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Sample records for base analog fret-pair

  1. Nucleic Acid Base Analog FRET-Pair Facilitating Detailed Structural Measurements in Nucleic Acid Containing Systems

    DEFF Research Database (Denmark)

    Börjesson, Karl; Preus, Søren; El-Sagheer, Afaf;

    2009-01-01

    We present the first nucleobase analog fluorescence resonance energy transfer (FRET)-pair. The pair consists of tCO, 1,3-diaza-2-oxophenoxazine, as an energy donor and the newly developed tC(nitro), 7-nitro-1,3-diaza-2-oxophenothiazine, as an energy acceptor. The FRET-pair successfully monitors...... as the number of bases separating tCO and tC(nitro) is varied. A set of DNA strands containing the FRET-pair at wisely chosen locations will, thus, make it possible to accurately distinguish distance- from orientation-changes using FRET. In combination with the good nucleobase analog properties, this points...

  2. A Guide to Fluorescent Protein FRET Pairs

    Science.gov (United States)

    Bajar, Bryce T.; Wang, Emily S.; Zhang, Shu; Lin, Michael Z.; Chu, Jun

    2016-01-01

    Förster or fluorescence resonance energy transfer (FRET) technology and genetically encoded FRET biosensors provide a powerful tool for visualizing signaling molecules in live cells with high spatiotemporal resolution. Fluorescent proteins (FPs) are most commonly used as both donor and acceptor fluorophores in FRET biosensors, especially since FPs are genetically encodable and live-cell compatible. In this review, we will provide an overview of methods to measure FRET changes in biological contexts, discuss the palette of FP FRET pairs developed and their relative strengths and weaknesses, and note important factors to consider when using FPs for FRET studies. PMID:27649177

  3. A Guide to Fluorescent Protein FRET Pairs

    Directory of Open Access Journals (Sweden)

    Bryce T. Bajar

    2016-09-01

    Full Text Available Förster or fluorescence resonance energy transfer (FRET technology and genetically encoded FRET biosensors provide a powerful tool for visualizing signaling molecules in live cells with high spatiotemporal resolution. Fluorescent proteins (FPs are most commonly used as both donor and acceptor fluorophores in FRET biosensors, especially since FPs are genetically encodable and live-cell compatible. In this review, we will provide an overview of methods to measure FRET changes in biological contexts, discuss the palette of FP FRET pairs developed and their relative strengths and weaknesses, and note important factors to consider when using FPs for FRET studies.

  4. A novel FRET pair for detection of parallel DNA triplexes by the LightCycler

    Directory of Open Access Journals (Sweden)

    Pedersen Erik B

    2010-01-01

    Full Text Available Abstract Background Melting temperature of DNA structures can be determined on the LightCycler using quenching of FAM. This method is very suitable for pH independent melting point (Tm determination performed at basic or neutral pH, as a high throughput alternative to UV absorbance measurements. At acidic pH quenching of FAM is not very suitable, since the fluorescence of FAM is strongly pH dependent and drops with acidic pH. Hoogsteen based parallel triplex helix formation requires protonation of cytosines in the triplex forming strand. Therefore, nucleic acid triplexes show strong pH dependence and are stable only at acidic pH. This led us to establish a new pH independent fluorophore based measuring system on the LightCycler for thermal stability studies of parallel triplexes. Results A novel LightCycler FRET pair labelled with ATTO495 and ATTO647N was established for parallel triplex detection with antiparallel duplex as a control for the general applicability of these fluorophores for Tm determination. The ATTO fluorophores were pH stable from pH 4.5 to 7.5. Melting of triplex and duplex structures were accompanied by a large decrease in fluorescence intensity leading to well defined Tm and high reproducibility. Validation of Tm showed low intra- and inter-assay coefficient of variation; 0.11% and 0.14% for parallel triplex and 0.19% and 0.12% for antiparallel duplex. Measurements of Tm and fluorescence intensity over time and multiple runs showed great time and light stability of the ATTO fluorophores. The variance on Tm determinations was significant lower on the LightCycler platform compared to UV absorbance measurements, which enable discrimination of DNA structures with very similar Tm. Labelling of DNA probes with ATTO fluorophore increased Tm of antiparallel duplexes significantly, but not Tm of parallel triplexes. Conclusions We have established a novel pH independent FRET pair with high fluorescence signals on the Light

  5. A novel FRET pair for detection of parallel DNA triplexes by the LightCycler

    DEFF Research Database (Denmark)

    Schneider, Uffe V.; Severinsen, Jette K.; Géci, Imrich;

    2010-01-01

    BACKGROUND: Melting temperature of DNA structures can be determined on the LightCycler using quenching of FAM. This method is very suitable for pH independent melting point (Tm) determination performed at basic or neutral pH, as a high throughput alternative to UV absorbance measurements. At acidic...... pH quenching of FAM is not very suitable, since the fluorescence of FAM is strongly pH dependent and drops with acidic pH.Hoogsteen based parallel triplex helix formation requires protonation of cytosines in the triplex forming strand. Therefore, nucleic acid triplexes show strong pH dependence and...... are stable only at acidic pH. This led us to establish a new pH independent fluorophore based measuring system on the LightCycler for thermal stability studies of parallel triplexes. RESULTS: A novel LightCycler FRET pair labelled with ATTO495 and ATTO647N was established for parallel triplex...

  6. Branched DNA nanostructures efficiently stabilised and monitored by novel pyrene-perylene 2'-α-l-amino-LNA FRET pairs

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Santhosh Kumar, T; Campbell, Meghan A;

    2013-01-01

    Novel pyrene-perylene α-l-LNA FRET pairs described herein effectively detect assembly of 2- and 3-way branched DNA nanostructures prepared by postsynthetic microwave-assisted CuAAC click chemistry. The fluorescent signalling of assembly by internally positioned FRET pairs is achieved with low...

  7. Fluorescence resonance energy transfer (FRET) for DNA biosensors: FRET pairs and Foerster distances for various dye-DNA conjugates

    International Nuclear Information System (INIS)

    Fluorescence resonance energy transfer (FRET) between the extrinsic dye labels Cyanine 3 (Cy3), Cyanine 5 (Cy5), Carboxytetramethyl Rhodamine (TAMRA), Iowa Black Fluorescence Quencher (IabFQ), and Iowa Black RQ (IabRQ) has been studied. The Foerster distances for these FRET-pairs in single- and double-stranded DNA conjugates have been determined. In particular, it should be noted that the quantum yield of the donors Cy3 and TAMRA varies between single- and double-stranded DNA. While this alters the Foerster distance for a donor-acceptor pair, this also allows for detection of thermal denaturation events with a single non-intercalating fluorophore. The utility of FRET in the development of nucleic acid biosensor technology is illustrated by using TAMRA and IabRQ as a FRET pair in selectivity experiments. The differential quenching of TAMRA fluorescence by IabRQ in solution has been used to discriminate between 0 and 3 base pair mismatches at 60 deg. C for a 19 base sequence. At room temperature, the quenching of TAMRA fluorescence was not an effective indicator of the degree of base pair mismatch. There appears to be a threshold of duplex stability at room temperature which occurs beyond two base pair mismatches and reverses the observed trend in TAMRA fluorescence prior to that degree of mismatch. When this experimental system is transferred to a glass surface through covalent coupling and organosilane chemistry, the observed trend in TAMRA fluorescence at room temperature is similar to that obtained in bulk solution, but without a threshold of duplex stability. In addition to quenching of fluorescence by FRET, it is believed that several other quenching mechanisms are occurring at the surface

  8. 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…

  9. Single cell FRET analysis for the identification of optimal FRET-pairs in Bacillus subtilis using a prototype MEM-FLIM system.

    Directory of Open Access Journals (Sweden)

    Ruud G J Detert Oude Weme

    Full Text Available Protein-protein interactions can be studied in vitro, e.g. with bacterial or yeast two-hybrid systems or surface plasmon resonance. In contrast to in vitro techniques, in vivo studies of protein-protein interactions allow examination of spatial and temporal behavior of such interactions in their native environment. One approach to study protein-protein interactions in vivo is via Förster Resonance Energy Transfer (FRET. Here, FRET efficiency of selected FRET-pairs was studied at the single cell level using sensitized emission and Frequency Domain-Fluorescence Lifetime Imaging Microscopy (FD-FLIM. For FRET-FLIM, a prototype Modulated Electron-Multiplied FLIM system was used, which is, to the best of our knowledge, the first account of Frequency Domain FLIM to analyze FRET in single bacterial cells. To perform FRET-FLIM, we first determined and benchmarked the best fluorescent protein-pair for FRET in Bacillus subtilis using a novel BglBrick-compatible integration vector. We show that GFP-tagRFP is an excellent donor-acceptor pair for B. subtilis in vivo FRET studies. As a proof of concept, selected donor and acceptor fluorescent proteins were fused using a linker that contained a tobacco etch virus (TEV-protease recognition sequence. Induction of TEV-protease results in loss of FRET efficiency and increase in fluorescence lifetime. The loss of FRET efficiency after TEV induction can be followed in time in single cells via time-lapse microscopy. This work will facilitate future studies of in vivo dynamics of protein complexes in single B. subtilis cells.

  10. 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...

  11. A gravito-electromagnetic analogy based on tidal tensors

    CERN Document Server

    Costa, L F; Herdeiro, Carlos A. R.

    2006-01-01

    We propose a new approach to a physical analogy between General Relativity and Electromagnetism, based on comparing tidal tensors of both theories. Using this approach we write a covariant form for the gravitational analogues of the Maxwell equations, from which the regime of validity of the analogy becomes manifest. Two explicit realisations of the analogy are given. The first one matches linearised gravitational tidal tensors to exact electromagnetic tidal tensors in Minkwoski spacetime. The second one matches exact magnetic gravitational tidal tensors for ultra-stationary metrics to exact magnetic tidal tensors of electromagnetism in curved spaces. We then establish a new proof for a class of tensor identities that define invariants of the type $\\vec{E}^2-\\vec{B}^2$ and $\\vec{E}\\cdot\\vec{B}$, and we exhibit the invariants built from tidal tensors in both gravity and electromagnetism. We contrast our approach with the two gravito-electromagnetic analogies commonly found in the literature, which are reviewed...

  12. Analog Group Delay Equalizers Design Based on Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    M. Laipert

    2006-04-01

    Full Text Available This paper deals with a design method of the analog all-pass filter designated for equalization of the group delay frequency response of the analog filter. This method is based on usage of evolutionary algorithm, the Differential Evolution algorithm in particular. We are able to design such equalizers to be obtained equal-ripple group delay frequency response in the pass-band of the low-pass filter. The procedure works automatically without an input estimation. The method is presented on solving practical examples.

  13. 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.

  14. 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.

  15. Analogy between gambling and measurement-based work extraction

    Science.gov (United States)

    Vinkler, Dror A.; Permuter, Haim H.; Merhav, Neri

    2016-04-01

    In information theory, one area of interest is gambling, where mutual information characterizes the maximal gain in wealth growth rate due to knowledge of side information; the betting strategy that achieves this maximum is named the Kelly strategy. In the field of physics, it was recently shown that mutual information can characterize the maximal amount of work that can be extracted from a single heat bath using measurement-based control protocols, i.e. using ‘information engines’. However, to the best of our knowledge, no relation between gambling and information engines has been presented before. In this paper, we briefly review the two concepts and then demonstrate an analogy between gambling, where bits are converted into wealth, and information engines, where bits representing measurements are converted into energy. From this analogy follows an extension of gambling to the continuous-valued case, which is shown to be useful for investments in currency exchange rates or in the stock market using options. Moreover, the analogy enables us to use well-known methods and results from one field to solve problems in the other. We present three such cases: maximum work extraction when the probability distributions governing the system and measurements are unknown, work extraction when some energy is lost in each cycle, e.g. due to friction, and an analysis of systems with memory. In all three cases, the analogy enables us to use known results in order to obtain new ones.

  16. Wavelet neural network based fault diagnosis in nonlinear analog circuits

    Institute of Scientific and Technical Information of China (English)

    Yin Shirong; Chen Guangju; Xie Yongle

    2006-01-01

    The theories of diagnosing nonlinear analog circuits by means of the transient response testing are studied. Wavelet analysis is made to extract the transient response signature of nonlinear circuits and compress the signature dada. The best wavelet function is selected based on the between-category total scatter of signature. The fault dictionary of nonlinear circuits is constructed based on improved back-propagation(BP) neural network. Experimental results demonstrate that the method proposed has high diagnostic sensitivity and fast fault identification and deducibility.

  17. Hamiltonian system for orthotropic plate bending based on analogy theory

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on analogy between plane elasticity and plate bending as well as variational principles of mixed energy, Hamiltonian system is further led to orthotropic plate bending problems in this paper. Thus many effective methods of mathematical physics such as separation of variables and eigenfunction expansion can be employed in orthotropic plate bending problems as they are used in plane elasticity. Analytical solutions of rectangular plate are presented directly, which expands the range of analytical solutions. There is an essential distinction between this method and traditional semi-inverse method. Numerical results of orthotropic plate with two lateral sides fixed are included to demonstrate the effectiveness and accuracy of this method.

  18. Analog Optical Computing Based on Dielectric Meta-reflect-array

    CERN Document Server

    Chizari, Ata; Jamali, Mohammad Vahid; Salehi, Jawad A

    2016-01-01

    In this paper, we realize the concept of analog computing using an array of engineered gradient dielectric meta-reflect-array. The proposed configuration consists of individual subwavelength silicon nanobricks in combination with fused silica spacer and silver ground plane realizing a reflection beam with full phase coverage $2\\pi$ degrees as well as amplitude range $0$ to $1$. Spectrally overlapping electric and magnetic dipole resonances, such high-index dielectric metasurfaces can locally and independently manipulate the amplitude and phase of the incident electromagnetic wave. This practically feasible structure overcomes substantial limitations imposed by plasmonic metasurfaces such as absorption losses and low polarization conversion efficiency in the visible range. Using such CMOS-compatible and easily integrable platforms promises highly efficient ultrathin planar wave-based computing systems which circumvent the drawbacks of conventional bulky lens-based signal processors. Based on these key properti...

  19. Visualizing Uncertainty for Probabilistic Weather Forecasting based on Reforecast Analogs

    Science.gov (United States)

    Pelorosso, Leandro; Diehl, Alexandra; Matković, Krešimir; Delrieux, Claudio; Ruiz, Juan; Gröeller, M. Eduard; Bruckner, Stefan

    2016-04-01

    Numerical weather forecasts are prone to uncertainty coming from inaccuracies in the initial and boundary conditions and lack of precision in numerical models. Ensemble of forecasts partially addresses these problems by considering several runs of the numerical model. Each forecast is generated with different initial and boundary conditions and different model configurations [GR05]. The ensembles can be expressed as probabilistic forecasts, which have proven to be very effective in the decision-making processes [DE06]. The ensemble of forecasts represents only some of the possible future atmospheric states, usually underestimating the degree of uncertainty in the predictions [KAL03, PH06]. Hamill and Whitaker [HW06] introduced the "Reforecast Analog Regression" (RAR) technique to overcome the limitations of ensemble forecasting. This technique produces probabilistic predictions based on the analysis of historical forecasts and observations. Visual analytics provides tools for processing, visualizing, and exploring data to get new insights and discover hidden information patterns in an interactive exchange between the user and the application [KMS08]. In this work, we introduce Albero, a visual analytics solution for probabilistic weather forecasting based on the RAR technique. Albero targets at least two different type of users: "forecasters", who are meteorologists working in operational weather forecasting and "researchers", who work in the construction of numerical prediction models. Albero is an efficient tool for analyzing precipitation forecasts, allowing forecasters to make and communicate quick decisions. Our solution facilitates the analysis of a set of probabilistic forecasts, associated statistical data, observations and uncertainty. A dashboard with small-multiples of probabilistic forecasts allows the forecasters to analyze at a glance the distribution of probabilities as a function of time, space, and magnitude. It provides the user with a more

  20. Human Time Allocation in Time-based Analog of Concurrent Interval-ratio Schedules

    OpenAIRE

    TAJIMA, HIROYUKI

    1999-01-01

    Six undergraduates participated in concurrent-choice experiment with monetary reinforcers. Each subject was exposed to a time-based analog of concurrent variable-interval variable-ratio schedule with equal time interval values. The time-based analog of variable-interval schedule arranged reinforcers throughout the session, and delivered them while the schedule was chosen. The time-based analog of variable-ratio schedule arranged and immediately delivered reinforcers only while the schedule wa...

  1. 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.

  2. Dataset Quality Assessment: An extension for analogy based effort estimation

    Directory of Open Access Journals (Sweden)

    Mohammad Azzeh

    2013-03-01

    Full Text Available Estimation by Analogy(EBAisanincreasingly active researchmethod in the area ofsoftwareengineering. Thefundamentalassumption of this method is thatthesimilarprojects in terms of attributevalueswillalsobesimilar in terms of effortvalues.It is well recognized thatthequality ofsoftwaredatasets hasaconsiderable impact on the reliability and accuracy of such method.Therefore,if thesoftwaredataset does notsatisfythe aforementionedassumptionthenitis notratherusefulfor EBAmethod.This paperpresentsa new methodbased on Kendall’s row-wise rank correlationthat enablesdataqualityevaluationandproviding a data pre-processing stagefor EBA.The proposedmethodprovidessound statistical basis and justification for the processofdataquality evaluation. Unlike Analogy-X,ourmethodhastheability to deal withcategorical attributesindividually withoutthe need for partitioningthedataset.Experimental results showed thatthe proposed method could formauseful extension forEBAas itenables: dataset quality evaluation, attribute selection and identifying abnormal observation

  3. Dynamic mesh optimization based on the spring analogy

    Directory of Open Access Journals (Sweden)

    Schmidt Jonas

    2014-01-01

    Full Text Available We present an implementation of the spring analogy for three dimensional meshes in OpenFOAM. All parameters of the spring system are treated as fields that can either be pre-defined by the user, or updated at each time step according to specified geometrical regions or diffusion equations. The purpose of the method is to provide a pre-processing tool for mesh optimization. We study three simple test cases, a deformed block, an airfoil and a hill, and we analyze the evolution of skewness, non-orthogonality and aspect ratio during the approach of dynamic equilibrium.

  4. A Loudness Function for Analog and Digital Sound Systems based on Equal Loudness Level Contours

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal

    2016-01-01

    frequency balance will been changed both for LL lower or higher than ML. The differences in ELLC ask for a level based equalization using fractional-order filters. A designing technique for both analog and digital fractional-order filters was developed. The analog solution is based on OPAMs and the digital...... solution is realized in a 16/32 bit fixed point DSP and could be implemented in any sound producing system....

  5. Liquid chromatographic resolution of mexiletine and its analogs on crown ether-based chiral stationary phases.

    Science.gov (United States)

    Jin, Kab Bong; Kim, Hee Eun; Hyun, Myung Ho

    2014-05-01

    Mexiletine, an effective class IB antiarrhythmic agent, and its analogs were resolved on three different crown ether-based chiral stationary phases (CSPs), one (CSP 1) of which is based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid and the other two (CSP 2 and CSP 3) are based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6. Mexiletine was resolved with a resolution (R(S)) of greater than 1.00 on CSP 1 and CSP 3 containing residual silanol group-protecting n-octyl groups on the silica surface, but with a resolution (R(S)) of less than 1.00 on CSP 2. The chromatographic behaviors for the resolution of mexiletine analogs containing a substituted phenyl group at the chiral center on the three CSPs were quite dependent on the phenoxy group of analytes. Namely, mexiletine analogs containing 2,6-dimethylphenoxy, 3,4-dimethylphenoxy, 3-methylphenoxy, 4-methylphenoxy, and a simple phenoxy group were resolved very well on the three CSPs even though the chiral recognition efficiencies vary with the CSPs. However, mexiletine analogs containing 2-methylphenoxy group were not resolved at all or only slightly resolved. Among the three CSPs, CSP 3 was found to show the highest chiral recognition efficiencies for the resolution of mexiletine and its analogs, especially in terms of resolution (R(S)). PMID:24677299

  6. Investigation of analog/RF performance of staggered heterojunctions based nanowire tunneling field-effect transistors

    Science.gov (United States)

    Chakraborty, Avik; Sarkar, Angsuman

    2015-04-01

    In this paper, the analog/RF performance of an III-V semiconductor based staggered hetero-tunnel-junction (HETJ) n-type nanowire (NW) tunneling FET (n-TFET) is investigated, for the first time. The device performance figure-of-merits governing the analog/RF performance such as transconductance (gm), transconductance-to-drive current ratio (gm/IDS), output resistance (Rout), intrinsic gain and unity-gain cutoff frequency (fT) have been studied. The analog/RF performance parameters is compared between HETJ NW TFET and a homojunction (HJ) NW n-type TFET of similar dimensions. In addition to enhanced ION and subthreshold swing, a significant improvement in the analog/RF performance parameters obtained by the HETJ n-TFET over HJ counterpart for use in analog/mixed signal System-on-Chip (SoC) applications is reported. Moreover, the analog/RF performance parameters of a III-V based staggered HETJ NW TFET is also compared with a heterojunction (HETJ) NW n-type MOSFET having same material as HETJ n-TFET and equal dimension in order to provide a systematic comparison between HETJ-TFET and HETJ-MOSFET for use in analog/mixed-signal applications. The results reveal that HETJ n-TFET provides higher Rout and hence, a higher intrinsic gain, an improved gm/IDS ratio, and reasonable fT at lower values of gate-overdrive voltage as compared to the HETJ NW n-MOSFET.

  7. Feature evaluation and extraction based on neural network in analog circuit fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    Yuan Haiying; Chen Guangju; Xie Yongle

    2007-01-01

    Choosing the right characteristic parameter is the key to fault diagnosis in analog circuit.The feature evaluation and extraction methods based on neural network are presented.Parameter evaluation of circuit features is realized by training results from neural network; the superior nonlinear mapping capability is competent for extracting fault features which are normalized and compressed subsequently.The complex classification problem on fault pattern recognition in analog circuit is transferred into feature processing stage by feature extraction based on neural network effectively, which improves the diagnosis efficiency.A fault diagnosis illustration validated this method.

  8. Larger bases and mixed analog/digital neural nets

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1998-12-31

    The paper overviews results dealing with the approximation capabilities of neural networks, and bounds on the size of threshold gate circuits. Based on an explicit numerical algorithm for Kolmogorov`s superpositions the authors show that minimum size neural networks--for implementing any Boolean function--have the identity function as the activation function. Conclusions and several comments on the required precision are ending the paper.

  9. 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.

  10. Model atmospheres for Mercury based on a lunar analogy

    Science.gov (United States)

    Hodges, R. R., Jr.

    1974-01-01

    Similarities in daytime spectral reflectivities and nighttime infrared emission from Mercury and the moon are shown to imply that the atmosphere of Mercury must be tenuous, like that of the moon. The theory of formation, transport, and loss in the lunar atmosphere is applied to Mercury. Models of the Hermian atmosphere at perihelion and aphelion are presented, based on the solar wind as the dominant source of gases. Only the noncondensable species - hydrogen, helium and neon - are considered. Of these, helium is the most abundant atmospheric gas, with maximum concentration of about 40,000,000 per cu cm at the nighttime surface. The maximum concentration of H2 is 6,000,000 per cu cm, and that of neon is 700,000 per cu cm.

  11. A Novel Prediction Method about Single Components of Analog Circuits Based on Complex Field Modeling

    Directory of Open Access Journals (Sweden)

    Jingyu Zhou

    2014-01-01

    Full Text Available Few researches pay attention to prediction about analog circuits. The few methods lack the correlation with circuit analysis during extracting and calculating features so that FI (fault indicator calculation often lack rationality, thus affecting prognostic performance. To solve the above problem, this paper proposes a novel prediction method about single components of analog circuits based on complex field modeling. Aiming at the feature that faults of single components hold the largest number in analog circuits, the method starts with circuit structure, analyzes transfer function of circuits, and implements complex field modeling. Then, by an established parameter scanning model related to complex field, it analyzes the relationship between parameter variation and degeneration of single components in the model in order to obtain a more reasonable FI feature set via calculation. According to the obtained FI feature set, it establishes a novel model about degeneration trend of analog circuits’ single components. At last, it uses particle filter (PF to update parameters for the model and predicts remaining useful performance (RUP of analog circuits’ single components. Since calculation about the FI feature set is more reasonable, accuracy of prediction is improved to some extent. Finally, the foregoing conclusions are verified by experiments.

  12. Diagnosis of soft faults in analog integrated circuits based on fractional correlation

    Institute of Scientific and Technical Information of China (English)

    Deng Yong; Shi Yibing; Zhang Wei

    2012-01-01

    Aiming at the problem of diagnosing soft faults in analog integrated circuits,an approach based on fractional correlation is proposed.First,the Volterra series of the circuit under test (CUT) decomposed by the fractional wavelet packet are used to calculate the fractional correlation functions.Then,the calculated fractional correlation functions are used to form the fault signatures of the CUT.By comparing the fault signatures,the different soft faulty conditions of the CUT are identified and the faults are located.Simulations of benchmark circuits illustrate the proposed method and validate its effectiveness in diagnosing soft faults in analog integrated circuits.

  13. A MEMS-Based Power-Scalable Hearing Aid Analog Front End.

    Science.gov (United States)

    Deligoz, I; Naqvi, S R; Copani, T; Kiaei, S; Bakkaloglu, B; Sang-Soo Je; Junseok Chae

    2011-06-01

    A dual-channel directional digital hearing aid front end using microelectromechanical-systems microphones, and an adaptive-power analog processing signal chain are presented. The analog front end consists of a double differential amplifier-based capacitance-to-voltage conversion circuit, 40-dB variable gain amplifier (VGA) and a power-scalable continuous time sigma delta analog-to-digital converter (ADC), with 68-dB signal-to-noise ratio dissipating 67 μ W from a 1.2-V supply. The MEMS microphones are fabricated using a standard surface micromachining technology. The VGA and power-scalable ADC are fabricated on a 0.25-μ m complementary metal-oxide semciconductor TSMC process.

  14. Demonstration of a 3-bit optical digital-to-analog converter based on silicon microring resonators.

    Science.gov (United States)

    Yang, Lin; Ding, Jianfeng; Chen, Qiaoshan; Zhou, Ping; Zhang, Fanfan; Zhang, Lei

    2014-10-01

    We propose an N-bit optical digital-to-analog converter based on silicon microring resonators (MRRs), which can transform an N-bit electrical digital signal to an optical analog signal. A 3-bit optical digital-to-analog convertor is fabricated as proof of concept through a CMOS-compatible process on a silicon-on-insulator platform. The silicon MRRs are modulated through the electric-field-induced carrier injection in forward biased PN junctions embedded in the ring waveguides. The electro-optical 3-dB bandwidths of the silicon MRRs are approximately 800 MHz. The device works well at a speed of 500  MSample/s under driving voltage swings of 0.75 V. PMID:25360972

  15. Canadian Tire Money: An Analogy for Use When Discussing Weak Acid Strong Base Titrations

    Science.gov (United States)

    Last, Arthur M.

    2003-12-01

    A simple analogy can often provide an instructor with a means of helping students to understand an unfamiliar concept. An analogy involving money can be particularly helpful as most students have experience in dealing with a range of financial transactions in their everyday lives. In this article, use is made of the practice of one well-known Canadian retail chain in returning to its customers a small percentage of an item's purchase price in the form of imitation bank notes that can subsequently be spent in the chain's stores. An analogy is drawn between this practice and the determination of the pKa of a weak acid by titrating it with a strong base, taking into account the hydrolysis of the anion produced.

  16. Mixing Problem Based Learning and Conventional Teaching Methods in an Analog Electronics Course

    Science.gov (United States)

    Podges, J. M.; Kommers, P. A. M.; Winnips, K.; van Joolingen, W. R.

    2014-01-01

    This study, undertaken at the Walter Sisulu University of Technology (WSU) in South Africa, describes how problem-based learning (PBL) affects the first year 'analog electronics course', when PBL and the lecturing mode is compared. Problems were designed to match real-life situations. Data between the experimental group and the control group that…

  17. Mixing Problem Based Learning And Conventional Teaching Methods In An Analog Electronics Course

    NARCIS (Netherlands)

    Podges, J.M.; Kommers, P.A.M.; Winnips, K.; Joolingen, van W.R.

    2014-01-01

    This study, undertaken at the Walter Sisulu University of Technology (WSU) in South Africa, describes how problem-based learning (PBL) affects the first year ‘analog electronics course’, when PBL and the lecturing mode is compared. Problems were designed to match real-life situations. Data betwee

  18. 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.

  19. Communication disruption of guava moth (Coscinoptycha improbana) using a pheromone analog based on chain length.

    Science.gov (United States)

    Suckling, D M; Dymock, J J; Park, K C; Wakelin, R H; Jamieson, L E

    2013-09-01

    The guava moth, Coscinoptycha improbana, an Australian species that infests fruit crops in commercial and home orchards, was first detected in New Zealand in 1997. A four-component pheromone blend was identified but is not yet commercially available. Using single sensillum recordings from male antennae, we established that the same olfactory receptor neurons responded to two guava moth sex pheromone components, (Z)-11-octadecen-8-one and (Z)-12-nonadecen-9-one, and to a chain length analog, (Z)-13-eicosen-10-one, the sex pheromone of the related peach fruit moth, Carposina sasakii. We then field tested whether this non-specificity of the olfactory neurons might enable disruption of sexual communication by the commercially available analog, using male catch to synthetic lures in traps in single-tree, nine-tree and 2-ha plots. A disruptive pheromone analog, based on chain length, is reported for the first time. Trap catches for guava moth were disrupted by three polyethylene tubing dispensers releasing the analog in single-tree plots (86% disruption of control catches) and in a plots of nine trees (99% disruption). Where peach fruit moth pheromone dispensers were deployed at a density of 1000/ha in two 2-ha areas, pheromone traps for guava moth were completely disrupted for an extended period (up to 470 days in peri-urban gardens in Mangonui and 422 days in macadamia nut orchards in Kerikeri). In contrast, traps in untreated areas over 100 m away caught 302.8 ± 128.1 moths/trap in Mangonui and 327.5 ± 78.5 moths/ trap in Kerikeri. The longer chain length in the pheromone analog has greater longevity than the natural pheromone due to its lower volatility. Chain length analogs may warrant further investigation for mating disruption in Lepidoptera, and screening using single-sensillum recording is recommended. PMID:24026215

  20. Simplified 2-bit photonic digital-to-analog conversion unit based on polarization multiplexing

    Science.gov (United States)

    Zhang, Fangzheng; Gao, Bindong; Ge, Xiaozhong; Pan, Shilong

    2016-03-01

    A 2-bit photonic digital-to-analog conversion unit is proposed and demonstrated based on polarization multiplexing. The proposed 2-bit digital-to-analog converter (DAC) unit is realized by optical intensity weighting and summing, and its complexity is greatly reduced compared with the traditional 2-bit photonic DACs. Performance of the proposed 2-bit DAC unit is experimentally investigated. The established 2-bit DAC unit achieves a good linear transfer function, and the effective number of bits is calculated to be 1.3. Based on the proposed 2-bit DAC unit, two DAC structures with higher (>2) bit resolutions are proposed and discussed, and the system complexity is expected to be reduced by half by using the proposed technique.

  1. 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.

  2. ANALOG I/O MODULE TEST SYSTEM BASED ON EPICS CA PROTOCOL AND ACTIVEX CA INTERFACE

    Energy Technology Data Exchange (ETDEWEB)

    YENG,YHOFF,L.

    2003-10-13

    Analog input (ADC) and output (DAC) modules play a substantial role in device level control of accelerator and large experiment physics control system. In order to get the best performance some features of analog modules including linearity, accuracy, crosstalk, thermal drift and so on have to be evaluated during the preliminary design phase. Gain and offset error calibration and thermal drift compensation (if needed) may have to be done in the implementation phase as well. A natural technique for performing these tasks is to interface the analog VO modules and GPIB interface programmable test instruments with a computer, which can complete measurements or calibration automatically. A difficulty is that drivers of analog modules and test instruments usually work on totally different platforms (vxworks VS Windows). Developing new test routines and drivers for testing instruments under VxWorks (or any other RTOS) platform is not a good solution because such systems have relatively poor user interface and developing such software requires substantial effort. EPICS CA protocol and ActiveX CA interface provide another choice, a PC and LabVIEW based test system. Analog 110 module can be interfaced from LabVIEW test routines via ActiveX CA interface. Test instruments can be controlled via LabVIEW drivers, most of which are provided by instrument vendors or by National Instruments. Labview also provides extensive data analysis and process functions. Using these functions, users can generate powerful test routines very easily. Several applications built for Spallation Neutron Source (SNS) Beam Loss Monitor (BLM) system are described in this paper.

  3. Wideband Analog Transmission System Based on the External Intensity Electro-Optic Modulator

    Directory of Open Access Journals (Sweden)

    Jiri Svarny

    2016-01-01

    Full Text Available The work deals with design and integration of an analog electro-optic transmission system suitable for some specialized tasks of diagnostics and measurements. The system is based on principle of external intensity modulation of fiber guided laser radiation. Besides wideband and almost lossless transmission the system tolerates extreme length of the transmitting medium and ensures ultimate galvanic barrier between the input and output.

  4. Design and Exploration of Low-Power Analog to Information Conversion Based on Compressed Sensing

    OpenAIRE

    Mamaghanian, Hossein; Khaled, Nadia; Atienza Alonso, David; Vandergheynst, Pierre

    2012-01-01

    The long-standing analog-to-digital conversion paradigm based on Shannon/Nyquist sampling has been challenged lately, mostly in situations such as radar and communication signal processing where signal bandwidth is so large that sampling architectures constraints are simply not manageable. Compressed Sensing (CS) [1], [2], [3] is a new emerging signal acquisition/compression paradigm that offers a striking alternative to traditional signal acquisition. CS states that a signal having a sparse ...

  5. 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...

  6. Modular Hybrid Energy Concept Employing a Novel Control Structure Based on a Simple Analog System

    OpenAIRE

    PETREUS, D.; DARABAN S.; CIRSTEA, M.

    2016-01-01

    This paper proposes a novel control topology which enables the setup of a low cost analog system leading to the implementation of a modular energy conversion system. The modular concept is based on hybrid renewable energy (solar and wind) and uses high voltage inverters already available on the market. An important feature of the proposed topology is a permanently active current loop, which assures short circuit protection and simplifies the control loops compensation. The inn...

  7. 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.

  8. 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.

  9. An analog integrated signal processing circuit for on-chip diffusion-based gas analysis

    International Nuclear Information System (INIS)

    In diffusion-based gas analysis, the transient of gas diffusion process is recorded by a generic gas sensor to serve as a fingerprint for qualitative and quantitative analysis of gaseous samples. Following the acquisition of these specific signals, any standalone gas analyzer requires a pattern recognition system for pattern classification. The classic digital pattern recognition methods require computing hardware of adequate computational throughput. In this paper, we have followed a straightforward mathematical procedure to relate the signals to their associated target gases. We have shown that the procedure can be implemented by a set of analog functions. Based on the results, we have designed an analog integrated circuit, in 0.18 µm standard CMOS process, for processing the diffusion-based transient signals. The main circuit components are a low-pass filter, the differentiator, the feature extractor and an artificial neural network. The output of the circuit is a 2-bit binary code that specifies the target gas. The circuit successfully classified four alcoholic vapors by processing the experimentally obtained response patterns. The proposed signal processing circuit, the semiconductor gas sensor and the diffusion channel can all be implemented on a single substrate to fabricate an integrated micro gas analyzer. (paper)

  10. Effective low-power wearable wireless surface EMG sensor design based on analog-compressed sensing.

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2014-01-01

    Surface Electromyography (sEMG) is a non-invasive measurement process that does not involve tools and instruments to break the skin or physically enter the body to investigate and evaluate the muscular activities produced by skeletal muscles. The main drawbacks of existing sEMG systems are: (1) they are not able to provide real-time monitoring; (2) they suffer from long processing time and low speed; (3) they are not effective for wireless healthcare systems because they consume huge power. In this work, we present an analog-based Compressed Sensing (CS) architecture, which consists of three novel algorithms for design and implementation of wearable wireless sEMG bio-sensor. At the transmitter side, two new algorithms are presented in order to apply the analog-CS theory before Analog to Digital Converter (ADC). At the receiver side, a robust reconstruction algorithm based on a combination of ℓ1-ℓ1-optimization and Block Sparse Bayesian Learning (BSBL) framework is presented to reconstruct the original bio-signals from the compressed bio-signals. The proposed architecture allows reducing the sampling rate to 25% of Nyquist Rate (NR). In addition, the proposed architecture reduces the power consumption to 40%, Percentage Residual Difference (PRD) to 24%, Root Mean Squared Error (RMSE) to 2%, and the computation time from 22 s to 9.01 s, which provide good background for establishing wearable wireless healthcare systems. The proposed architecture achieves robust performance in low Signal-to-Noise Ratio (SNR) for the reconstruction process. PMID:25526357

  11. Effective Low-Power Wearable Wireless Surface EMG Sensor Design Based on Analog-Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Mohammadreza Balouchestani

    2014-12-01

    Full Text Available Surface Electromyography (sEMG is a non-invasive measurement process that does not involve tools and instruments to break the skin or physically enter the body to investigate and evaluate the muscular activities produced by skeletal muscles. The main drawbacks of existing sEMG systems are: (1 they are not able to provide real-time monitoring; (2 they suffer from long processing time and low speed; (3 they are not effective for wireless healthcare systems because they consume huge power. In this work, we present an analog-based Compressed Sensing (CS architecture, which consists of three novel algorithms for design and implementation of wearable wireless sEMG bio-sensor. At the transmitter side, two new algorithms are presented in order to apply the analog-CS theory before Analog to Digital Converter (ADC. At the receiver side, a robust reconstruction algorithm based on a combination of ℓ1-ℓ1-optimization and Block Sparse Bayesian Learning (BSBL framework is presented to reconstruct the original bio-signals from the compressed bio-signals. The proposed architecture allows reducing the sampling rate to 25% of Nyquist Rate (NR. In addition, the proposed architecture reduces the power consumption to 40%, Percentage Residual Difference (PRD to 24%, Root Mean Squared Error (RMSE to 2%, and the computation time from 22 s to 9.01 s, which provide good background for establishing wearable wireless healthcare systems. The proposed architecture achieves robust performance in low Signal-to-Noise Ratio (SNR for the reconstruction process.

  12. A New Automated Design Method Based on Machine Learning for CMOS Analog Circuits

    Science.gov (United States)

    Moradi, Behzad; Mirzaei, Abdolreza

    2016-11-01

    A new simulation based automated CMOS analog circuit design method which applies a multi-objective non-Darwinian-type evolutionary algorithm based on Learnable Evolution Model (LEM) is proposed in this article. The multi-objective property of this automated design of CMOS analog circuits is governed by a modified Strength Pareto Evolutionary Algorithm (SPEA) incorporated in the LEM algorithm presented here. LEM includes a machine learning method such as the decision trees that makes a distinction between high- and low-fitness areas in the design space. The learning process can detect the right directions of the evolution and lead to high steps in the evolution of the individuals. The learning phase shortens the evolution process and makes remarkable reduction in the number of individual evaluations. The expert designer's knowledge on circuit is applied in the design process in order to reduce the design space as well as the design time. The circuit evaluation is made by HSPICE simulator. In order to improve the design accuracy, bsim3v3 CMOS transistor model is adopted in this proposed design method. This proposed design method is tested on three different operational amplifier circuits. The performance of this proposed design method is verified by comparing it with the evolutionary strategy algorithm and other similar methods.

  13. Design of Multi-Valued Quaternary Based Analog-to-Digital Converter

    Directory of Open Access Journals (Sweden)

    A. H.M.Z. Alam

    2009-01-01

    Full Text Available Problem statement: The design of multi-valued quaternary based Analog-to-Digital Converter (ADC circuit was presented. The ADC generates multi-valued logic outputs rather than the conventional binary output system to overall reduction in circuit complexity and size. Approach: Design was implemented using pipeline ADC architecture and was simulated using model parameters based on standard 0.13 µm CMOS process. Results: Performance analysis of the design showed desirable performance parameters in terms of response, low power consumption, and a sampling rate of 10 MHz at a supply voltage of 1.3V was achieved. Conclusion/Recommendations: The ADC design was suitable for the needs of mixed-signal integrated circuit design and can be implemented as a conversion circuit for systems based on multiple-valued logic design.

