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Sample records for test pattern generator

  1. Ring Counter Based ATPG for Low Transition Test Pattern Generation

    PubMed Central

    Begam, V. M. Thoulath; Baulkani, S.

    2015-01-01

    In test mode test patterns are applied in random fashion to the circuit under circuit. This increases switching transition between the consecutive test patterns and thereby increases dynamic power dissipation. The proposed ring counter based ATPG reduces vertical switching transitions by inserting test vectors only between the less correlative test patterns. This paper presents the RC-ATPG with an external circuit. The external circuit consists of XOR gates, full adders, and multiplexers. First the total number of transitions between the consecutive test patterns is determined. If it is more, then the external circuit generates and inserts test vectors in between the two test patterns. Test vector insertion increases the correlation between the test patterns and reduces dynamic power dissipation. The results prove that the test patterns generated by the proposed ATPG have fewer transitions than the conventional ATPG. Experimental results based on ISCAS'85 and ISCAS'89 benchmark circuits show 38.5% reduction in the average power and 50% reduction in the peak power attained during testing with a small size decoding logic. PMID:26075295

  2. A Single Input Change Test Pattern Generator for Sequential Circuits

    NASA Astrophysics Data System (ADS)

    Liang, Feng; Lei, Shaochong; Shao, Zhibiao

    An optimized Built-In Self-Test technology is proposed in this paper. A simplified algebraic model is developed to represent the configurations of single input change circuits. A novel single input change sequence generation technique is designed. It consists of a modified scan shift register, a seed storage array and a series of XOR gates. This circuitry can automatically generate single input change sequences of more unique vectors. Experimental results based on the ISCAS-89 benchmark show that the proposed method can achieve high stuck-at fault coverage with low switching activity during test applications.

  3. Pattern Generator for Bench Test of Digital Boards

    NASA Technical Reports Server (NTRS)

    Berkun, Andrew C.; Chu, Anhua J.

    2012-01-01

    All efforts to develop electronic equipment reach a stage where they need a board test station for each board. The SMAP digital system consists of three board types that interact with each other using interfaces with critical timing. Each board needs to be tested individually before combining into the integrated digital electronics system. Each board needs critical timing signals from the others to be able to operate. A bench test system was developed to support test of each board. The test system produces all the outputs of the control and timing unit, and is delivered much earlier than the timing unit. Timing signals are treated as data. A large file is generated containing the state of every timing signal at any instant. This file is streamed out to an IO card, which is wired directly to the device-under-test (DUT) input pins. This provides a flexible test environment that can be adapted to any of the boards required to test in a standalone configuration. The problem of generating the critical timing signals is then transferred from a hardware problem to a software problem where it is more easily dealt with.

  4. Automatic test pattern generation for logic circuits using the Boolean tree

    SciTech Connect

    Jeong Taegwon.

    1991-01-01

    The goal of this study was to develop an algorithm that can generate test patterns for combinational circuits and sequential logic circuits automatically. The new proposed algorithm generates a test pattern by using a special tree called a modified Boolean tree. In this algorithm, the construction of a modified Boolean tree is the most time-consuming step. Following the construction of a modified Boolean tree, a test pattern can be found by simply assigning a logic value 1 for even primary inputs and a logic value 0 for odd primary inputs of the constructed modified Boolean tree. The algorithm is applied to several benchmark circuits. The results showed the following: (1) for combinational circuits, the algorithm can generate test patterns 10-15% faster than the FAN algorithm, which is known as one of the most efficient algorithms to-date; (2) for sequential circuits, the algorithm shows more fault coverage than the nine valued algorithm.

  5. The Graphic Pattern Generation Test in Healthy Aging and Alzheimer's Disease: Psychometric Properties and Normative Data

    PubMed Central

    Sunderaraman, Preeti; Sokolov, Elisaveta; Cines, Sarah; Sullo, Elizabeth; Orly, Aidan; Lerer, Bianca; Karlawish, Jason; Huey, Edward; Cosentino, Stephanie

    2015-01-01

    Design fluency tests, commonly used in both clinical and research contexts to evaluate nonverbal concept generation, have the potential to offer useful information in the differentiation of healthy versus pathological aging. While normative data for older adults are available for multiple timed versions of this test, similar data have been unavailable for a previously published untimed task, the Graphic Pattern Generation Task (GPG). Time constraints common to almost all of the available design fluency tests may cloud interpretation of higher level executive abilities, for example in individuals with slow processing speed. The current study examined the psychometric properties of the GPG and presents normative data in a sample of 167 healthy older adults (OAs) and 110 individuals diagnosed with Alzheimer's disease (AD). Results suggest that a brief version of the GPG can be administered reliably, and that this short form has high test-retest and inter-rater reliability. Number of perseverations was higher in individuals with AD as compared to OAs. A cut-off score of 4 or more perseverations showed a moderate degree of sensitivity (76%) and specificity (37%) in distinguishing individuals with AD and OAs. Finally, perseverations were associated with nonmemory indices, underscoring the nonverbal nature of this error in OAs and individuals with AD. PMID:25679880

  6. A test of a dual central pattern generator hypothesis for subcortical control of locomotion.

    PubMed

    Guadagnoli, M A; Etnyre, B; Rodrigue, M L

    2000-08-01

    This study was designed to examine the nature of neural circuits involved in subcortical inter-limb coordination and reflex modulation mechanisms of locomotion. These circuits, called central pattern generators (CPGs), are believed to receive tonic input and generate rhythmically alternating sets of commands. Although CPGs have been theorized to exist in humans, their potential dual role in inter-limb coordination and reflex modulation is unclear. In the present study, nine participants walked on a treadmill, timing their heel-strikes to a metronome which varied the phase lag from 0.5 to 1.0 pi radians (0.1 pi intervals). A stimulus was delivered to the sural nerve and reflexes were measured in the ipsilateral and contralateral lower extremities through electromyography. The similarity between phase lag conditions for both temporal coordination (i.e., relative timing aspects between muscles and/or limbs) and reflex intensities suggested that they may be controlled by the same subcortical circuitry. Two plausible explanations exist: (1) a single CPG coordinates muscular contractions and phasically alters proprioceptive reflex modulation, as well as cutaneous input, using feed-forward control; (2) two separate circuits are strongly entrained, producing synchronous outputs for inter-limb coordination and reflex modulation. The out-of-phase task used in this study was limited in discerning such a difference, if it exists. PMID:10969197

  7. Resistive shorts characterization in CMOS standard cells for test pattern generation

    NASA Astrophysics Data System (ADS)

    Wielgus, Andrzej; Potrykus, Bartosz

    2013-07-01

    This paper presents an extended method of CMOS standard cells characterization for defect based voltage testing. Resistance of a short defect is taken into account while considering faulty behavior caused by this defect and finding the test vectors that detect this fault. Finally, all of found vectors are validated to check their effectiveness in fault covering and the optimal test sequence for all detectable faults is constructed. Experimental results for cells from industrial standard cell library are presented.

