam and Auriault's model yields better agreement with experimental noise measurements than the acoustic analogy. It is then shown that this result is not because of some fundamental flaw in the acoustic analogy approach: but, is associated with the assumptions made in the approximation of the turbulent source statistics. If consistent assumptions are made, both the acoustic analogy and Tam and Auriault's model yield identical noise predictions. The paper concludes with a proposal for an acoustic analogy that provides a clearer identification of the equivalent source mechanisms and a discussion of noise prediction issues that remain to be resolved.