  14. Event-Based Computation of Motion Flow on a Neuromorphic Analog Neural Platform.

    Science.gov (United States)

    Giulioni, Massimiliano; Lagorce, Xavier; Galluppi, Francesco; Benosman, Ryad B

    2016-01-01

    Estimating the speed and direction of moving objects is a crucial component of agents behaving in a dynamic world. Biological organisms perform this task by means of the neural connections originating from their retinal ganglion cells. In artificial systems the optic flow is usually extracted by comparing activity of two or more frames captured with a vision sensor. Designing artificial motion flow detectors which are as fast, robust, and efficient as the ones found in biological systems is however a challenging task. Inspired by the architecture proposed by Barlow and Levick in 1965 to explain the spiking activity of the direction-selective ganglion cells in the rabbit's retina, we introduce an architecture for robust optical flow extraction with an analog neuromorphic multi-chip system. The task is performed by a feed-forward network of analog integrate-and-fire neurons whose inputs are provided by contrast-sensitive photoreceptors. Computation is supported by the precise time of spike emission, and the extraction of the optical flow is based on time lag in the activation of nearby retinal neurons. Mimicking ganglion cells our neuromorphic detectors encode the amplitude and the direction of the apparent visual motion in their output spiking pattern. Hereby we describe the architectural aspects, discuss its latency, scalability, and robustness properties and demonstrate that a network of mismatched delicate analog elements can reliably extract the optical flow from a simple visual scene. This work shows how precise time of spike emission used as a computational basis, biological inspiration, and neuromorphic systems can be used together for solving specific tasks. PMID:26909015

  15. Modulation of DNA methylation and gene expression in cultured sycamore cells treated by hypomethylating base analog.

    Science.gov (United States)

    Ngernprasirtsiri, J; Akazawa, T

    1990-12-12

    The selective suppression of photosynthetic genes in both the nuclear and plastid genomes of the nonphotosynthetic white wild-type cell line of sycamore (Acer pseudoplatanus) has been found to be inversely related to the presence of a variety of methylated bases, especially 5-methylcytosine (5-MeCyt) and N6-methyladenine (N6-MeAde), localized in regions of the plastid genome containing silent genes. We used hypomethylating base analogs to manipulate the level of cytosine and adenine methylation in the white cells of sycamore, and examined the effects of changes in methylation on gene expression. Treatment with 5-azacytidine (5-AzaCyd) and N6-benzyladenine (N6-BzlAde) decreased cytosine and adenine methylation. This was accompanied by restoration of transcriptional activity in photosynthetic genes which are usually suppressed. Both 5-MeCyt and N6-MeAde suppressed nuclear gene expression, but only 5-MeCyt suppressed plastid gene expression.

  16. Structure-based design of eugenol analogs as potential estrogen receptor antagonists.

    Science.gov (United States)

    Anita, Yulia; Radifar, Muhammad; Kardono, Leonardus Bs; Hanafi, Muhammad; Istyastono, Enade P

    2012-01-01

    Eugenol is an essential oil mainly found in the buds and leaves of clove (Syzygium aromaticum (L.) Merrill and Perry), which has been reported to have activity on inhibition of cell proliferation and apoptosis induction in human MCF-7 breast cancer cells. This biological activity is correlated to its activity as an estrogen receptor antagonist. In this article, we present the construction and validation of structure-based virtual screening (SBVS) protocols to identify the potent estrogen receptor α (ER) antagonists. The selected protocol, which gave acceptable enrichment factors as a virtual screening protocol, subsequently used to virtually screen eugenol, its analogs and their dimers. Based on the virtual screening results, dimer eugenol of 4-[4-hydroxy-3-(prop-2-en-1- yl)phenyl]-2-(prop-2-en-1-yl)phenol is recommended to be developed further in order to discover novel and potent ER antagonists. PMID:23144548

  17. Dietary nucleotides prevent decrease in cellular immunity in ground-based microgravity analog

    Science.gov (United States)

    Yamauchi, Keiko; Hales, Nathan W.; Robinson, Sandra M.; Niehoff, Michael L.; Ramesh, Vani; Pellis, Neal R.; Kulkarni, Anil D.

    2002-01-01

    Microgravity and stress of spaceflights result in immune dysfunction. The role of nutrition, especially nucleotide supplementation, has become an area of intensive research and significant interest in immunomodulation for maintenance of cellular immune responses. The studies presented here evaluate the plausibility of administering nucleotides to obviate immune dysfunction in an Earth-based in vivo analog of microgravity as studied in anti-orthostatic tail suspension (AOS) of mice. Mice were divided into three housing groups: group, isolation, and AOS. Mice were fed either control chow diet (CD), or RNA-, adenine-, or uracil-supplemented CD for the 1-wk duration of the experiments. In AOS mice, supplemental nucleotides significantly increased in vivo lymph node proliferation and ex vivo lymphoproliferation response to alloantigen and mitogens, respectively, and interleukin-2 and interferon-gamma production. A lower corticosterone level was observed in uracil-supplemented CD compared with CD. These results suggest that exogenous nucleotide supplementation, especially uracil, of normal diet is beneficial in the maintenance and restoration of the immune response during the microgravity analog conditions.

  18. Is neoclassical microeconomics formally valid? An approach based on an analogy with equilibrium thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Tania; Domingos, Tiago [Environment and Energy Section, DEM, Instituto Superior Tecnico, Avenida Rovisco Pais, 1, 1049-001 Lisboa (Portugal)

    2006-06-10

    The relation between Thermodynamics and Economics is a paramount issue in Ecological Economics. Two different levels can be distinguished when discussing it: formal and substantive. At the formal level, a mathematical framework is used to describe both thermodynamic and economic systems. At the substantive level, thermodynamic laws are applied to economic processes. In Ecological Economics, there is a widespread claim that neoclassical economics has the same mathematical formulation as classical mechanics and is therefore fundamentally flawed because: (1) utility does not obey a conservation law as energy does; (2) an equilibrium theory cannot be used to study irreversible processes. Here, we show that neoclassical economics is based on a wrong formulation of classical mechanics, being in fact formally analogous to equilibrium thermodynamics. The similarity between both formalisms, namely that they are both cases of constrained optimisation, is easily perceived when thermodynamics is looked upon using the Tisza-Callen axiomatisation. In this paper, we take the formal analogy between equilibrium thermodynamics and economic systems far enough to answer the formal criticisms, proving that the formalism of neoclassical economics has irreversibility embedded in it. However, the formal similarity between equilibrium thermodynamics and neoclassical microeconomics does not mean that economic models are in accordance with mass, energy and entropy balance equations. In fact, neoclassical theory suffers from flaws in the substantive integration with thermodynamic laws as has already been fully demonstrated by valuable work done by ecological economists in this field. (author)

  19. Small Molecule AngIV-based Analogs to Treat Alzheimers Disease

    Directory of Open Access Journals (Sweden)

    John W Wright

    2016-06-01

    Full Text Available Alzheimer’s disease (AD patients are presently without adequate treatment thus new therapeutic approaches are needed to slow and hopefully reverse disease progression. Neurotrophic agents such as nerve growth factor and brain-derived neurotrophic factor have received research attention concerning their potential to treat AD but have not progressed to clinical trials due to their large size, inability to penetrate the blood-brain barrier (BBB, and the high cost of synthesis. This review focuses on one over looked neurotrophin, hepatocyte growth factor (HGF that acts via the Type 1 tyrosine kinase receptor Met to mediate stem cell differentiation, synaptogenesis, neurogenesis, and protect against tissue insults in a wide range of cell types including neurons. We have determined that the brain angiotensin and HGF/c-Met systems interact in such a way that angiotensin IV (AngIV-based analogs including Nle1-AngIV, Norleual-AngIV, Dihexa, and others influence HGF dimerization which is a prerequisite to binding at the Met receptor. Several of these analogs have shown the ability to facilitate the formation of new functional synaptic connections in hippocampal slices, promote neurogenesis, and augment memory consolidation and retrieval in animal models of AD. This family of compounds represents a new class of drugs with lead candidates that are orally active, penetrate the BBB sufficiently to reach therapeutic concentrations, and reverse memory deficits seen in animal models of dementia.

  20. Automatic calibration system for analog instruments based on DSP and CCD sensor

    Science.gov (United States)

    Lan, Jinhui; Wei, Xiangqin; Bai, Zhenlong

    2008-12-01

    Currently, the calibration work of analog measurement instruments is mainly completed by manual and there are many problems waiting for being solved. In this paper, an automatic calibration system (ACS) based on Digital Signal Processor (DSP) and Charge Coupled Device (CCD) sensor is developed and a real-time calibration algorithm is presented. In the ACS, TI DM643 DSP processes the data received by CCD sensor and the outcome is displayed on Liquid Crystal Display (LCD) screen. For the algorithm, pointer region is firstly extracted for improving calibration speed. And then a math model of the pointer is built to thin the pointer and determine the instrument's reading. Through numbers of experiments, the time of once reading is no more than 20 milliseconds while it needs several seconds if it is done manually. At the same time, the error of the instrument's reading satisfies the request of the instruments. It is proven that the automatic calibration system can effectively accomplish the calibration work of the analog measurement instruments.

  1. Photonic Beamformer Model Based on Analog Fiber-Optic Links’ Components

    Science.gov (United States)

    Volkov, V. A.; Gordeev, D. A.; Ivanov, S. I.; Lavrov, A. P.; Saenko, I. I.

    2016-08-01

    The model of photonic beamformer for wideband microwave phased array antenna is investigated. The main features of the photonic beamformer model based on true-time-delay technique, DWDM technology and fiber chromatic dispersion are briefly analyzed. The performance characteristics of the key components of photonic beamformer for phased array antenna in the receive mode are examined. The beamformer model composed of the components available on the market of fiber-optic analog communication links is designed and tentatively investigated. Experimental demonstration of the designed model beamforming features includes actual measurement of 5-element microwave linear array antenna far-field patterns in 6-16 GHz frequency range for antenna pattern steering up to 40°. The results of experimental testing show good accordance with the calculation estimates.

  2. Design and synthesis of simplified taxol analogs based on the T-Taxol bioactive conformation

    OpenAIRE

    Zhao, Jielu; Bane, Susan; Snyder, James P.; Hu, Haipeng; Mukherjee, Kamalika; Slebodnick, Carla; Kingston, David G I

    2011-01-01

    A series of compounds designed to adopt a conformation similar to the tubulin-binding T-Taxol conformation of the anticancer drug paclitaxel has been synthesized. Both the internally bridged analogs 37-39, 41 and the open-chain analogs 27-29 and 43 were prepared. The bridged analogs 37-39 and 41 were synthesized by Grubbs' metatheses of compounds 30-32 and 33, which, in turn, were prepared by coupling β-lactams 24-26 with alcohols 22 and 23. Both the bridged and the open-chain analogs showed ...

  3. 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

  4. Automatic generation of analogy questions for student assessment: an Ontology-based approach

    Directory of Open Access Journals (Sweden)

    Bijan Parsia

    2012-08-01

    Full Text Available Different computational models for generating analogies of the form “A is to B as C is to D” have been proposed over the past 35 years. However, analogy generation is a challenging problem that requires further research. In this article, we present a new approach for generating analogies in Multiple Choice Question (MCQ format that can be used for students’ assessment. We propose to use existing high-quality ontologies as a source for mining analogies to avoid the classic problem of hand-coding concepts in previous methods. We also describe the characteristics of a good analogy question and report on experiments carried out to evaluate the new approach.

  5. Analog optical computing based on a dielectric meta-reflect array.

    Science.gov (United States)

    Chizari, Ata; Abdollahramezani, Sajjad; Jamali, Mohammad Vahid; Salehi, Jawad A

    2016-08-01

    In this Letter, we realize the concept of analog computing using an engineered gradient dielectric meta-reflect-array. The proposed configuration consists of individual subwavelength silicon nanobricks, in combination with a fused silica spacer and silver ground plane, realizing a reflection beam with full phase coverage of 2π degrees, as well as an amplitude range of 0 to 1. Spectrally overlapping electric and magnetic dipole resonances, such high-index dielectric metasurfaces can locally and independently manipulate the amplitude and phase of the incident electromagnetic wave. This practically feasible structure overcomes substantial limitations imposed by plasmonic metasurfaces such as absorption losses and low polarization conversion efficiency in the visible range. Using such CMOS-compatible and easily integrable platforms promises highly efficient ultrathin planar wave-based computing systems that circumvent the drawbacks of conventional bulky lens-based signal processors. Based on these key properties and the general concept of spatial Fourier transformation, we design and realize broadband mathematical operators such as the differentiator and integrator in the telecommunication wavelengths.

  6. Analog optical computing based on a dielectric meta-reflect array.

    Science.gov (United States)

    Chizari, Ata; Abdollahramezani, Sajjad; Jamali, Mohammad Vahid; Salehi, Jawad A

    2016-08-01

    In this Letter, we realize the concept of analog computing using an engineered gradient dielectric meta-reflect-array. The proposed configuration consists of individual subwavelength silicon nanobricks, in combination with a fused silica spacer and silver ground plane, realizing a reflection beam with full phase coverage of 2π degrees, as well as an amplitude range of 0 to 1. Spectrally overlapping electric and magnetic dipole resonances, such high-index dielectric metasurfaces can locally and independently manipulate the amplitude and phase of the incident electromagnetic wave. This practically feasible structure overcomes substantial limitations imposed by plasmonic metasurfaces such as absorption losses and low polarization conversion efficiency in the visible range. Using such CMOS-compatible and easily integrable platforms promises highly efficient ultrathin planar wave-based computing systems that circumvent the drawbacks of conventional bulky lens-based signal processors. Based on these key properties and the general concept of spatial Fourier transformation, we design and realize broadband mathematical operators such as the differentiator and integrator in the telecommunication wavelengths. PMID:27472591

  7. Modular Hybrid Energy Concept Employing a Novel Control Structure Based on a Simple Analog System

    Directory of Open Access Journals (Sweden)

    PETREUS, D.

    2016-05-01

    Full Text Available This paper proposes a novel control topology which enables the setup of a low cost analog system leading to the implementation of a modular energy conversion system. The modular concept is based on hybrid renewable energy (solar and wind and uses high voltage inverters already available on the market. An important feature of the proposed topology is a permanently active current loop, which assures short circuit protection and simplifies the control loops compensation. The innovative analogue solution of the control structure is based on a dedicated integrated circuit (IC for power factor correction (PFC circuits, used in a new configuration, to assure an efficient inverter start-up. The energy conversion system (control structure and maximum power point tracking algorithm is simulated using a new macromodel-based concept, which reduces the usual computational burden of the simulator and achieves high processing speed. The proposed novel system is presented in this article from concept, through the design and implementation stages, is verified through simulation and is validated by experimental results.

  8. Synthesis of Novel Homo-N-Nucleoside Analogs Composed of a Homo-1,4-Dioxane Sugar Analog and Substituted 1,3,5-Triazine Base Equivalents

    Directory of Open Access Journals (Sweden)

    Qiang Yu

    2008-12-01

    Full Text Available Enantioselective syntheses from dimethyl tartrate of 1,3,5-triazine homo-N-nucleoside analogs, containing a 1,4-dioxane moiety replacing the sugar unit in natural nucleosides, were accomplished. The triazine heterocycle in the nucleoside analogs was further substituted with combinations of NH2, OH and Cl in the 2,4-triazine positions.

  9. A Vague Decision Method for Analog Circuit Fault Diagnosis Based on Description Sphere

    Institute of Scientific and Technical Information of China (English)

    LUO Hui; WANG Youren; CUI Jiang

    2011-01-01

    This paper proposes a vague decision method for analog circuit fault diagnosis based on description sphere.Firstly,the proposed method uses the wavelet transform as the preprocessor to extract fault features from the output voltages of the circuit under test (CUT).And then,each class sample is trained to produce a minimum description sphere.Finally,the test samples are detected by a defined vague decision rule,which is based on the vague weight distance between the test data and the center of description sphere.The defined decision rule fuses the truth and false membership degrees of the test sample and the weight of the description sphere,and it can effectively deal with the uncertain information.The reliability of the defined decision rule is proved theoretically.This new diagnostic method is first applied to testing two actual circuits,and then it is compared with other two diagnostic methods.The experimental results show that the proposed technique can achieve good performance and reduce the diagnostic time.

  10. Supporting Analogy-based Effort Estimation with the Use of Ontologies

    Directory of Open Access Journals (Sweden)

    Joanna Kowalska

    2014-06-01

    Full Text Available The paper concerns effort estimation of software development projects, in particular, at the level of product delivery stages. It proposes a new approach to model project data to support expert-supervised analogy-based effort estimation. The data is modeled using Semantic Web technologies, such as Resource Description Framework (RDF and Ontology Language for the Web (OWL. Moreover, in the paper, we define a method of supervised case-based reasoning. The method enables to search for similar projects’ tasks at different levels of abstraction. For instance, instead of searching for a task performed by a specific person, one could look for tasks performed by people with similar capabilities. The proposed method relies on ontology that defines the core concepts and relationships. However, it is possible to introduce new classes and relationships, without the need of altering the search mechanisms. Finally, we implemented a prototype tool that was used to preliminary validate the proposed approach. We observed that the proposed approach could potentially help experts in estimating non-trivial tasks that are often underestimated.

  11. Synthesis and anti-HBV activity of α-stereoisomer of aristeromycin based analogs.

    Science.gov (United States)

    Kasula, Mohan; Toyama, Masaaki; Samunuri, Ramakrishnamraju; Rozy, Farhana; Yadav, Monika; Bal, Chandralata; Jha, Ashok Kumar; Baba, Masanori; Sharon, Ashoke

    2016-08-15

    The potential antiviral activity of aristeromycin type of derivatives (I) is limited by associated toxicity due to its possible 5'-O-phosphorylation and S-adenosyl-l-homocysteine hydrolase (SAHase) inhibitory activity. Aristeromycin structure has major pharmacophoric motif as 5'-OH and adenosine base, which may have significant role in enzyme binding followed by activity and or toxicity. Thus, the structural optimization to alter this major motif by replacing with its bioisostere and changing the 5'-O conformation through stereochemistry reversal was of interest. Thus, the inverted stereochemistry at 4'-position coupled with bioisostere of adenosine base in the target compounds (6-7) to access antiviral potential. The stereoselective formation of a key stereoisomer (2a) was achieved exclusively from neplanocin sugar (1a) by reduction in a single step. The novel target molecules (6-7) were synthesized in 4 steps with 55-62% yield. Compound 6 was analyzed by single crystal X-ray diffraction, which confirms the stereoselective formation of α-analogs with highly puckered cyclopentane ring and 2'-endo conformation. The compound 6 shown significant anti-hepatitis B virus activity of 6.5μM with CC50>100μM and yielded a promising lead with novel structural feature. PMID:27426303

  12. Empirical source strength correlations for rans-based acoustic analogy methods

    Science.gov (United States)

    Kube-McDowell, Matthew Tyndall

    JeNo is a jet noise prediction code based on an acoustic analogy method developed by Mani, Gliebe, Balsa, and Khavaran. Using the flow predictions from a standard Reynolds-averaged Navier-Stokes computational fluid dynamics solver, JeNo predicts the overall sound pressure level and angular spectra for high-speed hot jets over a range of observer angles, with a processing time suitable for rapid design purposes. JeNo models the noise from hot jets as a combination of two types of noise sources; quadrupole sources dependent on velocity fluctuations, which represent the major noise of turbulent mixing, and dipole sources dependent on enthalpy fluctuations, which represent the effects of thermal variation. These two sources are modeled by JeNo as propagating independently into the far-field, with no cross-correlation at the observer location. However, high-fidelity computational fluid dynamics solutions demonstrate that this assumption is false. In this thesis, the theory, assumptions, and limitations of the JeNo code are briefly discussed, and a modification to the acoustic analogy method is proposed in which the cross-correlation of the two primary noise sources is allowed to vary with the speed of the jet and the observer location. As a proof-of-concept implementation, an empirical correlation correction function is derived from comparisons between JeNo's noise predictions and a set of experimental measurements taken for the Air Force Aero-Propulsion Laboratory. The empirical correlation correction is then applied to JeNo's predictions of a separate data set of hot jets tested at NASA's Glenn Research Center. Metrics are derived to measure the qualitative and quantitative performance of JeNo's acoustic predictions, and the empirical correction is shown to provide a quantitative improvement in the noise prediction at low observer angles with no freestream flow, and a qualitative improvement in the presence of freestream flow. However, the results also demonstrate

  13. A Fault Dictionary-Based Fault Diagnosis Approach for CMOS Analog Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Mouna Karmani

    2011-10-01

    Full Text Available In this paper, we propose a simulation-before-test (SBT fault diagnosis methodology based on the use of afault dictionary approach. This technique allows the detection and localization of the most likely defects ofopen-circuit type occurring in Complementary Metal–Oxide–Semiconductor (CMOS analog integratedcircuits (ICs interconnects. The fault dictionary is built by simulating the most likely defects causing thefaults to be detected at the layout level. Then, for each injected fault, the spectre’s frequency responses andthe power consumption obtained by simulation are stored in a table which constitutes the fault dictionary.In fact, each line in the fault dictionary constitutes a fault signature used to identify and locate aconsidered defect. When testing, the circuit under test is excited with the same stimulus, and the responsesobtained are compared to the stored ones. To prove the efficiency of the proposed technique, a full customCMOS operational amplifier is implemented in 0.25 μm technology and the most likely faults of opencircuittype are deliberately injected and simulated at the layout level.

  14. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  15. 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

  16. A reuse-based framework for the design of analog and mixed-signal ICs

    Science.gov (United States)

    Castro-Lopez, Rafael; Fernandez, Francisco V.; Rodriguez Vazquez, Angel

    2005-06-01

    Despite the spectacular breakthroughs of the semiconductor industry, the ability to design integrated circuits (ICs) under stringent time-to-market (TTM) requirements is lagging behind integration capacity, so far keeping pace with still valid Moore"s Law. The resulting gap is threatening with slowing down such a phenomenal growth. The design community believes that it is only by means of powerful CAD tools and design methodologies - and, possibly, a design paradigm shift - that this design gap can be bridged. In this sense, reuse-based design is seen as a promising solution, and concepts such as IP Block, Virtual Component, and Design Reuse have become commonplace thanks to the significant advances in the digital arena. Unfortunately, the very nature of analog and mixed-signal (AMS) design has hindered a similar level of consensus and development. This paper presents a framework for the reuse-based design of AMS circuits. The framework is founded on three key elements: (1) a CAD-supported hierarchical design flow that facilitates the incorporation of AMS reusable blocks, reduces the overall design time, and expedites the management of increasing AMS design complexity; (2) a complete, clear definition of the AMS reusable block, structured into three separate facets or views: the behavioral, structural, and layout facets, the two first for top-down electrical synthesis and bottom-up verification, the latter used during bottom-up physical synthesis; (3) the design for reusability set of tools, methods, and guidelines that, relying on intensive parameterization as well as on design knowledge capture and encapsulation, allows to produce fully reusable AMS blocks. A case study and a functional silicon prototype demonstrate the validity of the paper"s proposals.

  17. Optical Flow in a Smart Sensor Based on Hybrid Analog-Digital Architecture

    Directory of Open Access Journals (Sweden)

    Pablo Guzmán

    2010-03-01

    Full Text Available The purpose of this study is to develop a motion sensor (delivering optical flow estimations using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip. Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane and digital (NIOS II processor. The system is fully functional and is organized in different stages where the early processing (focal plane stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system’s performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains.

  18. Optical flow in a smart sensor based on hybrid analog-digital architecture.

    Science.gov (United States)

    Guzmán, Pablo; Díaz, Javier; Agís, Rodrigo; Ros, Eduardo

    2010-01-01

    The purpose of this study is to develop a motion sensor (delivering optical flow estimations) using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip). Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane) and digital (NIOS II) processor. The system is fully functional and is organized in different stages where the early processing (focal plane) stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II) stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system's performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains.

  19. 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

  20. 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

  1. Delay-based reservoir computing: noise effects in a combined analog and digital implementation.

    Science.gov (United States)

    Soriano, Miguel C; Ortín, Silvia; Keuninckx, Lars; Appeltant, Lennert; Danckaert, Jan; Pesquera, Luis; van der Sande, Guy

    2015-02-01

    Reservoir computing is a paradigm in machine learning whose processing capabilities rely on the dynamical behavior of recurrent neural networks. We present a mixed analog and digital implementation of this concept with a nonlinear analog electronic circuit as a main computational unit. In our approach, the reservoir network can be replaced by a single nonlinear element with delay via time-multiplexing. We analyze the influence of noise on the performance of the system for two benchmark tasks: 1) a classification problem and 2) a chaotic time-series prediction task. Special attention is given to the role of quantization noise, which is studied by varying the resolution in the conversion interface between the analog and digital worlds.

  2. Friction factor correlation for CICC's based on a porous media analogy

    CERN Document Server

    Bottura, L; Lewandowska, M

    2010-01-01

    We use an analogy to porous media to derive a correlation for the friction factor in CICC s We start with a review of selected literature work on this topic We then recall the principles of the porous medium analogy and present the main body of our work on the analysis of pressure drop data We finally conclude with the proposed correlation The main novelty of our work is to propose predictive correlations for the permeability and drag factor that include the dependency on void fraction of the CICC s.

  3. Flexible Analog Front Ends of Reconfigurable Radios Based on Sampling and Reconstruction with Internal Filtering

    Directory of Open Access Journals (Sweden)

    Poberezhskiy Gennady Y

    2005-01-01

    Full Text Available Bandpass sampling, reconstruction, and antialiasing filtering in analog front ends potentially provide the best performance of software defined radios. However, conventional techniques used for these procedures limit reconfigurability and adaptivity of the radios, complicate integrated circuit implementation, and preclude achieving potential performance. Novel sampling and reconstruction techniques with internal filtering eliminate these drawbacks and provide many additional advantages. Several ways to overcome the challenges of practical realization and implementation of these techniques are proposed and analyzed. The impact of sampling and reconstruction with internal filtering on the analog front end architectures and capabilities of software defined radios is discussed.

  4. Genome-wide screening for genes whose deletions confer sensitivity to mutagenic purine base analogs in yeast

    Directory of Open Access Journals (Sweden)

    Kozmin Stanislav G

    2005-06-01

    Full Text Available Abstract Background N-hydroxylated base analogs, such as 6-hydroxylaminopurine (HAP and 2-amino-6-hydroxylaminopurine (AHA, are strong mutagens in various organisms due to their ambiguous base-pairing properties. The systems protecting cells from HAP and related noncanonical purines in Escherichia coli include specialized deoxyribonucleoside triphosphatase RdgB, DNA repair endonuclease V, and a molybdenum cofactor-dependent system. Fewer HAP-detoxification systems have been identified in yeast Saccharomyces cerevisiae and other eukaryotes. Cellular systems protecting from AHA are unknown. In the present study, we performed a genome-wide search for genes whose deletions confer sensitivity to HAP and AHA in yeast. Results We screened the library of yeast deletion mutants for sensitivity to the toxic and mutagenic action of HAP and AHA. We identified novel genes involved in the genetic control of base analogs sensitivity, including genes controlling purine metabolism, cytoskeleton organization, and amino acid metabolism. Conclusion We developed a method for screening the yeast deletion library for sensitivity to the mutagenic and toxic action of base analogs and identified 16 novel genes controlling pathways of protection from HAP. Three of them also protect from AHA.

  5. A Physical Analog Model of Strike-Slip Faulting for Model-Based Inquiry in the Classroom

    Science.gov (United States)

    Curren, I. S.; Glesener, G.

    2013-12-01

    classroom setting. We hope to encourage discussion from session attendees on the use of physical analog models and real-time quantitative model-based inquiry in the development of the next generation of geoscientists.

  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. Mars extant-life campaign using an approach based on Earth-analog habitats

    Science.gov (United States)

    Palkovic, Lawrence A.; Wilson, Thomas J.

    2005-01-01

    The Mars Robotic Outpost group at JPL has identified sixteen potential momentous discoveries that if found on Mars would alter planning for the future Mars exploration program. This paper details one possible approach to the discovery of and response to the 'momentous discovery'' of extant life on Mars. The approach detailed in this paper, the Mars Extant-Life (MEL) campaign, is a comprehensive and flexible program to find living organisms on Mars by studying Earth-analog habitats of extremophile communities.

  8. Low-voltage analog front-end processor design for ISFET-based sensor and H+ sensing applications

    Science.gov (United States)

    Chung, Wen-Yaw; Yang, Chung-Huang; Peng, Kang-Chu; Yeh, M. H.

    2003-04-01

    This paper presents a modular-based low-voltage analog-front-end processor design in a 0.5mm double-poly double-metal CMOS technology for Ion Sensitive Field Effect Transistor (ISFET)-based sensor and H+ sensing applications. To meet the potentiometric response of the ISFET that is proportional to various H+ concentrations, the constant-voltage and constant current (CVCS) testing configuration has been used. Low-voltage design skills such as bulk-driven input pair, folded-cascode amplifier, bootstrap switch control circuits have been designed and integrated for 1.5V supply and nearly rail-to-rail analog to digital signal processing. Core modules consist of an 8-bit two-step analog-digital converter and bulk-driven pre-amplifiers have been developed in this research. The experimental results show that the proposed circuitry has an acceptable linearity to 0.1 pH-H+ sensing conversions with the buffer solution in the range of pH2 to pH12. The processor has a potential usage in battery-operated and portable healthcare devices and environmental monitoring applications.

  9. 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.

  10. Novel acridine-based N-acyl-homoserine lactone analogs induce endoreduplication in the human oral squamous carcinoma cell line SAS

    International Nuclear Information System (INIS)

    The cytotoxicity of novel acridine-based N-acyl-homoserine lactone (AHL) analogs was investigated on the human oral squamous carcinoma cell line SAS. One analog induced G2/M phase arrest at 5.3-10.6 μM and induced polyploidy at a higher dose (21.2 μM). Importantly, treatment of SAS cells with a combination of the AHL analog and the Jun N-terminal kinase (JNK) inhibitor, SP600125, prevented mitosis and induced polyploidy. The AHL analog synergized with X-irradiation to inhibit clonogenic survival of SAS cells; however, its radiosensitizing effects were relative to not X-irradiation-induced apoptosis but mitotic failure following enhanced expression of Aurora A and B. These results suggest that the active AHL analog showed growth-suppressive and radiosensitizing effects, which involve polyploidy followed by G2/M accumulation and atypical cell death in the SAS cell line. (author)

  11. A Mars Analog for Wet-Based Glacial Alteration of Volcanic Terrains: Thermal Infrared Remote Sensing at Three Sisters, Oregon, U.S.A.

    Science.gov (United States)

    Rutledge, A. M.; Scudder, N. A.; Horgan, B.; Rampe, E. B.

    2016-09-01

    This study characterizes wet-based glacial weathering products at a volcanic Mars analog site using thermal infrared remote sensing. Decorrelation stretches are used to examine the geographic relationships between compositional units.

  12. 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.

  13. Optical Analog-to-digital Conversion Scheme Based on Tunable Fabry-Perot Resonator

    Institute of Scientific and Technical Information of China (English)

    LI Zheng

    2007-01-01

    Proposed is an interference type of optical analog-to-digital conversion(ADC). The refractive index of Fabry-Perot cavity changes with different voltages. The Fabry-Perot resonator converts electronic intensity into light wavelength through selecting lights of different wavelengthes. The parameters of the scheme are acquired with the transmission matrix of optical element and the time of steady-state light field. The maximum sampling speedes of 4-bit, 6-bit, 7-bit, 8-bit and 9-bit(ADC) are 1.695×1010 count/s, 4.33×109 count/s, 2.38×109 count/s, 1.24×109 count/s and 5.9×108 count/s, respectively.

  14. Alternate source term models for Yucca Mountain performance assessment based on natural analog data and secondary mineral solubility

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, W.M.; Codell, R.B.

    1999-07-01

    Performance assessment calculations for the proposed high level radioactive waste repository at Yucca Mountain, Nevada, were conducted using the Nuclear Regulatory Commission Total-System Performance Assessment (TPA 3.2) code to test conceptual models and parameter values for the source term based on data from the Pena Blanca, Mexico, natural analog site and based on a model for coprecipitation and solubility of secondary schoepite. In previous studies the value for the maximum constant oxidative alteration rate of uraninite at the Nopal I uranium body at Pena Blanca was estimated. Scaling this rate to the mass of uranium for the proposed Yucca Mountain repository yields an oxidative alteration rate of 22 kg/y, which was assumed to be an upper limit on the release rate from the proposed repository. A second model was developed assuming releases of radionuclides are based on the solubility of secondary schoepite as a function of temperature and solution chemistry. Releases of uranium are given by the product of uranium concentrations at equilibrium with schoepite and the flow of water through the waste packages. For both models, radionuclides other than uranium and those in the cladding and gap fraction were modeled to be released at a rate proportional to the uranium release rate, with additional elemental solubility limits applied. Performance assessment results using the Pena Blanca oxidation rate and schoepite solubility models for Yucca Mountain were compared to the TPA 3.2 base case model, in which release was based on laboratory studies of spent fuel dissolution, cladding and gap release, and solubility limits. Doses calculated using the release rate based on natural analog data and the schoepite solubility models were smaller than doses generated using the base case model. These results provide a degree of confidence in safety predictions using the base case model and an indication of how conservatism in the base case model may be reduced in future analyses.

  15. Alternate source term models for Yucca Mountain performance assessment based on natural analog data and secondary mineral solubility

    International Nuclear Information System (INIS)

    Performance assessment calculations for the proposed high level radioactive waste repository at Yucca Mountain, Nevada, were conducted using the Nuclear Regulatory Commission Total-System Performance Assessment (TPA 3.2) code to test conceptual models and parameter values for the source term based on data from the Pena Blanca, Mexico, natural analog site and based on a model for coprecipitation and solubility of secondary schoepite. In previous studies the value for the maximum constant oxidative alteration rate of uraninite at the Nopal I uranium body at Pena Blanca was estimated. Scaling this rate to the mass of uranium for the proposed Yucca Mountain repository yields an oxidative alteration rate of 22 kg/y, which was assumed to be an upper limit on the release rate from the proposed repository. A second model was developed assuming releases of radionuclides are based on the solubility of secondary schoepite as a function of temperature and solution chemistry. Releases of uranium are given by the product of uranium concentrations at equilibrium with schoepite and the flow of water through the waste packages. For both models, radionuclides other than uranium and those in the cladding and gap fraction were modeled to be released at a rate proportional to the uranium release rate, with additional elemental solubility limits applied. Performance assessment results using the Pena Blanca oxidation rate and schoepite solubility models for Yucca Mountain were compared to the TPA 3.2 base case model, in which release was based on laboratory studies of spent fuel dissolution, cladding and gap release, and solubility limits. Doses calculated using the release rate based on natural analog data and the schoepite solubility models were smaller than doses generated using the base case model. These results provide a degree of confidence in safety predictions using the base case model and an indication of how conservatism in the base case model may be reduced in future analyses

  16. Design of A 5-Bit Fully Parallel Analog to Digital Converter Using Common Gate Differrential Mos Pair-Based Comparator

    Science.gov (United States)

    Aytar, Oktay

    2015-09-01

    This paper presents a novel comparator structure based on the common gate differential MOS pair. The proposed comparator has been applied to fully parallel analog to digital converter (A/D converter). Furthermore, this article presents 5 bit fully parallel A/D Converter design using the cadence IC5141 design platform and NCSU(North Carolina State University) design kit with 0.18 μm CMOS technology library. The proposed fully parallel A/D converter consist of resistor array block, comparator block, 1-n decoder block and programmable logic array. The 1-n decoder block includes latch block and thermometer code circuit that is implemented using transmission gate based multiplexer circuit. Thus, sampling frequency and analog bandwidth are increased. The INL and DNL of the proposed fully parallel A/D converter are (0/ + 0.63) LSB and (-0.26/ + 0.31) LSB at a sampling frequency of 5 GS/s with an input signal of 50 MHz, respectively. The proposed fully parallel A/D Converter consumes 340 mW from 1.8 V supply.

  17. A Sub Threshold Source Coupled Logic Based Design of Low Power CMOS Analog Multiplexer

    Directory of Open Access Journals (Sweden)

    G.Deepika

    2014-08-01

    Full Text Available A novel approach for designing Ultra Low Power and wide dynamic range circuit for multiplexing analog signals is presented. The design operates in weak i nversion (Sub threshold region and uses Source - Coupled Logic ( SCL circuit. The bias current of t he SCL gates is varied to scale down linearly the p ower consumption and the operating frequency. The multip lexer design employs CMOS transistors as transmission gate with dynamic threshold voltage. T he design exhibits low power dissipation, high dynamic range and good linearity. The design was im plemented in 180 nm technology and was operated at a supply voltage of 400 mV with a bias current rang ing in the order of few Pico-amperes. The ON and OFF resistance of the transmission gate achieved we re 27 ohms and 10 M ohms respectively. The power dissipation achieved is around 0.79 μ W for a dynami c range of 1μ V to 0.4 V.

  18. Fault Modeling and Testing for Analog Circuits in Complex Space Based on Supply Current and Output Voltage

    Directory of Open Access Journals (Sweden)

    Hongzhi Hu

    2015-01-01

    Full Text Available This paper deals with the modeling of fault for analog circuits. A two-dimensional (2D fault model is first proposed based on collaborative analysis of supply current and output voltage. This model is a family of circle loci on the complex plane, and it simplifies greatly the algorithms for test point selection and potential fault simulations, which are primary difficulties in fault diagnosis of analog circuits. Furthermore, in order to reduce the difficulty of fault location, an improved fault model in three-dimensional (3D complex space is proposed, which achieves a far better fault detection ratio (FDR against measurement error and parametric tolerance. To address the problem of fault masking in both 2D and 3D fault models, this paper proposes an effective design for testability (DFT method. By adding redundant bypassing-components in the circuit under test (CUT, this method achieves excellent fault isolation ratio (FIR in ambiguity group isolation. The efficacy of the proposed model and testing method is validated through experimental results provided in this paper.

  19. A Study of an Architecture Design Learning Process Based on Social Learning, Course Teaching, Interaction, and Analogical Thinking

    Directory of Open Access Journals (Sweden)

    Yun-Wu Wu

    2014-01-01

    Full Text Available The students in the vocational education of architecture design in Taiwan often face many learning obstacles, such as no problem solving ability and lack of creativity. Therefore, this study used a social learning model as a learning strategy in the architecture design learning process to solve related learning difficulties. Firstly, this study used cognitive development teaching activities and a learning process based on analogical thinking and analogical reasoning to build the social learning model. Secondly, the social learning model of this study was implemented in the teaching of a required course of architecture design for 120 freshmen in China University of Technology. The questionnaire survey results were then statically analyzed and compared to measure the differences in the students’ knowledge about architecture designs before and after the teaching in this study. In this study, the social learning model is proven helpful in inspiring the students’ creativity by converting new knowledge of architecture design into schemas and hence retaining the new knowledge for future application. The social learning model can be applied in the teaching of architecture design in other schools, while more research can be conducted in the future to further confirm its feasibility to promote effective learning.

  20. Performance investigation of InAs based dual electrode tunnel FET on the analog/RF platform

    Science.gov (United States)

    Anand, Sunny; Sarin, R. K.

    2016-09-01

    In this paper for the first time, InAs based doping-less Tunnel FET is proposed and investigated. This paper also demonstrates and discusses the impact of gate stacking (SiO2 + HfO2) with equivalent oxide thickness EOT = 0.8 for analog/RF performance. The charge plasma technique is used to form source/drain region on an intrinsic InAs body by selecting proper work function of metal electrode. The paper compares different combinations of gate stacking (SiO2 and HfO2) on the basis of different analog and RF parameters such as transconductance (gm), transconductance to drive current ratio (gm/ID), output conductance (gd), intrinsic gain (AV), total gate capacitance (Cgg) and unity-gain cutoff frequency (fT). The proposed device produces an ON state current of ION ∼6 mA along with ION/IOFF ∼1012, point subthreshold slope (SS ∼ 1.9 mV/dec), average subthreshold slope (AV-SS ∼ 14.2 mV/dec) and cut-off frequency in Terahertz. The focus of this work is to eliminate the fabrication issues and providing the enhanced performance compared to doped device.

  1. The Effects of Spaceflight and a Spaceflight Analog on Neurocognitive Perfonnance: Extent, Longevity, and Neural Bases

    Science.gov (United States)

    Seidler, R. D.; Mulavara, A. P.; Koppelmans, V.; Erdeniz, B.; Kofman, I. S.; DeDios, Y. E.; Szecsy, D. L.; Riascos-Castaneda, R. F.; Wood, S. J.; Bloomberg, J. J.

    2014-01-01

    We are conducting ongoing experiments in which we are performing structural and functional magnetic resonance brain imaging to identify the relationships between changes in neurocognitive function and neural structural alterations following a six month International Space Station mission and following 70 days exposure to a spaceflight analog, head down tilt bedrest. Our central hypothesis is that measures of brain structure, function, and network integrity will change from pre to post intervention (spaceflight, bedrest). Moreover, we predict that these changes will correlate with indices of cognitive, sensory, and motor function in a neuroanatomically selective fashion. Our interdisciplinary approach utilizes cutting edge neuroimaging techniques and a broad ranging battery of sensory, motor, and cognitive assessments that will be conducted pre flight, during flight, and post flight to investigate potential neuroplastic and maladaptive brain changes in crewmembers following long-duration spaceflight. Success in this endeavor would 1) result in identification of the underlying neural mechanisms and operational risks of spaceflight-induced changes in behavior, and 2) identify whether a return to normative behavioral function following re-adaptation to Earth's gravitational environment is associated with a restitution of brain structure and function or instead is supported by substitution with compensatory brain processes. With the bedrest study, we will be able to determine the neural and neurocognitive effects of extended duration unloading, reduced sensory inputs, and increased cephalic fluid distribution. This will enable us to parse out the multiple mechanisms contributing to any spaceflight-induced neural structural and behavioral changes that we observe in the flight study. In this presentation I will discuss preliminary results from six participants who have undergone the bed rest protocol. These individuals show decrements in balance and functional mobility

  2. Developments of gamma-ray imagers using CdTe semiconductors based on the analog ASIC technology

    International Nuclear Information System (INIS)

    Cadmium Telluride (CdTe) is one of the most promising semiconductor materials for hard X-ray and gamma-ray detection because of the high detection efficiency, and of the good energy resolution. Moreover, CdTe detectors with Schottky junction work as diode detectors, and show superior energy resolution. Based on the CdTe diode devices, we have developed CdTe pixel/strip imagers, and also realized a Si/CdTe Compton camera. These devices will be used for the Hard X-ray Imager (HXI) and the Soft Gamma-ray Detector (SGD) onboard ASTRO-H X-ray satellite to be launched in 2015. These developments are briefly reported in this article. We also describe our recent development of low-noise analog readout ASICs to be used for future development of CdTe gamma-ray imagers. (author)

  3. Rover-Based Instrumentation and Scientific Investigations During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

    Science.gov (United States)

    Graham, L. D.; Graff, T. G.