  8. Creative Test Generators

    ERIC Educational Resources Information Center

    Vickers, F. D.

    1973-01-01

    A brief description of a test generating program which generates questions concerning the Fortran programming language in a random but guided fashion and without resorting to an item bank.'' (Author/AK)

  9. Starter/generator testing

    NASA Astrophysics Data System (ADS)

    Anon

    1994-10-01

    Sundstrand Aerospace and GE Aircraft Engines have studied the switched reluctance machine for use as an integral starter/generator for future aircraft engines. They have conducted an initial, low-power testing of the starter/generator, which is based on power inverters using IGBT-technology semiconductors, to verify its feasibility in the externally mounted version of the integral starter/generator. This preliminary testing of the 250-kW starter/generator reveals favorable results.

  10. Fastrac Gas Generator Testing

    NASA Technical Reports Server (NTRS)

    Nesman, Tomas E.; Dennis, Jay

    1999-01-01

    A rocket engine gas generator component development test was recently conducted at the Marshall Space Flight Center. This gas generator was intended to power a rocket engine turbopump by the combustion of Lox and RP-1. The testing demonstrated design requirements for start sequence, wall compatibility, performance, and stable combustion. During testing the gas generator injector was modified to improve distribution of outer wall coolant and the igniter boss was modified to investigate the use of a pyrotechnic igniter, Expected chamber pressure oscillations at longitudinal acoustic modes were measured for three different chamber lengths tested. High amplitude discrete oscillations occurred in the chamber-alone configurations when chamber acoustic modes coupled with feed-system acoustics modes. For the full gas generator configuration, which included the turbine inlet manifold simulator, high amplitude oscillations occurred only at off-design very low power levels. This testing led to a successful gas generator design for the Fastrac 60,000 lb thrust engine.

  11. Fastrac Gas Generator Testing

    NASA Technical Reports Server (NTRS)

    Nesman, Tomas E.; Dennis, Jay

    2001-01-01

    A rocket engine gas generator component development test was recently conducted at the Marshall Space Flight Center. This gas generator is intended to power a rocket engine turbopump by the combustion of Lox and RP-1. The testing demonstrated design requirements for start sequence, wall compatibility, performance, and stable combustion. During testing the gas generator injector was modified to improve distribution of outer wall coolant and the igniter boss was modified to investigate the use of a pyrotechnic igniter. Expected chamber pressure oscillations at longitudinal acoustic mode were measured for three different chamber lengths tested. High amplitude discrete oscillations resulted in the chamber-alone configurations when chamber acoustic modes coupled with feed-system acoustics modes. For the full gas generator configuration, which included a turbine inlet manifold, high amplitude oscillations occurred only at off-design very low power levels. This testing led to a successful gas generator design for the Fastrac 60,000 lb thrust engine.

  12. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, Michiyuki

    1981-01-01

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Also, apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  13. Apparatus for generating nonlinear pulse patterns

    DOEpatents

    Nakamura, N.M.I.

    Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base is described. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

  14. Mask pattern generator employing EPL technology

    NASA Astrophysics Data System (ADS)

    Yoshioka, Nobuyuki; Yamabe, Masaki; Wakamiya, Wataru; Endo, Nobuhiro

    2003-08-01

    Mask cost is one of crucial issues in device fabrication, especially in SoC (System on a Chip) with small-volume production. The cost mainly depends on productivity of mask manufacturing tools such as mask writers and defect inspection tools. EPL (Electron Projection Lithography) has been developing as a high-throughput electron beam exposure technology that will succeed optical lithography. The application of EPL technology to mask writing will result in high productivity and contribute to decrease the mask cost. The concept of a mask pattern generator employing EPL technology is proposed in this paper. It is very similar to EPL technology used for pattern printing on a wafer. The mask patterns on the glass substrate are exposed by projecting the basic circuit patterns formed on the mother EPL mask. One example of the mother EPL mask is a stencil type made with 200-mm Si wafer. The basic circuit patterns are IP patterns and logical primitive patterns such as cell libraries (AND, OR, Inverter, Flip-Flop and etc.) to express the SoC device patterns. Since the SoC patterns are exposed with its collective units such as IP and logical primitive patterns by using this method, the high throughput will be expected comparing with conventional mask E-beam writers. In this paper, the mask pattern generator with the EPL technology is proposed. The concept, its advantages and issues to be solved are discussed.

  15. Optical Pattern Generator Using Excimer Laser

    NASA Astrophysics Data System (ADS)

    Hafner, Bernhard F.

    1988-01-01

    Reticles (masks on enlarged scale) are needed for optical pattern transfer in the production of integrated semiconductor circuits. In order to meet present requirements for 5X reticles only a direct writing technique is feasible. This means direct exposing of photoresist either with light or an electron beam. Many of todays highly dense reticles require some 10 5 to 10 6 discrete exposures when generated with an optical pattern generator. Optical pattern generators normally use mercury arc lamps to expose positive photoresist, which in turn need 200 milliseconds for each of these discrete exposures, thus requiring to stop the table at every exposure position ("stop and go" mode). This results in running times of several days per reticle. Therefore most reticles are nowadays being manufactured with very expensive e-beam machines. In the early 80's we started the first experiments to expose photoresist with an excimer laser. In order to obtain the maximum gain in speed, the goal was to operate with only one excimer laser pulse per exposure, so that a fast "flash on the fly" operation with an optical pattern generator became true. Equipping a conventional optical pattern generator with an excimer laser as the light source, it has become possible to expose substrates coated with standard photoresist in the "flash on the fly" mode with only 13 nanoseconds per flash. So the thruput could be increased up to 25 times in comparison to a pattern generator equipped with a mercury lamp. A comparison of both operation modes will show that an immense increase of speed is possible, even when a ten years old M3600 pattern generator is used. This system is in function now with very high reliability since more than three years in our IC development line.

  16. Silicon central pattern generators for cardiac diseases.

    PubMed

    Nogaret, Alain; O'Callaghan, Erin L; Lataro, Renata M; Salgado, Helio C; Meliza, C Daniel; Duncan, Edward; Abarbanel, Henry D I; Paton, Julian F R

    2015-02-15

    Cardiac rhythm management devices provide therapies for both arrhythmias and resynchronisation but not heart failure, which affects millions of patients worldwide. This paper reviews recent advances in biophysics and mathematical engineering that provide a novel technological platform for addressing heart disease and enabling beat-to-beat adaptation of cardiac pacing in response to physiological feedback. The technology consists of silicon hardware central pattern generators (hCPGs) that may be trained to emulate accurately the dynamical response of biological central pattern generators (bCPGs). We discuss the limitations of present CPGs and appraise the advantages of analog over digital circuits for application in bioelectronic medicine. To test the system, we have focused on the cardio-respiratory oscillators in the medulla oblongata that modulate heart rate in phase with respiration to induce respiratory sinus arrhythmia (RSA). We describe here a novel, scalable hCPG comprising physiologically realistic (Hodgkin-Huxley type) neurones and synapses. Our hCPG comprises two neurones that antagonise each other to provide rhythmic motor drive to the vagus nerve to slow the heart. We show how recent advances in modelling allow the motor output to adapt to physiological feedback such as respiration. In rats, we report on the restoration of RSA using an hCPG that receives diaphragmatic electromyography input and use it to stimulate the vagus nerve at specific time points of the respiratory cycle to slow the heart rate. We have validated the adaptation of stimulation to alterations in respiratory rate. We demonstrate that the hCPG is tuneable in terms of the depth and timing of the RSA relative to respiratory phase. These pioneering studies will now permit an analysis of the physiological role of RSA as well as its any potential therapeutic use in cardiac disease. PMID:25433077

  17. Combinatorial Generation of Test Suites

    NASA Technical Reports Server (NTRS)

    Dvorak, Daniel L.; Barrett, Anthony C.

    2009-01-01

    Testgen is a computer program that generates suites of input and configuration vectors for testing other software or software/hardware systems. As systems become ever more complex, often, there is not enough time to test systems against all possible combinations of inputs and configurations, so test engineers need to be selective in formulating test plans. Testgen helps to satisfy this need: In response to a test-suite-requirement-specification model, it generates a minimal set of test vectors that satisfies all the requirements.

  18. Microwave generators simplify swept tests

    NASA Astrophysics Data System (ADS)

    Foster, C. E.; Hagins, M. R.

    1986-01-01

    The utilization of the swept-frequency capability makes it possible to conduct any number of microwave tests. It is pointed out that today's microwave sweepers make such tests simple and straightforward. A filter test involving a high-pass filter with a cutoff frequency of 14.0 GHz is discussed, taking into account the use of a microwave sweeper operating in the range from 12 to 18 GHz. Attention is also given to swept-frequency amplifier testing, antenna swept-gain testing, and microwave antenna testing. With a sweep generator, it is simple to assemble a setup for testing amplifier small-signal gain, flatness, and rolloff.

  19. Intersecting Circuits Generate Precisely Patterned Retinal Waves

    PubMed Central

    Akrouh, Alejandro; Kerschensteiner, Daniel

    2013-01-01

    SUMMARY The developing retina generates spontaneous glutamatergic (stage III) waves of activity that sequentially recruit neighboring ganglion cells with opposite light responses (ON and OFF RGCs). This activity pattern is thought to help establish parallel ON and OFF pathways in downstream visual areas. The circuits that produce stage III waves and desynchronize ON and OFF RGC firing remain obscure. Using dual patch clamp recordings, we find that ON and OFF RGCs receive sequential excitatory input from ON and OFF cone bipolar cells (CBCs), respectively. This input sequence is generated by crossover circuits, in which ON CBCs control glutamate release from OFF CBCs via diffusely stratified inhibitory amacrine cells. In addition, neighboring ON CBCs communicate directly and indirectly through lateral glutamatergic transmission and gap junctions, both of which are required for wave initiation and propagation. Thus, intersecting lateral excitatory and vertical inhibitory circuits give rise to precisely patterned stage III retinal waves. PMID:23830830

  20. Automatically generating extraction patterns from untagged text

    SciTech Connect

    Riloff, E.

    1996-12-31

    Many corpus-based natural language processing systems rely on text corpora that have been manually annotated with syntactic or semantic tags. In particular, all previous dictionary construction systems for information extraction have used an annotated training corpus or some form of annotated input. We have developed a system called AutoSlog-TS that creates dictionaries of extraction patterns using only untagged text. AutoSlog-TS is based on the AutoSlog system, which generated extraction patterns using annotated text and a set of heuristic rules. By adapting AutoSlog and combining it with statistical techniques, we eliminated its dependency on tagged text. In experiments with the MUC-4 terrorism domain, AutoSlog-TS created a dictionary of extraction patterns that performed comparably to a dictionary created by AutoSlog, using only preclassified texts as input.

  1. Test Generator for MATLAB Simulations

    NASA Technical Reports Server (NTRS)

    Henry, Joel

    2011-01-01

    MATLAB Automated Test Tool, version 3.0 (MATT 3.0) is a software package that provides automated tools that reduce the time needed for extensive testing of simulation models that have been constructed in the MATLAB programming language by use of the Simulink and Real-Time Workshop programs. MATT 3.0 runs on top of the MATLAB engine application-program interface to communicate with the Simulink engine. MATT 3.0 automatically generates source code from the models, generates custom input data for testing both the models and the source code, and generates graphs and other presentations that facilitate comparison of the outputs of the models and the source code for the same input data. Context-sensitive and fully searchable help is provided in HyperText Markup Language (HTML) format.

  2. Patterning techniques for next generation IC's

    NASA Astrophysics Data System (ADS)

    Balasinski, A.

    2007-12-01

    Reduction of linear critical dimensions (CDs) beyond 45 nm would require significant increase of the complexity of pattern definition process. In this work, we discuss the key successor methodology to the current optical lithography, the Double Patterning Technique (DPT). We compare the complexity of CAD solutions, fab equipment, and wafer processing with its competitors, such as the nanoimprint (NIL) and the extreme UV (EUV) techniques. We also look ahead to the market availability for the product families enabled using the novel patterning solutions. DPT is often recognized as the most viable next generation lithography as it utilizes the existing equipment and processes and is considered a stop-gap solution before the advanced NIL or EUV equipment is developed. Using design for manufacturability (DfM) rules, DPT can drive the k1 factor down to 0.13. However, it faces a variety of challenges, from new mask overlay strategies, to layout pattern split, novel OPC, increased CD tolerances, new etch techniques, as well as long processing time, all of which compromise its return on investment (RoI). In contrast, it can be claimed e.g., that the RoI is the highest for the NIL but this technology bears significant risk. For all novel patterning techniques, the key questions remain: when and how should they be introduced, what is their long-term potential, when should they be replaced, and by what successor technology. We summarize the unpublished results of several panel discussions on DPT at the recent SPIE/BACUS conferences.