    2013-01-01

    Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) were recently completed on Mauna Kea Volcano, Hawaii. Scientific investigations, scientific input, and operational constraints were tested in the context of existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration [1]. Several investigations were conducted by the rover mounted instruments to determine key geophysical and geochemical properties of the site, as well as capture the geological context of the area and the samples investigated. The rover traverse and associated science investigations were conducted over a three day period on the southeast flank of the Mauna Kea Volcano, Hawaii. The test area was at an elevation of 11,500 feet and is known as "Apollo Valley" (Fig. 1). Here we report the integration and operation of the rover-mounted instruments, as well as the scientific investigations that were conducted.

  4. Low power analog front-end electronics in deep submicrometer CMOS technology based on gain enhancement techniques

    International Nuclear Information System (INIS)

    This paper evaluates the design of front-end electronics in modern technologies to be used in a new generation of heavy ion detectors—HYDE (FAIR, Germany)—proposing novel architectures to achieve high gain in a low voltage environment. As conventional topologies of operational amplifiers in modern CMOS processes show limitations in terms of gain, novel approaches must be raised. The work addresses the design using transistors with channel length of no more than double the feature size and a supply voltage as low as 1.2 V. A front-end system has been fabricated in a 90 nm process including gain boosting techniques based on regulated cascode circuits. The analog channel has been optimized to match a detector capacitance of 5 pF and exhibits a good performance in terms of gain, speed, linearity and power consumption

  5. 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.

  6. The Design of an Analogical Encoding Tool for Game-Based Virtual Learning Environments

    Science.gov (United States)

    Williams, Douglas; Ma, Yuxin; Feist, Steven; Richard, Charles E.; Prejean, Louise

    2007-01-01

    Game-based virtual learning environments have the potential to provide opportunities for engagement in authentic contexts while completing authentic tasks such as problem solving. However, research in problem-based learning indicates that scaffolding should be provided for learners to benefit from such learning environments. This paper describes…

  7. Parametric estimation in the wave buoy analogy - an elaborated approach based on energy considerations

    DEFF Research Database (Denmark)

    Montazeri, Najmeh; Nielsen, Ulrik Dam

    2014-01-01

    the ship’s wave-induced responses based on different statistical inferences including parametric and non-parametric approaches. This paper considers a concept to improve the estimate obtained by the parametric method for sea state estimation. The idea is illustrated by an analysis made on full-scale...

  8. Design of Butterworth analog filter based on Matlab%基于Matlab的巴特沃斯滤波器设计

    Institute of Scientific and Technical Information of China (English)

    王大伟; 贾荣丛; 王划一

    2012-01-01

    为了得到较纯净的真实信号,对巴特沃斯模拟滤波器的幅频特性、设计方法及设计步骤进行了研究,利用Matlab程序,设计了巴特沃斯模拟滤波器,给出了Matlab设计程序,并分析了巴特沃斯模拟滤波器的幅频特性.利用Matlab程序绘制了巴特沃斯模拟滤波器的幅频特性曲线,并利用Matlab实现了模拟滤波器原型到模拟低通、高通、带通、带阻滤波器的转换.由模拟滤波器原型设计模拟高通滤波器的实例说明了滤波器频率转换效果.%The paper described the amplitude-frequency characteristics, the design method and procedure of Butterworth analog filter to obtain real signal. Butterworth analog filter was designed based on Matlab. The paper presented the design procedure of the filter based on Matlab and analyzed the amplitude-frequency characteristics of Butterworth analog filter. Matlab program was used to draw the amplitude-frequency characteristic curve of Butterworth analog filter and realize the conversion from analog filter prototype to analog low-pass, high-pass, band-pass and band-stop filter. Through the design of analog filter prototype, high-pass filter simulation shows the effects of frequency conversion.

  9. Superconductivity in SnO: A Nonmagnetic Analog to Fe-Based Superconductors?

    DEFF Research Database (Denmark)

    Forthaus, M. K.; Sengupta, K.; Heyer, O.;

    2010-01-01

    We discovered that under pressure SnO with α-PbO structure, the same structure as in many Fe-based superconductors, e.g., β-FeSe, undergoes a transition to a superconducting state for p≳6  GPa with a maximum Tc of 1.4 K at p=9.3  GPa. The pressure dependence of Tc reveals a domelike shape...... and superconductivity disappears for p≳16  GPa. It is further shown from band structure calculations that SnO under pressure exhibits a Fermi surface topology similar to that reported for some Fe-based superconductors and that the nesting between the hole and electron pockets correlates with the change of Tc...

  10. 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)

  11. Time-to-digital converter based on analog time expansion for 3D time-of-flight cameras

    Science.gov (United States)

    Tanveer, Muhammad; Nissinen, Ilkka; Nissinen, Jan; Kostamovaara, Juha; Borg, Johan; Johansson, Jonny

    2014-03-01

    This paper presents an architecture and achievable performance for a time-to-digital converter, for 3D time-of-flight cameras. This design is partitioned in two levels. In the first level, an analog time expansion, where the time interval to be measured is stretched by a factor k, is achieved by charging a capacitor with current I, followed by discharging the capacitor with a current I/k. In the second level, the final time to digital conversion is performed by a global gated ring oscillator based time-to-digital converter. The performance can be increased by exploiting its properties of intrinsic scrambling of quantization noise and mismatch error, and first order noise shaping. The stretched time interval is measured by counting full clock cycles and storing the states of nine phases of the gated ring oscillator. The frequency of the gated ring oscillator is approximately 131 MHz, and an appropriate stretch factor k, can give a resolution of ≍ 57 ps. The combined low nonlinearity of the time stretcher and the gated ring oscillator-based time-to-digital converter can achieve a distance resolution of a few centimeters with low power consumption and small area occupation. The carefully optimized circuit configuration achieved by using an edge aligner, the time amplification property and the gated ring oscillator-based time-to-digital converter may lead to a compact, low power single photon configuration for 3D time-of-flight cameras, aimed for a measurement range of 10 meters.

  12. A comparison of acceptance- and control-based strategies for coping with food cravings: an analog study.

    Science.gov (United States)

    Forman, Evan M; Hoffman, Kimberly L; McGrath, Kathleen B; Herbert, James D; Brandsma, Lynn L; Lowe, Michael R

    2007-10-01

    The present study utilized an analog paradigm to investigate the effectiveness of two strategies for coping with food cravings, which was theorized to be critical to the maintenance of weight loss. Ninety-eight undergraduate students were given transparent boxes of chocolate Hershey's Kisses and instructed to keep the chocolates with them, but not to eat them, for 48 h. Before receiving the Kisses, participants were randomized to receive either (a) no intervention, (b) instruction in control-based coping strategies such as distraction and cognitive restructuring, or (c) instruction in acceptance-based strategies such as experiential acceptance and defusion techniques. Measures included the Power of Food Scale (PFS; a measure of psychological sensitivity to the food environment), self-report ratings of chocolate cravings and surreptitiously recorded chocolate consumption. Results suggested that the effect of the intervention depended on baseline PFS levels, such that acceptance-based strategies were associated with better outcomes (cravings, consumption) among those reporting the highest susceptibility to the presence of food, but greater cravings among those who scored lowest on the PFS. It was observed that craving self-report measures predicted chocolate consumption, and baseline PFS levels predicted both cravings and consumption. Results are discussed in terms of the implications for weight loss maintenance strategies. PMID:17544361

  13. Anti-Cocaine Vaccine Based on Coupling a Cocaine Analog to a Disrupted Adenovirus

    OpenAIRE

    Koob, George; Hicks, Martin J.; Wee, Sunmee; Rosenberg, Jonathan B; De, Bishnu P.; Kaminksy, Stephen M.; Moreno, Amira; Kim D. Janda; Crystal, Ronald G.

    2011-01-01

    The challenge in developing an anti-cocaine vaccine is that cocaine is a small molecule, invisible to the immune system. Leveraging the knowledge that adenovirus (Ad) capsid proteins are highly immunogenic in humans, we hypothesized that linking a cocaine hapten to Ad capsid proteins would elicit high-affinity, high-titer antibodies against cocaine, sufficient to sequester systemically administered cocaine and prevent access to the brain, thus suppressing cocaine-induced behaviors. Based on t...

  14. Regulation of the Contribution of Integrin to Cell Attachment on Poly(2-Methoxyethyl Acrylate (PMEA Analogous Polymers for Attachment-Based Cell Enrichment.

    Directory of Open Access Journals (Sweden)

    Takashi Hoshiba

    Full Text Available Cell enrichment is currently in high demand in medical engineering. We have reported that non-blood cells can attach to a blood-compatible poly(2-methoxyethyl acrylate (PMEA substrate through integrin-dependent and integrin-independent mechanisms because the PMEA substrate suppresses protein adsorption. Therefore, we assumed that PMEA analogous polymers can change the contribution of integrin to cell attachment through the regulation of protein adsorption. In the present study, we investigated protein adsorption, cell attachment profiles, and attachment mechanisms on PMEA analogous polymer substrates. Additionally, we demonstrated the possibility of attachment-based cell enrichment on PMEA analogous polymer substrates. HT-1080 and MDA-MB-231 cells started to attach to poly(butyl acrylate (PBA and poly(tetrahydrofurfuryl acrylate (PTHFA, on which proteins could adsorb well, within 1 h. HepG2 cells started to attach after 1 h. HT-1080, MDA-MB-231, and HepG2 cells started to attach within 30 min to PMEA, poly(2-(2-methoxyethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe2A and poly(2-(2-methoxyethoxy ethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe3A, which suppress protein adsorption. Moreover, the ratio of attached cells from a cell mixture can be changed on PMEA analogous polymers. These findings suggested that PMEA analogous polymers can be used for attachment-based cell enrichment.

  15. Single- and two-phase flow in microfluidic porous media analogs based on Voronoi tessellation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Mengjie [Colorado School of Mines, Golden; Xiao, Feng [Colorado School of Mines, Golden; Johnson-Paben, Rebecca [Colorado School of Mines, Golden; Retterer, Scott T [ORNL; Yin, Xiaolong [Colorado School of Mines, Golden; Neeves, Keith B [ORNL

    2012-01-01

    The objective of this study was to create a microfluidic model of complex porous media for studying single and multiphase flows. Most experimental porous media models consist of periodic geometries that lend themselves to comparison with well-developed theoretical predictions. However, most real porous media such as geological formations and biological tissues contain a degree of randomness and complexity that is not adequately represented in periodic geometries. To design an experimental tool to study these complex geometries, we created microfluidic models of random homogeneous and heterogeneous networks based on Voronoi tessellations. These networks consisted of approximately 600 grains separated by a highly connected network of channels with an overall porosity of 0.11 0.20. We found that introducing heterogeneities in the form of large cavities within the network changed the permeability in a way that cannot be predicted by the classical porosity-permeability relationship known as the Kozeny equation. The values of permeability found in experiments were in excellent agreement with those calculated from three-dimensional lattice Boltzmann simulations. In two-phase flow experiments of oil displacement with water we found that the surface energy of channel walls determined the pattern of water invasion, while the network topology determined the residual oil saturation. These results suggest that complex network topologies lead to fluid flow behavior that is difficult to predict based solely on porosity. The microfluidic models developed in this study using a novel geometry generation algorithm based on Voronoi tessellation are a new experimental tool for studying fluid and solute transport problems within complex porous media.

  16. Application of polymer films based on bacteriorhodopsin and its analogs for low-light-level imaging systems

    Science.gov (United States)

    Korchemskaya, Elena Y.; Soskin, Marat S.; Stepanchikov, Dmitriy A.; Djukova, T. V.; Druzhko, Anna B.; Vsevolodov, Nicolai N.

    1995-03-01

    In recent years polymer films based on bacteriorhodopsin (BR) have attracted a lot of attention in the area of optical imaging systems. The high photosensitivity of these films allows the processing of low-power optical signals (several mW/cm2 CW gas laser irradiation). Spatial resolution does not fall below 5000 lines/mm, photoresponse time is 50 microsecond(s) and images can be recorded and erased over million cycles. Polymer film with BR combine a dynamic recording with optical image processing. The characteristics of anisotropically-saturating nonlinearity of polymer films with BR allow a suppression of the background with greater intensity than usable signal intensity of be performed. Low saturation intensity of the polymer films with BR allows the operation of the polarization of low-intensity signals to be realized. Nonlinear photoresponse of the high photosensitivity BR genetic variant Asp96-Glu is studied in this work too. We hope that the polymer films based on BR and its analogs will find potential use precisely in the medical low- light-level imaging systems.

  17. Elevated Levels of DNA Strand Breaks Induced by a Base Analog in the Human Cell Line with the P32T ITPA Variant

    Directory of Open Access Journals (Sweden)

    Irina S.-R. Waisertreiger

    2010-01-01

    Full Text Available Base analogs are powerful antimetabolites and dangerous mutagens generated endogenously by oxidative stress, inflammation, and aberrant nucleotide biosynthesis. Human inosine triphosphate pyrophosphatase (ITPA hydrolyzes triphosphates of noncanonical purine bases (i.e., ITP, dITP, XTP, dXTP, or their mimic: 6-hydroxyaminopurine (HAP deoxynucleoside triphosphate and thus regulates nucleotide pools and protects cells from DNA damage. We demonstrate that the model purine base analog HAP induces DNA breaks in human cells and leads to elevation of levels of ITPA. A human polymorphic allele of the ITPA, 94C->A encodes for the enzyme with a P32T amino-acid change and leads to accumulation of nonhydrolyzed ITP. The polymorphism has been associated with adverse reaction to purine base-analog drugs. The level of both spontaneous and HAP-induced DNA breaks is elevated in the cell line with the ITPA P32T variant. The results suggested that human ITPA plays a pivotal role in the protection of DNA from noncanonical purine base analogs.

  18. The Effect of Combining Analogy-Based Simulation and Laboratory Activities on Turkish Elementary School Students' Understanding of Simple Electric Circuits

    Science.gov (United States)

    Unlu, Zeynep Koyunlu; Dokme, Ibilge

    2011-01-01

    The purpose of this study was to investigate whether the combination of both analogy-based simulation and laboratory activities as a teaching tool was more effective than utilizing them separately in teaching the concepts of simple electricity. The quasi-experimental design that involved 66 seventh grade students from urban Turkish elementary…

  19. Study of effect of gate-length downscaling on the analog/RF performance and linearity investigation of InAs-based nanowire Tunnel FET

    Science.gov (United States)

    Biswal, Sudhansu Mohan; Baral, Biswajit; De, Debashis; Sarkar, Angsuman

    2016-03-01

    In this paper, we present a simulation study to report the effect of gate-length downscaling on the analog/RF performance and linearity investigation of InAs-based nanowire (NW) Tunnel FET (TFET). The different RF/analog and linearity figure of merits such as gm, RO, gm*RO, fT, fmax, GBW and 1-dB compression point of a NW TFET are extracted and the influence of gate-length downscaling on these parameters is analyzed. The RF/analog performance parameters obtained from InAs TFET is compared with an InAs MOSFET of identical dimension. Results reveal that superior RF and Linearity performance was obtained with gate-length downscaling for both devices under consideration. However, advantages of achieving improved RF performance with gate-length downscaling diminishes in terms of poor analog performance with gate-length downscaling for both the devices. This clearly indicates a trade-off between the analog and RF performance of a down-scaled InAs-based NW TFET and MOSFET. The results reveal that InAs TFET provides better fT, fmax and linearity performance in the saturation region than its MOSFET counterpart. It provides a reasonable RO, gm*RO at lower values of gate-overdrive voltage as compared to the InAs MOSFET. Therefore, this paper concludes that InAs NW TFETs have enormous potential to be a promising contender to the conventional bulk MOSFETs for realization of future generation low-power analog/RF applications.

  20. Potential applications of curcumin and its novel synthetic analogs and nanotechnology-based formulations in cancer prevention and therapy

    Directory of Open Access Journals (Sweden)

    Batra Surinder K

    2011-08-01

    Full Text Available Abstract Curcumin has attracted great attention in the therapeutic arsenal in clinical oncology due to its chemopreventive, antitumoral, radiosensibilizing and chemosensibilizing activities against various types of aggressive and recurrent cancers. These malignancies include leukemias, lymphomas, multiple myeloma, brain cancer, melanoma and skin, lung, prostate, breast, ovarian, liver, gastrointestinal, pancreatic and colorectal epithelial cancers. Curcumin mediates its anti-proliferative, anti-invasive and apoptotic effects on cancer cells, including cancer stem/progenitor cells and their progenies, through multiple molecular mechanisms. The oncogenic pathways inhibited by curcumin encompass the members of epidermal growth factor receptors (EGFR and erbB2, sonic hedgehog (SHH/GLIs and Wnt/β-catenin and downstream signaling elements such as Akt, nuclear factor-kappa B (NF-κB and signal transducers and activators of transcription (STATs. In counterbalance, the high metabolic instability and poor systemic bioavailability of curcumin limit its therapeutic efficacy in human. Of great therapeutic interest, the selective delivery of synthetic analogs or nanotechnology-based formulations of curcumin to tumors, alone or in combination with other anticancer drugs, may improve their chemopreventive and chemotherapeutic efficacies against cancer progression and relapse. Novel curcumin formulations may also be used to reverse drug resistance, eradicate the total cancer cell mass and improve the anticarcinogenic efficacy of the current anti-hormonal and chemotherapeutic treatments for patients with various aggressive and lethal cancers.

  1. Analysis by NASA's VESGEN Software of Vascular Branching in the Human Retina with a Ground-Based Microgravity Analog

    Science.gov (United States)

    Parsons-Wingerter, Patricia; Vyas, Ruchi J.; Raghunandan, Sneha; Vu, Amanda C.; Zanello, Susana B.; Ploutz-Snyder, Robert; Taibbi, Giovanni; Vizzeri, Gianmarco

    2016-01-01

    Significant risks for visual impairment were discovered recently in astronauts following spaceflight, especially after long-duration missions.1 We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal vasculature that precede visual and other ocular impairments. We therefore are analyzing retinal vessels in healthy subjects with NASA's VESsel GENeration Analysis (VESGEN) software2 before and after head-down tilt (HDT), a ground-based microgravity analog For our preliminary study of masked images, two groups of venous trees with and without small veins (G=7) were clearly identified by VESGEN analysis. Upon completing all images and unmasking the subject status of pre- and post- HDT, we will determine whether differences in the presence or absence of small veins are important correlates, and perhaps reliable predictors, of other ocular and physiological adaptations to prolonged HDT and microgravity. Greater peripapillary retinal thickening was measured following 70-day HDT bed rest than 14-day HDT bed rest, suggesting that time of HDT may increase the amount of optic disc swelling.3 Spectralis OCT detected retinal nerve fiber layer thickening post HDT, without clinical signs of optic disc edema. Such changes may have resulted from HDT-induced cephalad fluid shifts. Clinical methods for examining adaptive microvascular remodeling in the retina to microgravity space flight are currently not established.

  2. Photonic compressive sensing for analog-to-information conversion with a delay-line based microwave photonic filter

    Science.gov (United States)

    Zhu, Zhijing; Chi, Hao; Jin, Tao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

    2016-07-01

    Compressive sensing (CS) in the photonic domain is highly promising for analog-to-information conversion of sparse signals due to its potential capability of high input bandwidth and digitization with sub-Nyquist sampling. In this paper, we suggest that the concept of delay-line based microwave photonic filter be used in photonic CS to realize the low-pass filtering (LPF) function which is required in CS. A microwave photonic filter (MPF) with a dispersive element and fiber delay lines is applied in photonic CS to achieve better performance and flexibility. In the approach, the input radio-frequency signal and the pseudorandom bit sequence (PRBS) are modulated on a multi-wavelength optical carrier and propagate through a dispersive element. The modulated optical signal is split into multiple channels with tunable delay lines. The multiple wavelengths, dispersive element and multiple channels constitute a reconfigurable low-pass microwave filter. Experiment and simulations are presented to demonstrate the feasibility and potentials of this approach.

  3. A 97 dB dynamic range CSA-based readout circuit with analog temperature compensation for MEMS capacitive sensors

    International Nuclear Information System (INIS)

    This paper presents a charge-sensitive-amplifier (CSA) based readout circuit for capacitive microelectro-mechanical-system (MEMS) sensors. A continuous-time (CT) readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier (OTA) structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35 μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF / √Hz capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/°C after optimized compensation. (semiconductor integrated circuits)

  4. Analog Testing of Operations Concepts for Integration of an Earth-Based Science Team During Human Exploration of Mars

    Science.gov (United States)

    Chappell, Steven P.; Beaton, Kara H.; Graff, Trevor; Newton, Carolyn; Abercromby, Andrew F.; Gernhardt, Michael L.

    2017-01-01

    NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. A mission was undertaken in 2016, NEEMO 21. The mission was performed at the Aquarius undersea research habitat. During the mission, the effects of varying operations concepts on representative communication latencies associated with Mars missions were studied. Six subjects were weighed out to simulate near-zero or partial gravity and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) to provide input and direction during exploration activities. Exploration traverses were planned in advance based on precursor data collected. Subjects completed science-related tasks including pre-sampling surveys and marine science-based sampling as a portion of their tasks on saturation dives up to 4 hours in duration that were to simulate extravehicular activity (EVA) on Mars. A one-way communication latency of 15 minutes between space and mission control was simulated throughout the missions. Objective data included task completion times, total EVA times, crew idle time, translation time, SBT assimilation time (defined as time available for ST to discuss data/imagery after it has been collected, in addition to the time taken to watch imagery and listen to audio streaming over latency). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. Results were collected and will be presented on the acceptability of the operations concepts studied and which capabilities are the most enabling/enhancing in the operations concept. Discussion is presented on the importance of designing EVA timelines to account for the length of the task, level of interaction with the ground that is required/desired, and communication latency.

  5. 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.

  6. Hierarchical self-assembly of switchable nucleolipid supramolecular gels based on environmentally-sensitive fluorescent nucleoside analogs

    Science.gov (United States)

    Nuthanakanti, Ashok; Srivatsan, Seergazhi G.

    2016-02-01

    Exquisite recognition and folding properties have rendered nucleic acids as useful supramolecular synthons for the construction of programmable architectures. Despite their proven applications in nanotechnology, scalability and fabrication of nucleic acid nanostructures still remain a challenge. Here, we describe a novel design strategy to construct new supramolecular nucleolipid synthons by using environmentally-sensitive fluorescent nucleoside analogs, based on 5-(benzofuran-2-yl)uracil and 5-(benzo[b]thiophen-2-yl)uracil cores, as the head group and fatty acids, attached to the ribose sugar, as the lipophilic group. These modified nucleoside-lipid hybrids formed organogels driven by hierarchical structures such as fibers, twisted ribbons, helical ribbons and nanotubes, which depended on the nature of fatty acid chain and nucleobase modification. NMR, single crystal X-ray and powder X-ray diffraction studies revealed the coordinated interplay of various non-covalent interactions invoked by modified nucleobase, sugar and fatty acid chains in setting up the pathway for the gelation process. Importantly, these nucleolipid gels retained or displayed aggregation-induced enhanced emission and their gelation behavior and photophysical properties could be reversibly switched by external stimuli such as temperature, ultrasound and chemicals. Furthermore, the switchable nature of nucleolipid gels to chemical stimuli enabled the selective two channel recognition of fluoride and Hg2+ ions through visual phase transition and fluorescence change. Fluorescent organogels exhibiting such a combination of useful features is rare, and hence, we expect that this innovative design of fluorescent nucleolipid supramolecular synthons could lead to the emergence of a new family of smart optical materials and probes.Exquisite recognition and folding properties have rendered nucleic acids as useful supramolecular synthons for the construction of programmable architectures. Despite their

  7. 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.

  8. Design and simulation of an integrated optical ring-resonator based frequency discriminator for analog optical links

    NARCIS (Netherlands)

    Timens, R.B.; Marpaung, D.A.I.; Roeloffzen, C.G.H.; Etten, van W.

    2008-01-01

    The performance of a conventional intensity modulation direct detection analog optical links is limited by the high noise power associated with large optical carrier power. This optical carrier can be suppressed by using optical frequency modulation in conjunction with a frequency discriminator. In

  9. Isoquinoline-based analogs of the cancer drug clinical candidate tipifarnib as anti-Trypanosoma cruzi agents

    OpenAIRE

    Chennamaneni, Naveen Kumar; Arif, Jenifer; Buckner, Frederick S.; Gelb, Michael H

    2009-01-01

    We developed a synthetic route to prepare isoquinoline analogs of the cancer drug clinical candidate tipifarnib. We show that these compounds kill Trypanosoma cruzi amastigotes grown in mammalian host cells at concentrations in the low nanomolar range. These isoquinolines represent new leads for the development of drugs to treat Chagas disease.

  10. 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.

  11. Automatic generation of a metamodel from an existing knowledge base to assist the development of a new analogous knowledge base.

    Science.gov (United States)

    Bouaud, J; Séroussi, B

    2002-01-01

    Knowledge acquisition is a key step in the development of knowledge-based systems and methods have been proposed to help elicitating a domain-specific task model from a generic task model. We explored how an existing validated knowledge base (KB) represented by a decision tree could be automatically processed to infer a higher level domain-specific task model. On-codoc is a guideline-based decision support system applied to breast cancer therapy. Assuming task identity and ontological proximity between breast and lung cancer domains, the generalization of the breast can-cer KB should allow to build a metamodel to serve as a guide for the elaboration of a new specific KB on lung cancer. Two types of parametrized generalization methods based on tree structure simplification and ontological abstraction were used. We defined a similarity distance and a generalization coefficient to select the best metamodel identified as the closest to the original decision tree of the most generalized metamodels. PMID:12463788

  12. Lumped time-delay compensation scheme for coding synchronization in the nonlinear spectral quantization-based all-optical analog-to-digital conversion

    OpenAIRE

    Kang, Zhe; Yuan, Jinhui; Wu, Qiang; WANG, Tao; Li, Sha; Sang, Xinzhu; Yu, Chongxiu; Farrell, Gerald

    2013-01-01

    In this paper, we propose a novel lumped time-delay compensation scheme for the all-optical analog-to-digital conversion based on soliton self-frequency shift and optical interconnection techniques. By inserting a segment of negative dispersion fiber between the quantization and the coding module, the time delay of different quantized pulses can be accurately compensated with a simple structure compared to the multiple time-delay lines. The simulation results show that the coding pulses...

  13. 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

  14. In Vitro Biologic Activities of the Antimicrobials Triclocarban, Its Analogs, and Triclosan in Bioassay Screens: Receptor-Based Bioassay Screens

    OpenAIRE

    Ahn, Ki Chang; Zhao, Bin; Chen, Jiangang; Cherednichenko, Gennady; Sanmarti, Enio; Denison, Michael S.; Lasley, Bill; Pessah, Isaac N; Kültz, Dietmar; Chang, Daniel P.Y.; Gee, Shirley J.; Hammock, Bruce D.

    2008-01-01

    Background Concerns have been raised about the biological and toxicologic effects of the antimicrobials triclocarban (TCC) and triclosan (TCS) in personal care products. Few studies have evaluated their biological activities in mammalian cells to assess their potential for adverse effects. Objectives In this study, we assessed the activity of TCC, its analogs, and TCS in in vitro nuclear-receptor–responsive and calcium signaling bioassays. Materials and methods We determined the biological ac...

  15. 脉冲控制忆阻模拟存储器%Analog Memory Based on Pulse Controlled Memristor

    Institute of Scientific and Technical Information of China (English)

    胡小方; 段书凯; 王丽丹; 李传东

    2011-01-01

    In this paper, the charge-controlled and flux-controlled memristor mathematical models are derived detailedly. The continuously variable conductance and memory properties of memristors are researched. An implementation scheme for analog memory using pulse controlled memristors is proposed, and its effectiveness is verified through theoretical analysis and simulation experiments. With crossbar array structure, the scheme is expected to achieve large-scale analog storage arrays, which may greatly promote the development of artificial neural networks and analog computers.%推导了忆阻器的电荷控制和磁通量控制数学模型,在该基础上研究了其电导状态连续可变的性质和记忆功能.提出了用脉冲控制忆阻器实现模拟信息存储的方案,通过理论分析、实验仿真验证了方案的有效性.结合交叉阵列结构,该方案有望实现大规模模拟存储阵列,推进人工神经网络和模拟式计算机的发展.

  16. Code synchronization based on lumped time-delay compensation scheme with a linearly chirped fiber Bragg grating in all-optical analog-to-digital conversion

    International Nuclear Information System (INIS)

    We propose a novel lumped time-delay compensation scheme for all-optical analog-to-digital conversion based on soliton self-frequency shift and optical interconnection techniques. A linearly chirped fiber Bragg grating is optimally designed and used to compensate for the entire time-delays of the quantized pulses precisely. Simulation results show that the compensated coding pulses are well synchronized with a time difference less than 3.3 ps, which can support a maximum sampling rate of 151.52 GSa/s. The proposed scheme can efficiently reduce the structure complexity and cost of all-optical analog-to-digital conversion compared to the previous schemes with multiple optical time-delay lines. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  17. Silicon, iron and titanium doped calcium phosphate-based glass reinforced biodegradable polyester composites as bone analogous materials

    Science.gov (United States)

    Shah Mohammadi, Maziar

    Bone defects resulting from disease or traumatic injury is a major health care problem worldwide. Tissue engineering offers an alternative approach to repair and regenerate bone through the use of a cell-scaffold construct. The scaffold should be biodegradable, biocompatible, porous with an open pore structure, and should be able to withstand the applied forces. Phosphate-based glasses (PGs) may be used as reinforcing agents in degradable composites since their degradation can be predicted and controlled through their chemistry. This doctoral dissertation describes the development and evaluation of PGs reinforced biodegradable polyesters for intended applications in bone augmentation and regeneration. This research was divided into three main objectives: 1) Investigating the composition dependent properties of novel PG formulations by doping a sodium-free calcium phosphate-based glass with SiO2, Fe2O3, and TiO2. Accordingly, (50P2 O5-40CaO- xSiO2-(10-x)Fe2O3, where x = 10, 5 and 0 mol.%) and (50P2O5-40CaO-xSiO 2-(10-x)TiO2 where x = 10, 7, 5, 3 and 0 mol.%) formulations were developed and characterised. SiO2 incorporation led to increased solubility, ion release, pH reduction, as well as hydrophilicity, surface energy, and surface polarity. In contrast, doping with Fe2O 3 or TiO2 resulted in more durable glasses, and improved cell attachment and viability. It was hypothesised that the presence of SiO 2 in the TiO2-doped formulations could up-regulate the ionic release from the PG leading to higher alkaline phosphatase activity of MC3T3-E1 cells. 2) Incorporating Si, Fe, and Ti doped PGs as fillers, either as particulates (PGPs) or fibres (PGFs), into biodegradable polyesters (polycaprolactone (PCL) and semi-crystalline and amorphous poly(lactic acid) (PLA and PDLLA)) with the aim of developing degradable bone analogous composites. It was found that PG composition and geometry dictated the weight loss, ionic release, and mechanical properties of the composites. It

  18. 基于五光谱TDICCD的模拟信号发生器设计%Design of Analog Signal Generator Based on Five-spectral TDICCD

    Institute of Scientific and Technical Information of China (English)

    王旭; 刘正敏; 樊奔; 何志宽

    2014-01-01

    首先介绍了延迟积分电荷耦合器件(TDICCD)的基本原理,并根据某高分辨率多光谱航天相机定制的一款五光谱TDICCD的输出特性,设计了一种基于五光谱TDICCD的模拟信号发生器,给出了该模拟信号发生器的系统组成,包括图像处理电路、数模转换电路和模拟信号滤波电路。最后通过测试验证了该系统的信号波形、信号噪声和输出图像都满足设计要求,其输出的16通道模拟五光谱TDICCD信号频率可以达到20MHz,噪声控制在10mV以内,具有高精度、多通道和低噪声等特点。目前该模拟信号发生器已成功应用到新一代高分辨率多光谱TDICCD相机成像电路系统的研制中。%The paper introduces the principle of TDICCD firstly, and then designs an analog signal generator based on five-spectral TDICCD, according to the output characteristic of five-spectral TDICCD customized by a high resolution multi-spectral TDICCD camera. Analog signal generator consists of image processing circuit, digital-to-analog conversion circuit and analog signal filter circuit. Finally, verified by the system of signal, signal to noise ratio and the output images meet the design requirements. The system has the characteristics of high precision, multi-channel and low noise, whose 16 channels can analog five-spectral TDICCD signal frequency up to 20MHz and the signal to noise ratio is less than 10mV. The analog signal generator has been successfully applied in the development of imaging circuit system of the new generation high resolution multi-spectral TDICCD camera.

  19. Firing Efficiency of Cluster Bomb Based on Method of Analogy%基于类比法的子母弹射击效率评定研究

    Institute of Scientific and Technical Information of China (English)

    殷培江; 李君; 张立生

    2012-01-01

    The method of analogy is a familiar logistic organon used in the mess of research domain, but it's rarely used in evaluation martial category. The firing efficiency of cluster bomb based on method of analogy have many advantage, for instance it is briefness, practicability, economy, and convenient for largely reckon. The paper builds the evaluation index system of the firing efficiency with cluster bomb, we found the comparable from cluster bomb to another ammunition in classical model, build the mathematics model based on method of analogy in the next place. The paper serve as an example of several emblematic targets, and display status of firing efficiency with several emblematic targets used the radar chart, we have compared the conclusions with method of analogy and emulation mode, validate the firing efficiency of cluster bomb based on method of analogy is feasible.%类比法是一种较为常见的逻辑推理方法,在各研究领域均有应用,但在军事评估领域却应用甚少.基于类比法的子母弹射击效率评定具有简单、实用、经济、便于大量计算等优点.根据子母弹与传统弹药在射击效率评定过程中的相似性,在经典毁伤评估模型的基础上,通过类比法建立字母弹的射击效率评定模型.列举了几种典型目标,并以子母弹的类比法模型进行射击效率评定,最后将类比法所得结论与目标仿真法的结论反映在雷达图上,通过数据比对验证了类比法对子母弹射击效率评定的可行性.

  20. 基于Aspen Plus的克劳斯硫回收过程模拟%Analog of ClausSulfur Recovery Process Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    林发现; 丁玲; 陈延林; 李繁荣; 师慧灵; 邹隐文

    2011-01-01

    Adopting Aspen Plus process analog calculation software,process flow for Claus sulfur recovery was simulated,simulated data was good coincident with the data demarcated by analog software used specially for sulfur recovery;on that basis,author has studied the influence of Claus key data on process flow by use of Aspen Plus modular analysis function,its conclusion was coincident with practical production process;result indicates that it has optimizing role for both design calculation and production operation based on the Claus sulfur recovery process analog.%采用Aspen P lus工艺模拟计算软件模拟了克劳斯硫回收工艺过程,模拟数据与硫回收专用模拟软件的标定数据吻合较好;在此基础上,利用Aspen P lus模块化分析功能,研究了克劳斯工艺的关键数据对工艺过程的影响,其结论与实际生产过程相符合;结果表明,基于Aspen P lus的克劳斯硫回收过程模拟,对设计计算和生产操作均具有优化作用。

  1. Selection of the optimum combination of responses for Wave Buoy Analogy - An approach based on local sensitivity analysis

    DEFF Research Database (Denmark)

    Montazeri, Najmeh; Nielsen, Ulrik Dam; Jensen, Jørgen Juncher

    2016-01-01

    One method to estimate the wave spectrum onboard ships is to use measured ship responses. In this method, known also as Wave Buoy Analogy, amongst various responses that are available from sensor measurements, a couple of responses (at least three) are usually utilized. Selec-tion of the best...... combination of ship responses is important. Optimally, this selection should not be implemented manually in onboard applications. Therefore, availability of an automatic response selection procedure would be a great advantage for decision support. In this paper, a local sensitivity analysis is applied to...

  2. Selection of the optimum combination of responses for Wave Buoy Analogy - An approach based on local sensitivity analysis

    DEFF Research Database (Denmark)

    Montazeri, Najmeh; Nielsen, Ulrik Dam; Jensen, Jørgen Juncher

    2016-01-01

    One method to estimate the wave spectrum onboard ships is to use measured ship responses. In this method, known also as Wave Buoy Analogy, amongst various responses that are available from sensor measurements, a couple of responses (at least three) are usually utilized. Selec-tion of the best...... combination of ship responses is important. Optimally, this selection should not be implemented manually in onboard applications. Therefore, availability of an automatic response selection procedure would be a great advantage for decision support. In this paper, a local sensitivity analysis is applied...

  3. 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

  4. Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system.

    Science.gov (United States)

    Jiang, Jia-Jia; Duan, Fa-Jie; Li, Yan-Chao; Hua, Xiang-Ning

    2014-03-01

    Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper. PMID:24689606

  5. Synchronization sampling method based on delta-sigma analog-digital converter for underwater towed array system

    Science.gov (United States)

    Jiang, Jia-Jia; Duan, Fa-Jie; Li, Yan-Chao; Hua, Xiang-Ning

    2014-03-01

    Synchronization sampling is very important in underwater towed array system where every acquisition node (AN) samples analog signals by its own analog-digital converter (ADC). In this paper, a simple and effective synchronization sampling method is proposed to ensure synchronized operation among different ANs of the underwater towed array system. We first present a master-slave synchronization sampling model, and then design a high accuracy phase-locked loop to synchronize all delta-sigma ADCs to a reference clock. However, when the master-slave synchronization sampling model is used, both the time-delay (TD) of messages traveling along the wired transmission medium and the jitter of the clocks will bring out synchronization sampling error (SSE). Therefore, a simple method is proposed to estimate and compensate the TD of the messages transmission, and then another effective method is presented to overcome the SSE caused by the jitter of the clocks. An experimental system with three ANs is set up, and the related experimental results verify the validity of the synchronization sampling method proposed in this paper.

  6. 基于GEP的模拟电路系统辨识技术%System Identification of Analog Circuits Based on Gene Expression Programming

    Institute of Scientific and Technical Information of China (English)

    王俊亚; 陈棣湘; 潘孟春

    2011-01-01

    Identifying the mathematical model of the analog circuit through the IO data is the key technology in the model - based fast equipment test method. According to the electrical characteristics of the analog circuit system, we designed R-square-based fitness function, and the selection strategy combined with elitism and roulette. The establishment method of analog circuit system identification based on gene expression programming (GEP) was constituted with the partially mapped crossover operator, the heuristic mutation operator, and the sequence insertion operator. Compared with the MATLAB system identification toolbox, this method can identify not only the system parameter, but also the structure. If you set the suitable identification precision, we can get the theoretical system model via the SISO and MIMO tests.%根据模拟电路系统的输入输出数据辨识,其数学模型是基于模型的装备快速测试方法中的关键技术之一.针对模拟电路系统的特点,设计了基于R-square的适应度函数、基于精英主义和轮盘赌算法的选择策略,采用部分映射、启发式变异算子,提出了一种基于基因表达式编程算法的模拟电路系统辨识方法并进行了系统实现.与MATLAB系统辨识工具箱对比,该方法不仅能够辨识电路系统的参数,而且还能辨识系统的结构.实验表明,通过设置适当的辨识精度,可以得到与理论模型一致的系统模型.

  7. 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...

  8. Understanding the link between circumferential dikes and eruptive fissures around calderas based on numerical and analog models

    Science.gov (United States)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-06-01

    Active calderas are seldom associated with circumferential eruptive fissures, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential fissure development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential fissures.

  9. 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

  10. All-optical analog comparator

    Science.gov (United States)

    Li, Pu; Yi, Xiaogang; Liu, Xianglian; Zhao, Dongliang; Zhao, Yongpeng; Wang, Yuncai

    2016-08-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function.

  11. 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

  12. 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. <

  13. 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

  14. Demonstration of an online tool to assist managed care formulary evidence-based decision making: meta-analysis of topical prostaglandin analog efficacy

    Directory of Open Access Journals (Sweden)

    Kymes SM

    2011-07-01

    Full Text Available Steven M Kymes1, Caroline Burk2, Todd Feinman3, Julia M Williams4, David A Hollander41Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO, USA; 2Health Outcomes, Allergan Inc, Irvine, CA, USA; 3Doctor Evidence LLC, Santa Monica, CA, USA; 4Global Medical Affairs, Allergan Inc, Irvine, CA, USABackground: The purpose of this paper was to demonstrate the use of an online service for conducting a systematic review and meta-analysis of the efficacy of topical prostaglandin analogs in reducing intraocular pressure (IOP in glaucoma and ocular hypertension.Methods: An online service provider (Doctor Evidence reviewed and extracted data from the peer-reviewed literature through September 2009. Randomized controlled studies of at least three months' duration assessing at least two prostaglandin analogs in patients with primary open-angle glaucoma, ocular hypertension, or normal-tension glaucoma were included. The primary endpoint was mean IOP. Summary estimates were created using random-effects models. The Q Chi-square test was used to assess statistical heterogeneity.Results: Sixteen studies satisfied the inclusion criteria and were analyzed. On average, greater IOP-lowering was seen with bimatoprost relative to latanoprost (1 mmHg, P = 0.025 and travoprost (0.8 mmHg, P = 0.033 based on mean IOP after 12–26 weeks of treatment. No statistical difference was observed in IOP-lowering between latanoprost and travoprost (P = 0.841. Findings were similar to previously published meta-analyses of topical prostaglandin analogs.Conclusion: Systematic reviews relying on meta-analytic techniques to create summary statistics are considered to be the "gold standard" for synthesizing evidence to support clinical decision-making. However, the process is time-consuming, labor-intensive, and outside the capability of most formulary managers. We have demonstrated the effectiveness of a commercial service that facilitates

  15. A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems

    Science.gov (United States)

    Sun, Kai; Wu, Hongfei; Cai, Yan; Xing, Yan

    2014-06-01

    A thermoelectric generator (TEG) is a very important kind of power supply for spacecraft, especially for deep-space missions, due to its long lifetime and high reliability. To develop a practical TEG power supply for spacecraft, a power conditioning stage is indispensable, being employed to convert the varying output voltage of the TEG modules to a definite voltage for feeding batteries or loads. To enhance the system reliability, a power conditioning stage based on analog-circuit maximum-power-point tracking (MPPT) control and a superbuck converter is proposed in this paper. The input of this power conditioning stage is connected to the output of the TEG modules, and the output of this stage is connected to the battery and loads. The superbuck converter is employed as the main circuit, featuring low input current ripples and high conversion efficiency. Since for spacecraft power systems reliable operation is the key target for control circuits, a reset-set flip-flop-based analog circuit is used as the basic control circuit to implement MPPT, being much simpler than digital control circuits and offering higher reliability. Experiments have verified the feasibility and effectiveness of the proposed power conditioning stage. The results show the advantages of the proposed stage, such as maximum utilization of TEG power, small input ripples, and good stability.