  3. New downhole steam generator tested

    SciTech Connect

    Bleakley, W.B.

    1981-07-01

    Completion of 2 field tests of a new-model down-hole steam generator paves the way for further evaluation and development of a system destined to increase California's heavy oil production. Current air pollution restrictions there prevent installation of conventional steam generators in several areas of interest to oil operators. The current series of tests, conducted by Chemical Oil Recovery Co. (CORCO) of Bakersfield, California, follows an earlier prototype operation conducted by Sandia National Laboratories in conjunction with the US Department of Energy. The CORCO tests were conducted on the surface with the generator's output going into Tenneco Oil Exploration and Production Co.'s overland-Riokern Well No. 80, located in the Kern River field 4 miles north of Bakersfield. The first test was concluded with just under 1000 bbl of steam injected, less than planned due to a higher-than-expected injection pressure. The unit operated at less than 25% capacity because of the air compressor limitation. Compressor output was only 285 psi, not enough to inject the desired volumes into the reservoir. Test data shows that injection amounted to 150 bpd of 90 to 95% quality steam at 225-psi wellhead pressure. After injection, the well was shut in for 3 days to allow soaking, then put on production. Initial production was 40 bopd at 175 F.

  4. Temperature distortion generator for turboshaft engine testing

    NASA Technical Reports Server (NTRS)

    Klann, G. A.; Barth, R. L.; Biesiadny, T. J.

    1984-01-01

    The procedures and unique hardware used to conduct an experimental investigation into the response of a small-turboshaft-engine compression system to various hot gas ingestion patterns are presented. The temperature distortion generator described herein uses gaseous hydrogen to create both steady-state and time-variant, or transient, temperature distortion at the engine inlet. The range of transient temperature ramps produced by the distortion generator during the engine tests was from less than 111 deg K/sec (200 deg R/sec) to above 611 deg K/sec (1100 deg R/sec); instantaneous temperatures to 422 deg K (760 deg R) above ambient were generated. The distortion generator was used to document the maximum inlet temperatures and temperature rise rates that the compression system could tolerate before the onset of stall for various circumferential distortions as well as the compressor system response during stall.

  5. Downhole steam generator: field tests

    SciTech Connect

    Eson, R.L.

    1982-01-01

    Excessive air pollution and heat losses up to 32% in the surface lines and out the stacks of conventional generators are reasons why conventional steam generation is efficient. These problems are addressed and overcome through the use of a direct-fired down-hole steam generator (DSG). By performing the combustion process at high pressure, and then adding water, a mixture of carbon dioxide, nitrogen, and steam is discharged directly into the heavy oil reservoir. This study documents a series of field tests of a direct-fired DSG showing its ability to produce and inject high quality steam into heavy oil reservoirs without the need for expensive stack scrubbers to remove sulfur dioxide (SO/sub 2/), as well as sophisticated nitrogen oxides (NO/sub x/) control techniques. Results from the 6-in. diameter, 6-ft long, 7.1-mmBtu/hr DSG showed that corrosion can be controlled and production can be improved dramatically in actual field tests in California heavy oil reservoirs.

  6. Automatic optometer operates with infrared test pattern

    NASA Technical Reports Server (NTRS)

    Cornsweet, T. N.; Crane, H. D.

    1970-01-01

    Refractive strength of human eye is monitored by optometer that automatically and continuously images infrared test pattern onto the retina. Condition of focus of the eye at any instant is determined from optometer settings needed to maintain focus of the pattern on the retina.

  7. Test patterns and quality metrics for digital video compression

    NASA Astrophysics Data System (ADS)

    Fenimore, Charles P.; Field, Bruce F.; Van Degrift, Craig

    1997-06-01

    Lossy video compression systems such as MPEG2 introduce picture impairments such as image blocking, color distortion and persistent color fragments, 'mosquito noise,' and blurring in their outputs. While there are video test clips which exhibit one or more of these distortions upon coding, there is need of a set of well-characterized test patterns and video quality metrics. Digital test patterns can deliver calibrated stresses to specific features of the encoder, much as the test patterns for analog video stress critical characteristics of that system. Metrics quantify the error effects of compression by a computation. NIST is developing such test patterns and metrics for compression rates that typically introduce perceptually negligible artifacts, i.e. for high quality video. The test patterns are designed for subjective and objective evaluation. The test patterns include a family of computer-generated spinning wheels to stress luminance-based macro-block motion estimation algorithms and images with strongly directional high-frequency content to stress quantization algorithms. In this paper we discuss the spinning wheel test pattern. It has been encoded at a variety of bit rates near the threshold for the perception of impairments. We have observed that impairment perceptibility depends on the local contrast. For the spinning wheel we report the contrast at the threshold for perception of impairments as a function of the bit rate. To quantify perceptual image blocking we have developed a metric which detects 'flats:' image blocks of constant (or near constant) luminance. The effectiveness of this metric is appraised.

  8. Testing Whether and When Abstract Symmetric Patterns Produce Affective Responses

    PubMed Central

    Bertamini, Marco; Makin, Alexis; Pecchinenda, Anna

    2013-01-01

    Symmetry has a central role in visual art, it is often linked to beauty, and observers can detect it efficiently in the lab. We studied what kind of fast and automatic responses are generated by visual presentation of symmetrical patterns. Specifically, we tested whether a brief presentation of novel symmetrical patterns engenders positive affect using a priming paradigm. The abstract patterns were used as primes in a pattern-word interference task. To ensure that familiarity was not a factor, no pattern and no word was ever repeated within each experiment. The task was to classify words that were selected to have either positive or negative valence. We tested irregular patterns, patterns containing vertical and horizontal reflectional symmetry, and patterns containing a 90 deg rotation. In a series of 7 experiments we found that the effect of affective congruence was present for both types of regularity but only when observers had to classify the regularity of the pattern after responding to the word. The findings show that processing abstract symmetrical shapes or random pattern can engender positive or negative affect as long as the regularity of the pattern is a feature that observers have to attend to and classify. PMID:23840892

  9. Performance testing of thermoelectric generators at JPL

    NASA Technical Reports Server (NTRS)

    Rouklove, P.; Truscello, V.