  16. A low-power inverter-based CMOS level-crossing analog-to-digital converter for low-frequency biosignal sensing

    Science.gov (United States)

    Tanaka, Suiki; Niitsu, Kiichi; Nakazato, Kazuo

    2016-03-01

    Low-power analog-to-digital conversion is a key technique for power-limited biomedical applications such as power-limited continuous glucose monitoring. However, a conventional uniform-sampling analog-to-digital converter (ADC) is not suitable for nonuniform biosignals. A level-crossing ADC (LC-ADC) is a promising candidate for low-power biosignal processing because of its event-driven properties. The LC-ADC acquires data by level-crossing sampling. When an input signal crosses the threshold level, the LC-ADC samples the signal. The conventional LC-ADC employs a power-hungry comparator. In this paper, we present a low-power inverter-based LC-ADC. By adjusting the threshold level of the inverter, it can be used as a threshold-fixed window comparator. By using the inverter as an alternative to a comparator, power consumption can be markedly reduced. As a result, the total power consumption is successfully reduced by 90% of that of previous LC-ADC. The inverter-based LC-ADC was found to be very suitable for use in power-limited biomedical devices.

  17. The Bipolar Field-Effect Transistor:Ⅶ. The Unipolar Current Mode for Analog-RF Operation(Two-MOS-Gates on Pure-Base

    Institute of Scientific and Technical Information of China (English)

    Jie Binbin; Sah Chih-Tang

    2009-01-01

    This paper reports the DC steady-state current-voltage and conductance-voltage characteristics of a Bipolar Field-Effect Transistor (BiFET) under the unipolar (electron) current mode of operation, with bipolar (elec-tron and hole) charge distributions considered. The model BiFET example presented has two MOS-gates on the two surfaces of a thin pure silicon base layer with electron and hole contacts on both edges of the thin base. The hole contacts on both edges of the thin pure base layer are grounded to give zero hole current. This 1-transistor analog-RF Basic Building Block nMOS amplifier circuit, operated in the unipolar current mode, complements the 1-transistor digital Basic Build Block CMOS voltage inverter circuit, operated in the bipolar-current mode just presented by us.

  18. Analog circuit diagnosis with fault dictionary method based on DAGSVC*%基于DAGSVC的模拟电路故障字典法

    Institute of Scientific and Technical Information of China (English)

    姜媛媛; 韩振云; 崔江

    2011-01-01

    Focusing on the design of problem of fault diagnosis of analog circuit and classifier with support vector machines(SVMs) ,a new method of fault dictionary based on directed acyclic graph SVMs classifier (DAGSVC) is presented, and a specification for estimating the average test complexity of the support vector machine classifier (SVC) is also compared. Two actual analog filter are tested to validate the proposed method,whose performance is proven to be superior to the traditional methods, such as “1-v-r” SVC and “l-v-1” SVC. The proposed method, being proper to perform analog circuit diagnosis and faults isolation,could also achieve almost the same diagnosis rate as the clustering binary tree SVC,whose test structure is not unique.%针对模拟电路的故障诊断和支持向量机分类器的设计问题,讨论了一种基于有向无环图支持向量机分类器(DAGSVC)的故障字典新方法,并比较了几种支持向量机故障分类器的平均测试复杂度指标.通过对2个实际模拟滤波器的实际测试和验证表明:该方法性能要优于"1-v-r"SVC,"1-v-1"SVC等常规的故障分类器,并和聚类二叉树SVC的诊断性能接近,适合模拟电路的故障分类和诊断.

  19. Structure-Activity Relationship-based Optimization of Small Temporin-SHf Analogs with Potent Antibacterial Activity.

    Science.gov (United States)

    André, Sonia; Washington, Shannon K; Darby, Emily; Vega, Marvin M; Filip, Ari D; Ash, Nathaniel S; Muzikar, Katy A; Piesse, Christophe; Foulon, Thierry; O'Leary, Daniel J; Ladram, Ali

    2015-10-16

    Short antimicrobial peptides represent attractive compounds for the development of new antibiotic agents. Previously, we identified an ultrashort hydrophobic and phenylalanine-rich peptide, called temporin-SHf, representing the smallest natural amphibian antimicrobial peptide known to date. Here, we report on the first structure-activity relationship study of this peptide. A series of temporin-SHf derivatives containing insertion of a basic arginine residue as well as residues containing neutral hydrophilic (serine and α-hydroxymethylserine) and hydrophobic (α-methyl phenylalanine and p-(t)butyl phenylalanine) groups were designed to improve the antimicrobial activity, and their α-helical structure was investigated by circular dichroism and nuclear magnetic resonance spectroscopy. Three compounds were found to display higher antimicrobial activity with the ability to disrupt (permeabilization/depolarization) the bacterial membrane while retaining the nontoxic character of the parent peptide toward rat erythrocytes and human cells (THP-1 derived macrophages and HEK-293). Antimicrobial assays were carried out to explore the influence of serum and physiological salt concentration on peptide activity. Analogs containing d-amino acid residues were also tested. Our study revealed that [p-(t)BuF(2), R(5)]SHf is an attractive ultrashort candidate that is highly potent (bactericidal) against Gram-positive bacteria (including multidrug resistant S. aureus) and against a wider range of clinically interesting Gram-negative bacteria than temporin-SHf, and also active at physiological salt concentrations and in 30% serum. PMID:26181487

  20. Regioselective enzymatic undecylenoylation of 8-chloroadenosine and its analogs with biomass-based 2-methyltetrahydrofuran as solvent.

    Science.gov (United States)

    Gao, Wen-Li; Liu, Huan; Li, Ning; Zong, Min-Hua

    2012-08-01

    2-Methyltetrahydrofuran (MeTHF), a biomass-derived compound, is a promising medium for biocatalysis and organometallic reactions. The regioselective acylation of 8-chloroadenosine (8-Cl-Ado) and its analogs was carried out in MeTHF with immobilized Penicillium expansum lipase. The lipase displayed more than twofold higher catalytic activity and much better thermostability in MeTHF than in other organic solvents and co-solvent systems. The optimum reaction medium, enzyme dosage, molar ratio of viny ester to nucleoside and reaction temperature for the enzymatic acylation of 8-Cl-Ado were MeTHF, 25 U/mL, 7.5 and 35 °C, respectively, under which the desirable 5'-O-undecylenoyl-8-Cl-Ado was obtained with a yield of 95% and a regioselectivity of >99% in 3 h. In addition, the lipase catalyzed regioselective undecylenoylation of other purine nucleosides, producing 5'-undecylenic acid esters with moderate to high yields (63-94%) and excellent 5'-regioselectivities (94->99%). Use of biomass-derived solvents might open up novel opportunities for sustainable and greener biocatalytic processes. PMID:22705510

  1. Mineral formation on metallic copper in a 'Future repository site environment': Textural considerations based on natural analogs

    International Nuclear Information System (INIS)

    Copper mineral formation in the Swedish 'repository site environment' is discussed. Special attention is given to ore mineral textures (=the spatial relation among minerals), with examples given from nature. It is concluded: By analogy with observations from natural occurrences, an initial coating of Cu-oxide on the canister surface (because of entrapped air during construction) will probably not hinder a later sulphidation process. Early formation of Cu-sulphides on the canister surface may be accompanied by formation of CuFe-sulphides. The latter phase(s) may form through replacement of the Cu-sulphides or, alternatively, by means of reaction between dissolved copper and fine-grained iron sulphide (pyrite) in the surrounding bentonite. Should for some reason the bentonite barrier fail and the conditions become strongly oxidizing, we can expect crustifications and rhythmic growths of Cu(II)-phases, like malachite (Cu2(OH)2CO3). A presence of Fe2 in the clay minerals making up the bentonite might prove to have an adverse effect on the canister stability, since, in this case, the bentonite might be expected to act as a sink for dissolved copper. The mode of mineral growth along the copper - bentonite interface remains an open question

  2. 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.

  3. 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.

  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. Digital to Analog Converter

    NARCIS (Netherlands)

    Westra, Jan R.; Annema, Anne J.; Boom, van den Jeroen M.; Dijkmans, Eise C.

    2002-01-01

    A digital to analog converter (DAC) for converting a digital signal (DS) having a maximum voltage range which corresponds to a first supply voltage (UL) into an analog signal (UOUT) having a maximum voltage range which corresponds to a second supply voltage (UH). The first supply voltage (UL) is off

  6. Digital to Analog Converter

    NARCIS (Netherlands)

    Westra, Jan R.; Annema, Anne J.; Boom, van den Jeroen M.; Dijkmans, Eise C.

    2006-01-01

    A digital to analog converter (DAC) for converting a digital signal (DS) having a maximum voltage range which corresponds to a first supply voltage (UL) into an analog signal (UOUT) having a maximum voltage range which corresponds to a second supply voltage (UH). The first supply voltage (UL) is off

  7. Efficiency and hardware comparison of analog control-based and digital control-based 70 W two-stage power factor corrector and DC-DC converters

    DEFF Research Database (Denmark)

    Török, Lajos; Munk-Nielsen, Stig

    2011-01-01

    A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling is...

  8. Estimation of channel mismatches in time-interleaved analog-to-digital converters based on fractional delay and sine curve fitting.

    Science.gov (United States)

    Guo, Lianping; Tian, Shulin; Jiang, Jun

    2015-03-01

    This paper proposes an algorithm to estimate the channel mismatches in time-interleaved analog-to-digital converter (TIADC) based on fractional delay (FD) and sine curve fitting. Choose one channel as the reference channel and apply FD to the output samples of reference channel to obtain the ideal samples of non-reference channels with no mismatches. Based on least square method, the sine curves are adopted to fit the ideal and the actual samples of non-reference channels, and then the mismatch parameters can be estimated by comparing the ideal sine curves and the actual ones. The principle of this algorithm is simple and easily understood. Moreover, its implementation needs no extra circuits, lowering the hardware cost. Simulation results show that the estimation accuracy of this algorithm can be controlled within 2%. Finally, the practicability of this algorithm is verified by the measurement results of channel mismatch errors of a two-channel TIADC prototype. PMID:25832264

  9. Cyclic pentapeptide analogs based on endomorphin-2 structure: cyclization studies using liquid chromatography combined with on-line mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Piekielna, Justyna; Kluczyk, Alicja; Perlikowska, Renata; Janecka, Anna

    2014-05-01

    The cyclization of linear analogs based on endomorphin-2 structure, Tyr/Dmt-d-Lys-Phe-Phe-Asp-NH2 and Tyr/Dmt-d-Cys-Phe-Phe-Cys-NH2 (where Dmt=2',6'-dimethyltyrosine), resulting in obtaining lactam or disulfide derivatives, was studied using liquid chromatography combined with on-line mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In case of cyclization via an amide bond, the formation of the cyclic monomers, cyclic but not linear dimers and even traces of cyclic trimers was observed. Disulfide bridge containing peptides was obtained by the solid-phase synthesis of the linear sequences, followed by either in-solution or on-resin cyclization. In case of the in-solution cyclization, the expected cyclic monomers were the only products. When oxidation of the cysteine residues was performed when the peptides were still on the resin, cyclic monomer and two cyclodimers, parallel and antiparallel, were found. Digestion of the isolated cyclodimers with α-chymotrypsin allowed for their unambiguous identification. The comparison of the cyclic monomer/dimer ratios for analogs with Tyr versus Dmt in position 1 revealed that the presence of the exocyclic Dmt favored formation of the cyclic monomer, most likely due to the increased steric bulk of this amino acid side-chain as compared with Tyr. PMID:24525024

  10. Cyclic pentapeptide analogs based on endomorphin-2 structure: cyclization studies using liquid chromatography combined with on-line mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Piekielna, Justyna; Kluczyk, Alicja; Perlikowska, Renata; Janecka, Anna

    2014-05-01

    The cyclization of linear analogs based on endomorphin-2 structure, Tyr/Dmt-d-Lys-Phe-Phe-Asp-NH2 and Tyr/Dmt-d-Cys-Phe-Phe-Cys-NH2 (where Dmt=2',6'-dimethyltyrosine), resulting in obtaining lactam or disulfide derivatives, was studied using liquid chromatography combined with on-line mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS). In case of cyclization via an amide bond, the formation of the cyclic monomers, cyclic but not linear dimers and even traces of cyclic trimers was observed. Disulfide bridge containing peptides was obtained by the solid-phase synthesis of the linear sequences, followed by either in-solution or on-resin cyclization. In case of the in-solution cyclization, the expected cyclic monomers were the only products. When oxidation of the cysteine residues was performed when the peptides were still on the resin, cyclic monomer and two cyclodimers, parallel and antiparallel, were found. Digestion of the isolated cyclodimers with α-chymotrypsin allowed for their unambiguous identification. The comparison of the cyclic monomer/dimer ratios for analogs with Tyr versus Dmt in position 1 revealed that the presence of the exocyclic Dmt favored formation of the cyclic monomer, most likely due to the increased steric bulk of this amino acid side-chain as compared with Tyr.

  11. Splitting Compounds by Semantic Analogy

    OpenAIRE

    Daiber, Joachim; Quiroz, Lautaro; Wechsler, Roger; Frank, Stella

    2015-01-01

    Compounding is a highly productive word-formation process in some languages that is often problematic for natural language processing applications. In this paper, we investigate whether distributional semantics in the form of word embeddings can enable a deeper, i.e., more knowledge-rich, processing of compounds than the standard string-based methods. We present an unsupervised approach that exploits regularities in the semantic vector space (based on analogies such as "bookshop is to shop as...

  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. 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

  14. Satellite-Based Thermophysical Analysis of Volcaniclastic Deposits: A Terrestrial Analog for Mantled Lava Flows on Mars

    Directory of Open Access Journals (Sweden)

    Mark A. Price

    2016-02-01

    Full Text Available Orbital thermal infrared (TIR remote sensing is an important tool for characterizing geologic surfaces on Earth and Mars. However, deposition of material from volcanic or eolian activity results in bedrock surfaces becoming significantly mantled over time, hindering the accuracy of TIR compositional analysis. Moreover, interplay between particle size, albedo, composition and surface roughness add complexity to these interpretations. Apparent Thermal Inertia (ATI is the measure of the resistance to temperature change and has been used to determine parameters such as grain/block size, density/mantling, and the presence of subsurface soil moisture/ice. Our objective is to document the quantitative relationship between ATI derived from orbital visible/near infrared (VNIR and thermal infrared (TIR data and tephra fall mantling of the Mono Craters and Domes (MCD in California, which were chosen as an analog for partially mantled flows observed at Arsia Mons volcano on Mars. The ATI data were created from two images collected ~12 h apart by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER instrument. The results were validated with a quantitative framework developed using fieldwork that was conducted at 13 pre-chosen sites. These sites ranged in grain size from ash-sized to meter-scale blocks and were all rhyolitic in composition. Block size and mantling were directly correlated with ATI. Areas with ATI under 2.3 × 10−2 were well-mantled with average grain size below 4 cm; whereas values greater than 3.0 × 10−2 corresponded to mantle-free surfaces. Correlation was less accurate where checkerboard-style mixing between mantled and non-mantled surfaces occurred below the pixel scale as well as in locations where strong shadowing occurred. However, the results validate that the approach is viable for a large majority of mantled surfaces on Earth and Mars. This is relevant for determining the volcanic history of Mars, for

  15. Investigation of Higher Brain Functions in Music Composition Using Models of the Cortex Based on Physical System Analogies.

    Science.gov (United States)

    Leng, Xiaodan

    The trion model was developed using the Mountcastle organizational principle for the column as the basic neuronal network in the cortex and the physical system analogy of Fisher's ANNNI spin model. An essential feature is that it is highly structured in time and in spatial connections. Simulations of a network of trions have shown that large numbers of quasi-stable, periodic spatial-temporal firing patterns can be excited. Characteristics of these patterns include the quality of being readily enhanced by only a small change in connection strengths, and that the patterns evolve in certain natural sequences from one to another. With only somewhat different parameters than used for studying memory and pattern recognition, much more flowing and intriguing patterns emerged from the simulations. The results were striking when these probabilistic evolutions were mapped onto pitches and instruments to produce music: For example different simple mappings of the same evolution give music having the "flavor" of a minuet, a waltz, folk music, or styles of specific periods. A theme can be learned so that evolutions have this theme and its variations reoccurring more often. That the trion model is a viable model for the coding of musical structure in human composition and perception is suggested. It is further proposed that model is relevant for examining creativity in the higher cognitive functions of mathematics and chess, which are similar to music. An even higher level of cortical organization was modeled by coupling together several trion networks. Further, one of the crucial features of higher brain function, especially in music composition or appreciation, is the role of emotion and mood as controlled by the many neuromodulators or neuropeptides. The MILA model whose underlying basis is zero-level representation of Kac-Moody algebra is used to modulate periodically the firing threshold of each network. Our preliminary results show that the introduction of "neuromodulation

  16. 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

  17. All-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an analog on the electromagnetically induced transparency effect

    Science.gov (United States)

    Wang, Boyun; Xiong, Liangbin; Zeng, Qingdong; Chen, Zhihong; Lv, Hao; Ding, Yaoming; Du, Jun; Yu, Huaqing

    2016-06-01

    We theoretically and numerically investigate all-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an all-optical analog on the electromagnetically induced transparency effect. The free-carrier plasma dispersion effect modulation method is applied to improve the tuning rate with a response time of picoseconds. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Compared with no phase-shift multiplication effect, the average pump power of all-optical switching required to yield the π-phase shift difference decreases by 55.1%, and the size of the modulation region is reduced by 50.1% when the average pump power reaches 60.8 mW. This work provides a new direction for low-power consumption and miniaturization of microstructure integration light-controlled switching devices in optical communication and quantum information processing.

  18. A High-Resolution Transmission-Type (TT) Phaser Based on Reflection-Type (RT) Units for Radio Analog Signal Processing (R-ASP)

    CERN Document Server

    Zou, Lianfeng

    2014-01-01

    A high Radio Analog Signal Processing (R-ASP) resolution transmission-type (TT) phaser based on reflection-type (RT) phaser units is introduced, theoretically studied and experimentally demonstrated. It is first shown that RT phasers inherently exhibit higher R-ASP resolution than their TT counterparts because their group delay swing is proportional to the reflection coefficient associated with a resonator coupling mechanism (admittance inverter), easy to maximize towards unity, rather than to a coupled-line coupling coefficient, typically restricted to values will inferior to unity, as in the RT case. Moreover, a detailed sensitivity analysis reveals that the proposed phaser is simultaneously features high R-ASP resolution and low sensitivity to fabrication tolerance, which makes it an ideal solution for R-ASP. The proposed phaser exhibits a 5 ns group delay swing over a fractional bandwidth of about 50% around 4 GHz.

  19. Full characterization of self-phase-modulation based low-noise, cavity-less pulse source for photonic-assisted analog-to-digital conversion.

    Science.gov (United States)

    Liu, Lan; Tong, Zhi; Wiberg, Andreas O J; Myslivets, Evgeny; Alic, Nikola; Radic, Stojan

    2012-12-10

    A high quality cavity-less pulse source, realized as a combination of linear pulse compression and self-phase-modulation (SPM) based regeneration is demonstrated and strictly characterized for the first time. The regenerated pulses, with 3.6 GHz repetition rate, are optimized through rigorous relative intensity-noise (RIN) measurement. Temporal intensity and chirp characterizations demonstrate that the pulses exhibit characteristic of low RIN, and are chirp- and pedestal-free. The cavity-less pulse source is further tested in a photonic-assisted analog-to-digital (ADC) configuration as the sampling source. A record result of more than 8 effective quantization bits at 202 MHz is demonstrated. PMID:23262840

  20. FGF growth factor analogs

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  1. 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.

  2. 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...

  3. Synthesis of a fluorescence resonance energy transfer-based probe containing a tricyclic nucleoside analog for single nucleotide polymorphism typing.

    Science.gov (United States)

    Hayai, Aya; Maeda, Yusuke; Ueno, Yoshihito

    2016-08-01

    Here, we report the synthesis of a fluorescence resonance energy transfer (FRET)-based probe for single nucleotide polymorphism (SNP) typing. The probe contains a fluorescent tricyclic base, 8-amino-3-(2,3-dihydroxypropyl)imidazo[4',5':5,6]pyrido[2,3-d]pyrimidine, as a donor molecule and 7-diethylaminocoumarin-3-carboxylic acid as an acceptor molecule. FRET was observed between the donor and acceptor molecules on the probe. The identity of the target bases on DNA and RNA strands could be determined using the probe. PMID:27329795

  4. A computational model of analogical reasoning

    Institute of Scientific and Technical Information of China (English)

    李波; 赵沁平

    1997-01-01

    A computational model of analogical reasoning is presented, which divides analogical reasoning process into four subprocesses, i.e. reminding, elaboration, matching and transfer. For each subprocess, its role and the principles it follows are given. The model is discussed in detail, including salient feature-based reminding, relevance-directed elaboration, an improved matching model and a transfer model. And the advantages of this model are summarized based on the results of BHARS, which is an analogical reasoning system implemented by this model.

  5. 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)

  6. Design of the Q Meter Based on AD633 Analog Phase Detection%基于AD633模拟鉴相的Q表设计

    Institute of Scientific and Technical Information of China (English)

    葛维亮; 奚大顺; 庹先国; 王洪辉; 李怀良; 张赓; 宋茜茜

    2011-01-01

    In order to solve the problem that the multimeters are unable to measure the parameters of Q, D, etc., the Q meter based on AD633 analog phase detection has been designed. In the instrument, the sine energizing signal and reference signal are generated by the DDS chip AD9851, and phase detection of the signal is implemented by using highly integrated analog multiplier AD633. The single end output signal of phase detection is then converted into differential signal by the differential converter AD8138; and the differential signal is converted into digital and processed by the self-contained ADC of C8051F060. This instrument offers the functions of automatic range changeover, LCD real-time display; and features of compact, low cost as well an meets the measurement demands in engineering projects, teaching and research areas.%为解决万用表无法测量Q、D等参数的问题,设计了基于A1D633模拟鉴相的Q表.该测量仪采用DDS芯片AD9851产生正弦激励信号和基准信号,利用高集成度模拟乘法器AD633对信号进行模拟鉴相,并采用差分转换器AD8138对鉴相输出信号进行单端转差分变换,由C8051F060内部自带的ADC对差分信号进行模数转换和数据处理.Q表具有多量程自动切换和LCD实时显示等功能,且体积小、成本低,能满足工程、教学科研测量的需要.

  7. Structure Based Docking and Molecular Dynamic Studies of Plasmodial Cysteine Proteases against a South African Natural Compound and its Analogs.

    Science.gov (United States)

    Musyoka, Thommas M; Kanzi, Aquillah M; Lobb, Kevin A; Tastan Bishop, Özlem

    2016-01-01

    Identification of potential drug targets as well as development of novel antimalarial chemotherapies with unique mode of actions due to drug resistance by Plasmodium parasites are inevitable. Falcipains (falcipain-2 and falcipain-3) of Plasmodium falciparum, which catalyse the haemoglobin degradation process, are validated drug targets. Previous attempts to develop peptide based drugs against these enzymes have been futile due to the poor pharmacological profiles and susceptibility to degradation by host enzymes. This study aimed to identify potential non-peptide inhibitors against falcipains and their homologs from other Plasmodium species. Structure based virtual docking approach was used to screen a small non-peptidic library of natural compounds from South Africa against 11 proteins. A potential hit, 5α-Pregna-1,20-dien-3-one (5PGA), with inhibitory activity against plasmodial proteases and selectivity on human cathepsins was identified. A 3D similarity search on the ZINC database using 5PGA identified five potential hits based on their docking energies. The key interacting residues of proteins with compounds were identified via molecular dynamics and free binding energy calculations. Overall, this study provides a basis for further chemical design for more effective derivatives of these compounds. Interestingly, as these compounds have cholesterol-like nuclei, they and their derivatives might be well tolerated in humans. PMID:27030511

  8. 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.

  9. Kinetics and Mechanisms of the Acid-base Reaction Between NH3 and HCOOH in Interstellar Ice Analogs

    Science.gov (United States)

    Bergner, Jennifer B.; Öberg, Karin I.; Rajappan, Mahesh; Fayolle, Edith C.

    2016-10-01

    Interstellar complex organic molecules are commonly observed during star formation, and are proposed to form through radical chemistry in icy grain mantles. Reactions between ions and neutral molecules in ices may provide an alternative cold channel to complexity, as ion-neutral reactions are thought to have low or even no-energy barriers. Here we present a study of the kinetics and mechanisms of a potential ion-generating, acid-base reaction between NH3 and HCOOH to form the salt NH{}4+HCOO-. We observe salt growth at temperatures as low as 15 K, indicating that this reaction is feasible in cold environments. The kinetics of salt growth are best fit by a two-step model involving a slow “pre-reaction” step followed by a fast reaction step. The reaction energy barrier is determined to be 70 ± 30 K with a pre-exponential factor 1.4 ± 0.4 × 10-3 s-1. The pre-reaction rate varies under different experimental conditions and likely represents a combination of diffusion and orientation of reactant molecules. For a diffusion-limited case, the pre-reaction barrier is 770 ± 110 K with a pre-exponential factor of ˜7.6 × 10-3 s-1. Acid-base chemistry of common ice constituents is thus a potential cold pathway to generating ions in interstellar ices.

  10. Analog to Digital Conversion in Physical Measurements

    CERN Document Server

    Kapitaniak, T; 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 discuss the sources of errors that are inevitable in physical realizations of such systems and suggest methods for error reduction.

  11. 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…

  12. 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.

  13. MEMS-based flexible reflective analog modulators (FRAM) for projection displays: a technology review and scale-down study

    Science.gov (United States)

    Picard, Francis; Ilias, Samir; Asselin, Daniel; Boucher, Marc-André; Duchesne, François; Jacob, Michel; Larouche, Carl; Vachon, Carl; Niall, Keith K.; Jerominek, Hubert

    2011-02-01

    A MEMS based technology for projection display is reviewed. This technology relies on mechanically flexible and reflective microbridges made of aluminum alloy. A linear array of such micromirrors is combined with illumination and Schlieren optics to produce a pixels line. Each microbridge in the array is individually controlled using electrostatic actuation to adjust the pixels intensities. Results of the simulation, fabrication and characterization of these microdevices are presented. Activation voltages below 250 V with response times below 10 μs were obtained for 25 μm × 25 μm micromirrors. With appropriate actuation voltage waveforms, response times of 5 μs and less are achievable. A damage threshold of the mirrors above 8 kW/cm2 has been evaluated. Development of the technology has produced projector engines demonstrating this light modulation principle. The most recent of these engines is DVI compatible and displays VGA video streams at 60 Hz. Recently applications have emerged that impose more stringent requirements on the dimensions of the MEMS array and associated optical system. This triggered a scale down study to evaluate the minimum micromirror size achievable, the impact of this reduced size on the damage threshold and the achievable minimum size of the associated optical system. Preliminary results of this scale down study are reported. FRAM with active surface as small as 5 μm × 5 μm have been investigated. Simulations have shown that such micromirrors could be activated with 107 V to achieve f-number of 1.25. The damage threshold has been estimated for various FRAM sizes. Finally, design of a conceptual miniaturized projector based on 1000×1 array of 5 μm × 5 μm micromirrors is presented. The volume of this projector concept is about 12 cm3.

  14. 基于果蝇优化算法的模拟滤波器设计%Design of Analog Filter Based on Fruit Fly Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    肖正安

    2012-01-01

    基于粒子群优化算法的无源模拟滤波器优化设计方法容易陷入局部最优,收敛速度慢迭代次数多、运算量大且稳定性不够好。提出果蝇优化算法对滤波器的整个参数空间进行高效并行搜索直到获得最优的参数值,实例仿真表明,采用该方法设计的滤波器在相同的带宽准确度及阻带衰减的情况下,具有更快的运算速度及收敛性能。%The optimum design of passive simulation filters based on Particle Swarm Optimization algorithm has slow convergence velocity and may easily fall into local optimum,more iterative times,large computational complexity,and stability is not good enough.A passive analog filter optimization design method is proposed based on the Fruit Fly Optimization Algorithm(FOA),and it optimizes the circuit's parameters in the whole parameters space effectively and globally by FOA until gain the best parameters.The simulation results on the MATLAB show that our algorithm has global convergence and higher speed of optimization.

  15. Kinetics and mechanisms of the acid-base reaction between NH$_3$ and HCOOH in interstellar ice analogs

    CERN Document Server

    Bergner, Jennifer B; Rajappan, Mahesh; Fayolle, Edith C

    2016-01-01

    Interstellar complex organic molecules (COMs) are commonly observed during star formation, and are proposed to form through radical chemistry in icy grain mantles. Reactions between ions and neutral molecules in ices may provide an alternative cold channel to complexity, as ion-neutral reactions are thought to have low or even no energy barriers. Here we present a study of a the kinetics and mechanisms of a potential ion-generating acid-base reaction between NH$_{3}$ and HCOOH to form the salt NH$_{4}^{+}$HCOO$^{-}$. We observe salt growth at temperatures as low as 15K, indicating that this reaction is feasible in cold environments. The kinetics of salt growth are best fit by a two-step model involving a slow "pre-reaction" step followed by a fast reaction step. The reaction energy barrier is determined to be 70 $\\pm$ 30K with a pre-exponential factor 1.4 $\\pm$ 0.4 x 10$^{-3}$ s$^{-1}$. The pre-reaction rate varies under different experimental conditions and likely represents a combination of diffusion and or...

  16. Playing with a double-edged sword: Analogies in biochemistry

    Science.gov (United States)

    Orgill, Marykay

    Analogy pervades our everyday reasoning. No situation we encounter is exactly like a situation we have encountered previously, and our ability to learn and survive in the world is based on our ability to find similarities between past and present situations and use the knowledge we have gained from past situations to manage current situations. Analogies can be powerful teaching tools because they can make new material intelligible to students by comparing it to material that is already familiar. It is clear, though, that not all analogies are good and that not all good analogies are useful to all students. In this study, I have used textbook analysis, classroom observations, student interviews and instructor interviews to determine the role that analogies play in biochemistry learning. Analogies are an important teaching technique in biochemistry classes, being used more often in both biochemistry classes and textbooks than they are in high school chemistry classes and textbooks. Most biochemistry students like, pay particular attention to, and remember the analogies their instructors provide; and they use these analogies to understand, visualize, and recall information from class. Even though students like and use analogies, they do not understand what analogies are or the mechanism by which they improve learning. For the students, analogies are simply any teaching technique that eases understanding, visualization, or recall. Instructors, on the other hand, have a good understanding of what analogies are and of how they should be presented in class; but they do not use analogies as effectively as they should. They do not plan, explain or identify the limitations of the analogies they use in class. However, regardless of how effectively instructors present analogies in class, this study indicates that, in general, analogies are useful in promoting understanding, visualization, recall, and motivation in biochemistry students at all levels. They would be even more

  17. Orbital evidence for clay and acidic sulfate assemblages on Mars based on mineralogical analogs from Rio Tinto, Spain

    Science.gov (United States)

    Kaplan, Hannah H.; Milliken, Ralph E.; Fernández-Remolar, David; Amils, Ricardo; Robertson, Kevin; Knoll, Andrew H.

    2016-09-01

    Outcrops of hydrated minerals are widespread across the surface of Mars, with clay minerals and sulfates being commonly identified phases. Orbitally-based reflectance spectra are often used to classify these hydrated components in terms of a single mineralogy, although most surfaces likely contain multiple minerals that have the potential to record local geochemical conditions and processes. Reflectance spectra for previously identified deposits in Ius and Melas Chasma within the Valles Marineris, Mars, exhibit an enigmatic feature with two distinct absorptions between 2.2 and 2.3 μm. This spectral 'doublet' feature is proposed to result from a mixture of hydrated minerals, although the identity of the minerals has remained ambiguous. Here we demonstrate that similar spectral doublet features are observed in airborne, field, and laboratory reflectance spectra of rock and sediment samples from Rio Tinto, Spain. Combined visible-near infrared reflectance spectra and X-ray diffraction measurements of these samples reveal that the doublet feature arises from a mixture of Al-phyllosilicate (illite or muscovite) and jarosite. Analyses of orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) shows that the martian spectral equivalents are also consistent with mixtures of Al-phyllosilicates and jarosite, where the Al-phyllosilicate may also include kaolinite and/or halloysite. A case study for a region within Ius Chasma demonstrates that the relative proportions of the Al-phyllosilicate(s) and jarosite vary within one stratigraphic unit as well as between stratigraphic units. The former observation suggests that the jarosite may be a diagenetic (authigenic) product and thus indicative of local pH and redox conditions, whereas the latter observation may be consistent with variations in sediment flux and/or fluid chemistry during sediment deposition.

  18. 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.

  19. 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...

  20. The effects of analogy-based instruction on concept learning and retention in a non-formal coral reef ecology program

    Science.gov (United States)

    Brylske, Alexander Frederick

    While a number of instructional models focus on the use of analogies, research into their effectiveness in enhancing comprehension and retention of scientific concepts, particularly involving adult learners, has been limited. The purpose of this study was to determine the efficacy of using the common teaching strategy for comparing the function of a coral reef to that of a city by using an analogy-based instructional model termed FAR. The training program entitled "Marine Resource Management for Dive Professionals" (MRMDP) was developed for this study. It was targeted to professionals in the recreational scuba industry to improve their understanding of coal reef ecology, as well as orient them to pertinent marine resource management issues, and promote environmentally-responsible attitudes and diving practices among their clients. A quasi-experimental pre-post-delayed posttest control group design was used to explore five research questions and corresponding hypotheses. A 55-item researcher-developed test of coral reef ecology was administered pre and post instruction. The delayed posttest was self-administered by the subjects three weeks after course completion. Data on seven experiential variables hypothesized as research factors were collected. Ten MRMPD courses were taught in seven nations, involving 194 subjects (85 subjects in four control courses, 109 in six treatment course). The results were analyzed using multiple regression/correlation (MRC) techniques to determine: (1) any significant relationship between pretest performance and experiential variables, (2) treatment versus control group posttest performance, and (3) treatment versus control group delayed posttest performance. Within the treatment group, learning gains and retention were determined by t-test analysis. Results indicated: (1) all research factors except one were significant predictors of pretest scores in the presence of the covariate; (2) no significant difference was found between

  1. Strip silicon waveguide for code synchronization in all-optical analog-to-digital conversion based on a lumped time-delay compensation scheme

    Science.gov (United States)

    Sha, Li; Zhi-Guo, Shi; Zhe, Kang; Chong-Xiu, Yu; Jian-Ping, Wang

    2016-04-01

    An all-optical analog-to-digital converter (ADC) based on the nonlinear effect in a silicon waveguide is a promising candidate for overcoming the limitation of electronic devices and is suitable for photonic integration. In this paper, a lumped time-delay compensation scheme with 2-bit quantization resolution is proposed. A strip silicon waveguide is designed and used to compensate for the entire time-delays of the optical pulses after a soliton self-frequency shift (SSFS) module within a wavelength range of 1550 nm–1580 nm. A dispersion coefficient as high as –19800 ps/(km·nm) with ±0.5 ps/(km·nm) variation is predicted for the strip waveguide. The simulation results show that the maximum supportable sampling rate (MSSR) is 50.45 GSa/s with full width at half maximum (FWHM) variation less than 2.52 ps, along with the 2-bit effective-number-of-bit and Gray code output. Project supported by the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-15-030A1) and China Postdoctoral Science Foundation (Grant No. 2015M580978).

  2. Hardware-Algorithms Co-Design and Implementation of an Analog-to-Information Converter for Biosignals Based on Compressed Sensing.

    Science.gov (United States)

    Pareschi, Fabio; Albertini, Pierluigi; Frattini, Giovanni; Mangia, Mauro; Rovatti, Riccardo; Setti, Gianluca

    2016-02-01

    We report the design and implementation of an Analog-to-Information Converter (AIC) based on Compressed Sensing (CS). The system is realized in a CMOS 180 nm technology and targets the acquisition of bio-signals with Nyquist frequency up to 100 kHz. To maximize performance and reduce hardware complexity, we co-design hardware together with acquisition and reconstruction algorithms. The resulting AIC outperforms previously proposed solutions mainly thanks to two key features. First, we adopt a novel method to deal with saturations in the computation of CS measurements. This allows no loss in performance even when 60% of measurements saturate. Second, the system is able to adapt itself to the energy distribution of the input by exploiting the so-called rakeness to maximize the amount of information contained in the measurements. With this approach, the 16 measurement channels integrated into a single device are expected to allow the acquisition and the correct reconstruction of most biomedical signals. As a case study, measurements on real electrocardiograms (ECGs) and electromyograms (EMGs) show signals that these can be reconstructed without any noticeable degradation with a compression rate, respectively, of 8 and 10.

  3. 基于粒子群优化算法的模拟滤波器设计%Design of Analog Filter Based on Particle Swarm Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    李鹏; 马红梅; 张旭珍

    2011-01-01

    采用传统的网络综合法设计计波器存在带宽不精确及阻带衰减过小的问题,为此,提出一种基于粒子群优化算法的无源模拟滤波器优化设计方法.在网络综合法设计的滤波器电路基础上,利用粒子群优化算法对滤波器的整个参数空间进行高效并行搜索直到获得最优的参数值.实例表明,采用该方法设计的滤波器带宽更加准确,且具有更加陡峭的阻带衰减.%As for the problem of the filter's bandwidth imprecision and stop-band attenuation too small, a passive analog filter optimization design method is proposed based on the Particle Swarm Optimization(PSO) algorithm.The filter is designed by the network synthesis design method, and it optimizes the circuit's parameters in the whole parameters space effectively and globally by PSO until gain the best parameters.This method can improve the filter's bandwidth imprecision and the high stop-band suppression.

  4. Synthesis, structure-activity relationship and molecular docking of cyclohexenone based analogous as potent non-nucleoside reverse-transcriptase inhibitors

    Science.gov (United States)

    Nazar, Muhammad Faizan; Abdullah, Muhammad Imran; Badshah, Amir; Mahmood, Asif; Rana, Usman Ali; Khan, Salah Ud-Din

    2015-04-01

    The chalcones core in compounds is advantageously chosen effective synthons, which offer exciting perspectives in biological and pharmacological research. The present study reports the successful development of eight new cyclohexenone based anti-reverse transcriptase analogous using rational drug design synthesis principles. These new cyclohexenone derivatives (CDs) were synthesized by following a convenient route of Robinson annulation, and the molecular structure of these CDs were later confirmed by various analytical techniques such as 1H NMR, 13C NMR, FT-IR, UV-Vis spectroscopy and mass spectrometry. All the synthesized compounds were screened theoretically and experimentally against reverse transcriptase (RT) and found potentially active reverse transcriptase (RT) inhibitors. Of the compounds studied, the compound 2FC4 showed high interaction with RT at non-nucleoside binding site, contributing high free binding energy (ΔG -8.01 Kcal) and IC50 (0.207 μg/ml), respectively. Further results revealed that the compounds bearing more halogen groups, with additional hydrophobic character, offered superior anti-reverse transcriptase activity as compared to rest of compounds. It is anticipate that the present study would be very useful for the selection of potential reverse transcriptase inhibitors featuring inclusive pharmacological profiles.

  5. Research of AC Analog Modulated Based on LVDT/RVDT%基于LVDT/RVDT的交流模拟量解调方法研究

    Institute of Scientific and Technical Information of China (English)

    魏婷; 夏德天

    2013-01-01

    Differential Transformer Type Sensor is an electromagnetic switch unit widely used in the flight control system. Real- time and accurate fault identification and detection of the sensor output is critical. This paper researches a new method of AC analog monitored and modulated based on LVDT/RVDT Sensor, and gives the result of the verification. The method is very effective at demodulating and monitoring the sensor output, which improves the security and reliability of the system dramatically.%差动变压器式传感器是在飞行控制系统中广泛采用的电磁式变换元件,实时准确地对传感器输出进行识别和故障检测非常关键.研究了一种基于LVDT/RVDT传感器的交流模拟量的解调和监控方法,并进行测试验证,方法可有效地对传感器的输出进行解调和监控,提高系统的安全可靠性.