    1974-01-01

    Results of life tests of thermoelectric generators ranging in output power from 800 microwatts to 170 watts. Emphasis is placed on the results obtained from tests of three advanced prototypes - a high-performance generator, a transit-type generator, and a ring converter. In addition, the results of life tests of a number of generators representing Nimbus, Pioneer, and Viking technology are presented.

  10. Generation 1.5 Written Error Patterns: A Comparative Study

    ERIC Educational Resources Information Center

    Doolan, Stephen M.; Miller, Donald

    2012-01-01

    In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student…

  11. Generating Spatiotemporal Joint Torque Patterns from Dynamical Synchronization of Distributed Pattern Generators

    PubMed Central

    Pitti, Alexandre; Lungarella, Max; Kuniyoshi, Yasuo

    2009-01-01

    Pattern generators found in the spinal cord are no more seen as simple rhythmic oscillators for motion control. Indeed, they achieve flexible and dynamical coordination in interaction with the body and the environment dynamics giving to rise motor synergies. Discovering the mechanisms underlying the control of motor synergies constitutes an important research question not only for neuroscience but also for robotics: the motors coordination of high dimensional robotic systems is still a drawback and new control methods based on biological solutions may reduce their overall complexity. We propose to model the flexible combination of motor synergies in embodied systems via partial phase synchronization of distributed chaotic systems; for specific coupling strength, chaotic systems are able to phase synchronize their dynamics to the resonant frequencies of one external force. We take advantage of this property to explore and exploit the intrinsic dynamics of one specified embodied system. In two experiments with bipedal walkers, we show how motor synergies emerge when the controllers phase synchronize to the body's dynamics, entraining it to its intrinsic behavioral patterns. This stage is characterized by directed information flow from the sensors to the motors exhibiting the optimal situation when the body dynamics drive the controllers (mutual entrainment). Based on our results, we discuss the relevance of our findings for modeling the modular control of distributed pattern generators exhibited in the spinal cord, and for exploring the motor synergies in robots. PMID:20011216

  12. Test Writing Made Simple: Generate Tests and Worksheets Electronically.

    ERIC Educational Resources Information Center

    Lodish, Erica

    1986-01-01

    Describes capabilities of test and worksheet generator software; discusses features to consider when evaluating the software for purchase; and presents reviews of eight test and worksheet generators: P.D.Q., Testmaster, Easy Quiz Maker, EA Mathematics Worksheet Generator, Mathematics Worksheet Generator, Earth Science Test Maker, Individualized…

  13. A hierarchical approach to test generation for CMOS VLSI circuits

    NASA Astrophysics Data System (ADS)

    Weening, Edward Christiaan

    A hierarchical approach to the automatic test pattern generation for large digital VLSI circuits, fabricated in CMOS technology, is developed and implemented. The use of information on the circuit's hierarchy, which is readily available from most modern CAD (Computer Aided Design) systems, speeds up the test generation process considerably and enhances the quality of the tests generated. The hierarchical test generation tool can also be integrated in future CAD systems making test generation and testability enhancement during circuit design feasible. The hierarchical approach is described at the switch, functional, and behavioral level. A test pattern generation algorithm at the switch level is presented. Test generation and fault simulation algorithms both using OBDD (Ordered Binary Decision Diagram) functional descriptions of the circuit modules are presented. A test plan generation method at the behavioral level is presented. Practical results show that the hierarchical approach to test generation is more efficient than a conventional, non-hierarchical approach, especially for switch level faults. The results also show that the use of Design For Testability (DFT) circuitry is supported at the behavioral level.

  14. Vapor-Generator Wand Helps To Reveal Airflow Patterns

    NASA Technical Reports Server (NTRS)

    Robelen, David B.

    1993-01-01

    In vapor-generator wand, liquid propylene glycol flows into electrically heated stainless-steel tube. Liquid boils in heated tube, and emerging vapor forms dense, smoke-like fog used to make airflow patterns visible. Built in variety of sizes, suitable for uses ranging from tabletop demonstrations to research in wind tunnels. For best viewing, plume illuminated by bright, focused incandescent spotlight at right angle to viewing direction. Viewing further enhanced by coating walls of test chamber with flat, dark color to minimize reflections and increase contrast.

  15. Automated Test-Form Generation

    ERIC Educational Resources Information Center

    van der Linden, Wim J.; Diao, Qi

    2011-01-01

    In automated test assembly (ATA), the methodology of mixed-integer programming is used to select test items from an item bank to meet the specifications for a desired test form and optimize its measurement accuracy. The same methodology can be used to automate the formatting of the set of selected items into the actual test form. Three different…

  16. Pattern Generation by Dissipative Parametric Instability

    NASA Astrophysics Data System (ADS)

    Perego, A. M.; Tarasov, N.; Churkin, D. V.; Turitsyn, S. K.; Staliunas, K.

    2016-01-01

    Nonlinear instabilities are responsible for spontaneous pattern formation in a vast number of natural and engineered systems, ranging from biology to galaxy buildup. We propose a new instability mechanism leading to pattern formation in spatially extended nonlinear systems, which is based on a periodic antiphase modulation of spectrally dependent losses arranged in a zigzag way: an effective filtering is imposed at symmetrically located wave numbers k and -k in alternating order. The properties of the dissipative parametric instability differ from the features of both key classical concepts of modulation instabilities, i.e., the Benjamin-Feir instability and the Faraday instabiltyity. We demonstrate how the dissipative parametric instability can lead to the formation of stable patterns in one- and two-dimensional systems. The proposed instability mechanism is generic and can naturally occur or can be implemented in various physical systems.

  17. Pattern Generation by Dissipative Parametric Instability.

    PubMed

    Perego, A M; Tarasov, N; Churkin, D V; Turitsyn, S K; Staliunas, K

    2016-01-15

    Nonlinear instabilities are responsible for spontaneous pattern formation in a vast number of natural and engineered systems, ranging from biology to galaxy buildup. We propose a new instability mechanism leading to pattern formation in spatially extended nonlinear systems, which is based on a periodic antiphase modulation of spectrally dependent losses arranged in a zigzag way: an effective filtering is imposed at symmetrically located wave numbers k and -k in alternating order. The properties of the dissipative parametric instability differ from the features of both key classical concepts of modulation instabilities, i.e., the Benjamin-Feir instability and the Faraday instabiltyity. We demonstrate how the dissipative parametric instability can lead to the formation of stable patterns in one- and two-dimensional systems. The proposed instability mechanism is generic and can naturally occur or can be implemented in various physical systems. PMID:26824573

  18. Generator acceptance test and inspection report

    SciTech Connect

    Johns, B.R.

    1997-07-24

    This Acceptance Test Report(ATR) is the completed testing and inspection of the new portable generator. The testing and inspection is to verify that the generator provided by the vendor meets the requirements of specification WHC-S-0252, Revision 2. Attached is various other documentation to support the inspection and testing.

  19. A central pattern generator producing alternative outputs: temporal pattern of premotor activity.

    PubMed

    Norris, Brian J; Weaver, Adam L; Morris, Lee G; Wenning, Angela; García, Paul A; Calabrese, Ronald L

    2006-07-01

    The central pattern generator for heartbeat in medicinal leeches constitutes seven identified pairs of segmental heart interneurons. Four identified pairs of heart interneurons make a staggered pattern of inhibitory synaptic connections with segmental heart motor neurons. Using extracellular recording from multiple interneurons in the network in 56 isolated nerve cords, we show that this pattern generator produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons. This pattern corresponds to a similarly asymmetric fictive motor pattern in heart motor neurons and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. We provide a quantitative description of the firing pattern of all the premotor interneurons, including phase, duty cycle, and intraburst frequency of this premotor activity pattern. This analysis identifies two stereotypical coordination modes corresponding to synchronous and peristaltic, which show phase constancy over a broad range of periods as do the fictive motor pattern and the heart constriction pattern. Coordination mode is controlled through one segmental pair of heart interneurons (switch interneurons). Side-to-side switches in coordination mode are a regular feature of this pattern generator and occur with changes in activity state of these switch interneurons. Associated with synchronous coordination of premotor interneurons, the ipsilateral switch interneuron is in an active state, during which it produces rhythmic bursts, whereas associated with peristaltic coordination, the ipsilateral switch interneuron is largely silent. We argue that timing and pattern elaboration are separate functions produced by overlapping subnetworks in the heartbeat central pattern generator. PMID:16611849

  20. Electronic load for testing power generating devices

    NASA Technical Reports Server (NTRS)

    Friedman, E. B.; Stepfer, G.

    1968-01-01

    Instrument tests various electric power generating devices by connecting the devices to the input of the load and comparing their outputs with a reference voltage. The load automatically adjusts until voltage output of the power generating device matches the reference.

  1. Tests of pattern separation and pattern completion in humans-A systematic review.

    PubMed

    Liu, Kathy Y; Gould, Rebecca L; Coulson, Mark C; Ward, Emma V; Howard, Robert J

    2016-06-01

    To systematically review the characteristics, validity and outcome measures of tasks that have been described in the literature as assessing pattern separation and pattern completion in humans. Electronic databases were searched for articles. Parameters for task validity were obtained from two reviews that described optimal task design factors to evaluate pattern separation and pattern completion processes. These were that pattern separation should be tested during an encoding task using abstract, never-before-seen visual stimuli, and pattern completion during a retrieval task using partial cues; parametric alteration of the degree of interference of stimuli or degradation of cues should be used to generate a corresponding gradient in behavioral output; studies should explicitly identify the specific memory domain under investigation (sensory/perceptual, temporal, spatial, affect, response, or language) and account for the contribution of other potential attributes involved in performance of the task. A systematic, qualitative assessment of validity in relation to these parameters was performed, along with a review of general validity and task outcome measures. Sixty-two studies were included. The majority of studies investigated pattern separation and most tasks were performed on young, healthy adults. Pattern separation and pattern completion were most frequently tested during a retrieval task using familiar or recognizable visual stimuli and cues. Not all studies parametrically altered the degree of stimulus interference or cue degradation, or controlled for potential confounding factors. This review found evidence that some of the parameters for task validity have been followed in some human studies of pattern separation and pattern completion, but no study was judged to have adequately met all the parameters for task validity. The contribution of these parameters and other task design factors towards an optimal behavioral paradigm is discussed and

  2. F-1 Engine Gas Generator Testing

    NASA Video Gallery

    The gas generator from an F-1 engine is test-fired at the Marshall Space Flight Center in Huntsville, Ala., on Jan. 24, 2013. Data from the 30 second test will be used in the development of advance...

  3. Automated branching pattern report generation for laparoscopic surgery assistance

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Matsuzaki, Tetsuro; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

    2015-05-01

    This paper presents a method for generating branching pattern reports of abdominal blood vessels for laparoscopic gastrectomy. In gastrectomy, it is very important to understand branching structure of abdominal arteries and veins, which feed and drain specific abdominal organs including the stomach, the liver and the pancreas. In the real clinical stage, a surgeon creates a diagnostic report of the patient anatomy. This report summarizes the branching patterns of the blood vessels related to the stomach. The surgeon decides actual operative procedure. This paper shows an automated method to generate a branching pattern report for abdominal blood vessels based on automated anatomical labeling. The report contains 3D rendering showing important blood vessels and descriptions of branching patterns of each vessel. We have applied this method for fifty cases of 3D abdominal CT scans and confirmed the proposed method can automatically generate branching pattern reports of abdominal arteries.

  4. Revised evaluation of steam generator testing alternatives

    SciTech Connect

    1981-01-01

    A scoping evaluation was made of various facility alternatives for test of LMFBR prototype steam generators and models. Recommendations are given for modifications to EBR-II and SCTI (Sodium Components Test Installation) for prototype SG testing, and for few-tube model testing. (DLC)

  5. An optical pattern classification using computer-generated holograms

    NASA Astrophysics Data System (ADS)

    Kajiki, Yoshinori; Matsushita, Kenji; Shimizu, Eiji

    1990-07-01

    An optical pattern classification system is proposed which performs weighting and summation by the optical system using computer-generated holograms (CGHs). The system makes it possible to simplify the structure and to improve the processing speed. A trainable pattern classification system which performs weight modification by using a CGH matrix and a dot matrix liquid crystal display (LCD) as a shutter array is proposed. The trainable pattern classifier using a CGH matrix and LCD is described, and the experimental results are presented.

  6. Characteristic flow patterns generated by macrozoobenthic structures

    NASA Astrophysics Data System (ADS)

    Friedrichs, M.; Graf, G.