  6. Successive approximation-like 4-bit full-optical analog-to-digital converter based on Kerr-like nonlinear photonic crystal ring resonators

    Science.gov (United States)

    Tavousi, Alireza; Mansouri-Birjandi, Mohammad Ali; Saffari, Mehdi

    2016-09-01

    Implementing of photonic sampling and quantizing analog-to-digital converters (ADCs) enable us to extract a single binary word from optical signals without need for extra electronic assisting parts. This would enormously increase the sampling and quantizing time as well as decreasing the consumed power. To this end, based on the concept of successive approximation method, a 4-bit full-optical ADC that operates using the intensity-dependent Kerr-like nonlinearity in a two dimensional photonic crystal (2DPhC) platform is proposed. The Silicon (Si) nanocrystal is chosen because of the suitable nonlinear material characteristic. An optical limiter is used for the clamping and quantization of each successive levels that represent the ADC bits. In the proposal, an energy efficient optical ADC circuit is implemented by controlling the system parameters such as ring-to-waveguide coupling coefficients, the ring's nonlinear refractive index, and the ring's length. The performance of the ADC structure is verified by the simulation using finite difference time domain (FDTD) method.

  7. Counting-Based Digital-to-Analog Converter Scheme for Compact Column Driver with Low-Temperature Polycrystalline Silicon Thin-Film Transistors

    Science.gov (United States)

    Choi, Byong-Deok; Kim, Eui-Sik

    2008-03-01

    The concept of a counting-based digital-to-analog converter (CNT-DAC) is proposed to realize a compact column driver circuit for system-on-panel (SoP) applications. The traditional ramp DAC is very promising in the circuit-area respect, because it replaces the area-consuming read only memory (ROM)-type decoder with a counter; however, it is not widely used for display column drivers because it has several problems such as ramp signal distortion, charge sharing between column lines and pixel electrode and ramp signal generation. The CNT-DAC was inspired by the ramp DAC, which uses a counter instead of an area-consuming ROM-type decoder but can avoid the problems mentioned above by using a resistor string at each channel and a global shift register. Instead of designing an 8-bit DAC with the counting-based DAC alone, we combine the 3-bit traditional decoder-based DAC and the 5-bit CNT-DAC, because the 8-bit CNT-DAC needs a clock frequency of about 20 MHz for a portrait qVGA format (H: 240, V: 320), which is a fairy difficult requirement to meet. For a 2-in. diagonal portrait qVGA AMOLED panel, the circuit area of one channel DAC is 73×1,010 µm2 with the design rule of 2 µm and a TFT channel length of 4 µm. The total power consumption of the CNT-DAC is about 3.2 mW; the static power consumption due to the resistor string at each channel is 1.7 mW, the dynamic power consumption for driving the column lines is about 1.0 mW, and the global shift register consumes about 0.5 mW.

  8. 基于乘法器的模拟电路参数测量系统的设计与实现%Design of measurement system for the analog circuits parameters based on the multiplier

    Institute of Scientific and Technical Information of China (English)

    王永喜; 胡玫; 马胜前

    2012-01-01

    针对现有模拟电路参数测量方法复杂、测量结果精度低的缺点,构建了基于乘法器的模拟电路参数测量系统.系统中由信号源产生2路正交同频正弦模拟信号,取出一路信号通过待测模拟电路与原信号源产生的2路信号做乘法、滤波处理,产生两路直流信号,之后通过DAQ、LABVIEW采集,得到模拟电路相位差和幅度.经测量,幅度和相位的误差均小于3%,表明该系统具有电路简单、易于实现、误差小、运算速度快等优点,为模拟电路参数测量的研究提出一种可行性方案.%For the more complicated principle and the lower accuracy for the existing methods of the measurement of the analog circuits' parameters) a measurement system for the analog circuits' parameters based on the multiplier is put forward. The signal source generates two orthogonal sinusoidal analog signals with same frequency and takes a signal through the analog circuits. Then the multiplication and filtering are completed with the two DC signals. At last the phase and amplitude of the analog circuit are obtained through the DAQ and LABVIEW. The amplitude and phase errors are less than 3%. The results show that the system has many advantages of simple circuit, fast speed and high accuracy. So it is a feasible plan for the measurement system of the analog circuit parameters at present.

  9. Performance analysis of gamma ray spectrometric parameters on digital signal and analog signal processing based MCA systems using NaI(Tl) detector

    Energy Technology Data Exchange (ETDEWEB)

    Kukreti, B.M., E-mail: bharatkuk@gmail.com [Atomic Minerals Directorate for Exploration and Research, Physics Laboratory, Department of Atomic Energy, Nongmynsong, AMD Complex, Shillong, Meghalaya 793019 (India); Sharma, G.K. [Atomic Minerals Directorate for Exploration and Research, Physics Laboratory, Department of Atomic Energy, Nongmynsong, AMD Complex, Shillong, Meghalaya 793019 (India)

    2012-05-15

    Accurate and speedy estimations of ppm range uranium and thorium in the geological and rock samples are most useful towards ongoing uranium investigations and identification of favorable radioactive zones in the exploration field areas. In this study with the existing 5 in. Multiplication-Sign 4 in. NaI(Tl) detector setup, prevailing background and time constraints, an enhanced geometrical setup has been worked out to improve the minimum detection limits for primordial radioelements K{sup 40}, U{sup 238} and Th{sup 232}. This geometrical setup has been integrated with the newly introduced, digital signal processing based MCA system for the routine spectrometric analysis of low concentration rock samples. Stability performance, during the long counting hours, for digital signal processing MCA system and its predecessor NIM bin based MCA system has been monitored, using the concept of statistical process control. Monitored results, over a time span of few months, have been quantified in terms of spectrometer's parameters such as Compton striping constants and Channel sensitivities, used for evaluating primordial radio element concentrations (K{sup 40}, U{sup 238} and Th{sup 232}) in geological samples. Results indicate stable dMCA performance, with a tendency of higher relative variance, about mean, particularly for Compton stripping constants. - Highlights: Black-Right-Pointing-Pointer Geometrical enhancement for ppm range primordial radio elemental determination. Black-Right-Pointing-Pointer Experimental constraints include detector setup, background and counting time. Black-Right-Pointing-Pointer Gamma spectrometric performance monitored on digital and analog MCA systems. Black-Right-Pointing-Pointer Study indicates higher variance of Compton stripping constants on digital MCA system.

  10. 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...

  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. Pan-pathway based interaction profiling of FDA-approved nucleoside and nucleobase analogs with enzymes of the human nucleotide metabolism.

    Directory of Open Access Journals (Sweden)

    Louise Egeblad

    Full Text Available To identify interactions a nucleoside analog library (NAL consisting of 45 FDA-approved nucleoside analogs was screened against 23 enzymes of the human nucleotide metabolism using a thermal shift assay. The method was validated with deoxycytidine kinase; eight interactions known from the literature were detected and five additional interactions were revealed after the addition of ATP, the second substrate. The NAL screening gave relatively few significant hits, supporting a low rate of "off target effects." However, unexpected ligands were identified for two catabolic enzymes guanine deaminase (GDA and uridine phosphorylase 1 (UPP1. An acyclic guanosine prodrug analog, valaciclovir, was shown to stabilize GDA to the same degree as the natural substrate, guanine, with a ΔT(agg around 7°C. Aciclovir, penciclovir, ganciclovir, thioguanine and mercaptopurine were also identified as ligands for GDA. The crystal structure of GDA with valaciclovir bound in the active site was determined, revealing the binding of the long unbranched chain of valaciclovir in the active site of the enzyme. Several ligands were identified for UPP1: vidarabine, an antiviral nucleoside analog, as well as trifluridine, idoxuridine, floxuridine, zidovudine, telbivudine, fluorouracil and thioguanine caused concentration-dependent stabilization of UPP1. A kinetic study of UPP1 with vidarabine revealed that vidarabine was a mixed-type competitive inhibitor with the natural substrate uridine. The unexpected ligands identified for UPP1 and GDA imply further metabolic consequences for these nucleoside analogs, which could also serve as a starting point for future drug design.

  13. Analog computing by Brewster effect.

    Science.gov (United States)

    Youssefi, Amir; Zangeneh-Nejad, Farzad; Abdollahramezani, Sajjad; Khavasi, Amin

    2016-08-01

    Optical computing has emerged as a promising candidate for real-time and parallel continuous data processing. Motivated by recent progresses in metamaterial-based analog computing [Science343, 160 (2014)SCIEAS0036-807510.1126/science.1242818], we theoretically investigate the realization of two-dimensional complex mathematical operations using rotated configurations, recently reported in [Opt. Lett.39, 1278 (2014)OPLEDP0146-959210.1364/OL.39.001278]. Breaking the reflection symmetry, such configurations could realize both even and odd Green's functions associated with spatial operators. Based on such an appealing theory and by using the Brewster effect, we demonstrate realization of a first-order differentiator. Such an efficient wave-based computation method not only circumvents the major potential drawbacks of metamaterials, but also offers the most compact possible device compared to conventional bulky lens-based optical signal and data processors.

  14. 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 ...

  15. Analogies as categorization phenomena: Studies from scientific discourse

    Science.gov (United States)

    Atkins, Leslie Jill

    Studies on the role of analogies in science classrooms have tended to focus on analogies that come from the teacher or curriculum, and not the analogies that students generate. Such studies are derivative of an educational system that values content knowledge over scientific creativity, and derivative of a model of teaching in which the teacher's role is to convey content knowledge. This dissertation begins with the contention that science classrooms should encourage scientific thinking and one role of the teacher is to model that behavior and identify and encourage it in her students. One element of scientific thinking is analogy. This dissertation focuses on student-generated analogies in science, and offers a model for understanding these. I provide evidence that generated analogies are assertions of categorization, and the base of an analogy is the constructed prototype of an ad hoc category. Drawing from research on categorization, I argue that generated analogies are based in schemas and cognitive models. This model allows for a clear distinction between analogy and literal similarity; prior to this research analogy has been considered to exist on a spectrum of similarity, differing from literal similarity to the degree that structural relations hold but features do not. I argue for a definition in which generated analogies are an assertion of an unexpected categorization: that is, they are asserted as contradictions to an expected schema.

  16. 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...

  17. Development of analogical problem-solving skill.

    Science.gov (United States)

    Holyoak, K J; Junn, E N; Billman, D O

    1984-12-01

    3 experiments were performed to assess children's ability to solve a problem by analogy to a superficially dissimilar situation. Preschoolers and fifth and sixth graders were asked to solve a problem that allowed multiple solutions. Some subjects were first read a story that included an analogous problem and its solution. When the mapping between the relations involved in the corresponding solutions was relatively simple, and the corresponding instruments were perceptually and functionally similar, even preschoolers were able to use the analogy to derive a solution to the transfer problem (Experiment 1). Furthermore, salient similarity of the instruments was neither sufficient (Experiment 2) nor necessary (Experiment 3) for success by preschool subjects. When the story analog mapped well onto the transfer problem, 4-year-olds were often able to generate a solution that required transformation of an object with little perceptual or semantic similarity to the instrument used in the base analog (Experiment 3). The older children used analogies in a manner qualitatively similar to that observed in comparable studies with adults (Experiment 1), whereas the younger children exhibited different limitations.

  18. Design challenges of EO polymer based leaky waveguide deflector for 40 Gs/s all-optical analog-to-digital converters

    Science.gov (United States)

    Hadjloum, Massinissa; El Gibari, Mohammed; Li, Hongwu; Daryoush, Afshin S.

    2016-08-01

    Design challenges and performance optimization of an all-optical analog-to-digital converter (AOADC) is presented here. The paper addresses both microwave and optical design of a leaky waveguide optical deflector using electro-optic (E-O) polymer. The optical deflector converts magnitude variation of the applied RF voltage into variation of deflection angle out of a leaky waveguide optical beam using the linear E-O effect (Pockels effect) as part of the E-O polymer based optical waveguide. This variation of deflection angle as result of the applied RF signal is then quantized using optical windows followed by an array of high-speed photodetectors. We optimized the leakage coefficient of the leaky waveguide and its physical length to achieve the best trade-off between bandwidth and the deflected optical beam resolution, by improving the phase velocity matching between lightwave and microwave on one hand and using pre-emphasis technique to compensate for the RF signal attenuation on the other hand. In addition, for ease of access from both optical and RF perspective, a via-hole less broad bandwidth transition is designed between coplanar pads and coupled microstrip (CPW-CMS) driving electrodes. With the best reported E-O coefficient of 350 pm/V, the designed E-O deflector should allow an AOADC operating over 44 giga-samples-per-seconds with an estimated effective resolution of 6.5 bits on RF signals with Nyquist bandwidth of 22 GHz. The overall DC power consumption of all components used in this AOADC is of order of 4 W and is dominated by power consumption in the power amplifier to generate a 20 V RF voltage in 50 Ohm system. A higher sampling rate can be achieved at similar bits of resolution by interleaving a number of this elementary AOADC at the expense of a higher power consumption.

  19. Sensitive detection of p65 homodimers using red-shifted and fluorescent protein-based FRET couples.

    Directory of Open Access Journals (Sweden)

    Joachim Goedhart

    Full Text Available BACKGROUND: Fluorescence Resonance Energy Transfer (FRET between the green fluorescent protein (GFP variants CFP and YFP is widely used for the detection of protein-protein interactions. Nowadays, several monomeric red-shifted fluorescent proteins are available that potentially improve the efficiency of FRET. METHODOLOGY/PRINCIPAL FINDINGS: To allow side-by-side comparison of several fluorescent protein combinations for detection of FRET, yellow or orange fluorescent proteins were directly fused to red fluorescent proteins. FRET from yellow fluorescent proteins to red fluorescent proteins was detected by both FLIM and donor dequenching upon acceptor photobleaching, showing that mCherry and mStrawberry were more efficient acceptors than mRFP1. Circular permutated yellow fluorescent protein variants revealed that in the tandem constructs the orientation of the transition dipole moment influences the FRET efficiency. In addition, it was demonstrated that the orange fluorescent proteins mKO and mOrange are both suitable as donor for FRET studies. The most favorable orange-red FRET pair was mKO-mCherry, which was used to detect homodimerization of the NF-kappaB subunit p65 in single living cells, with a threefold higher lifetime contrast and a twofold higher FRET efficiency than for CFP-YFP. CONCLUSIONS/SIGNIFICANCE: The observed high FRET efficiency of red-shifted couples is in accordance with increased Förster radii of up to 64 A, being significantly higher than the Förster radius of the commonly used CFP-YFP pair. Thus, red-shifted FRET pairs are preferable for detecting protein-protein interactions by donor-based FRET methods in single living cells.

  20. Thin-bedded reservoir analogs in an ancient delta using terrestrial laser scanner and high-resolution ground-based hyperspectral cameras

    Science.gov (United States)

    Snyder, Casey J.; Khan, Shuhab D.; Bhattacharya, Janok P.; Glennie, Craig; Seepersad, Darsel

    2016-08-01

    Ground-based terrestrial laser scanning and hyperspectral sensors were used to image fine-scale heterogeneity in outcrops of prodeltaic heterolithic facies of Parasequence 6 of the Cretaceous Ferron Notom delta in Southern Utah. Previous work shows that Parasequence 6 is an upward coarsening fluvial-dominated, wave-influenced deltaic deposit containing heterolithic thin-bedded facies representing distal delta front and proximal prodelta environments. Primarily, the thin beds have been interpreted as turbidites, storm beds (tempestites), and hyperpycnites. These deposits represent analogs for thin-bedded unconventional pay zones that lie at the margins of conventional deltaic sandstone reservoirs. The terrestrial laser scanner was used to create a centimeter- to decimeter-scale, digital representation of the outcrops in three dimensions. Hyperspectral sensors record electromagnetic radiation reflected off the outcrops in 840 contiguous bands, which were then used to generate a spectral signature for each pixel sampled. The spectral signatures are a function of mineralogy, chemistry, surface alteration, grain-size, and cements, and were used to distinguish thin mudstones from sandstones within an interbedded succession at the base of a deltaic parasequence. Comparison between the spectral signatures recorded from the outcrop and those of reference materials, and with previous facies architecture studies, enables lithofacies to be identified and subsequently accurately mapped. Hyperspectral data are then draped over the terrestrial laser scanner model to generate a spatially-accurate detailed three-dimensional (3D) geologic map of the heterogeneity. Approximately 100 m of outcrop was imaged laterally with the hyperspectral camera and terrestrial laser scanner on the previously mapped distal delta front and prodeltaic facies of Parasequence 6. Bed thickness data, based on measurements made along depositional dip versus strike, show that bed geometries are anisotropic

  1. Thin-bedded reservoir analogs in an ancient delta using terrestrial laser scanner and high-resolution ground-based hyperspectral cameras

    Science.gov (United States)

    Snyder, Casey J.; Khan, Shuhab D.; Bhattacharya, Janok P.; Glennie, Craig; Seepersad, Darsel

    2016-08-01

    Ground-based terrestrial laser scanning and hyperspectral sensors were used to image fine-scale heterogeneity in outcrops of prodeltaic heterolithic facies of Parasequence 6 of the Cretaceous Ferron Notom delta in Southern Utah. Previous work shows that Parasequence 6 is an upward coarsening fluvial-dominated, wave-influenced deltaic deposit containing heterolithic thin-bedded facies representing distal delta front and proximal prodelta environments. Primarily, the thin beds have been interpreted as turbidites, storm beds (tempestites), and hyperpycnites. These deposits represent analogs for thin-bedded unconventional pay zones that lie at the margins of conventional deltaic sandstone reservoirs. The terrestrial laser scanner was used to create a centimeter- to decimeter-scale, digital representation of the outcrops in three dimensions. Hyperspectral sensors record electromagnetic radiation reflected off the outcrops in 840 contiguous bands, which were then used to generate a spectral signature for each pixel sampled. The spectral signatures are a function of mineralogy, chemistry, surface alteration, grain-size, and cements, and were used to distinguish thin mudstones from sandstones within an interbedded succession at the base of a deltaic parasequence. Comparison between the spectral signatures recorded from the outcrop and those of reference materials, and with previous facies architecture studies, enables lithofacies to be identified and subsequently accurately mapped. Hyperspectral data are then draped over the terrestrial laser scanner model to generate a spatially-accurate detailed three-dimensional (3D) geologic map of the heterogeneity. Approximately 100 m of outcrop was imaged laterally with the hyperspectral camera and terrestrial laser scanner on the previously mapped distal delta front and prodeltaic facies of Parasequence 6. Bed thickness data, based on measurements made along depositional dip versus strike, show that bed geometries are anisotropic

  2. 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...

  3. A putative RNA-interference-based immune system in prokaryotes: computational analysis of the predicted enzymatic machinery, functional analogies with eukaryotic RNAi, and hypothetical mechanisms of action

    Directory of Open Access Journals (Sweden)

    Wolf Yuri I

    2006-03-01

    Full Text Available Abstract Background All archaeal and many bacterial genomes contain Clustered Regularly Interspaced Short Palindrome Repeats (CRISPR and variable arrays of the CRISPR-associated (cas genes that have been previously implicated in a novel form of DNA repair on the basis of comparative analysis of their protein product sequences. However, the proximity of CRISPR and cas genes strongly suggests that they have related functions which is hard to reconcile with the repair hypothesis. Results The protein sequences of the numerous cas gene products were classified into ~25 distinct protein families; several new functional and structural predictions are described. Comparative-genomic analysis of CRISPR and cas genes leads to the hypothesis that the CRISPR-Cas system (CASS is a mechanism of defense against invading phages and plasmids that functions analogously to the eukaryotic RNA interference (RNAi systems. Specific functional analogies are drawn between several components of CASS and proteins involved in eukaryotic RNAi, including the double-stranded RNA-specific helicase-nuclease (dicer, the endonuclease cleaving target mRNAs (slicer, and the RNA-dependent RNA polymerase. However, none of the CASS components is orthologous to its apparent eukaryotic functional counterpart. It is proposed that unique inserts of CRISPR, some of which are homologous to fragments of bacteriophage and plasmid genes, function as prokaryotic siRNAs (psiRNA, by base-pairing with the target mRNAs and promoting their degradation or translation shutdown. Specific hypothetical schemes are developed for the functioning of the predicted prokaryotic siRNA system and for the formation of new CRISPR units with unique inserts encoding psiRNA conferring immunity to the respective newly encountered phages or plasmids. The unique inserts in CRISPR show virtually no similarity even between closely related bacterial strains which suggests their rapid turnover, on evolutionary scale

  4. 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

  5. Gullies on Mars: Origin by Snow and Ice Melting and Potential for Life Based on Possible Analogs from Devon Island, High Arctic

    Science.gov (United States)

    Lee, Pascal; Cockell, Charles S.; McKay, Christopher P.

    2004-01-01

    Gullies on Devon Island, High Arctic, which form by melting of transient surface ice and snow covers and offer morphologic and contextual analogs for gullies reported on Mars are reported to display enhancements in biological activity in contrast to surrounding polar desert terrain.

  6. 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

  7. 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

  8. Analog Module Placement Design Using Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper presents a novel genetic algorithm for analog module placement based on ageneralization of the two-dimensional bin packing problem. The genetic encoding and operators assure that allproblem constraints are always satisfied. Thus the potential problems of adding penalty terms to the costfunction are eliminated so that the search configuration space is drastically decreased. The dedicated costfunction is based on the special requirements of analog integrated circuits. A fractional factorial experimentwas conducted using an orthogonal array to study the algorithm parameters. A meta GA was applied todetermine the optimal parameter values. The algorithm was tested with several local benchmark circuits. Theexperimental results show that the algorithm has better performance than the simulated annealing approachwith satisfactory results comparable to manual placement. This study demonstrates the effectiveness of thegenetic algorithm in the analog module placement problem. The algorithm has been successfully used in alayout synthesis tool.

  9. 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.

  10. Sustained First Remission in an Adolescent With Hepatosplenic T-Cell Lymphoma Treated With T-Cell Leukemia Induction, Nucleoside Analog-Based Consolidation, and Early Hematopoietic Stem Cell Transplant

    OpenAIRE

    Schafer, Eric; Chen, Allen; Arceci, Robert J.

    2009-01-01

    Hepatosplenic T-cell lymphoma (HTCL) is a rare malignancy. Prognosis is poor with only a few case reports of long-term survivors. While HTCL universally involves the bone marrow, the condition has been most often treated with multimodal lymphoma specific chemotherapy. We report a durable, sustained first remission in an adolescent treated for HTCL who received induction therapy according to a high risk T-cell leukemia regimen, a nucleoside analog-based consolidation, and allogeneic transplant...

  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. 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

  13. 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...

  14. 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.

  15. Magnetic activity of seismic solar analogs

    CERN Document Server

    Salabert, D

    2016-01-01

    We present our latest results on the solar-stellar connection by studying 18 solar analogs that we identified among the Kepler seismic sample (Salabert et al., 2016a). We measured their magnetic activity properties using observations collected by the Kepler satellite and the ground-based, high-resolution Hermes spectrograph. The photospheric (Sph) and chromospheric (S) magnetic activity proxies of these seismic solar analogs are compared in relation to solar activity. We show that the activity of the Sun is actually comparable to the activity of the seismic solar analogs. Furthermore, we report on the discovery of temporal variability in the acoustic frequencies of the young (1 Gyr-old) solar analog KIC10644253 with a modulation of about 1.5 years, which agrees with the derived photospheric activity (Salabert et al., 2016b). It could actually be the signature of the short-period modulation, or quasi-biennal oscillation, of its magnetic activity as observed in the Sun and the 1-Gyr-old solar analog HD30495. In...

  16. 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.

  17. 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

  18. 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.

  19. Generating Analog IC Layouts with LAYGEN II

    CERN Document Server

    Martins, Ricardo M F; Horta, Nuno C G

    2013-01-01

    This book presents an innovative methodology for the automatic generation of analog integrated circuits (ICs) layout, based on template descriptions and on evolutionary computational techniques. A design automation tool, LAYGEN II, was implemented to validate the proposed approach giving special emphasis to reusability of expert design knowledge and to efficiency on retargeting operations.

  20. 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)

  1. 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.

  2. FET comparator detects analog signal levels without loading analog device

    Science.gov (United States)

    Wallace, H. L.

    1966-01-01

    FET comparator circuit detects discrete analog computer output levels without excessively loading the output amplifier of the computer. An FET common source amplifier is coupled by a differential amplifier to a bistable transistor flip-flop. This circuit provides a digital output for analog voltages above or below a predetermined level.

  3. [Analogies and analogy research in technical biology and bionics].

    Science.gov (United States)

    Nachtigall, Werner

    2010-01-01

    The procedural approaches of Technical Biology and Bionics are characterized, and analogy research is identified as their common basis. The actual creative aspect in bionical research lies in recognizing and exploiting technically oriented analogies underlying a specific biological prototype to indicate a specific technical application.

  4. 基于跨导运算放大器的可重构模拟电路及应用设计%Reconfigurable Analog Circuit and Application Design Based on Operational Transconductance Amplifier

    Institute of Scientific and Technical Information of China (English)

    马伟伟; 王友仁; 石玉; 崔江

    2009-01-01

    常规的粗粒度可重构模拟电路灵活性不高,而且可重构模拟单元(CAB)结构较为复杂.针对此类问题,该文改进并设计了一种新的基于OTA的可重构模拟电路.该电路设计方案降低了CAB的复杂度,提高了CAB的使用效率.该文方法的有效性通过3个模拟设计实例(二阶低通滤波器、高通滤波器和三阶巴特沃思低通滤波器)的设计加以验证.实验结果表明,所提出的方法正确有效,可以较好地兼顾CAB资源与所要求功能的平衡.%The conventional coarse-grained reconfigurable analog circuits have bad flexibility, and the reConfigurable Analog Block (CAB) structure is complicated. In order to solve such problems, a new OTA-based reconfigurable analog circuit is presented in this paper. In this circuit scheme, the complexity of CAB is reduced and the CAB utilization rate is increased. To verify the effectiveness, three examples of analog circuit design (a second-order low pass filter, a second-order high pass filter and a low-pass third-order Butterworth filter) are presented. The experimental results indicate that the proposed circuits is effective and feasible, which make a better balance between circuit resources and functions.

  5. Using Analogies to Prevent Misconceptions about Chemical Equilibrium

    Science.gov (United States)

    Sahin Pekmez, Esin

    2010-01-01

    The main purpose of this study was to find the effectiveness of using analogies to prevent misconceptions about chemical equilibrium. Nineteen analogies, which were based on dynamic aspects of chemical equilibrium and application of Le Chatelier's principle, were developed. The participations of this study consisted of 11th grade students (n: 151)…

  6. 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.

  7. 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…

  8. A digital-analog hybrid random numb er generator based on memristor%基于忆阻器的数模混合随机数发生器∗

    Institute of Scientific and Technical Information of China (English)

    袁泽世; 李洪涛; 朱晓华

    2015-01-01

    integral system. In this paper, a novel digital-analog hybrid chaotic system with only one analog device is constructed for the pro-duction of RN. The chosen analog device is a generalized memristor consisting of a diode bridge and a parallel RC filter. Memristor is the fourth fundamental electronic component which has provoked extensive researches since the suc-cessful realization by Stan Williams’s group at HP Labs in 2008. The paper is arranged as follows. Firstly, a generalized memristor realized by a memristive circuit is introduced and its basic properties are given. Then the block diagram of the digital-analog hybrid system based on a single memristor feedback is depicted, and the mathematical model of the system is derived from the block diagram. Thirdly, the simple Logistic map is applied to the hybrid model and its dynamic behaviors are simulated and compared with those from the ideal Logistic before a more complex two-way coupled saw tooth map is applied to the same simulation, verifying the effectiveness of the proposed hybrid system. Finally, the complex coupled map is applied to the practical circuit producing RN which passes the NIST test suite smoothly. The hybrid system has the following advantages: firstly, the introduction of the analog memristor is able to over-come the dynamical degradation in a digital system, avoiding the limited word length effect essentially. Secondly, the least analog device alleviates the sensibility to parameters and the restriction on bit rate in analog systems, ensuring that the hybrid system is robust. Thirdly, the system structure can be easily integrated into a relevant system. By designing the circuits of the system, the field programmable logic gate array of digital part can be used to realize chaotic map while the single memristor acts as a feedback to the digital part. The experimental results show that the novel hybrid system is insensitive to the variations of circuit parameters and the produced RN is of great

  9. An experimental distribution of analog and digital information in a hybrid wireless visible light communication system based on acousto-optic modulation and sinusoidal gratings

    Science.gov (United States)

    Gómez Colín, R.; García Juárez, A.; Zaldívar Huerta, I. E.; Marquina, A. Vera; García Delgado, L. A.; Leal Cruz, A. L.; Gómez Fuentes, R.

    2016-03-01

    In this paper we propose a photonic architecture as an alternative tool to distribute point to multipoint analog and digital information over a hybrid wireless visible optical communication system. The experimental set-up is composed of a red laser pointer, an acousto-optic modulator, a sinusoidal grating and a photo-detector array. By using a simple and variable interferometric system, diffraction gratings with different spatial frequencies are generated and recorded on a photoemulsion which is composed of vanilla with dichromate gelatin. Analog video and digital information are first transmitted and recovered over a wireless communication system using a microwave carrier at 4.52 GHz which is generated by distributed feedback lasers operating in the low laser threshold current region. Separately, the recovered video information and digital data are combined with a radio frequency signal of 80 MHz, obtaining a subcarrier of information that is imposed on the optical carrier of the pointer laser using an acousto-optic modulator which is operated with an angle of incident light that satisfies the Bragg condition. The modulated optical carrier is sent to a sinusoidal grating, the diffraction pattern is photo-detected using an array of PIN photo-detectors. The use of sinusoidal gratings with acousto-optic modulators allows that number of channels to be increased when both components are placed in cascade.

  10. Implementation of a 10.24 GS/s 12-bit Optoelectronics Analog-to- Digital Converter Based on a Polyphase Demultiplexing Architecture

    Directory of Open Access Journals (Sweden)

    C. Villa-Angulo

    2013-01-01

    Full Text Available In this paper we present the practical implementation of a high-speed polyphase sampling and demultiplexingarchitecture for optoelectronics analog-to-digital converters (OADCs. The architecture consists of a one-stage divideby-eight decimator circuit where optically-triggered samplers are cascaded to sample an analog input signal, anddemultiplex different phases of the sampled signal to yield low data rate for electronic quantization. Electrical-in toelectrical-out data format is maintained through the sampling, demultiplexing and quantization processes of thearchitecture thereby avoiding the need for electrical-to-optical and optical-to-electrical signal conversions. Weexperimentally demonstrate a 10.24 giga samples per second (GS/s, 12-bit resolution OADC system comprising theoptically-triggered sampling circuits integrated with commercial electronic quantizers. Measurements performed on theOADC yielded an effective bit resolution (ENOB of 10.3 bits, spurious free dynamic range (SFDR of -32 dB andsignal-to-noise and distortion ratio (SNDR of 63.7 dB.

  11. An experimental distribution of analog and digital information in a hybrid wireless visible light communication system based on acousto-optic modulation and sinusoidal gratings

    International Nuclear Information System (INIS)

    In this paper we propose a photonic architecture as an alternative tool to distribute point to multipoint analog and digital information over a hybrid wireless visible optical communication system. The experimental set-up is composed of a red laser pointer, an acousto-optic modulator, a sinusoidal grating and a photo-detector array. By using a simple and variable interferometric system, diffraction gratings with different spatial frequencies are generated and recorded on a photoemulsion which is composed of vanilla with dichromate gelatin. Analog video and digital information are first transmitted and recovered over a wireless communication system using a microwave carrier at 4.52 GHz which is generated by distributed feedback lasers operating in the low laser threshold current region. Separately, the recovered video information and digital data are combined with a radio frequency signal of 80 MHz, obtaining a subcarrier of information that is imposed on the optical carrier of the pointer laser using an acousto-optic modulator which is operated with an angle of incident light that satisfies the Bragg condition. The modulated optical carrier is sent to a sinusoidal grating, the diffraction pattern is photo-detected using an array of PIN photo-detectors. The use of sinusoidal gratings with acousto-optic modulators allows that number of channels to be increased when both components are placed in cascade. (paper)

  12. A Low-cost 4 Bit, 10 Giga-samples-per-second Analog-to-digital Converter Printed Circuit Board Assembly for FPGA-based Backends

    Science.gov (United States)

    Jiang, Homin; Yu, Chen-Yu; Kubo, Derek; Chen, Ming-Tang; Guzzino, Kim

    2016-11-01

    In this study, a 4 bit, 10 giga-samples-per-second analog-to-digital converter (ADC) printed circuit board assembly (PCBA) was designed, manufactured, and characterized for digitizing radio telescopes. For this purpose, an Adsantec ANST7120A-KMA flash ADC chip was used. Together with the field-programmable gate array platform, developed by the Collaboration for Astronomy Signal Processing and Electronics Research community, the PCBA enables data acquisition with a wide bandwidth and simplifies the intermediate frequency section. In the current version, the PCBA and the chip exhibit an analog bandwidth of 10 GHz (3 dB loss) and 20 GHz, respectively, which facilitates second, third, and even fourth Nyquist sampling. The following average performance parameters were obtained from the first and second Nyquist zones of the three boards: a spurious-free dynamic range of 31.35/30.45 dB, a signal-to-noise and distortion ratio of 22.95/21.83 dB, and an effective number of bits of 3.65/3.43, respectively.

  13. 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...

  14. 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 ...

  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. Sulfonimidamide analogs of oncolytic sulfonylureas.

    Science.gov (United States)

    Toth, J E; Grindey, G B; Ehlhardt, W J; Ray, J E; Boder, G B; Bewley, J R; Klingerman, K K; Gates, S B; Rinzel, S M; Schultz, R M; Weir, L C; Worzalla, J F

    1997-03-14

    A series of sulfonimidamide analogs of the oncolytic diarylsulfonylureas was synthesized and evaluated for (1) in vitro cytotoxicity against CEM cells, (2) in vivo antitumor activity against subaxillary implanted 6C3HED lymphosarcoma, and (3) metabolic breakdown to the o-sulfate of p-chloroaniline. The separated enantiomers of one sulfonimidamide analog displayed very different activities in the in vivo screening model. In general, several analogs demonstrated excellent growth inhibitory activity in the 6C3HED model when dosed orally or intraperitoneally. A correlative structure-activity relationship to the oncolytic sulfonylureas was not apparent.

  17. How strategists really think. Tapping the power of analogy.

    Science.gov (United States)

    Gavetti, Giovanni; Rivkin, Jan W

    2005-04-01

    Leaders tend to be so immersed in the specifics of strategy that they rarely stop to think how much of their reasoning is done by analogy. As a result, they miss useful insights that psychologists and other scientists have generated about analogies' pitfalls. Managers who pay attention to their own analogical thinking will make better strategic decisions and fewer mistakes. Charles Lazarus was inspired by the supermarket when he founded Toys R Us; Intel promoted its low-end chips to avoid becoming like U.S. Steel; and Circuit City created CarMax because it saw the used-car market as analogous to the consumer-electronics market. Each example displays the core elements of analogical reasoning: a novel problem or a new opportunity, a specific prior context that managers deem to be similar in its essentials, and a solution that managers can transfer from its original setting to the new one. Analogical reasoning is a powerful tool for sparking breakthrough ideas. But dangers arise when analogies are built on surface similarities (headlong diversification based on loose analogies played a role in Enron's collapse, for instance). Psychologists have discovered that it's all too easy to overlook the superficiality of analogies. The situation is further complicated by people's tendency to hang on to beliefs even after contrary evidence comes along (a phenomenon known as anchoring) and their tendency to seek only the data that confirm their beliefs (an effect known as the confirmation bias). Four straightforward steps can improve a management team's odds of using an analogy well: Recognize the analogy and identify its purpose; thoroughly understand its source; determine whether the resemblance is more than superficial; and decide whether the original strategy, properly translated, will work in the target industry. PMID:15807039

  18. 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 ...

  19. Parabolic flight as a spaceflight analog.

    Science.gov (United States)

    Shelhamer, Mark

    2016-06-15

    Ground-based analog facilities have had wide use in mimicking some of the features of spaceflight in a more-controlled and less-expensive manner. One such analog is parabolic flight, in which an aircraft flies repeated parabolic trajectories that provide short-duration periods of free fall (0 g) alternating with high-g pullout or recovery phases. Parabolic flight is unique in being able to provide true 0 g in a ground-based facility. Accordingly, it lends itself well to the investigation of specific areas of human spaceflight that can benefit from this capability, which predominantly includes neurovestibular effects, but also others such as human factors, locomotion, and medical procedures. Applications to research in artificial gravity and to effects likely to occur in upcoming commercial suborbital flights are also possible.

  20. 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...

  1. 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...

  2. Resistance to somatostatin analogs in acromegaly: an evolving concept?

    Science.gov (United States)

    Gola, M; Bonadonna, S; Mazziotti, G; Amato, G; Giustina, A

    2006-01-01

    The aim of acromegaly treatment is to control the disease by suppressing GH hyperactivity and reducing the size or impeding the growth of the pituitary GH secreting mass. Over recent years, many studies have emphasized the role of SS analogs in the treatment of acromegaly. In fact, SS analogs have been demonstrated to be an effective tool not only in the control of GH hypersecretion but also more recently in the control of tumor growth, in a relevant number of acromegalic patients both as primary or adjunctive treatment. In this context, the therapeutic failure of medical treatment with SS analogs needs to be accurately defined particularly when they are used as primary treatment but also when they are given to patients previously operated upon, since other effective therapeutic options are nowadays available. Current definition of resistance to SS analogs is based on their efficacy to control GH and IGF-I. However, due to the emerging significance of the shrinkage effect of SS analogs on pituitary adenomas as well as to the apparent dissociation between this effect and the biochemical effects of treatment with these analogs, an evolution in the concept of SS resistance is likely to be occurring. In this review, we will discuss the biological basis of the discordance between biochemical and volumetric effects of SS analogs, and we will address the intriguing clinical and therapeutic aspects related to a possible redefinition of the resistance to SS analogs. PMID:16553040

  3. The Effect of Mini-PEG-Based Spacer Length on Binding and Pharmacokinetic Properties of a 68Ga-Labeled NOTA-Conjugated Antagonistic Analog of Bombesin

    Directory of Open Access Journals (Sweden)

    Zohreh Varasteh

    2014-07-01

    Full Text Available The overexpression of gastrin-releasing peptide receptor (GRPR in cancer can be used for peptide-receptor mediated radionuclide imaging and therapy. We have previously shown that an antagonist analog of bombesin RM26 conjugated to 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA via a diethyleneglycol (PEG2 spacer (NOTA-PEG2-RM26 and labeled with 68Ga can be used for imaging of GRPR-expressing tumors. In this study, we evaluated if a variation of mini-PEG spacer length can be used for optimization of targeting properties of the NOTA-conjugated RM26. A series of analogs with different PEG-length (n = 2, 3, 4, 6 was synthesized, radiolabeled and evaluated in vitro and in vivo. The IC50 values of natGa-NOTA-PEGn-RM26 (n = 2, 3, 4, 6 were 3.1 ± 0.2, 3.9 ± 0.3, 5.4 ± 0.4 and 5.8 ± 0.3 nM, respectively. In normal mice all conjugates demonstrated similar biodistribution pattern, however 68Ga-NOTA-PEG3-RM26 showed lower liver uptake. Biodistribution of 68Ga-NOTA-PEG3-RM26 was evaluated in nude mice bearing PC-3 (prostate cancer and BT-474 (breast cancer xenografts. High uptake in tumors (4.6 ± 0.6%ID/g and 2.8 ± 0.4%ID/g for PC-3 and BT-474 xenografts, respectively and high tumor-to-background ratios (tumor/blood of 44 ± 12 and 42 ± 5 for PC-3 and BT-474 xenografts, respectively were found already at 2 h p.i. of 68Ga-NOTA-PEG3-RM26. Results of this study suggest that variation in the length of the PEG spacer can be used for optimization of targeting properties of peptide-chelator conjugates. However, the influence of the mini-PEG length on biodistribution is minor when di-, tri-, tetra- and hexaethylene glycol are compared.

  4. Classical Analog of Quantum Interference Effects in Microstrip System Based on Phase-Coupling Mechanism%微带线系统中基于相位耦合机制的类量子干涉行为

    Institute of Scientific and Technical Information of China (English)

    王治国; 高童童; 谭为

    2012-01-01

    基于对相位耦合机制的旁路微带线结构中类量子干涉行为的理论研究.通过格林函数框架下的界面响应理论,解析、计算了该结构中的波传播特性,得出了3种具有代表性的类量子干涉现象:两个谐振结构之间的干涉增强导致的反射加强,两者的干涉相消导致的类电磁诱导透明行为,以及谐振结构与波导结构的干涉导致的类Fano共振现象.引入相位耦合机制为结构中的波传播特性提供了更加丰富的调控手段,有望设计成新型调控器件.%The paper theoretically demonstrates the classical analog of quantum interference effects in microstrip system containing phase-coupled side-branch components. By employing the Interface Response Theory which is in the framework of Green's function method, the propagation properties of the system are analytically obtained, and three typical phenomena are presented. The first is the enhancement of reflection resulting from the constructive interference between two resonances; the second is the analogous electromag-netically induced transparency effect due to the destructive interference; and the third is the analogous Fano resonance based on the interference between resonances and propagating waves. The introduction of phase-coupling mechanism provides us great flexibility in manipulating wave propagations, which may pave a way to novel devices.

  5. Frequency Transformation of Analog Filter Based on MATLAB%基于MATLAB的模拟滤波器的频率变换

    Institute of Scientific and Technical Information of China (English)

    赵普渡

    2012-01-01

    Under normal circumstances, filter design is only focused on lowpass filter, while by means of the frequency conversion technology the integration of high - pass, band - pass filter can work out any filter circuit except the low - pass. The use of MATLAB software greatly simplifies the actual calculation workload and verifies by simulation whether it can reach the expected design specifications. The article describes the frequency conversion of the analog filter and makes a simulative study respectively in the application of the software.%一般情况下,设计滤波器只着重研究低通滤波器,而高通、带通滤波器的综合要借助频率变换技术来实现低通以外各种滤波电路。MATLAB应用软件的使用大大简化了实际的计算工作量,并可以通过仿真来验证是否可以达到预期的设计指标。文章介绍了模拟滤波器的频率转换并运用软件实现了相应的仿真研究。

  6. 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.