    2009-02-01

    A laboratory flume channel, equipped with an acoustic Doppler flow sensor and a bottom scanning laser, was used for detailed, non-intrusive flow measurements (at 2 cm s - 1 and 10 cm s - 1 ) around solitary biogenic structures, combined with high-resolution mapping of the structure shape and position. The structures were replicates of typical macrozoobenthic species commonly found in the Mecklenburg Bight and with a presumed influence on both, the near-bed current regime and sediment transport dynamics: a worm tube, a snail shell, a mussel, a sand mound, a pit, and a cross-stream track furrow. The flow was considerably altered locally by the different protruding structures (worm tube, snail, mussel and mound). They reduced the horizontal approach velocity by 72% to 79% in the wake zone at about 1-2 cm height, and the flow was deflected around the structures with vertical and lateral velocities of up to 10% and 20% of the free-stream velocity respectively in a region adjacent to the structures. The resulting flow separation (at flow Reynolds number of about 4000 and 20,000 respectively) divided an outer deflection region from an inner region with characteristic vortices and the wake region. All protruding structures showed this general pattern, but also produced individual characteristics. Conversely, the depressions (track and pit) only had a weak influence on the local boundary layer flow, combined with a considerable flow reduction within their cavities (between 29% and 53% of the free-stream velocity). A longitudinal vortex formed, below which a stagnant space was found. The average height affected by the structure-related mass flow rate deficit for the two velocities was 1.6 cm and 1.3 cm respectively (80% of height and 64%) for the protruding structures and 0.6 cm and 0.9 cm (90% and 127% of depth) for the depressions. Marine benthic soft-bottom macrozoobenthos species are expected to benefit from the flow modifications they induce, particularly in terms of

  7. Delay test generation for synchronous sequential circuits

    NASA Astrophysics Data System (ADS)

    Devadas, Srinivas

    1989-05-01

    We address the problem of generating tests for delay faults in non-scan synchronous sequential circuits. Delay test generation for sequential circuits is a considerably more difficult problem than delay testing of combinational circuits and has received much less attention. In this paper, we present a method for generating test sequences to detect delay faults in sequential circuits using the stuck-at fault sequential test generator STALLION. The method is complete in that it will generate a delay test sequence for a targeted fault given sufficient CPU time, if such a sequence exists. We term faults for which no delay test sequence exists, under out test methodology, sequentially delay redundant. We describe means of eliminating sequential delay redundancies in logic circuits. We present a partial-scan methodology for enhancing the testability of difficult-to-test of untestable sequential circuits, wherein a small number of flip-flops are selected and made controllable/observable. The selection process guarantees the elimination of all sequential delay redundancies. We show that an intimate relationship exists between state assignment and delay testability of a sequential machine. We describe a state assignment algorithm for the synthesis of sequential machines with maximal delay fault testability. Preliminary experimental results using the test generation, partial-scan and synthesis algorithm are presented.

  8. Generating Test Templates via Automated Theorem Proving

    NASA Technical Reports Server (NTRS)

    Kancherla, Mani Prasad

    1997-01-01

    Testing can be used during the software development process to maintain fidelity between evolving specifications, program designs, and code implementations. We use a form of specification-based testing that employs the use of an automated theorem prover to generate test templates. A similar approach was developed using a model checker on state-intensive systems. This method applies to systems with functional rather than state-based behaviors. This approach allows for the use of incomplete specifications to aid in generation of tests for potential failure cases. We illustrate the technique on the cannonical triangle testing problem and discuss its use on analysis of a spacecraft scheduling system.

  9. Generating circuit tests by exploiting designed behavior

    NASA Astrophysics Data System (ADS)

    Shirley, Mark H.

    1988-12-01

    Generating tests for sequential devices is one of the hardest problems in designing and manufacturing digital circuits. This task is difficult primarily because internal components are accessible only indirectly, forcing a test generator to use the surrounding components collectively as a probe for detecting faults. This in turn forces the test generator to reason about complex interactions between the behaviors of these surrounding components. Current automated solutions are becoming ineffective as designs grow larger and more complex. Yet, despite the complexity, human experts remain remarkably successful, in part, because they use knowledge from many sources and use a variety of reasoning techniques. This thesis exploits several kinds of expert knowledge about circuits and test generation not used by the current algorithms. First, many test generation problems can be solved efficiently using operation relations, a novel representation of circuit behavior that connects internal component operations with directly executable circuit operations. Operation relations can be computed efficiently for sequential circuits that provide few operations at their interfaces by searching traces of simulated circuit behavior. Second, experts write test programs rather than test vectors because programs are a more readable and compact representation for tests than vectors are. Test programs can be constructed automatically by merging test program fragments using expert supplied goal-refined rules and domain independent planning techniques from artificial intelligence.

  10. Fringe patterns generated by micro-optical sensors for pattern recognition.

    PubMed

    Tamee, Kreangsak; Chaiwong, Khomyuth; Yothapakdee, Kriengsak; Yupapin, Preecha P

    2015-01-01

    We present a new result of pattern recognition generation scheme using a small-scale optical muscle sensing system, which consisted of an optical add-drop filter incorporating two nonlinear optical side ring resonators. When light from laser source enters into the system, the device is stimulated by an external physical parameter that introduces a change in the phase of light propagation within the sensing device, which can be formed by the interference fringe patterns. Results obtained have shown that the fringe patterns can be used to form the relationship between signal patterns and fringe pattern recognitions. PMID:24450752

  11. Self-testing quantum random number generator.

    PubMed

    Lunghi, Tommaso; Brask, Jonatan Bohr; Lim, Charles Ci Wen; Lavigne, Quentin; Bowles, Joseph; Martin, Anthony; Zbinden, Hugo; Brunner, Nicolas

    2015-04-17

    The generation of random numbers is a task of paramount importance in modern science. A central problem for both classical and quantum randomness generation is to estimate the entropy of the data generated by a given device. Here we present a protocol for self-testing quantum random number generation, in which the user can monitor the entropy in real time. Based on a few general assumptions, our protocol guarantees continuous generation of high quality randomness, without the need for a detailed characterization of the devices. Using a fully optical setup, we implement our protocol and illustrate its self-testing capacity. Our work thus provides a practical approach to quantum randomness generation in a scenario of trusted but error-prone devices. PMID:25933297

  12. Self-Testing Quantum Random Number Generator

    NASA Astrophysics Data System (ADS)

    Lunghi, Tommaso; Brask, Jonatan Bohr; Lim, Charles Ci Wen; Lavigne, Quentin; Bowles, Joseph; Martin, Anthony; Zbinden, Hugo; Brunner, Nicolas

    2015-04-01

    The generation of random numbers is a task of paramount importance in modern science. A central problem for both classical and quantum randomness generation is to estimate the entropy of the data generated by a given device. Here we present a protocol for self-testing quantum random number generation, in which the user can monitor the entropy in real time. Based on a few general assumptions, our protocol guarantees continuous generation of high quality randomness, without the need for a detailed characterization of the devices. Using a fully optical setup, we implement our protocol and illustrate its self-testing capacity. Our work thus provides a practical approach to quantum randomness generation in a scenario of trusted but error-prone devices.