  7. Determination of structure-activity relationships between fentanyl analogs and human μ-opioid receptors based on active binding site models

    Institute of Scientific and Technical Information of China (English)

    Ming Liu; Xiaoli Liu; Ping Wan; Qiangsan Wu; Wenxiang Hu

    2011-01-01

    Fentanyl is a potent and widely used clinical narcotic analgesic, as well as a highly selective μ-opioid agonist. The present study established a homologous model of the human μ-opioid receptor; an intercomparison of three types of μ-opioid receptor protein sequence homologous rates was made. The secondary receptor structure was predicted, the model reliability was assessed and verified using the Ramachandran plot and ProTab analysis. The predictive ability of the CoMFA model was further validated using an external test set. Using the Surflex-Dock program, a series of fentanyl analog molecules were docked to the receptor, the calculation results from Biopolymer/SiteID showed that the receptor had a deep binding area situated in the extracellular side of the transmembrane domains (TM) among TM3, TM5, TM6, and TM7. Results suggested that there might be 5 active areas in the receptor. The important residues were Asp147, Tyr148, and Tyr149 in TM3, Trp293, and His297 in TM6, and Trp318, His319, Ile322, and Tyr326 in TM7, which were located at the 5 active areas. The best fentanyl docking orientation position was the piperidine ring, which was nearly perpendicular to the membrane surface in the 7 TM domains. Molecular dynamic simulations were applied to evaluate potential relationships between ligand conformation and fentanyl substitution.

  8. Digital-Analog Converter Based on Pulse Width Modulated Force Feedback in Sigma-Delta Accelerometer%Σ△微加速度计中基于脉宽调制的力反馈回路

    Institute of Scientific and Technical Information of China (English)

    陶呈瑶; 邓康发

    2013-01-01

    针对微加速度计接口电路的Sigma-Delta(撞驻)数字反馈系统,提出了一种基于脉宽调制( PWM)的力反馈回路:利用模拟低通滤波器将PWM波解调成模拟输出信号,具有滤波和数模转换功能。首先建立微加速度计撞驻闭环反馈系统的Simulink模型并进行了系统级仿真。之后采用Filter Solutions滤波器设计软件确定三阶低通巴特沃斯滤波器,并采用Pspice仿真软件进行电路级仿真。最后将制作的PCB版电路进行测试:PWM波通过力反馈回路能还原成高保真度的模拟信号,输出信号和输入信号的频率相对误差小于0.36%,等效DAC分辨率为8 bit。试验表明,此方案结构简单、成本低,能以较低电路复杂度实现高精度的模拟信号输出。%Aiming at the Sigma-Delta(Σ△) digital force feedback system in Mcro-accelerometer interface circuit,this paper presents a force feedback loop based on Pulse Width Modulator(PWM). The PWM wave can be translated into output analog singal using low pass filter,indicating that this circuit has a dual function of filter and digital to analog conversion( DAC) . Firstly,Σ△closed loop feedback system was simulated in Simulink model for system level simulation,then Filter Solutions software was used for designing three-order Butterworth low pass filter,and Pspice software was adopted for circuit level simulation. Finally electronic circuit was made by PCB and then tested. Through the force back loop,the wave can be successfully translate to undistorted analog signal,and the maximun relative error is below 0. 36% compared to the input signal,the equivalent DAC resolution is 8 bit. This experiment shows that this method has the advantages of simple structure,low cost,and easy way to produce high precise output analog signal.

  9. 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

  10. A new program on digitizing analog seismograms

    Science.gov (United States)

    Wang, Maofa; Jiang, Qigang; Liu, Qingjie; Huang, Meng

    2016-08-01

    Historical seismograms contain a great variety of useful information which can be used in the study of earthquakes. It is necessary for researchers to digitize analog records and extract the information just as modern computing analysis requires. Firstly, an algorithm based on color scene filed method is presented in order to digitize analog seismograms. Secondly, an interactive software program using C# has been developed to digitize seismogram traces from raster files quickly and accurately. The program can deal with gray-scale images stored in a suitable file format and it offers two different methods: manual digitization and automatic digitization. The test result of the program shows that the methods presented in this paper can lead to good performance.

  11. 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

  12. 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.

  13. 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.

  14. Conformation driven complexation of two analogous benzimidazole based tripodal ligands with Ag(I) resulting in a trigonal prism and a coordination polymer

    Indian Academy of Sciences (India)

    Suman Bhattacharya; Binoy K Saha

    2016-02-01

    Two analogous tripodal ligands, namely, 1,3,5-tris(benzimidazol-1-ylmethyl)-2,4,6-triethylbenzene (1-Et) and 1,3,5-tris(benzimidazol-1-ylmethyl)-2,4,6-trimethoxybenzene (1-OMe) have been used for complexation with silver(I) tetrafluoroborate. A trinuclear Ag(I) salt, formulated as $\\mathbf{[Ag_3(1-Et)_2]^{3+}(BF_4){}^{−}_{3}\\bullet 7CH_3CN\\bullet yH_2O}$ was formed in the complexation reaction of 1-Et with silver(I) tetrafluoroborate, which consists of a trigonal prismatic cation formed by three bicoordinated Ag(I) coordinated with two 1-Et ligands. In case of the 1-OMe ligand, however, a one dimensional ladder, formulated as $\\mathbf{[(Ag(1-OMe)OH_2)^{+}(BF_4)^{−}\\bullet MeOH]_{\\infty}}$ was obtained which is constituted of a tetracoordinated Ag(I) center in a distorted tetrahedral environment. The crystal structures of the ligand hydrates namely $\\mathbf{1-Et\\bullet H_2O}$ and $\\mathbf{1-OMe\\bullet 3.6H_2O}$ have been discussed along with the structure of methanol solvate-hydrate of 1-Et. The imidazole rings of the Bim groups in 1-Et in the crystal structures of the ligand as well as in its coordination complex with the Ag(I) are pointed inward with respect to the central ring, whereas it is pointed outwards in the crystal structures of 1-OMe as well as its Ag(I) complex.

  15. 基于CDIO模式下的模拟电子技术教学研究%Research on analog electronic technology teaching based on CDIO model

    Institute of Scientific and Technical Information of China (English)

    房俊杰; 张桂凤; 赵承滨

    2014-01-01

    Closely contacting with students and teachers,focusing on ability education,according to the characteristics of the analog electronic technology,adopt the CDIO mode,it can expand the knowledge level,improve the operation ability and innovative thinking deeply.Through the theory with practice,teach them according to their aptitude,and increasing the chance of students physical operation to meet the needs of engineering.Through the advantage of the characteristics of different grade students,complementing each other,they jointly complete the task.In this way, it can improve the students' practical ability,and improve the ability of team work,make the students' overall ability to get promoted.%紧密联系教师与学生,以能力教育为重点,针对模拟电子技术的特点,采用CDIO模式,扩展知识层面,提高操作能力,深入创新思想。理论联系实际,因材施教,增加学生操作实物机会,并结合工程需要,利用不同年级学生的特点,取长补短,共同完成任务。通过这种方式既提高了学生的动手能力,又提高了团队协作能力,使学生的整体能力得到提升。

  16. 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 ...

  17. Test Wiseness and Analogy Test Performance

    Science.gov (United States)

    Moore, James C.

    1971-01-01

    Subjects received self instruction on how to approach analogy questions. Instruction was directed toward knowledge of the general format of analogy questions in standarized tests and the 15 types of relationships commonly asked for in analogy questions. An analogies post-test showed a significant effect for the group. (Author)

  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. 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 ...

  20. 运用类比启发探究式数学归纳法的教学研究%Teaching and Research of Mathematical Induction Based on Analogy Inspired Inquiry

    Institute of Scientific and Technical Information of China (English)

    郭敏

    2012-01-01

    The mathematical induction is an important mathematical proof,occupies an important position in the high school mathematics content,which reflects the mathematical thinking of students to further study mathematics,and understand mathematical thinking is essential.In this paper,the analogy inspired inquiry-based analysis of mathematical induction.%数学归纳法是一种重要的数学证明方法,在高中数学内容中占有重要的地位,其中体现的数学思想方法对学生进一步学习数学、领悟数学思想至关重要。本文利用类比启发探究式进行数学归纳法的分析研究。

  1. 49205 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1997-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course 49205 Analog and Digital Filters...

  2. 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.

  3. 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.

  4. 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

  5. Analogy between Thermodynamics and Mechanics.

    Science.gov (United States)

    Peterson, Mark A.

    1979-01-01

    Establishes and illustrates a formal analogy between the motion of a particle and the "motion" of the equilibrium state of a homogeneous system in a quasistatic process. The purpose is to show that there is a much larger set of natural coordinate transformations in thermodynamics. (GA)

  6. 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

  7. Study on Single-phase VIENNA Rectifier based on Simple Analog Control Scheme%基于简单模拟控制的单相VIENNA整流器研究

    Institute of Scientific and Technical Information of China (English)

    江涛; 毛鹏; 谢少军

    2009-01-01

    Aimed at single-phase VIENNA rectifier,a new simple analog control scheme is proposed.The scheme is based on one-circle control is simple,and can improve the stability of the controller without the S-R flip-flop.Only using one volt-age loop,the stabilization and balance of the output voltage and higher input power factor are realized.The principle of the realization of high unity power factor of the single-phase VIENNA rectifier based on simple analog control is analyzed.Some control equations and implementation of the scheme are presented.The principle of capacitors voltage balance is illustrated. The validity of the theoretical analysis and feasibility of the control scheme are proved by simulation and experiment.%针对单相单开关三电平(VIENNA)整流器提出了新的简单模拟控制方案.该方案以单周期控制技术为基础,结构简单,无需R-S触发器.在实现较高输入功率因数的同时,仅用单个电压环即可实现直流侧电压的稳定以及电容电压的均衡.介绍了采用简单模拟控制方案的单相VIENNA整流器实现高功率因数运行的工作原理,给出了控制方程和具体实现方案.阐述了变换器实现电容电压均衡的工作机理.仿真和实验证明了理论分析的正确性,以及控制方案的可行性.

  8. 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

    reviewed. DISCUSSION. A true ground-based flight analog for sensorimotor function is not feasible. A combination of flight analogs; however, can be used to selectively mimic different aspects of the spaceflight-induced sensorimotor performance decrements.

  9. 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.

  10. 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

  11. 基于0.11μm CMOS工艺的时域SAR模数转换器%Time Domain SAR Analog-to-Digital Conversion Based on 0.11μm CMOS Process

    Institute of Scientific and Technical Information of China (English)

    李莎

    2016-01-01

    In order to avoid the linear degradation caused by multiple delay lines,an approximation register analog-to-digital converter based on the time domain comparator is proposed. By using a single delay line to implement the time domain comparator of the mode converter,the delay line includes the numerical control delay line and the volt⁃age controlled delay line. The proposed analog-to-digital converter has 8 effective bits,with the use of an area of 0.11μm CMOS process to achieve 0.128 mm2. Experimental results show that the power consumption of the time do⁃main SAR ADC is 1.8 μW when the power supply voltage is 0.6 V.%为避免因多种延迟线之间不匹配造成的线性退化,提出了一种基于时域比较器的逐次逼近型SAR(Successive Approximation Register)模数转换器。通过使用单个延迟线来实现该模转换器的时域比较器,此延迟线包括数控延迟线和压控延迟线。提出的模数转换器具有8个有效位,使用面积为0.128 mm2的0.11μm CMOS工艺实现。实验结果表明,当工作电源电压低至0.6 V时,提出的时域SAR模数转换器功耗为1.8μW。

  12. Analog Circuit Fault Classification Based on All Samples Support Vector Data Description%全样本支持矢量数据描述模拟电路故障分类

    Institute of Scientific and Technical Information of China (English)

    李传亮; 王友仁; 罗慧; 崔江

    2012-01-01

    传统支持矢量数据描述(Support Vector Domain Description,SVDD)分类规则完全忽略非支持矢量所包含的样本信息,为此本文提出了一种全样本SVDD分类方法,并应用到模拟电路故障诊断中。该方法以贝叶斯理论和分类器模糊融合思想为基础,利用核密度估计得到的类条件概率密度和先验概率的乘积对SVDD相对距离进行加权。实验结果表明,与SVM扩展的多分类器相比,本文方法能够有效提高模拟电路故障诊断的准确率,且全样本SVDD分类模型对参数变化具有较强的稳健性。%The information included in the non-support vectors is completely ignored for the classification rules of the classical support vector domain description(SVDD),so an all samples SVDD method is proposed in this paper,and it is applied to analog circuit fault diagnosis.The new method is based on Bayes theory and classifier fuzzy fusion strategy.The relative distances of this classifier are weighted by the product of prior probability value and conditional probability value,which are calculated by kernel density estimation.The simulation results show that,compared with the multi-class SVM classifiers,the introduced method improves the fault diagnosis accuracy of analog circuit.Moreover,the all samples SVDD classifier is robust against the changes of classifier parameter.

  13. Integrated Analogic Filter Tuning System Design

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2016-06-01

    Full Text Available Parameters of integrated analog filters can vary due to temperatu-re change, IC process variation and therefore they should have dedicated tuning circuits that compensate these imperfections. A method is proposed that speeds up switched resistor bank design while taking into account the required tuning range and step size. A novel counter structure is used in the tuning circuit that is ba-sed on successive approximation approach. The proposed swit-ched resistor design method and tuning circuit are designed in 0.18 μm CMOS technology and verified. Results are compared to existing tuning circuit designs.

  14. A direct method for the identification of the permeability field based on flux assimilation by a discrete analog of Darcy's law

    NARCIS (Netherlands)

    Zijl, W.

    2004-01-01

    Inverse models to determine the permeability are generally based on existing forward models for the pressure. The permeabilities are adapted in such a way that the calculated pressures match the specified pressures in a number of points. To assimilate a priori knowledge about the flux, we introduce

  15. 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

  16. 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.

  17. 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

  18. Reasoning by analogy requires the left frontal pole: lesion-deficit mapping and clinical implications.

    Science.gov (United States)

    Urbanski, Marika; Bréchemier, Marie-Laure; Garcin, Béatrice; Bendetowicz, David; Thiebaut de Schotten, Michel; Foulon, Chris; Rosso, Charlotte; Clarençon, Frédéric; Dupont, Sophie; Pradat-Diehl, Pascale; Labeyrie, Marc-Antoine; Levy, Richard; Volle, Emmanuelle

    2016-06-01

    SEE BURGESS DOI101093/BRAIN/AWW092 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE  : Analogical reasoning is at the core of the generalization and abstraction processes that enable concept formation and creativity. The impact of neurological diseases on analogical reasoning is poorly known, despite its importance in everyday life and in society. Neuroimaging studies of healthy subjects and the few studies that have been performed on patients have highlighted the importance of the prefrontal cortex in analogical reasoning. However, the critical cerebral bases for analogical reasoning deficits remain elusive. In the current study, we examined analogical reasoning abilities in 27 patients with focal damage in the frontal lobes and performed voxel-based lesion-behaviour mapping and tractography analyses to investigate the structures critical for analogical reasoning. The findings revealed that damage to the left rostrolateral prefrontal region (or some of its long-range connections) specifically impaired the ability to reason by analogies. A short version of the analogy task predicted the existence of a left rostrolateral prefrontal lesion with good accuracy. Experimental manipulations of the analogy tasks suggested that this region plays a role in relational matching or integration. The current lesion approach demonstrated that the left rostrolateral prefrontal region is a critical node in the analogy network. Our results also suggested that analogy tasks should be translated to clinical practice to refine the neuropsychological assessment of patients with frontal lobe lesions. PMID:27076181

  19. Dienone-phenol Rearrangement of C-9 Oxygenated Decalinic Dienone and Analogs through B-Ring Cleavage

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Dehydrogenation of 9-hydroxy decalinic enones and analogs with DDQ resulted in a formal dienone-phenol type rearrangement via B-ring cleavage, while the corresponding dienone acetates underwent base-catalyzed formal dienone-phenol type rearrangement analogously.

  20. 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.

  1. Hegel, Analogy, and Extraterrestrial Life

    Science.gov (United States)

    Ross, Joseph T.

    Georg Wilhelm Friedrich Hegel rejected the possibility of life outside of the Earth, according to several scholars of extraterrestrial life. Their position is that the solar system and specifically the planet Earth is the unique place in the cosmos where life, intelligence, and rationality can be. The present study offers a very different interpretation of Hegel's statements about the place of life on Earth by suggesting that, although Hegel did not believe that there were other solar systems where rationality is present, he did in fact suggest that planets in general, not the Earth exclusively, have life and possibly also intelligent inhabitants. Analogical syllogisms are superficial, according to Hegel, insofar as they try to conclude that there is life on the Moon even though there is no evidence of water or air on that body. Similar analogical arguments for life on the Sun made by Johann Elert Bode and William Herschel were considered by Hegel to be equally superficial. Analogical arguments were also used by astronomers and philosophers to suggest that life could be found on other planets in our solar system. Hegel offers no critique of analogical arguments for life on other planets, and in fact Hegel believed that life would be found on other planets. Planets, after all, have meteorological processes and therefore are "living" according to his philosophical account, unlike the Moon, Sun, and comets. Whereas William Herschel was already finding great similarities between the Sun and the stars and had extended these similarities to the property of having planets or being themselves inhabitable worlds, Hegel rejected this analogy. The Sun and stars have some properties in common, but for Hegel one cannot conclude from these similarities to the necessity that stars have planets. Hegel's arguments against the presence of life in the solar system were not directed against other planets, but rather against the Sun and Moon, both of which he said have a different

  2. C-Glycosyl Analogs of Oligosaccharides

    Science.gov (United States)

    Vauzeilles, Boris; Urban, Dominique; Doisneau, Gilles; Beau, Jean-Marie

    This chapter covers the synthesis of a large collection of "C-oligosaccharides ", synthetic analogs of naturally occurring oligosaccharides in which a carbon atom replaces the anomeric, interglycosidic oxygen atom. These non-natural constructs are stable to chemical and enzymatic degradation, and are primarily devised to probe carbohydrate-based biological processes. These mainly target carbohydrate-protein interactions such as the modulation of glycoenzyme (glycosylhydrolases and transferases) activities or the design of ligands for lectin Carbohydrate Recognition Domains. The discussion is based on the key carbon-carbon bond assembling steps on carbohydrate templates: ionic (anionic and cationic chemistries, sigmatropic rearrangements) or radical assemblage, and olefin metathesis. Synthetic schemes in which at least one of the monosaccharide units is constructed by total synthesis or by cyclization of acyclic chiral chains are presented separately in a "partial de novo synthesis" section. The review also provides comments, when they are known, on the conformational and binding properties of these synthetic analogs, as well as their biological behavior when tested.

  3. 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...

  4. 基于Model Chemlab的实验室仿真模拟%Laboratory analog simulation based on Model Chemlab software

    Institute of Scientific and Technical Information of China (English)

    常艳香

    2013-01-01

    计算机作为一种现代化工具在日常生活及科研工作中得到了越来越广泛的应用,为我们提供了极大的方便和快捷.Model Chemlab是一款计算机模拟化学实验的软件,预先内置了一些常用的大学水平化学实验,并可通过自带的LabWizard开发工具在原有基础上开发新的实验项目,具有较高的自主性,可以满足不同使用者的需求.通过交互式仿真技术直观的展现实验过程和结论;同时对于危险性高或费用高及耗时长的实验可以很好地起到辅助作用.%Computer as a modern tool in daily life and has been more and more widely used in scientific research work,provides us great convenience and shortcut.Model Chemlab is a computer simulation of chemical experiment software,some commonly used built-in college level chemistry experiment,and can through own LabWizard development tool based on the original development new experiment project,has the high autonomy,can meet the needs of different users.Through the interactive simulation technology intuitive show the experimental process and results:At the same time for high risk or high cost and time-consuming long experiment may well play a supplementary role.

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. Design of Self-tracking Robot Based on Analog CCD Sensor and Image Correction%基于模拟CCD传感器和图像矫正的自循迹机器人设计

    Institute of Scientific and Technical Information of China (English)

    赵思蕊; 吴亚东; 杨文超; 蒋宏宇

    2015-01-01

    设计了一种基于模拟CCD图像传感器和图像透视矫正算法的自动循迹机器人。分别完成了机器人的总体设计和软硬件设计。该循迹机器人以32位单片机MK60DN512ZVLQ10为主控制器,采用模拟CCD摄像头获取黑色引导线信息,并转化为有效的舵机和电机控制量。为提高控制精度,利用PID控制算法实现机器人的闭环控制。由于采集的图像存在梯形失真,所以利用图像透视变换对原始图像校正,实现机器人精确的循迹。测试结果表明:该循迹机器人对场地适应性强,具有低成本、低功耗等优点,在核辐射和高压电等特殊环境下有很大的使用价值。%A self-tracking robot has been designed based on analog CCD image sensor and image per-spective correction. The overall design as well as hardware/software design is completed. The tracking ro-bot uses the MK60 DN512 ZVLQ10 as main controller and collects the black guide line image information using analog CCD camera,the image information is converted to effective steering gear and motor control. In order to improve control accuracy,using the PID control algorithm to realize the closed-loop control of the robot. Due to the collection of image is trapezoidal distortion,perspective transformation is used to correct the original image and realize accurate tracking of robot. Result of the test indicates that the track-ing robot which has strong adaptability is strong and has the advantages of low cost,low power consump-tion,it has great value in the special environment such as radiation,high voltage,etc.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. Design of Multifunctional Platform Analog Computer Peripherals Based on Android Smartphone%基于Android智能手机的模拟计算机外设的多功能平台设计

    Institute of Scientific and Technical Information of China (English)

    罗圆; 刘世鑫; 瞿绍军

    2014-01-01

    随着计算技术和通信技术的快速发展,人类正逐步进入普适计算(Ubiquitous Computing)时代。而智能空间正是普适计算本质特点的一种具体而集中的体现,智能手机在其中可以获得增强化的个性服务。论文实现了一种基于Android智能手机的模拟电脑外设的多功能平台,手机和电脑端通过TCP/IP协议连接,使得用户在一定的距离内用手机远程的控制电脑。%With the rapid development of computer technology and communication technology, human beings is gradually enter⁃ing the Ubiquitous Computing age. The Smart Space is a specific and concentrated expression of an essential feature of pervasive computing.Due to them,Intelligent phone can get personalized service. This paper realizes a multifunctional platform analog computer peripherals based on Android smartphone, mobile phones and computer connected via TCP/IP protocol, allowing us⁃ers remote control the computer at the appropriate distance using a mobile phone.

  16. 基于现场可编程模拟阵列FPAA的全波整流器的设计%Design of Whole Wave Rectifier Based on Field Programmable Analog Array

    Institute of Scientific and Technical Information of China (English)

    常龙; 朱正伟

    2012-01-01

    针对已有的传统整流器,其滤波性能与无源元件的精度、温度变化特性密切相关等的缺点,尝试采用基于开关电容技术的现场可编程模拟阵列(FPAA)芯片AN221E04来实现一个调节简便、成本低的整流滤波器的设计.该设计充分利用了FPAA的优点,提高整流器的精度,减弱温度、电压漂移.且在FPAA中可动态可调控,进一步提高处理的精度和效果.%Existing traditional rectifier has a shortcoming that its filter performance is closely related to the accuracy of passive components and the temperature changes and so on. To overcome these shortcomings, this study tries to achieve the design of the rectifier using the field programmable analog chips (FPAA) AN221E04 based on the technology of switching capacity. The rectifier is regulation simple, low — cost commuting filter. The design makes full use of advantages of FPAA to improve the precision of the rectifier, abate drifts of temperature and voltage. Dynamic—controling quality factor can be easily used in the FPAA, which can further improve the accuracy and effectiveness.

  17. 基于类比分析的强势产品进化及其效应%The Evolution and Effects of Dominant Products Based on Analogy Method

    Institute of Scientific and Technical Information of China (English)

    罗军

    2011-01-01

    Based on analogy method between species evolution & products design, it analyzed the reasons why dominant products succeed. Combined with related consumption IT products, it illustrated the similarities on evolution of dominant species & dominant products, and summarized impacts on nature ecology, design progress and culture field. In conclusion, evolution of dominant products is harmful to environment and design' s diversity. It is meaningful to study on dominant products and make its definition as a whole, to protect eco-diversity, while avoid as far as possible its negative influence against culture.%从进化的角度类比了物种与产品,以消费类IT产品为例,分析了强势产品成功的原因,就强势产品对产品设计、自然环境和文化的影响进行了总结。认为:强势产品的进化加速了环境恶化与人的异化,阻碍了设计的多样化,研究IT产品中的强势产品对于从普遍意义上定义强势产品,维护产品的多样性,减少对文化的负面影响具有一定启示意义。

  18. 基于选择性SVM集成的模拟电路故障诊断方法%A Method of Analog Circuit Fault Diagnosis Based on Selective SVM Ensemble

    Institute of Scientific and Technical Information of China (English)

    吴杰长; 刘海松; 陈国钧

    2011-01-01

    为克服支持向量机在故障诊断应用中存在的不足,设计了基于聚类分析的选择性支持向量机集成学习算法,并应用于模拟电路故障诊断.该方法采用K-means聚类算法去除相似冗余个体,提高剩余个体学习机的差异性,增强了支持向量机集成模型的泛化能力.以ITC' 97标准电路中的Leap-Frog滤波电路为诊断实例进行了仿真实验.%A method of analog circuit fault diagnosis based on selective SVM ensemble is pres-ented in this paper. K - means clustering algorithm is used to improve the diversity of individuals in SVM ensemble, he method overcomes disadvantages of single SVM and greatly improves the generation ability. Simulation experiments on a Leap -Frog filter circuit are carried out.

  19. Application of Research-based Teaching Mode in Analog Electronic Technology Course%研究型教学在“模拟电子技术”中的应用

    Institute of Scientific and Technical Information of China (English)

    史雪飞; 李江昀; 李擎; 刘蕴络

    2012-01-01

    Research-based teaching mode is applied to the class of Analog Electronic Technology according to the features of the course and the practical problems which students have during their study. Many teaching cases and seminar topics are presented in detail in this paper. For every topic the proposed background and cultivating object are also analyzed in the following part. Evaluation about this new teaching mode among students is discussed in the end.%本文从“模拟电子技术”课程的特点和学生的实际问题出发,开展了将研究型教学模式引入“模拟电子技术”课堂的实践和探索工作。文章还详细介绍了具体的研究型教学案例和多个研讨专题,并分析了每个专题提出的背景和设置的培养目标,最后给出了学生对于本课程研究型教学模式的评价。

  20. High school biology students' participation in a year-long sequence of analogical activities: The relationship of development of analogical thought to student learning and classroom interactions

    Science.gov (United States)

    Hackney, Marcella Wichser

    1999-10-01

    This research explored development of analogical thought through high school biology students' participation in a year-long sequence of analogical activities. Analogizing involves: selecting a familiar analog; mapping similarities and differences between the analog and less familiar target; making inferences from the analogy; evaluating validity of the inferences; and ultimately, understanding the biological target (Holyoak & Thagard, 1995). This investigation considered: student development of independence in learning through analogical thought, student learning of biology, the relationship between development of students' analogical thinking and students' learning of biology, and the quality of student interactions in the classroom This researcher, as teacher participant, used three approaches for teaching by analogy: traditional didactic, teacher-guided, and analogy-generated-by-the-student (Zeitoun, 1983). Within cooperative groups, students in one honors biology class actively engaged in research-based analogical activities that targeted specific biological topics. Two honors biology classes participated in similar, but nonanalogical activities that targeted the same biological topics. This two-class comparison group permitted analytical separation of effects of the analogical emphasis from the effects of biology content and activity-based learning. Data collected included: fieldnotes of researcher observations, student responses to guidesheets, tapes of group interactions, student products, student perceptions survey evaluations, ratings of students' expressed analogical development, pre- and posttest scores on a biology achievement test, essay responses, and selected student interviews. These data formed the basis for researcher qualitative analysis, augmented by quantitative techniques. Through participation in the sequence of analogical activities, students developed their abilities to engage in the processes of analogical thinking, but attained different

  1. Fluid friction in incompressible laminar convection: Reynolds' analogy revisited for variable fluid properties

    Science.gov (United States)

    Mahulikar, S. P.; Herwig, H.

    2008-03-01

    The Reynolds' analogy between the Stanton number (St) and the skin friction coefficient (cf) is popularly believed to hold when St increases with increasing cf, for simple situations. In this investigation, the validity of Reynolds' analogy between St and cf for micro-convection of liquids with variations in fluid properties is re-examined. It is found that the Sieder-Tate's property-ratio method for obtaining Nusselt number corrections is theoretically based on the validity of Reynolds' analogy. The inverse dependence of Reynolds number and skin friction coefficient is the basis for validity of the Reynolds' analogy, in convective flows with fluid property variations. This leads to the unexpected outcome that Reynolds' analogy now results in St increasing with decreasing cf. These results and their analyses indicate that the validity of Reynolds' analogy is based on deeper foundations, and the well-known validity criterion is a special case.

  2. High accuracy computation with linear analog optical systems: a critical study

    OpenAIRE

    Psaltis, Demetri; Athale, Ravindra A.

    1986-01-01

    High accuracy optical processors based on the algorithm of digital multiplication by analog convolution (DMAC) are studied for ultimate performance limitations. Variations of optical processors that perform high accuracy vector-vector inner products are studied in abstract and with specific examples. It is concluded that the use of linear analog optical processors in performing digital computations with DMAC leads to impractical requirements for the accuracy of analog optical systems and the ...

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

    OpenAIRE

    Yuan Cao; Xiaofang Pan; Xiaojin Zhao; Huisi Wu

    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 p...

  4. 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.

  5. Silicon analog components device design, process integration, characterization, and reliability

    CERN Document Server

    El-Kareh, Badih

    2015-01-01

    This book covers modern analog components, their characteristics, and interactions with process parameters. It serves as a comprehensive guide, addressing both the theoretical and practical aspects of modern silicon devices and the relationship between their electrical properties and processing conditions. Based on the authors’ extensive experience in the development of analog devices, this book is intended for engineers and scientists in semiconductor research, development and manufacturing. The problems at the end of each chapter and the numerous charts, figures and tables also make it appropriate for use as a text in graduate and advanced undergraduate courses in electrical engineering and materials science.

  6. Ultra Low-Power Analog Median Filters

    Directory of Open Access Journals (Sweden)

    A. Diaz-Sanchez

    2013-09-01

    Full Text Available The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used.

  7. Development of a Cell-Based Fluorescence Resonance Energy Transfer Reporter for Bacillus anthracis Lethal Factor Protease

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, R H; Steenblock, E R; Camarero, J A

    2007-03-22

    We report the construction of a cell-based fluorescent reporter for anthrax lethal factor (LF) protease activity using the principle of fluorescence resonance energy transfer (FRET). This was accomplished by engineering an Escherichia coli cell line to express a genetically encoded FRET reporter and LF protease. Both proteins were encoded in two different expression plasmids under the control of different tightly controlled inducible promoters. The FRET-based reporter was designed to contain a LF recognition sequence flanked by the FRET pair formed by CyPet and YPet fluorescent proteins. The length of the linker between both fluorescent proteins was optimized using a flexible peptide linker containing several Gly-Gly-Ser repeats. Our results indicate that this FRET-based LF reporter was readily expressed in E. coli cells showing high levels of FRET in vivo in the absence of LF. The FRET signal, however, decreased 5 times after inducing LF expression in the same cell. These results suggest that this cell-based LF FRET reporter may be used to screen genetically encoded libraries in vivo against LF.

  8. 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...

  9. Diagnosis Method for Analog Circuit Hard fault and Soft Fault

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2013-09-01

    Full Text Available Because the traditional BP neural network slow convergence speed, easily falling in local minimum and the learning process will appear oscillation phenomena. This paper introduces a tolerance analog circuit hard fault and soft fault diagnosis method based on adaptive learning rate and the additional momentum algorithm BP neural network. Firstly, tolerance analog circuit is simulated by OrCAD / Pspice circuit simulation software, accurately extracts fault waveform data by matlab program automatically. Secondly, using the adaptive learning rate and momentum BP algorithm to train neural network, and then applies it to analog circuit hard fault and soft fault diagnosis. With shorter training time, high precision and global convergence effectively reduces the misjudgment, missing, it can improve the accuracy of fault diagnosis and fast.  

  10. 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.

  11. Analogical scaffolding and the learning of abstract ideas in physics: An example from electromagnetic waves

    Directory of Open Access Journals (Sweden)

    Noah D. Finkelstein

    2007-06-01

    Full Text Available This paper describes a model of analogy, analogical scaffolding, which explains present and prior results of student learning with analogies. We build on prior models of representation, blending, and layering of ideas. Extending this model’s explanatory power, we propose ways in which the model can be applied to design a curriculum directed at teaching abstract ideas in physics using multiple, layered analogies. We report on a recent empirical study that motivates this model. Students taught about electromagnetic waves in a curriculum that builds on the model of analogical scaffolding posted substantially greater gains pre- to postinstruction than students taught using a more traditional (non-analogy-based tutorial (21% vs 7%.

  12. Fabricating abutment crowns for existing removable partial dentures using custom resin clasp analogs.

    Science.gov (United States)

    Livaditis, G J

    1998-11-01

    A universal approach for fabricating abutment crowns for existing removable partial dentures is described. A replica (analog) of the clasp assembly is generated and transferred to a traditional working cast, which includes the abutment die. The analog is incorporated into the working cast as a removable component to allow the formation of the crown contours. The article reviews in detail the procedures required to transfer accurately all the essential components and information from the mouth to the working cast while allowing the patient uninterrupted use of the removable partial denture. Prestabilizing the removable partial denture, creating the analog impression, avoiding errors due to soft tissue components, forming a precise analog base, selecting materials, generating a rigid resin analog, and prescribing a path of insertion and withdrawal to the analog are described. The method replicates all types of clasps and can generate all types of fixed prosthodontic retainers to function harmoniously with the existing partial denture.

  13. Fabricating abutment crowns for existing removable partial dentures using custom resin clasp analogs.

    Science.gov (United States)

    Livaditis, G J

    1998-11-01

    A universal approach for fabricating abutment crowns for existing removable partial dentures is described. A replica (analog) of the clasp assembly is generated and transferred to a traditional working cast, which includes the abutment die. The analog is incorporated into the working cast as a removable component to allow the formation of the crown contours. The article reviews in detail the procedures required to transfer accurately all the essential components and information from the mouth to the working cast while allowing the patient uninterrupted use of the removable partial denture. Prestabilizing the removable partial denture, creating the analog impression, avoiding errors due to soft tissue components, forming a precise analog base, selecting materials, generating a rigid resin analog, and prescribing a path of insertion and withdrawal to the analog are described. The method replicates all types of clasps and can generate all types of fixed prosthodontic retainers to function harmoniously with the existing partial denture. PMID:9813815

  14. 基于LabVIEW的模拟电路实验教学平台设计%Design of analog circuit experiment teaching platform based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    唐辉平; 彭良玉

    2013-01-01

      In this paper,a typical resistance and capacitance coupling common emitter amplifier in the analog circuit is simulated with LabVIEW software. The circuit has amplification state,saturated distortion state and cut⁃off distortion state. The quiescent operating point and normal amplification output waveform of the amplification state are given in this paper. The corre⁃sponding distortion waveform of the saturation distortion state and cut⁃off distortion state is also offered. The voltage series nega⁃tive feedback circuit is designed in this paper based on resistance and capacitance coupling common emitter circuit. The inf⁃luence of the negative feedback on input/output resistance and the amplification factor of the whole circuit was verified.%  在此运用LabVIEW软件仿真了模拟电路中的典型阻容耦合共发射极放大电路,此电路有放大状态、饱和失真状态和截止失真状态。针对放大状态给出了它的静态工作点和正常的放大输出波形;针对饱和失真状态和截止失真状态给出了相应的失真波形。在典型阻容耦合共发射极电路基础上,设计了电压串联负反馈电路,验证了负反馈对整个电路输入/输出电阻及放大倍数的影响。

  15. Los pasiegos. La analogía salvaje y lo salvaje de la analogía

    Directory of Open Access Journals (Sweden)

    JAIME DE LA CALLE VALVERDE

    2007-01-01

    -entendiendo salvaje como un pensamiento humano prístino-: por un lado en sus relaciones con el racionalismo (¿emerge la analogía desde el racionalismo?, ¿qué relación guarda con éste?, ¿su nacimiento es resultado de una función «natural»? y por otro sobre la naturaleza social de lo salvaje a partir de las bases sociales que lo producen. Es decir, se rastrea lo que de salvaje tiene la analogía, si la analogía es o no una función ahistórica y asocial del intelecto humano. No se examina todo el complejo analógico de los pasiegos, únicamente aquél que establece relaciones homólogas entre las vacas y el entorno.

  16. Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain

    Directory of Open Access Journals (Sweden)

    Yukiko eMishina

    2014-09-01

    Full Text Available Deciphering how the brain generates cognitive function from patterns of electrical signals is one of the ultimate challenges in neuroscience. To this end, it would be highly desirable to monitor the activities of very large numbers of neurons while an animal engages in complex behaviours. Optical imaging of electrical activity using genetically encoded voltage indicators (GEVIs has the potential to meet this challenge. Currently prevalent GEVIs are based on the voltage-sensitive fluorescent protein (VSFP prototypical design or on the voltage dependent state transitions of microbial opsins.We recently introduced a new VSFP design in which the voltage-sensing domain (VSD is sandwiched between a FRET pair of fluorescent proteins (termed VSFP-Butterflies and also demonstrated a series of chimeric VSD in which portions of the VSD of Ciona intestinalis voltage-sensitive phosphatase (Ci-VSP are substituted by homologous portions of a voltage-gated potassium channel subunit. These chimeric VSD had faster sensing kinetics than that of the native Ci-VSD. Here, we describe a new set of VSFPs that combine chimeric VSD with the Butterfly structure. We show that these chimeric VSFP-Butterflies can report membrane voltage oscillations of up to 200 Hz in cultured cells and report sensory evoked cortical population responses in living mice. This class of GEVIs may be suitable for imaging of brain rhythms in behaving mammalians.

  17. 根据R基因保守区分离小麦R基因类似序列%Isolation of Resistance Gene Analogs from Wheat Based on Conserved Domains of Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    秦跟基; 陈佩度; 顾红雅; 冯袆高; 牛吉山

    2003-01-01

    用根据核苷酸结合位点(nucleotide binding site, NBS)和丝氨酸/苏氨酸蛋白质激酶域设计的2对简并性引物,以小麦-簇毛麦6VS/6AL易位系的cDNA为模板进行PCR扩增.扩增产物克隆到pGEM-T载体中,经测序,共获得具有NBS结构域特征的片段克隆9个和具有丝氨酸/苏氨酸蛋白质激酶域特征的片段的克隆1个.将克隆之间核苷酸序列同源性高于90%的克隆归为一类,把9个NBS片段分为6类.这6类抗病基因类似序列(resistance gene analogs, RGA)均具有阅读框,并与已克隆的小麦抗条锈病基因Yr10、大麦抗白粉病基因Mla1和Mla6、拟南芥的抗病基因RPS2以及其他一些抗病基因在NBS保守区内具有高度的同源性.用小麦中国春缺体-四体初步将它们分别定位于小麦第一、第二和第五部分同源群上.进一步用5′-RACE技术获得RGA N5的5′-端,发现其编码产物的N端还具有6个亮氨酸拉链(leucine zipper, LZ),与RPS2的N-端有较高同源性.%Two pairs of degenerate primers were designed based on nucleotide-binding site (NBS) and serine/threonine kinase domain. PCR was performed with the primers and cDNA from the Triticum aestivum-Haynaldia villosa translocation line 6VS/6AL. Amplified products were cloned and sequenced. Nine clones with NBS and one with serine/threonine kinase domain were obtained. The NBS clones were classified to six groups according to their nucleotide sequence identities (90% or higher). These resistance gene analogs (RGAs) all have open reading frames (ORF), and their amino acid sequences show high similarity to Yr10 in wheat, Mla1 and Mla6 in barley, RPS2 in Arabidopsis and other resistance (R) genes with conserved motifs. They were preliminarily mapped on the chromosomes of homoeologous groups 1, 2 and 5 of common wheat by nulli-tetrasomic analysis. The 5′-end sequence of an RGA N5 was obtained by 5′-RACE PCR. It encodes six leucine zipper (LZ) and has high sequence similarity to RPS2.

  18. Soft Fault Diagnosis Based on Waveform Similarity for Tolerance Analog Circuit%基于波形相似度的容差模拟电路软故障诊断

    Institute of Scientific and Technical Information of China (English)

    钟建林; 何友; 任献彬

    2012-01-01

    针对容差模拟电路输出波形参数的随机性,构造了描述特定电路状态的特征区间向量,据此提出了一种基于多频响应波形相似度的软故障诊断方法。对每一种软故障,分别施加K种不同频率的激励信号,获取K个由输出响应构成的标准特征区间向量作为该故障状态的信号特征。对待测电路施加相同的K种频率的激励信号,获取K个待测样本,分别与每种故障模式的K个相应的标准特征区间向量进行相似度计算,获取K个波形相似度,在波形相似度融合中考虑了均方差权重系数和可信度权重系数,得到待测样本与该故障模式的总体相似度。最后依据一定的模糊规则进行故障定位。仿真实验证明,本方法在保证较高诊断准确率的情况下,对测点要求低,易于在自动测试系统中实现诊断的自动化。%Regarding to the random attribute of the parameters of tolerance analog circuit output waveform,the feature interval vector used to describe the tolerance analog circuit in a certain mode is constructed.Accordingly,a novel soft fault diagnosis method based on waveform similarity acquired by multi-frequency tests is proposed.For each fault mode of the circuit under test,K standard feature interval vectors are acquired by K tests with alternating current signal inputs with different frequencies respectively.In order to diagnose the fault mode of the circuit,it is input with the same signals with K different frequencies to form K output wave parameter samples.K wave similarities are calculated by the K output wave parameter samples with the K standard feature interval vectors of each fault mode.The integrated similarity is the fusion of the K wave similarities considering mean square deviation weight and credibility weight.Finally,fault location is realized by a set of fuzzy rules.The simulation results show that the proposed method gains satisfactory accuracy while less limited by accessible

  19. 基于模拟航天任务的心理学研究:任务、内容和方法%Psychological Studies Based on Analog Spaceflight Missions: Task, Content and Method

    Institute of Scientific and Technical Information of China (English)

    吴瑞林; 王雅

    2016-01-01

    模拟空间环境是现阶段开展航天心理学研究的最主要手段之一.本文从任务设定、研究内容和研究方法3个方面,分析了包括火星-500(Mars-500)在内的6个模拟航天任务心理学研究.6个任务的环境设定各有特点,覆盖了从近地轨道到火星探索等不同时程和类型的航天任务,并将跨文化乘组和通讯延迟等因素设计在内.航天员情绪、认知变化,乘组的人际关系与内部凝聚力、自治情况成为模拟任务研究的重点.问卷、访谈、日志分析、计算机化测试、行为观察分析等研究方法在各任务中有不同程度的使用.今后,我国可以在乘组人际互动和人际关系、团队构成对人际互动和关系的作用、个体情绪变化规律和调节措施、个体高级认知功能变化等几方面开展中长期航天任务模拟研究.%Analog space environment is an important mean for space psychology researches.Six major analog missions including CAPSULS,HUBES,SFINCSS-99,NEEMO,HMP-2008 and Mars-500 were reviewed in this paper.The task and environment settings,study contents,research methods were compared and discussed.There were varieties of environment settings ranging from on-orbit station to Mars exploration.Besides,cross-culture crew and communication delay were considered in some of experiments.The topics covered included crew emotions,cognitive performance,motivation,interpersonal relationship,crew cohesion and autonomy.These topics were especially important for the future Lunar and Mars mission design and research.These contents under a series of quantitative and qualitative methods were discussed containing questionnaire,interview,dairy analysis,computer-based test,behavioral observation,expression identification and so on.Recommendations for each topic were offered and summarized for future researches in the field.According to the results,long-term simulation experiments should be conducted to further analyze human

  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 optical analog signal transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Fudzita, K.; Itida, T.; Tanaka, Kh.

    1984-01-11

    An optical laser analog signal transmitter employing an amplitude modulated subcarrier is patented; this transmitter performs stable and high quality transmission of information signals over great distances. A feature of the proposed transmitter is a special transmitter operational mode in which the light emission reflected off the connection point to the fiber optic conduit is sent back to the laser diode in a transient period. As a result, the critical mode of the generated emission is not influenced by the reflected signal. The transmitter consists of a laser diode with biasing near the cutoff point, an amplitude modulator with a subcarrier frequency oscillator, a section of flexible fiber-optic cable of length L, which connects the laser diode to the primary optical fiber conduit, and the connector itself. The subcarrier frequency may vary over wide ranges to establish the necessary correlation between the length of the light conduit section L and the return propagation time of the reflected light signal from the connection point to the laser diode. The difference between the lasing time of the light signal and the return time to the laser diode of the signal reflected off the connector is determined by the relation tau equals 2nL/c - mtauc, where L is the length of the connecting section; n is the refractivity of the optical fiber; c is the velocity of light; tauc is the period of the high frequency subcarrier signal; and m is an integer.

  2. A Mechanical Analogy for the Photoelectric Effect

    Science.gov (United States)

    Kovacevic, Milan S.; Djordjevich, Alexandar

    2006-01-01

    Analogy is a potent tool in the teacher's repertoire. It has been particularly well recognized in the teaching of science. However, careful planning is required for its effective application to prevent documented drawbacks when analogies are stretched too far. Befitting the occasion of the World Year of Physics commemorating Albert Einstein's 1905…

  3. 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....

  4. 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…

  5. 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.

  6. Antibacterial and Antibiofilm Activities of Makaluvamine Analogs

    Directory of Open Access Journals (Sweden)

    Bhavitavya Nijampatnam

    2014-09-01

    Full Text Available Streptococcus mutans is a key etiological agent in the formation of dental caries. The major virulence factor is its ability to form biofilms. Inhibition of S. mutans biofilms offers therapeutic prospects for the treatment and the prevention of dental caries. In this study, 14 analogs of makaluvamine, a marine alkaloid, were evaluated for their antibacterial activity against S. mutans and for their ability to inhibit S. mutans biofilm formation. All analogs contained the tricyclic pyrroloiminoquinone core of makaluvamines. The structural variations of the analogs are on the amino substituents at the 7-position of the ring and the inclusion of a tosyl group on the pyrrole ring N of the makaluvamine core. The makaluvamine analogs displayed biofilm inhibition with IC50 values ranging from 0.4 μM to 88 μM. Further, the observed bactericidal activity of the majority of the analogs was found to be consistent with the anti-biofilm activity, leading to the conclusion that the anti-biofilm activity of these analogs stems from their ability to kill S. mutans. However, three of the most potent N-tosyl analogs showed biofilm IC50 values at least an order of magnitude lower than that of bactericidal activity, indicating that the biofilm activity of these analogs is more selective and perhaps independent of bactericidal activity.

  7. 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…

  8. Analogies in biology textbooks in zoology teaching

    Directory of Open Access Journals (Sweden)

    Saulo Cézar Seiffert Santos

    2011-05-01

    Full Text Available The biologic structures of living creatures are of difficult understanding for students, because they are usually unknown by those, in needs of strategic didactics in order to facilitate the student understanding. There are several strategies and methods for teaching, such as, analogies, metaphors, descriptions, among others. In this article we aim to identify, assess and classify the analogies used in the Higher School Biology textbooks, commonly used in Public State Schools of Manaus – AM, related to the zoology theme. The methodological procedure includes: a analysis of the whole zoological content of the most used textbooks in the public state network of Amazonas throughout the year; b three didactic textbooks have been specifically analyzed in order to specify the class taxon of “Fish” for the comparison of possible variations of types and quantities of analogies. The adopted classification of analogies was of Curtis & Reigeluth (1984 and the model of enriching analysis was according to the TWA Glynn model (Harrison & Treagust, 1993. It has been concluded that the use of analogies is greater in the content of invertebrates than that of vertebrates. Most Analogies are presented in a simple and direct manner, comparing structures, concrete to concrete, and of verbal mediation, almost nothing is presented in a diverse and heuristic manner of Zoology content on the LD. The development of limits of comparison and reflexion about the analogies was rare, only the presentation of the analogue and the target of analogy occurred.

  9. Evaluation of quantum dot-based concentric FRET configurations with a fluorescent dye and dark quencher for multiplexed bioanalyses

    Science.gov (United States)

    Conroy, Erin M.; Algar, W. Russ

    2014-03-01

    Semiconductor quantum dots (QDs) continue to emerge as a highly advantageous platform for bioanalysis. Their unique physical and optical properties are especially well suited for Förster resonance energy transfer (FRET)-based bioprobes. Concentric FRET configurations are a recent development in this area of research and are best described as QD bioconjugates where multiple energy transfer pathways have been assembled around the central QD. Concentric FRET configurations permit multiplexed bioanalysis using one type of QD vector, but require more sophisticated analyses than conventional FRET pairs. In this paper, we describe the design and characterization of a new concentric FRET configuration that assembles both a fluorescent dye, Alexa Fluor 555 or Alexa Fluor 647, and a dark quencher, QSY9, at different ratios around a central CdSeS/ZnS QD. It was found that the magnitudes of the total photoluminescence (PL) intensity and either the A555/QD or A647/QD PL ratio can be related to the number of QSY9 and A555 or A647 per QD. The trends in these parameters with changes in the number of each dye molecule per QD have both similarities and differences between configurations with A555 and A647. In each case, a system of equations can be defined to permit calculation of the number of each dye molecule per QD from PL measurements. Both of these dark quencher-based concentric FRET configurations are therefore good candidates for quantitative, multiplexed bioanalysis.

  10. Continuous Monitoring of Specific mRNA Expression Responses with a Fluorescence Resonance Energy Transfer-Based DNA Nano-tweezer Technique That Does Not Require Gene Recombination.

    Science.gov (United States)

    Shigeto, Hajime; Nakatsuka, Keisuke; Ikeda, Takeshi; Hirota, Ryuichi; Kuroda, Akio; Funabashi, Hisakage

    2016-08-16

    This letter discusses the feasibility of continuously monitoring specific mRNA expression responses in a living cell with a probe structured as a fluorescence resonance energy transfer (FRET)-based DNA nano-tweezer (DNA-NT). The FRET-based DNA-NT, self-assembled from three single-stranded DNAs, alters its structure from an open state to a closed state in recognition of a target mRNA, resulting in the closing of the distal relation of previously modified FRET-paired fluorescent dyes and generating a FRET signal. The expressions of glucose transporters (GLUT) 1 and 4 in a mouse hepato-carcinoma (Hepa 1-6 cells) were selected as the target model. Live-cell imaging analysis of Hepa 1-6 cells with both FRET-based DNA-NTs indicated that the behaviors of the FRET signals integrated in each individual cell were similar to those measured with the conventional mass analysis technique of semiquantitative real-time (RT) polymerase chain reaction (PCR). From these results, it is concluded that continuous monitoring of gene expression response without gene recombination is feasible with a FRET-based DNA-NT, even in a single cell manner. PMID:27458920

  11. Application of natural analog studies to exploration for ore deposits

    International Nuclear Information System (INIS)

    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure

  12. Application of natural analog studies to exploration for ore deposits

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, D.L. [Consulting Economic Geologist, Reno, NV (United States)

    1995-09-01

    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure.

  13. A dark business, full of shadows: analogy and theology in William Harvey.

    Science.gov (United States)

    Goldberg, Benjamin

    2013-09-01

    In a short work called De conceptione appended to the end of his Exercitationes de generatione animalium (1651), William Harvey developed a rather strange analogy. To explain how such marvelous productions as living beings were generated from the rather inauspicious ingredients of animal reproduction, Harvey argued that conception in the womb was like conception in the brain. It was mostly rejected at the time; it now seems a ludicrous theory based upon homonymy. However, this analogy offers insight into the structure and function of analogies in early modern natural philosophy. In this essay I hope to not only describe the complex nature of Harvey's analogy, but also offer a novel interpretation of his use of analogical reasoning, substantially revising the account offered by Guido Giglioni (1993). I discuss two points of conceptual change and negotiation in connection with Harvey's analogy, understanding it as both a confrontation between the border of the natural and the supernatural, as well as a moment in the history of psychology. My interpretation touches upon a number of important aspects, including why the analogy was rejected, how Harvey systematically deployed analogies according to his notions of natural philosophical method, how the analogy fits into contemporary discussions of analogies in science, and finally, how the analogy must be seen in the context of changing Renaissance notions of the science of the soul, ultimately confronting the problem of how to understand final causality in Aristotelian science. In connection with the last, I conclude the essay by turning to how Harvey embeds the analogy within a natural theological cosmology.

  14. An Analog Earth Climate Model

    Science.gov (United States)

    Varekamp, J. C.

    2010-12-01

    The earth climate is broadly governed by the radiative power of the sun as well as the heat retention and convective cooling of the atmosphere. I have constructed an analog earth model for an undergraduate climate class that simulates mean climate using these three parameters. The ‘earth’ is a hollow, black, bronze sphere (4 cm diameter) mounted on a thin insulated rod, and illuminated by two opposite optic fibers, with light focused on the sphere by a set of lenses. The sphere is encased in a large double-walled aluminum cylinder (34 cm diameter by 26 cm high) with separate water cooling jackets at the top, bottom, and sides. The cylinder can be filled with a gas of choice at a variety of pressures or can be run in vacuum. The exterior is cladded with insulation, and the temperature of the sphere, atmosphere and walls is monitored with thermocouples. The temperature and waterflow of the three cooling jackets can be monitored to establish the energy output of the whole system; the energy input is the energy yield of the two optic fibers. A small IR transmissive lens at the top provides the opportunity to hook up the fiber of a hyper spectrometer to monitor the emission spectrum of the black ‘earth’ sphere. A pressure gauge and gas inlet-outlet system for flushing of the cell completes it. The heat yield of the cooling water at the top is the sum of the radiative and convective components, whereas the bottom jacket only carries off the radiative heat of the sphere. Undergraduate E&ES students at Wesleyan University have run experiments with dry air, pure CO2, N2 and Ar at 1 atmosphere, and a low vacuum run was accomplished to calibrate the energy input. For each experiment, the lights are flipped on, the temperature acquisition routine is activated, and the sphere starts to warm up until an equilibrium temperature has been reached. The lights are then flipped off and the cooling sequence towards ambient is registered. The energy input is constant for a given

  15. 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

  16. Nyquist AD Converters, Sensor Interfaces, and Robustness Advances in Analog Circuit Design, 2012

    CERN Document Server

    Baschirotto, Andrea; Steyaert, Michiel

    2013-01-01

    This book is based on the presentations during the 21st workshop on Advances in Analog Circuit Design.  Expert designers provide readers with information about a variety of topics at the frontier of analog circuit design, including Nyquist analog-to-digital converters, capacitive sensor interfaces, reliability, variability, and connectivity.  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 Nyquist A/D converters, capacitive sensor interfaces, reliability, variability, and connectivity.

  17. Effects of fat and/or methionine hydroxy analog added to a molasses-urea-based supplement on ruminal and postruminal digestion and duodenal flow of nutrients in beef steers consuming low-quality lovegrass hay.

    Science.gov (United States)

    Lopez, R; Pulsipher, G D; Guerra-Liera, J E; Soto-Navarro, S A; Balstad, L A; Petersen, M K; Dhuyvetter, D V; Brown, M S; Krehbiel, C R

    2016-06-01

    Five crossbred beef steers (initial BW = 338.6 ± 7.8 kg) fitted with ruminal and duodenal cannulas were used in a 5 × 5 Latin square design experiment to evaluate the effects of methionine hydroxy analog (MHA) and/or yellow grease (fat) added to a molasses-urea-based supplement on intake and characteristics of digestion. Steers were fed low-quality hay (long-stem lovegrass : 3.3% CP, 76.8% NDF; DM basis) ad libitum and supplemented with 0.91 kg/d (as fed) of 1 of 4 supplements in a 2 × 2 + 1 factorial arrangement of treatments. Supplemental treatments were 1) control (no supplement, NC); 2) molasses-urea liquid supplement (U); 3) U containing (as-fed basis) 1.65% MHA (UM); 4) U containing (as-fed basis) 12% fat (UF); and 5) U containing (as-fed basis) 1.65% MHA and 12% fat (UMF). Total and forage OM intake (kg/d and as % of BW) increased ( supplementation. Total tract NDF digestibility increased ( = 0.01) with molasses-urea supplementation, and was less ( = 0.01) for fat than for nonfat supplementation. Total and microbial N flowing to the duodenum increased ( = 0.01) with molasses-urea supplementation. Although, total N flowing to duodenum was not affected ( = 0.27), microbial N decreased ( = 0.01), and nonammonia nonmicrobial N (NANMN) increased ( = 0.01) with fat supplementation. Extent of in situ OM and NDF digestibility at 96 h increased ( = 0.01) with molasses-urea supplementation, but were not affected ( ≥ 0.14) by either MHA or fat supplementation. Duodenal flow of total AA, essential AA, and nonessential AA increased ( ≤ 0.02) with molasses-urea supplementation. Total and nonessential serum AA concentration decreased ( supplementation. Total ruminal VFA concentration increased ( = 0.01) with molasses-urea supplementation, and was not affected ( ≥ 0.14) by MHA or fat supplementation. Fat can be used in molasses-urea liquid supplements for cattle consuming low-quality forage to increase energy intake without negatively affecting forage intake or

  18. Moon and Mars Analog Mission Activities for Mauna Kea 2012

    Science.gov (United States)

    Graham, Lee D.; Morris, Richard V.; Graff, Trevor G.; Yingst, R. Aileen; tenKate, I. L.; Glavin, Daniel P.; Hedlund, Magnus; Malespin, Charles A.; Mumm, Erik

    2012-01-01

    Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were recently completed at Mauna Kea, Hawaii. Scientific investigations, scientific input, and science operations constraints were tested in the context of an existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration. Initial science operations were planned based on a model similar to the operations control of the Mars Exploration Rovers (MER). However, evolution of the operations process occurred as the analog mission progressed. We report here on the preliminary sensor data results, an applicable methodology for developing an optimum science input based on productive engineering and science trades discussions and the science operations approach for an investigation into the valley on the upper slopes of Mauna Kea identified as "Apollo Valley".

  19. 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.

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

    Science.gov (United States)

    Mayr, Christian G; 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 are thus not technology portable. In this paper, we present an ADC based on the Neural Engineering Framework (NEF). It carries out a large fraction of the overall ADC process in the digital domain, i.e., it is easily portable across technologies. The analog-digital conversion takes full advantage of the high degree of parallelism inherent in neuromorphic networks, making for a very scalable ADC. In addition, it has a number of features not commonly found in conventional ADCs, such as a runtime reconfigurability of the ADC sampling rate, resolution and transfer characteristic. PMID:25100933

  1. ON THE FREQUENCY OF POTENTIAL VENUS ANALOGS FROM KEPLER DATA

    Energy Technology Data Exchange (ETDEWEB)

    Kane, Stephen R. [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); Kopparapu, Ravi Kumar [Department of Geosciences, Penn State University, 443 Deike Building, University Park, PA 16802 (United States); Domagal-Goldman, Shawn D., E-mail: skane@sfsu.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-10-10

    The field of exoplanetary science has seen a dramatic improvement in sensitivity to terrestrial planets over recent years. Such discoveries have been a key feature of results from the Kepler mission which utilizes the transit method to determine the size of the planet. These discoveries have resulted in a corresponding interest in the topic of the Habitable Zone and the search for potential Earth analogs. Within the solar system, there is a clear dichotomy between Venus and Earth in terms of atmospheric evolution, likely the result of the large difference (approximately a factor of two) in incident flux from the Sun. Since Venus is 95% of the Earth's radius in size, it is impossible to distinguish between these two planets based only on size. In this Letter we discuss planetary insolation in the context of atmospheric erosion and runaway greenhouse limits for planets similar to Venus. We define a ''Venus Zone'' in which the planet is more likely to be a Venus analog rather than an Earth analog. We identify 43 potential Venus analogs with an occurrence rate (η{sub ♀}) of 0.32{sub −0.07}{sup +0.05} and 0.45{sub −0.09}{sup +0.06} for M dwarfs and GK dwarfs, respectively.

  2. 基于Multisim1O的心电检测系统模拟滤波器的设计%Analog Filter Design of Electrocardioscanner Based on Multisim10

    Institute of Scientific and Technical Information of China (English)

    董有尔; 吴宏雷; 陈宝明; 乔晓燕

    2011-01-01

    针对目前心电检测模拟滤波器设计的不足,本文利用Multisim10对滤波电路的相频特性、幅频特性、交流容差、直流容差和瞬态响应参数进行全面仿真分析,设计出了满足心电信号要求的滤波器.对滤波的结果与数字滤波器的结果进行误差对比,其E[e2]的值为0.0035,表明该滤波器性能稳定、信号保真度高.%In view of the shortage about ECG detection analog filter designing at present.comprehensive simulation analysis about phase frequency characteristics and amplitude-frequency characteristics and Exchange of tolerance and DC tolerance and Transient response of analog filter by Multisim10 were studied, and a filter to meet requirements of ECG signals was desiqed.Analog filter results compared with the digital filter result of error the E[e2]value is 0.0035,it shows that the filter stable performance and high fidelity of signal.

  3. 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.

  4. 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)

  5. 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)

  6. Synthesis and Biological Activity of Philanthotoxin Analogs

    Institute of Scientific and Technical Information of China (English)

    Yong An ZHANG; Ke Zhong LIU; Deng Yuan WANG; Yu Zhu WANG; Liang Jian QU; Chang Jin ZHU

    2006-01-01

    The synthesis of four analogs of philanthotoxin is described. The preliminary bioassay showed that these compounds all had good insecticidal activities, and the compound 6a had the best killing effect.

  7. Synthetic heparin-binding growth factor analogs

    Science.gov (United States)

    Pena, Louis A.; Zamora, Paul; Lin, Xinhua; Glass, John D.

    2007-01-23

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain that binds a heparin-binding growth factor receptor, covalently bound to a hydrophobic linker, which is in turn covalently bound to a non-signaling peptide that includes a heparin-binding domain. The synthetic heparin-binding growth factor analogs are useful as soluble biologics or as surface coatings for medical devices.

  8. 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...

  9. 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.

  10. 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...

  11. 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.

  12. 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

  13. Basalt: Biologic Analog Science Associated with Lava Terrains

    Science.gov (United States)

    Lim, D. S. S.; Abercromby, A.; Kobs-Nawotniak, S. E.; Kobayashi, L.; Hughes, S. S.; Chappell, S.; Bramall, N. E.; Deans, M. C.; Heldmann, J. L.; Downs, M.; Cockell, C. S.; Stevens, A. H.; Caldwell, B.; Hoffman, J.; Vadhavk, N.; Marquez, J.; Miller, M.; Squyres, S. W.; Lees, D. S.; Fong, T.; Cohen, T.; Smith, T.; Lee, G.; Frank, J.; Colaprete, A.

    2015-12-01

    This presentation will provide an overview of the BASALT (Biologic Analog Science Associated with Lava Terrains) program. BASALT research addresses Science, Science Operations, and Technology. Specifically, BASALT is focused on the investigation of terrestrial volcanic terrains and their habitability as analog environments for early and present-day Mars. Our scientific fieldwork is conducted under simulated Mars mission constraints to evaluate strategically selected concepts of operations (ConOps) and capabilities with respect to their anticipated value for the joint human and robotic exploration of Mars. a) Science: The BASALT science program is focused on understanding habitability conditions of early and present-day Mars in two relevant Mars-analog locations (the Southwest Rift Zone (SWRZ) and the East Rift Zone (ERZ) flows on the Big Island of Hawai'i and the eastern Snake River Plain (ESRP) in Idaho) to characterize and compare the physical and geochemical conditions of life in these environments and to learn how to seek, identify, and characterize life and life-related chemistry in basaltic environments representing these two epochs of martian history. b) Science Operations: The BASALT team will conduct real (non-simulated) biological and geological science at two high-fidelity Mars analogs, all within simulated Mars mission conditions (including communication latencies and bandwidth constraints) that are based on current architectural assumptions for Mars exploration missions. We will identify which human-robotic ConOps and supporting capabilities enable science return and discovery. c) Technology: BASALT will incorporate and evaluate technologies in to our field operations that are directly relevant to conducting the scientific investigations regarding life and life-related chemistry in Mars-analogous terrestrial environments. BASALT technologies include the use of mobile science platforms, extravehicular informatics, display technologies, communication

  14. Serial Pixel Analog-to-Digital Converter

    Energy Technology Data Exchange (ETDEWEB)

    Larson, E D

    2010-02-01

    This method reduces the data path from the counter to the pixel register of the analog-to-digital converter (ADC) from as many as 10 bits to a single bit. The reduction in data path width is accomplished by using a coded serial data stream similar to a pseudo random number (PRN) generator. The resulting encoded pixel data is then decoded into a standard hexadecimal format before storage. The high-speed serial pixel ADC concept is based on the single-slope integrating pixel ADC architecture. Previous work has described a massively parallel pixel readout of a similar architecture. The serial ADC connection is similar to the state-of-the art method with the exception that the pixel ADC register is a shift register and the data path is a single bit. A state-of-the-art individual-pixel ADC uses a single-slope charge integration converter architecture with integral registers and “one-hot” counters. This implies that parallel data bits are routed among the counter and the individual on-chip pixel ADC registers. The data path bit-width to the pixel is therefore equivalent to the pixel ADC bit resolution.

  15. The role of natural analogs in the repository licensing process

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, W.M. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    The concept of a permanent geologic repository for high-level nuclear waste (NLW) is implicitly based on analogy to natural systems that have been stable for millions or billions of years. The time of radioactive and chemical toxicity of HLW exceeds the duration of human civilization, and it is impossible to demonstrate the accuracy of predictions of the behavior of engineered or social systems over such long periods.

  16. 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...

  17. Analog Delta-Back-Propagation Neural-Network Circuitry

    Science.gov (United States)

    Eberhart, Silvio

    1990-01-01

    Changes in synapse weights due to circuit drifts suppressed. Proposed fully parallel analog version of electronic neural-network processor based on delta-back-propagation algorithm. Processor able to "learn" when provided with suitable combinations of inputs and enforced outputs. Includes programmable resistive memory elements (corresponding to synapses), conductances (synapse weights) adjusted during learning. Buffer amplifiers, summing circuits, and sample-and-hold circuits arranged in layers of electronic neurons in accordance with delta-back-propagation algorithm.

  18. Proposal for a digital converter of analog magnetic signals

    OpenAIRE

    Ertler, Christian; Fabian, Jaroslav

    2006-01-01

    A device which converts analog magnetic signals directly into digital information is proposed. The device concept is based on the monostable-bistable transition logic element, which consists of two resonant tunneling diodes (load and driver) connected in series and employs the monostable to bistable working point transition of the circuit. Using a magnetic resonant tunneling diode as the driver allows to control the resulting working point of the bistable region by an external magnetic field ...

  19. 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...

  20. FRET based quantification and screening technology platform for the interactions of leukocyte function-associated antigen-1 (LFA-1 with intercellular adhesion molecule-1 (ICAM-1.

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    Full Text Available The interaction between leukocyte function-associated antigen-1(LFA-1 and intercellular adhesion molecule-1 (ICAM-1 plays a pivotal role in cellular adhesion including the extravasation and inflammatory response of leukocytes, and also in the formation of immunological synapse. However, irregular expressions of LFA-1 or ICAM-1 or both may lead to autoimmune diseases, metastasis cancer, etc. Thus, the LFA-1/ICAM-1 interaction may serve as a potential therapeutic target for the treatment of these diseases. Here, we developed one simple 'in solution' steady state fluorescence resonance energy transfer (FRET technique to obtain the dissociation constant (Kd of the interaction between LFA-1 and ICAM-1. Moreover, we developed the assay into a screening platform to identify peptides and small molecules that inhibit the LFA-1/ICAM-1 interaction. For the FRET pair, we used Alexa Fluor 488-LFA-1 conjugate as donor and Alexa Fluor 555-human recombinant ICAM-1 (D1-D2-Fc as acceptor. From our quantitative FRET analysis, the Kd between LFA-1 and D1-D2-Fc was determined to be 17.93±1.34 nM. Both the Kd determination and screening assay were performed in a 96-well plate platform, providing the opportunity to develop it into a high-throughput assay. This is the first reported work which applies FRET based technique to determine Kd as well as classifying inhibitors of the LFA-1/ICAM-1 interaction.

  1. 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

  2. Anti-Plasmodium activity of ceramide analogs

    Directory of Open Access Journals (Sweden)

    Gatt Shimon

    2004-12-01

    Full Text Available Abstract Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range. The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the

  3. 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.

  4. 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

  5. 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.

  6. Foucault's pendulum, a classical analog for the electron spin state

    Science.gov (United States)

    Linck, Rebecca A.

    Spin has long been regarded as a fundamentally quantum phenomena that is incapable of being described classically. To bridge the gap and show that aspects of spin's quantum nature can be described classically, this work uses a classical Lagrangian based on the coupled oscillations of Foucault's pendulum as an analog for the electron spin state in an external magnetic field. With this analog it is possible to demonstrate that Foucault's pendulum not only serves as a basis for explaining geometric phase, but is also a basis for reproducing a broad range of behavior from Zeeman-like frequency splitting to precession of the spin state. By demonstrating that unmeasured electron spin states can be fully described in classical terms, this research opens the door to using the tools of classical physics to examine an inherently quantum phenomenon.

  7. Analog parallel processor hardware for high speed pattern recognition

    Science.gov (United States)

    Daud, T.; Tawel, R.; Langenbacher, H.; Eberhardt, S. P.; Thakoor, A. P.

    1990-01-01

    A VLSI-based analog processor for fully parallel, associative, high-speed pattern matching is reported. The processor consists of two main components: an analog memory matrix for storage of a library of patterns, and a winner-take-all (WTA) circuit for selection of the stored pattern that best matches an input pattern. An inner product is generated between the input vector and each of the stored memories. The resulting values are applied to a WTA network for determination of the closest match. Patterns with up to 22 percent overlap are successfully classified with a WTA settling time of less than 10 microsec. Applications such as star pattern recognition and mineral classification with bounded overlap patterns have been successfully demonstrated. This architecture has a potential for an overall pattern matching speed in excess of 10 exp 9 bits per second for a large memory.

  8. A Multi-Gigahertz Analog Transient Recorder Integrated Circuit

    CERN Document Server

    Kleinfelder, Stuart A

    2015-01-01

    A monolithic multi-channel analog transient recorder, implemented using switched capacitor sample-and-hold circuits and a high-speed analogically-adjustable delay-line-based write clock, has been designed, fabricated and tested. The 2.1 by 6.9 mm layout, in 1.2 micron CMOS, includes over 31,000 transistors and 2048 double polysilicon capacitors. The circuit contains four parallel channels, each with a 512 deep switched-capacitor sample-and-hold system. A 512 deep edge sensitive tapped active delay line uses look-ahead and 16 way interleaving to develop the 512 sample and hold clocks, each as little as 3.2 ns wide and 200 ps apart. Measurements of the device have demonstrated 5 GHz maximum sample rate, at least 350 MHz bandwidth, an extrapolated rms aperture uncertainty per sample of 0.7 ps, and a signal to rms noise ratio of 2000:1.

  9. 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...

  10. Riboswitch-based sensor in low optical background

    Science.gov (United States)

    Harbaugh, Svetlana V.; Davidson, Molly E.; Chushak, Yaroslav G.; Kelley-Loughnane, Nancy; Stone, Morley O.

    2008-08-01

    Riboswitches are a type of natural genetic control element that use untranslated sequence in the RNA to recognize and bind to small molecules that regulate expression of that gene. Creation of synthetic riboswitches to novel ligands depends on the ability to screen for analyte binding sensitivity and specificity. In our work, we have coupled a synthetic riboswitch to an optical reporter assay based on fluorescence resonance energy transfer (FRET) between two genetically-coded fluorescent proteins. Specifically, a theophylline-sensitive riboswitch was placed upstream of the Tobacco Etch Virus (TEV) protease coding sequence, and a FRET-based construct, BFP-eGFP or eGFP-REACh, was linked by a peptide encoding the recognition sequence for TEV protease. Cells expressing the riboswitch showed a marked optical difference in fluorescence emission in the presence of theophylline. However, the BFP-eGFP FRET pair posses significant optical background that reduces the sensitivity of a FRET-based assay. To improve the optical assay, we designed a nonfluorescent yellow fluorescent protein (YFP) mutant called REACh (for Resonance Energy-Accepting Chromoprotein) as the FRET acceptor for eGFP. The advantage of using an eGFP-REACh pair is the elimination of acceptor fluorescence which leads to an improved detection of FRET via better signal-to-noise ratio. The EGFP-REACh fusion protein was constructed with the TEV protease cleavage site; thus upon TEV translation, cleavage occurs diminishing REACh quenching and increasing eGFP emission resulting in a 4.5-fold improvement in assay sensitivity.

  11. Not All Analogies Are Created Equal: Associative and Categorical Analogy Processing following Brain Damage

    Science.gov (United States)

    Schmidt, Gwenda L.; Cardillo, Eileen R.; Kranjec, Alexander; Lehet, Matthew; Widick, Page; Chatterjee, Anjan

    2012-01-01

    Current research on analogy processing assumes that different conceptual relations are treated similarly. However, just as words and concepts are related in distinct ways, different kinds of analogies may employ distinct types of relationships. An important distinction in how words are related is the difference between associative (dog-bone) and…

  12. Time-stretch analog-to-digital conversion with a photonic crystal fiber

    Institute of Scientific and Technical Information of China (English)

    TENG Yun; YU Chong-xiu; YUAN Jin-hui; CHEN Jing-xuan; JIN Cang; XU Qian

    2011-01-01

    All-optical analog-to-digital conversion (ADC) has been extensively researched to break through the inherently limited operating speed of electronic devices. In this paper, we use the photonic crystal fiber (PCF) for time-stretch (TS) analog-todigital (A/D) conversion system through generating low noise, linear chirp distribution and fiat super-continuum (SC).Based on the radio frequency (RF) analog signal modulated to the linearly chirped super-continuum, the large-dispersion photonic crystal fiber is used for time-domain stretching.

  13. The experiment of monthly mean circulation prediction using the analogy-dynamical model

    Institute of Scientific and Technical Information of China (English)

    BAO Ming; NI Yunqi; CHOU Jifan

    2004-01-01

    Based on the past related research work, a new analogy-dynamical monthly prediction model is established with the operational dynamic extended-range forecast model T63L16 (hereafter T63) as a dynamic kernel. The monthly mean circulation prediction with T63 is considered as a control experiment, and the prediction with the analogy-dynamical model as a contrast one. It is found that the analogy-dynamical model has more precise forecast skill than the T63 model through monthly mean numerical prediction experiment.

  14. 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 ...

  15. 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...

  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. Formal analogies in physics teacher education

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio

    2012-01-01

    Reasoning by similarities, especially the ones associated with formal aspects, is one of the most valuable sources for the development of physical theories. The essential role of formal analogies in science can be highlighted by the fact that several equations for different physical situations have...... the exact same appearance. Coulomb’s law’s similarity with Newton’s, Maxwell’s application of fluid theory to electromagnetism and Hamilton’s optical mechanical analogy are some among many other examples. These cases illustrate the power of mathematics in providing unifying structures for physics. 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 known...

  18. 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…

  19. Resistance to somatostatin analogs in acromegaly.

    Science.gov (United States)

    Colao, Annamaria; Auriemma, Renata S; Lombardi, Gaetano; Pivonello, Rosario

    2011-04-01

    Somatostatin analogs (SA) are widely used in acromegaly, either as first-line or adjuvant treatment after surgery. First-line treatment with these drugs is generally used in the patients with macroadenomas or in those with clinical conditions so severe as to prevent unsafe reactions during anesthesia. Generally, the response to SA takes into account both control of GH and IGF-I excess, with consequent improvement of clinical symptoms directly related to GH and IGF-I excess, and tumor shrinkage. This latter effect is more prominent in the patients treated first-line and bearing large macroadenomas, but it is also observed in patients with microadenomas, even with little clinical implication. Predictors of response are patients' gender, age, initial GH and IGF-I levels, and tumor mass, as well as adequate expression of somatostatin receptor types 2 and 5, those with the highest affinity for octreotide and lanreotide. Only sporadic cases of somatostatin receptor gene mutation or impaired signaling pathways have been described in GH-secreting tumors so far. The response to SA also depends on treatment duration and dosage of the drug used, so that a definition of resistance based on short-term treatments using low doses of long-acting SA is limited. Current data suggest that response to these drugs is better analyzed taking together biochemical and tumoral effects because only the absence of both responses might be considered as a poor response or resistance. This latter evidence seems to occur in 25% of treated patients after 12 months of currently available long-acting SA. PMID:21123741

  20. Analogies between a Meniscus and a Cantilever

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Lin

    2009-01-01

    Systematic and quantitative analyses of exact analogies between a meniscus and an elastica are performed. It is shown that the two governing equations take the same style after coordinate translation and scale transformation. The morphologies of the liquid bridge and the cantilever are calculated in terms of elliptic integrations, which can be reduced to the same shape,after converting the boundary conditions. The present analyses can make us grasp the nature of this physical phenomenon deeply and show some inspiration for designing the analogy experiments. Moreover, the calculated results are helpful to engineering applications, such as design and fabrication of MEMS, and micro-manipulations in micro/nano- technology.

  1. Synthetic heparin-binding factor analogs

    Science.gov (United States)

    Pena, Louis A.; Zamora, Paul O.; Lin, Xinhua; Glass, John D.

    2010-04-20

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain, and preferably two peptide chains branched from a dipeptide branch moiety composed of two trifunctional amino acid residues, which peptide chain or chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a linker, which may be a hydrophobic linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  2. An Optical Analog of a Black Holes

    CERN Document Server

    Royston, A; Royston, Andrew; Gass, Richard

    2002-01-01

    Using media with extremely low group velocities one can create an optical analog of a curved space-time. Leonhardt and Piwnicki have proposed that a vortex flow will act as an optical black hole. We show that although the Leonhardt - Piwnicki flow has an orbit of no return and an infinite red-shift surface, it is not a true black hole since it lacks a null hypersurface. However a radial flow will produce a true optical black hole that has a Hawking temperature and obeys the first law of black hole mechanics. By combining the Leonhardt - Piwnicki flow with a radial flow we obtain the analog of the Kerr black hole.

  3. 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...

  4. Landauer bound for analog computing systems.

    Science.gov (United States)

    Diamantini, M Cristina; Gammaitoni, Luca; Trugenberger, Carlo A

    2016-07-01

    By establishing a relation between information erasure and continuous phase transitions we generalize 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. PMID:27575108

  5. Landauer bound for analog computing systems

    Science.gov (United States)

    Diamantini, M. Cristina; Gammaitoni, Luca; Trugenberger, Carlo A.

    2016-07-01

    By establishing a relation between information erasure and continuous phase transitions we generalize 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.

  6. 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.

  7. 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

  8. 电流模式可重构模拟信号处理电路%Current-Mode Reconfigurable Analog Circuit for Analog Signal Processing

    Institute of Scientific and Technical Information of China (English)

    王友仁; 祝鸣涛; 崔江; 林华; 姜媛媛

    2011-01-01

    There are problems of limited function, low operational speed and insufficient flexibility in the conventional reconfigurable analog circuits. A new current-mode reconfigurable analog circuit is proposed to solve them. The configurable analog block (CAB) based on second-generation current controlled conveyor (CCCII) is designed, which has the advantages of smaller nonlinear distortion, higher operational speed and better anti-interference ability. A new crossbar switch inter-connection network is developed, which can reduce the number of switches, and improve the flexibility and high frequency response of the reconfigurable analog circuit. The forth-order butterworth low-pass filter (LPF) and the analog multiplier are reconfigured with 2X4 reconfigurable analog circuit array. The experimental results show that the proposed reconfigurable analog circuit can effectively realize analog signal processing circuits of different functions through reconfiguration.%针对现有的可重构模拟电路存在功能有限、带宽小、灵活性不足等同题,设计了一种新的电流模式可重构模拟电路.设计了基于二代电流传输控制器的可重构模拟单元,能减小电路非线性失真,提高电路工作速度与抗干扰能力.设计了一种可编程开关数量较少的纵横交叉开关网络结构,提高了电路灵活性和高频性能.在2×4一阵列结构上分别重构实现了四阶低通滤波器和模拟乘法器,实验结果表明所设计可重构模拟电路是有效的.

  9. Tremor suppression using functional electrical stimulation: a comparison between digital and analog controllers.

    Science.gov (United States)

    Gillard, D M; Cameron, T; Prochazka, A; Gauthier, M J

    1999-09-01

    In this study, we compared digital and analog versions of a functional electrical stimulator designed to suppress tremor. The device was based on a closed-loop control system designed to attenuate movements in the tremor frequency range, without significantly affecting slower, voluntary movements. Testing of the digital filter was done on three patients with Parkinsonian tremor and the results compared to those of a functional electrical stimulation device based on an analog filter evaluated in a previous study. Additional testing of both the analog and digital filters was done on three subjects with no neurological impairment performing tremor-like movements and slow voluntary movements. We found that the digital controller provided a mean attenuation of 84%, compared to 65% for the analog controller.

  10. Mechatronics by Analogy and Application to Legged Locomotion

    Science.gov (United States)

    Ragusila, Victor

    A new design methodology for mechatronic systems, dubbed as Mechatronics by Analogy (MbA), is introduced and applied to designing a leg mechanism. The new methodology argues that by establishing a similarity relation between a complex system and a number of simpler models it is possible to design the former using the analysis and synthesis means developed for the latter. The methodology provides a framework for concurrent engineering of complex systems while maintaining the transparency of the system behaviour through making formal analogies between the system and those with more tractable dynamics. The application of the MbA methodology to the design of a monopod robot leg, called the Linkage Leg, is also studied. A series of simulations show that the dynamic behaviour of the Linkage Leg is similar to that of a combination of a double pendulum and a spring-loaded inverted pendulum, based on which the system kinematic, dynamic, and control parameters can be designed concurrently. The first stage of Mechatronics by Analogy is a method of extracting significant features of system dynamics through simpler models. The goal is to determine a set of simpler mechanisms with similar dynamic behaviour to that of the original system in various phases of its motion. A modular bond-graph representation of the system is determined, and subsequently simplified using two simplification algorithms. The first algorithm determines the relevant dynamic elements of the system for each phase of motion, and the second algorithm finds the simple mechanism described by the remaining dynamic elements. In addition to greatly simplifying the controller for the system, using simpler mechanisms with similar behaviour provides a greater insight into the dynamics of the system. This is seen in the second stage of the new methodology, which concurrently optimizes the simpler mechanisms together with a control system based on their dynamics. Once the optimal configuration of the simpler system is

  11. 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

  12. Method of analog circuit fault diagnosis based on FOA-neural network%基于果蝇-构造小波神经网络模拟电路诊断方法

    Institute of Scientific and Technical Information of China (English)

    于文新; 何怡刚; 吴先明; 高坤

    2015-01-01

    利用果蝇算法优化构造小波神经网络,建立FOA-构造小波神经网络模型,并将模型应用于模拟电路故障分析当中,通过仿真试验可发现该方法在故障诊断中有较高的准确性。%In the paper, FOA and wavelet-neural network are applied to establish a FOA-structure wavelet neural network algorithm. The model is applied to an analog circuit fault analysis by simulation. The method has higher accuracy in fault diagnosis.

  13. Analog Ensemble Methodology: Expansion and Optimization for Renewable Energy Applications

    Science.gov (United States)

    Harding, L.; Cervone, G.; Delle Monache, L.

    2015-12-01

    Renewable energy is fundamental for sustaining and developing society. Solar and wind energy are promising sources because of their decreased environmental impact relative to conventional energy sources, improved efficiency, and increased use. A key challenge with renewable energy production is the generation of accurate renewable energy forecasts at varying spatial and temporal scales to assist utility companies in effective energy management. Specifically, this research applies the Analog Ensemble (AnEn) methodology to short-term (0-48 hour) wind speed forecasting for power generation and short-term (0-72) hour solar power measured (PM) output predictions. AnEn uses a set of past observations corresponding to the best analogs of a deterministic numerical weather prediction model to generate a probability distribution of future atmospheric states: an ensemble of analogs. Currently the AnEn methodology equally weights predictors and only handles 1D(time). We determine an optimal distribution of predictor weights based upon parameter characteristics, investigate spatial variations in the application of the methodology and develop a theory expanding the methodology into 2D. The AnEn methodology improves short-term prediction accuracy, decreases computational costs and provides uncertainty quantification allowing utility companies to manage over- or under power generation for renewable energy sources.

  14. On the Frequency of Potential Venus Analogs from Kepler Data

    CERN Document Server

    Kane, Stephen R; Domagal-Goldman, Shawn D

    2014-01-01

    The field of exoplanetary science has seen a dramatic improvement in sensitivity to terrestrial planets over recent years. Such discoveries have been a key feature of results from the {\\it Kepler} mission which utilizes the transit method to determine the size of the planet. These discoveries have resulted in a corresponding interest in the topic of the Habitable Zone (HZ) and the search for potential Earth analogs. Within the Solar System, there is a clear dichotomy between Venus and Earth in terms of atmospheric evolution, likely the result of the large difference ($\\sim$ factor of two) in incident flux from the Sun. Since Venus is 95\\% of the Earth's radius in size, it is impossible to distinguish between these two planets based only on size. In this paper we discuss planetary insolation in the context of atmospheric erosion and runaway greenhouse limits for planets similar to Venus. We define a ``Venus Zone'' (VZ) in which the planet is more likely to be a Venus analog rather than an Earth analog. We iden...

  15. Mathematical analogies in physics. Thin-layer wave theory

    Directory of Open Access Journals (Sweden)

    José M. Carcione

    2014-03-01

    Full Text Available Field theory applies to elastodynamics, electromagnetism, quantum mechanics, gravitation and other similar fields of physics, where the basic equations describing the phenomenon are based on constitutive relations and balance equations. For instance, in elastodynamics, these are the stress-strain relations and the equations of momentum conservation (Euler-Newton law. In these cases, the same mathematical theory can be used, by establishing appropriate mathematical equivalences (or analogies between material properties and field variables. For instance, the wave equation and the related mathematical developments can be used to describe anelastic and electromagnetic wave propagation, and are extensively used in quantum mechanics. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission problem of a thin layer embedded between dissimilar media, considering the presence of anisotropy and attenuation/viscosity in the viscoelastic case, conductivity in the electromagnetic case and a potential barrier in quantum physics (the tunnel effect. The analogy is mainly illustrated with geophysical examples of propagation of S (shear, P (compressional, TM (transverse-magnetic and TE (transverse-electric waves. The tunnel effect is obtained as a special case of viscoelastic waves at normal incidence.

  16. Design, synthesis and aphicidal activity of N-terminal modified insect kinin analogs.

    Science.gov (United States)

    Zhang, Chuanliang; Qu, Yanyan; Wu, Xiaoqing; Song, Dunlun; Ling, Yun; Yang, Xinling

    2015-06-01

    The insect kinins are a class of multifunctional insect neuropeptides present in a diverse variety of insects. Insect kinin analogs showed multiple bioactivities, especially, the aphicidal activity. To find a biostable and bioactive insecticide candidate with simplified structure, a series of N-terminal modified insect kinin analogs was designed and synthesized based on the lead compound [Aib]-Phe-Phe-[Aib]-Trp-Gly-NH2. Their aphicidal activity against the soybean aphid Aphis glycines was evaluated. The results showed that all the analogs maintained the aphicidal activity. In particular, the aphicidal activity of the pentapeptide analog X Phe-Phe-[Aib]-Trp-Gly-NH2 (LC50=0.045mmol/L) was similar to the lead compound (LC50=0.048mmol/L). This indicated that the N-terminal protective group may not play an important role in the activity and the analogs structure could be simplified to pentapeptide analogs while retaining good aphicidal activity. The core pentapeptide analog X can be used as the lead compound for further chemical modifications to discover potential insecticides. PMID:25116632

  17. 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.

  18. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  19. Generalizing the Nagel line to circumscribed polygons by analogy and constructive defining

    Directory of Open Access Journals (Sweden)

    Michael de Villiers

    2008-10-01

    Full Text Available This paper first discusses the genetic approach and the relevance of the history of mathematics for teaching, reasoning by analogy, and the role of constructive defining in the creation of new mathematical content. It then uses constructive defining to generate a new generalization of the Nagel line of a triangle to polygons circumscribed around a circle, based on an analogy between the Nagel line and the Euler line of a triangle.

  20. 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.

  1. 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.

  2. Analog Acoustic Expression in Speech Communication

    Science.gov (United States)

    Shintel, Hadas; Nusbaum, Howard C.; Okrent, Arika

    2006-01-01

    We present the first experimental evidence of a phenomenon in speech communication we call "analog acoustic expression." Speech is generally thought of as conveying information in two distinct ways: discrete linguistic-symbolic units such as words and sentences represent linguistic meaning, and continuous prosodic forms convey information about…

  3. 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…

  4. 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.

  5. C4913 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1996-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course C4913 Analog and Digital Filters...

  6. CMOS circuits for analog signal processing

    NARCIS (Netherlands)

    Wallinga, Hans

    1988-01-01

    Design choices in CMOS analog signal processing circuits are presented. Special attention is focussed on continuous-time filter technologies. The basics of MOSFET-C continuous-time filters and CMOS Square Law Circuits are explained at the hand of a graphical MOST characteristics representation.

  7. 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)

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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)

  13. Classical Analog of Electromagnetically Induced Transparency

    CERN Document Server

    Alzar, C L G; Nussenzveig, P

    2002-01-01

    We present a classical analog for Electromagnetically Induced Transparency (EIT). In a system of just two coupled harmonic oscillators subject to a harmonic driving force we can reproduce the phenomenology observed in EIT. We describe a simple experiment performed with two linearly coupled RLC circuits which can be taught in an undergraduate laboratory class.

  14. Analogy between thermal convective and magnetohydrodynamic instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Valdmanis, Ya.Ya.; Kukainis, O.A.

    1977-01-01

    An examination is made of the analogy between thermo-convective instability and instability produced by various electromagnetic forces both in steady and alternating thermal and electromagnetic fields. An example is given for calculating an assumed bubble instability which could occur in an alternating magnetic field. 17 references.

  15. Analogy, an Alternative Model.
 Critics to the standard model of analogical problems solving and proposals for an alternative one

    Directory of Open Access Journals (Sweden)

    Ricardo A. Minervino

    2016-02-01

    Full Text Available The authors made an extension of Hofstadter‘s criticisms against the standard approach in analogical thinking represented by the structure-mapping theory of Gentner and the multiconstraint theory of Holyoak and Thagard. Based on this extension, they proposed a non-serial model of analogical problem solving. Against the standard approach, the model postulates that: (a people detect and evaluate differences between mapped elements before the subprocess of inference generation and consider them in order to control it, and (b properties of an element that explain why the element could fill a certain role in the base problem resolution (PERs play a crucial role in these detection and evaluation operations, and also in post-inferences subprocesses. An experiment showed that: (a people detect and evaluate the relevance of differences between mapped elements before inference generation, (b that they inhibit the generation of literal inferences when they face relevant differences, and (c that they stop the subprocess when they recognize insuperable ones. The results also showed that base PERs are reactivated at different moments of analogical transfer. The data obtained are incompatible with the standard theories of analogical thinking, which treat inference generation as a syntactic mechanism and exclude contextual semantic analysis from the study of analogy

  16. 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

  17. The solar-stellar connection: Magnetic activity of seismic solar analogs

    CERN Document Server

    Salabert, D; Beck, P G; Regulo, C; Ballot, J; Creevey, O L; Egeland, R; Nascimento, J -D do; Hernandez, F Perez; Bigot, L; Mathur, S; Metcalfe, T S; Corsaro, E; Palle, P L

    2016-01-01

    Finding solar-analog stars with fundamental properties as close as possible to the Sun and studying the characteristics of their surface magnetic activity is a very promising way to understand the solar variability and its associated dynamo process. However, the identification of solar-analog stars depends on the accuracy of the estimated stellar parameters. Thanks to the photometric CoROT and Kepler space missions, the addition of asteroseismic data was proven to provide the most accurate fundamental properties that can be derived from stellar modeling today. Here, we present our latest results on the solar-stellar connection by studying 18 solar analogs that we identified among the Kepler seismic sample (Salabert et al., 2016a). We measured their magnetic activity properties using the observations collected by the Kepler satellite and the ground-based, high-resolution HERMES spectrograph. The photospheric (Sph) and chromospheric (S) magnetic activity proxies of these seismic solar analogs are compared in re...

  18. 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.

  19. 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

  20. 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...... 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...... suppressive for dehydrogenase activity of soil microorganisms compared to all carbendazim sulfur analogs....

  1. An 8-bit Data Driving Scheme Based on Two-Step Digital-to-Analog Conversion for Integrated Data Drivers of Active-Matrix Organic Light-Emitting Diodes

    Science.gov (United States)

    Kim, Tae-Wook; Choi, Byong-Deok

    2012-03-01

    The two-step digital-to-analog conversion (DAC) scheme has been reported to be very area-efficient for thin-film transistor-liquid crystal display (TFT-LCD) data driver ICs, but it is not as well suited as it is for polycrystalline silicon (poly-Si) TFT integrated circuits. The charge redistribution in the two-step DAC process requires an operational amplifier in principle, which is most challenging for poly-Si TFT circuits. The proposed two-step DAC for active-matrix organic light-emitting diodes (AMOLEDs) makes the operational amplifier unnecessary by appropriately exploiting the preexisting capacitors in the pixel to compensate for the characteristic variations of TFTs. Moreover, the second-step DAC occurs at the same time as threshold voltage compensation, and it does not require additional time. By thoroughly analyzing area efficiency depending on the resolution decomposition between the first- and second-step DACs, we found that 5-bit coarse plus 3-bit fine DACs are best in terms of circuit area. When we designed a layout of the proposed 8-bit DAC on the basis of the 4 µm design rules, the DAC circuit area is no more than 72×637 µm2, which, to the best of our knowledge, is the most compact to date.

  2. Implementing size-optimal discrete neural networks require analog circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1998-12-01

    This paper starts by overviewing results dealing with the approximation capabilities of neural networks, as well as bounds on the size of threshold gate circuits. Based on a constructive solution for Kolmogorov`s superpositions the authors show that implementing Boolean functions can be done using neurons having an identity transfer function. Because in this case the size of the network is minimized, it follows that size-optimal solutions for implementing Boolean functions can be obtained using analog circuitry. Conclusions and several comments on the required precision are ending the paper.

  3. Criteria for eliminating items of a Test of Figural Analogies

    Directory of Open Access Journals (Sweden)

    Diego Blum

    2013-12-01

    Full Text Available This paper describes the steps taken to eliminate two of the items in a Test of Figural Analogies (TFA. The main guidelines of psychometric analysis concerning Classical Test Theory (CTT and Item Response Theory (IRT are explained. The item elimination process was based on both the study of the CTT difficulty and discrimination index, and the unidimensionality analysis. The a, b, and c parameters of the Three Parameter Logistic Model of IRT were also considered for this purpose, as well as the assessment of each item fitting this model. The unfavourable characteristics of a group of TFA items are detailed, and decisions leading to their possible elimination are discussed.

  4. A Neural Network Appraoch to Fault Diagnosis in Analog Circuits

    Institute of Scientific and Technical Information of China (English)

    尉乃红; 杨士元; 等

    1996-01-01

    Thia paper presents a neural network based fault diagnosis approach for analog circuits,taking the tolerances of circuit elements into account.Specifically,a normalization rule of input information,a pseudo-fault domain border(PFDB)pattern selection method and a new output error function are proposed for training the backpropagation(BP) network to be a fault diagnoser.Experimental results demonstrate that the diagnoser performs as well as or better than any classical approaches in terms of accuracy,and provides at least an order-of-magnitude improvement in post-fault diagnostic speed.

  5. Programmable Analog Memory Resistors For Electronic Neural Networks

    Science.gov (United States)

    Ramesham, Rajeshuni; Thakoor, Sarita; Daud, Taher; Thakoor, Anilkumar P.

    1990-01-01

    Electrical resistance of new solid-state device altered repeatedly by suitable control signals, yet remains at steady value when control signal removed. Resistance set at low value ("on" state), high value ("off" state), or at any convenient intermediate value and left there until new value desired. Circuits of this type particularly useful in nonvolatile, associative electronic memories based on models of neural networks. Such programmable analog memory resistors ideally suited as synaptic interconnects in "self-learning" neural nets. Operation of device depends on electrochromic property of WO3, which when pure is insulator. Potential uses include nonvolatile, erasable, electronically programmable read-only memories.

  6. A simple analog boxcar integrator for pulsed NMR spectrometer

    International Nuclear Information System (INIS)

    The design aspects of an analog boxcar integrator constructed for the recovery of FID and spin echo waveforms from a pulsed NMR experiment conducted on a single seed of ground nut are described. The instrument facilitates the selection of any part of the waveform for observation and incorporates necessary circuitry for base-line correction. The scan time may be varied upto 10,000 seconds, with a linearity of better than 0.1%. The hold time for sampling gate used is over 15 minutes, which is more than adequate for studying all kinds of solid samples. (auth.)

  7. 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.

  8. 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).

  9. 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.

  10. 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

  11. Synthesis and Evaluation of Desmethyl Azumamide Analogs

    DEFF Research Database (Denmark)

    Maolanon, Alex

    the azumamide analogs; however, removal of the methyl group had a significant impact relative to the natural products. To understand this effect, the NMR structure was solved with the assistance from Casper Hoeck and Charlotte H. Gotfredsen and docked conformations were obtained from Niels J. Christensen...... and Peter Fristrup. Compared to the natural compounds, the 3Dstructure of the scaffold in the azumamide analogs were similar. Although a conclusion was not found, the preliminary docking results indicated favorable lipophilic interaction with the methyl group in the azumamides. Largazole is another...... macrocylic natural product with HDAC inhibitory activity. The compound has a thioester functionality in the side chain, which is hydrolyzed before interaction with the enzymes. In the attempt to mimic the prodrug nature of largazole, compounds containing a thiol group were designed, as it was hypothesized...

  12. 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...

  13. Analog optical computing primitives in silicon photonics.

    Science.gov (United States)

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

    2016-03-15

    Optical computing accelerators 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 and the recovery of a signal in the presence of multiplicative distortion. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide. PMID:26977687

  14. 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.

  15. 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.

  16. Electrical Analogy to an Atomic Force Microscope

    Directory of Open Access Journals (Sweden)

    O. Kucera

    2010-04-01

    Full Text Available Several applications of the atomic force microscopy (AFM, such as measurement of soft samples, manipulation with molecules, etc., require mechanical analysis of the AFM probe behavior. In this article we suggest the electrical circuit analogy to AFM cantilever tip motion. Well developed circuit theories in connection with fairly accessible software for circuit analysis make this alternative method easy to use for a wide community of AFM users.

  17. 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.

  18. 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...

  19. 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...

  20. Status of the CALICE analog calorimeter technological prototypes

    CERN Document Server

    Terwort, Mark

    2012-01-01

    The CALICE collaboration is currently developing engineering prototypes of electromagnetic and hadronic calorimeters for a future linear collider detector. This detector is designed to be used in particle-flow based event reconstruction. In particular, the calorimeters are optimized for the individual reconstruction and separation of electromagnetic and hadronic showers. They are conceived as sampling calorimeters with tungsten and steel absorbers, respectively. Two electromagnetic calorimeters are being developed, one with silicon-based active layers and one based on scintillator strips that are read out by MPPCs, allowing highly granular readout. The analog hadron calorimeter is based on scintillating tiles that are also read out individually by silicon photomultipliers. The multi-channel, auto-triggered front-end chips are integrated into the active layers of the calorimeters and are designed for minimal power consumption (power pulsing). The goal of the construction of these prototypes is to demonstrate t...

  1. 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.

  2. 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)

  3. 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.

  4. 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)

  5. Synthesis and characterization of novel N3O3-Schiff base complexes of 99gTc, and in vivo imaging studies with analogous 99mTc complexes.

    Science.gov (United States)

    Marmion, M E; Woulfe, S R; Newmann, W L; Pilcher, G; Nosco, D L

    1996-07-01

    Sixteen novel derivatives of 1,1,1-tris (salicylaldiminomethyl)ethane have been synthesized for the purpose of encapsulating 99mTc(IV) ions and generating new 99mTc radiopharmaceuticals. Two methods for the preparation of the 99gTc(IV) analog complexes are presented; one utilizes SnCl2 reduction on 99gTcO4- and the other a direct substitution route starting with [99gTcCl6]2-. Free ligands (H3L) are characterized by melting points, 1H NMR, 13C NMR, mass spectroscopy, TLC, and/or elemental analyses. [99gTcL]+ complexes are characterized by FAB-ms, UV-VIS, IR and/or CV. An X-ray structural analysis was performed on a crystal of [M(6,6'-[[2-[[((4-Methoxy-2-hydroxyphenyl) methylene)-amino]methyl]-2-methyl- 1,3-propanediyl]bis(nitrilomethylidyne)]-bis-3-methoxyphenol )] tetraphenylborate, where M represents a 1/3 isomorphous mixture of 99gTc/Sn as determined by SEM. The metal coordination site is 6-coordinate, composed of N3O3 donor atoms, and intermediate between octahedral and trigonal prismatic geometry. The [99mTcL]+ complexes were prepared in a stannous environment; equivalence of the 99mTc and 99gTc complexes is demonstrated by HPLC techniques. The [SnL]+ complex was prepared for comparison purposes. An unusual ligand oxidation occurs for one series of ligands in which in situ amine-->imine conversion is observed during the complexation reaction in reducing media. Guinea pig, rat, dog, and human metabolism studies are reported for selected [99mTcL]+ complexes, the myocardial uptake of which approaches 2% of the injected dose. PMID:8905821

  6. Electronic analogy of Goos-H\\"{a}nchen effect: a review

    OpenAIRE

    Chen, Xi; Lu, Xiao-Jing; Ban, Yue; Li, Chun-Fang

    2013-01-01

    The analogies between optical and electronic Goos-H\\"{a}nchen effects are established based on electron wave optics in semiconductor or graphene-based nanostructures. In this paper, we give a brief overview of the progress achieved so far in the field of electronic Goos-H\\"{a}nchen shifts, and show the relevant optical analogies. In particular, we present several theoretical results on the giant positive and negative Goos-H\\"{a}nchen shifts in various semiconductor or graphen-based nanostruct...

  7. A Kolmogorov Complexity View of Analogy: From Logical Modeling to Experimentations

    Science.gov (United States)

    Bayoudh, Meriam; Prade, Henri; Richard, Gilles

    Analogical reasoning is considered as one of the main mechanisms underlying human intelligence and creativity, allowing the paradigm shift essential to a creative process. More specific is the notion of analogical proportion like "2 is to 4 as 5 is to 10" or "read is to reader as lecture is to lecturer": such statements can be precisely described within an algebraic framework. When the proportion holds between concepts as in "engine is to car as heart is to human" or "wine is to France as beer is to England", applying an algebraic framework is less straightforward and a new way to understand analogical proportions on the basis of Kolmogorov complexity theory may seem more appropriate. This viewpoint has been used to develop a classifier detecting analogies in natural language. Despite their apparent difference, it is quite clear that the two viewpoints should be strongly related. In this paper, we investigate the link between a purely abstract view of analogical proportions and a definition based on Kolmogorov complexity theory. This theory is used as a backbone to experiment a classifier of natural language analogies whose results are consistent with the abstract setting.

  8. Combined Self-Test of Analog Portion and ADCs in Integrated Mixed-Signal Circuits

    Science.gov (United States)

    Hu, Geng; Wang, Hong; Yang, Shiyuan

    Testing is a critical stage in integrated circuits production in order to guarantee reliability. The complexity and high integration level of mixed-signal ICs has put forward new challenges to circuit testing. This paper describes an oscillation-based combined self-test strategy for the analog portion and analog-to-digital converters (ADCs) in integrated mixed-signal circuits. In test mode, the analog portion under test is reconfigured into an oscillator, generating periodic signals as the test stimulus of ADC. By analyzing the A/D conversion results, a histogram test of ADC can be performed, and the oscillation frequency as well as amplitude can be checked, and in this way the oscillation test of the analog portion is realized simultaneously. For an analog benchmark circuit combined with an ADC, triangle oscillation and sinusoid oscillation schemes are both given to test their faults. Experimental results show that fault coverage of the analog portion is 92.2% and 94.3% in the two schemes respectively, and faults in the ADC can also be tested.

  9. FITPix COMBO—Timepix detector with integrated analog signal spectrometric readout

    Science.gov (United States)

    Holik, M.; Kraus, V.; Georgiev, V.; Granja, C.

    2016-02-01

    The hybrid semiconductor pixel detector Timepix has proven a powerful tool in radiation detection and imaging. Energy loss and directional sensitivity as well as particle type resolving power are possible by high resolution particle tracking and per-pixel energy and quantum-counting capability. The spectrometric resolving power of the detector can be further enhanced by analyzing the analog signal of the detector common sensor electrode (also called back-side pulse). In this work we present a new compact readout interface, based on the FITPix readout architecture, extended with integrated analog electronics for the detector's common sensor signal. Integrating simultaneous operation of the digital per-pixel information with the common sensor (called also back-side electrode) analog pulse processing circuitry into one device enhances the detector capabilities and opens new applications. Thanks to noise suppression and built-in electromagnetic interference shielding the common hardware platform enables parallel analog signal spectroscopy on the back side pulse signal with full operation and read-out of the pixelated digital part, the noise level is 600 keV and spectrometric resolution around 100 keV for 5.5 MeV alpha particles. Self-triggering is implemented with delay of few tens of ns making use of adjustable low-energy threshold of the particle analog signal amplitude. The digital pixelated full frame can be thus triggered and recorded together with the common sensor analog signal. The waveform, which is sampled with frequency 100 MHz, can be recorded in adjustable time window including time prior to the trigger level. An integrated software tool provides control, on-line display and read-out of both analog and digital channels. Both the pixelated digital record and the analog waveform are synchronized and written out by common time stamp.

  10. Analogies in Medicine: Valuable for Learning, Reasoning, Remembering and Naming

    Science.gov (United States)

    Pena, Gil Patrus; Andrade-Filho, Jose de Souza

    2010-01-01

    Analogies are important tools in human reasoning and learning, for resolving problems and providing arguments, and are extensively used in medicine. Analogy and similarity involve a structural alignment or mapping between domains. This cognitive mechanism can be used to make inferences and learn new abstractions. Through analogies, we try to…

  11. 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…

  12. Anti-inflammatory effect of thalidomide dithiocarbamate and dithioate analogs.

    Science.gov (United States)

    Talaat, Roba; El-Sayed, Waheba; Agwa, Hussein S; Gamal-Eldeen, Amira M; Moawia, Shaden; Zahran, Magdy A H

    2015-08-01

    Thalidomide has anti-inflammatory, immunomodulatory, and anti-angiogenic properties. It has been used to treat a variety of cancers and autoimmune diseases. This study aimed to characterize anti-inflammatory activities of novel thalidomide analogs by exploring their effects on splenocytes proliferation and macrophage functions and their antioxidant activity. MTT assay was used to assess the cytotoxic effect of thalidomide analogs against splenocytes. Tumor necrosis factor (TNF-α) and nuclear factor kappa B (NF-κB-P65) were determined by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) was estimated by colorimetric assay. Antioxidant activity was examined by ORAC assay. Our results demonstrated that thalidomide dithioate analog 2 and thalidomide dithiocarbamate analog 4 produced a slight increase in splenocyte proliferation compared with thalidomide. Thalidomide dithiocarbamate analog 1 is a potent inhibitor of TNF-α production, whereas thalidomide dithiocarbamate analog 5 is a potent inhibitor of both TNF-α and NO. Analog 2 has a pronounced inhibitory effect on NF-κB-P65 production level. All thalidomide analogs showed prooxidant activity against hydroxyl (OH) radical. Analog 1 and thalidomide dithioate analog 3 have prooxidant activity against peroxyl (ROO) radical in relation to thalidomide. On the other hand, analog 4 has a potent scavenging capacity against peroxyl (ROO) radical compared with thalidomide. Taken together, the results of this study suggest that thalidomide analogs might have valuable anti-inflammatory activities with more pronounced effect than thalidomide itself.

  13. Chain elongation analog of resveratrol as potent cancer chemoprevention agent.

    Science.gov (United States)

    Kang, Yan-Fei; Qiao, Hai-Xia; Xin, Long-Zuo; Ge, Li-Ping

    2016-09-01

    Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism. PMID:27160168

  14. 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.

  15. 2012 Moon Mars Analog Mission Activities on Mauna Kea, Hawai'i

    Science.gov (United States)

    Graham, Lee; Graff, Trevor G.; Aileen Yingst, R.; ten Kate, Inge L.; Russell, Patrick

    2015-05-01

    Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were completed at Mauna Kea, Hawaii. Scientific investigations, scientific input, and science operations constraints were tested in the context of an existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration. Four separate science investigations were integrated in a Martian analog environment with initial science operations planned based on a model similar to the operations control of the Mars Exploration Rovers (MER). However, evolution of the operations process occurred during the initial planning sessions and as the analog mission progressed. We review here the overall program of the investigation into the origin of the valley including preliminary sensor data results, an applicable methodology for developing an optimum science input based on productive engineering, and science trades and the science operations approach for an investigation into the valley on the upper slopes of Mauna Kea identified as “Apollo Valley”.

  16. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters.

    Science.gov (United States)

    Sezgin, Erdinc; Can, Fatma Betul; Schneider, Falk; Clausen, Mathias P; Galiani, Silvia; Stanly, Tess A; Waithe, Dominic; Colaco, Alexandria; Honigmann, Alf; Wüstner, Daniel; Platt, Frances; Eggeling, Christian

    2016-02-01

    Cholesterol (Chol) is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of Chol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently labeled Chol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction, and trafficking in cells; hence, it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase-separated giant unilamellar vesicles and giant plasma membrane vesicles; 2) cellular trafficking, specifically subcellular localization in Niemann-Pick type C disease cells; and 3) applicability in fluorescence correlation spectroscopy (FCS)-based and super-resolution stimulated emission depletion-FCS-based measurements of membrane diffusion dynamics. The analogs exhibited strong differences, with some indicating positive performance in the membrane-based experiments and others in the intracellular trafficking assay. However, none showed positive performance in all assays. Our results constitute a concise guide for the careful use of fluorescent Chol analogs in visualizing cellular Chol dynamics. PMID:26701325

  17. Structural studies of nucleoside analog and feedback inhibitor binding to Drosophila melanogaster multisubstrate deoxyribonucleoside kinase

    DEFF Research Database (Denmark)

    Mikkelsen, Niels Egil; Munch-Petersen, Birgitte; Eklund, Hans

    2008-01-01

    relate them to the binding of substrate and feedback inhibitors. dCTP and dGTP binds similarly as the feedback inhibitor dTTP with the base in the substrate site. All investigated nucleoside analogs bind similarly as the pyrimidine substrates with many interactions in common. In contrast, the base of d...

  18. SSERVI Analog Regolith Simulant Testbed Facility

    Science.gov (United States)

    Minafra, Joseph; Schmidt, Gregory; Bailey, Brad; Gibbs, Kristina

    2016-10-01

    The Solar System Exploration Research Virtual Institute (SSERVI) at NASA's Ames Research Center in California's Silicon Valley was founded in 2013 to act as a virtual institute that provides interdisciplinary research centered on the goals of its supporting directorates: NASA Science Mission Directorate (SMD) and the Human Exploration & Operations Mission Directorate (HEOMD).Primary research goals of the Institute revolve around the integration of science and exploration to gain knowledge required for the future of human space exploration beyond low Earth orbit. SSERVI intends to leverage existing JSC1A regolith simulant resources into the creation of a regolith simulant testbed facility. The purpose of this testbed concept is to provide the planetary exploration community with a readily available capability to test hardware and conduct research in a large simulant environment.SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers.SSERVI provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment.The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area, including dust mitigation and safety oversight.Facility hardware and environment testing scenarios could include, Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, Surface features (i.e. grades and rocks)Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and

  19. Novel Gemini vitamin D3 analogs

    DEFF Research Database (Denmark)

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

    2014-01-01

    anticancer potency, but similar toxicity causing hypercalcemia. We focused on the effect of these compounds on the stimulation of expression of human cathelicidin antimicrobial peptide (CAMP) whose gene has a vitamin D response element in its promoter. Expression of CAMP mRNA and protein increased in a dose......-response fashion after exposure of acute myeloid leukemia (AML) cells to the Gemini analog, BXL-01-126, in vitro. A xenograft model of AML was developed using U937 AML cells injected into NSG-immunodeficient mice. Administration of vitamin D3 compounds to these mice resulted in substantial levels of CAMP...

  20. Analogic China map constructed by DNA

    Institute of Scientific and Technical Information of China (English)

    QIAN Lulu; HE Lin; WANG Ying; ZHANG Zhao; ZHAO Jian; PAN Dun; ZHANG Yi; LIU Qiang; FAN Chunhai; HU Jun

    2006-01-01

    In this research, a nanoscale DNA structure of analogic China map is created. The nanostructure of roughly 150 nm in diameter with a spatial resolution of 6 nm is purely constructed by folding DNA. The picture observed by atomic force microscopy (AFM) is almost identical with the designed shape. The DNA origami technology invented by Rothemund in 2006 is employed in the construction of this shape, which has proved the capability of constructing almost any complicated shape enabled by DNA origami, and provides new bottom-up method for constructing nanostructures.

  1. 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 ...

  2. 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

  3. Microstore: the Stanford analog memory unit

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.T.; Chae, S.I.; Shapiro, S.; Larsen, R.S.

    1984-11-01

    An NMOS device has been developed which provides high speed analog signal storage and readout for time expansion of transient signals. This device takes advantage of HMOS-1 VLSI technology to implement an array of 256 storage cells. Sequential samples of an input waveform can be taken every 5 ns while providing an effective sampling aperture time of less than 1 ns. The design signal-to-noise ratio is 1 part in 2000. Digital control circuitry is provided on the chip for controlling the read-in and read-out processes. A reference circuit is incorporated in the chip for first order compensation of leakage drifts, sampling pedestals, and temperature effects.

  4. 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.

  5. Energy Savings Assessment for Digital-to-Analog Converter Boxes

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Hoi Ying Iris; Meier, Alan; Brown, Richard

    2011-01-18

    The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.

  6. Error Models of the Analog to Digital Converters

    Directory of Open Access Journals (Sweden)

    Michaeli Linus

    2014-04-01

    Full Text Available Error models of the Analog to Digital Converters describe metrological properties of the signal conversion from analog to digital domain in a concise form using few dominant error parameters. Knowledge of the error models allows the end user to provide fast testing in the crucial points of the full input signal range and to use identified error models for post correction in the digital domain. The imperfections of the internal ADC structure determine the error characteristics represented by the nonlinearities as a function of the output code. Progress in the microelectronics and missing information about circuital details together with the lack of knowledge about interfering effects caused by ADC installation prefers another modeling approach based on the input-output behavioral characterization by the input-output error box. Internal links in the ADC structure cause that the input-output error function could be described in a concise form by suitable function. Modeled functional parameters allow determining the integral error parameters of ADC. Paper is a survey of error models starting from the structural models for the most common architectures and their linkage with the behavioral models represented by the simple look up table or the functional description of nonlinear errors for the output codes.

  7. 2-acetylphenol analogs as potent reversible monoamine oxidase inhibitors

    Directory of Open Access Journals (Sweden)

    Legoabe LJ

    2015-07-01

    Full Text Available Lesetja J Legoabe,1 Anél Petzer,1 Jacobus P Petzer1,21Centre of Excellence for Pharmaceutical Sciences, 2Department of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South AfricaAbstract: Based on a previous report that substituted 2-acetylphenols may be promising leads for the design of novel monoamine oxidase (MAO inhibitors, a series of C5-substituted 2-acetylphenol analogs (15 and related compounds (two were synthesized and evaluated as inhibitors of human MAO-A and MAO-B. Generally, the study compounds exhibited inhibitory activities against both MAO-A and MAO-B, with selectivity for the B isoform. Among the compounds evaluated, seven compounds exhibited IC50 values <0.01 µM for MAO-B inhibition, with the most selective compound being 17,000-fold selective for MAO-B over the MAO-A isoform. Analyses of the structure–activity relationships for MAO inhibition show that substitution on the C5 position of the 2-acetylphenol moiety is a requirement for MAO-B inhibition, and the benzyloxy substituent is particularly favorable in this regard. This study concludes that C5-substituted 2-acetylphenol analogs are potent and selective MAO-B inhibitors, appropriate for the design of therapies for neurodegenerative disorders such as Parkinson’s disease.Keywords: monoamine oxidase, MAO, inhibition, 2-acetylphenol, structure–activity relationship

  8. 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.

  9. Design rules for superconducting analog-digital transducers

    International Nuclear Information System (INIS)

    This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor electronics. Mainly superconductor comparators inclusive Josephson comparators as well as QOJS-Comparators are investigated. Both types were investigated in terms of speed and sensitivity. The influence of the thermal noise on the decision process of the comparators represent in so called gray zone, which is analysed in this thesis. Thereby, different relations between design parameters were derived. A circuit model of the Josephson comparator was verified by experiments. Concepts of superconductor analog-to-digital converters, which are based on above called comparators, were investigated in detail. From the comparator design rules, new rules for AD-converters were derived. Because of the reduced switching energy, the signal to noise ratio (SNR) of the circuits is affected and therefore the reliability of the decision-process is affected. For special applications with very demanding requirements in terms of the speed and accuracy superconductor analog-to-digital converters offer an excellent performance. This thesis provides relations between different design paramenters and shows resulting trade-offs, This method is transparent and easy to transfer to other circuit topologies. As a main result, a highly predictive tool for dimensioning of superconducting ADC's is proved.

  10. DESIGN AND ANALOG VLSI IMPLEMENTATION OF ARTIFICIAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    D.Yammenavar

    2011-08-01

    Full Text Available Nature has evolved highly advanced systems capable of performing complex computations, adoption andlearning using analog computations. Furthermore nature has evolved techniques to deal with impreciseanalog computations by using redundancy and massive connectivity. In this paper we are making use ofArtificial Neural Network to demonstrate the way in which the biological system processes in analogdomain.We are using 180nm CMOS VLSI technology for implementing circuits which performs arithmeticoperations and for implementing Neural Network. The arithmetic circuits presented here are based onMOS transistors operating in subthreshold region. The basic blocks of artificial neuron are multiplier,adder and neuron activation function.The functionality of designed neural network is verified for analog operations like signal amplificationand frequency multiplication. The network designed can be adopted for digital operations like AND, ORand NOT. The network realizes its functionality for the trained targets which is verified using simulationresults. The schematic, Layout design and verification of proposed Neural Network is carried out usingCadence Virtuoso tool.

  11. Exact solutions and physical analogies for unidirectional flows

    Science.gov (United States)

    Bazant, Martin Z.

    2016-06-01

    Unidirectional flow is the simplest phenomenon of fluid mechanics. Its mathematical description, the Dirichlet problem for Poisson's equation in two dimensions with constant forcing, arises in many physical contexts, such as the torsion of elastic beams, first solved by de Saint-Venant for complex shapes. Here the literature is unified and extended by identifying 17 physical analogies for unidirectional flow and describing their common mathematical structure. Besides classical analogies in fluid and solid mechanics, applications are discussed in stochastic processes (first passage in two dimensions), pattern formation (river growth by erosion), and electrokinetics (ion transport in nanochannels), which also involve Poisson's equation with nonconstant forcing. Methods are given to construct approximate geometries that admit exact solutions, by adding harmonic functions to quadratic forms or by truncating eigenfunction expansions. Exact solutions for given geometries are also derived by conformal mapping. We prove that the remarkable geometrical interpretation of Poiseuille flow in an equilateral triangular pipe (the product of the distances from an interior point to the sides) is only shared by parallel plates and unbounded equilateral wedges (with the third side hidden behind the apex). We also prove Onsager reciprocity for linear electrokinetic phenomena in straight pores of arbitrary shape and surface charge, based on the mathematics of unidirectional flow.

  12. Electrochemical Bioelectronic Device Consisting of Metalloprotein for Analog Decision Making

    Science.gov (United States)

    Chung, Yong-Ho; Lee, Taek; Yoo, Si-Youl; Min, Junhong; Choi, Jeong-Woo

    2015-09-01

    We demonstrate an analog type logical device that combines metalloprotein and organic/inorganic materials and can make an interactive analog decision. Myoglobin is used as a functional biomolecule to generate electrochemical signals, and its original redox signal is controlled with various mercapto-acids by the distance effect between myoglobin and a metal surface in the process of electron transfer. Controlled signals are modulated with the introduction of inorganic materials including nanoparticles and metal ions. By forming a hybrid structure with various constituents of organic/inorganic materials, several functions for signal manipulation were achieved, including enhancement, suppression, and shift. Based on the manipulated signals of biomolecules, a novel logical system for interactive decision-making processes is proposed by selectively combining different signals. Through the arrangement of various output signals, we can define interactive logical results regulated by an inherent tendency (by metalloprotein), personal experience (by organic spacer sets), and environments (by inorganic materials). As a practical application, a group decision process is presented using the proposed logical device. The proposed flexible logic process could facilitate the realization of an artificial intelligence system by mimicking the sophisticated human logic process.

  13. Ratchet Baryogenesis with an Analogy to the Forced Pendulum

    CERN Document Server

    Bamba, Kazuharu; Sugamoto, Akio; Takeuchi, Tatsu; Yamashita, Kimiko

    2016-01-01

    A new scenario of baryogenesis, via the ratchet mechanism, is proposed based on an analogy to a forced pendulum. The oscillation of the inflaton field, of the Starobinsky type, in the reheating epoch after inflation plays the role of the driving force, while the phase $\\theta$ of a scalar baryon field (a complex field with a baryon number) plays the role of the angle of the pendulum, or of the molecular motor in the case of a biological ratchet. If the inflaton and the scalar baryon couple, the behavior of the angle $\\theta$ can be analogous to that of the forced pendulum. If the oscillation of the driven force is adjusted to the pendulum's motion, a directed rotation of the pendulum is obtained with a non-vanishing value of $\\dot{\\theta}$, which can realize successful baryogenesis, since $\\dot{\\theta}$ is proportional to the baryon number density. In the ratchet model of molecular motors, the driven force is supplied by chemical reactions, while in our scenario this role is played by the inflaton during the ...

  14. Planar CMOS analog SiPMs: design, modeling, and characterization

    Science.gov (United States)

    Zou, Yu; Villa, Federica; Bronzi, Danilo; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2015-11-01

    Silicon photomultipliers (SiPMs) are large area detectors consisting of an array of single-photon-sensitive microcells, which make SiPMs extremely attractive to substitute the photomultiplier tubes in many applications. We present the design, fabrication, and characterization of analog SiPMs in standard planar 0.35 μm CMOS technology, with about 1 mm × 1 mm total area and different kinds of microcells, based on single-photon avalanche diodes with 30 μm diameter reaching 21.0% fill-factor (FF), 50 μm diameter (FF = 58.3%) or 50 μm square active area with rounded corner of 5 μm radius (FF = 73.7%). We also developed the electrical SPICE model for CMOS SiPMs. Our CMOS SiPMs have 25 V breakdown voltage, in line with most commercial SiPMs and higher gain (8.8 × 106, 13.2 × 106, and 15.0 × 106, respectively). Although dark count rate density is slightly higher than state-of-the-art analog SiPMs, the proposed standard CMOS processing opens the feasibility of integration with active electronics, for switching hot pixels off, drastically reducing the overall dark count rate, or for further on-chip processing.

  15. 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.

  16. Antarctic Analog for Dilational Bands on Europa

    Science.gov (United States)

    Hurford, T. A.; Brunt, K. M.

    2014-01-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  17. 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...

  18. Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

    Science.gov (United States)

    Costa, Ricardo; Bacchi, Carlos E.; Almeida Filho, Paulo

    2013-01-01

    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). PMID:24455330

  19. 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.

  20. 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