  13. Test generation for highly sequential circuits

    NASA Astrophysics Data System (ADS)

    Ghosh, Abhijit; Devadas, Srinivas; Newton, A. Richard

    1989-08-01

    We address the problem of generating test sequences for stuck-at faults in non-scan synchronous sequential circuits. We present a novel test procedure that exploits both the structure of the combinational logic in the circuit as well as the sequential behavior of the circuit. In contrast to previous approaches, we decompose the problem of sequential test generation into three subproblems of combinational test generation, fault-free state justification and fault-free state differentiation. We describe fast algorithms for state justification and state differentiation using the ON-sets and OFF-sets of flip-flop inputs and primary outputs. The decomposition of the testing problems into three subproblems rather than the traditional two, performing the justification and differentiation steps on the fault free rather than the faulty machine and the use of efficient techniques for cube intersection results in significant performance improvements over previous approaches.

  14. The thermoelectric generator test program at JPL.

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Rouklove, P.

    1972-01-01

    Discussion of the test results and analysis performed on data obtained from eight thermoelectric generators exhibiting a total combined operating time of about 21 years. Three (3) SNAP-19 type generators are discussed. Generator SN-20, the engineering model of the units presently operating on the Nimbus S/C, has been in operation for over 4 years and has shown drastic degradation after losing the internal cover gas. Generator SN-21, with more than four years of operating time, is operated in an air environment. The performance of this generator appears predictable and stable. For the last 2 years of operation generator degradation has been negligible. Generator SN-31, which utilizes the TAGS material for the P thermoelectric leg, is similar in design to the units to be used on the Pioneer S/C and has operated for over two years in an all-argon atmosphere.

  15. Using Test Generating Software for Assessment

    NASA Astrophysics Data System (ADS)

    Singh Aurora, Tarlok

    2007-04-01

    Assessment is an important part of teaching and learning. Designing suitable tests and quizzes for assessment is a time consuming task. With faculty's much commitment at work, sometimes it is not easy to find enough time to design a good test before the test day. Searching for and modifying older tests can take considerable amount of time. There is a need to develop a customized test bank that one could use to generate a quiz or test quickly before class time or before a test. A number of commercial software is available for e-learning that has this capability. Some of these are - Test Generator, Examview, Test Pro Developer etc. Application of Examview software in developing a test bank for physics will be presented. A physics test bank, with applications in other disciplines, can be gradually built over time and used to create a test or quiz quickly. Multiple scrambled versions of a single test (and answer sheets) can be created to discourage cheating in a large class setting. The presentation will show how to build a test bank.

  16. Digitally based pattern generator for an electron-beam welder

    SciTech Connect

    Whitten, L.G. III

    1981-02-19

    A digitally based deflection generator for an electron-beam welder is presented. Up to seven patterns of any shape are stored in programmable read-only memory (PROM). The pattern resolution is 39% at frequencies from 10 Hz to 1 kHz and can be x-t, y-t, or x-y formed. Frequency and pattern selections may be chosen by the welder computer or manually selected on the front panel. The ability to repeatedly synchronize two waveforms of any shape and frequency enables an unlimited variety of welds.

  17. A movement pattern generator model using artificial neural networks.

    PubMed

    Srinivasan, S; Gander, R E; Wood, H C

    1992-07-01

    Artificial neural networks (ANN's) allow a new approach to biological modeling. The main applications of ANN's have been geared towards the modeling of the association and learning mechanisms of the brain; only a few researchers have explored them for motor control. The fact that ANN's are based on biological systems indicates their potential application for a biological act such as locomotion. Towards this goal, we have developed a "movement pattern generator," using an ANN for generating periodic movement trajectories. This model is based on the concept of "central pattern generators." Jordan's sequential network, which is capable of learning sequences of patterns, was modified and used to generate several bipedal trajectories (or gaits), coded in task space, at different frequencies. The network model successfully learned all of the trajectories presented to it. The model has many attractive properties such as limit cycle behavior, generalization of trajectories and frequencies, phase maintenance, and fault tolerance. The movement pattern generator model is potentially applicable for improved understanding of animal locomotion and for use in legged robots and rehabilitation medicine. PMID:1516938

  18. MYSID TWO-GENERATION TEST GUIDELINE

    EPA Science Inventory

    McKenney, Charles L., Jr. In press. Mysid Two-Generation Test Guideline. OECD Expert Group on Invertebrate Testing for Endocrine Disruptors, Organisation for Economic Co-operation and Development, Paris, France. 17 p. (ERL,GB 1215).

    This guideline describes a two-generati...

  19. Testing and Troubleshooting Automatically Generated Source Code

    NASA Technical Reports Server (NTRS)

    Henry, Joel

    1998-01-01

    Tools allowing engineers to model the real-time behavior of systems that control many types of NASA systems have become widespread. These tools automatically generate source code that is compiled, linked, then downloaded into computers controlling everything from wind tunnels to space flight systems. These tools save hundreds of hours of software development time and allow engineers with thorough application area knowledge but little software development experience to generate software to control the systems they use daily. These systems are verified and validated by simulating the real-time models, and by other techniques that focus on the model or the hardware. The automatically generated source code is typically not subjected to rigorous testing using conventional software testing techniques. Given the criticality and safety issues surrounding these systems, the application of conventional and new software testing and troubleshooting techniques to the automatically generated will improve the reliability of the resulting systems.

  20. Alcohol LOX Steam Generator Test Experience

    NASA Astrophysics Data System (ADS)

    Schaefer, K.; Dommers, M.

    2004-10-01

    At the DLR test centre in Lampoldshausen there is a long experience in the development of rocket steam generators as a main subsystem for the altitude simulation. The rocket steam generators make it possible to supply the required quantities of steam at short notice with reduced investment and operating costs. The rocket steam generators are based on the combustion of liquid oxygen (LOX) and ethyl alcohol (ALC). The paper deals with the experience of the development of the steam generators and the operation at the altitude simulation P1.0 for satellite propulsion and P4.2 for altitude simulation of AESTUS upper stage engine.

  1. Test signal generation for analog circuits

    NASA Astrophysics Data System (ADS)

    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.

  2. Formal methods for test case generation

    NASA Technical Reports Server (NTRS)

    Rushby, John (Inventor); De Moura, Leonardo Mendonga (Inventor); Hamon, Gregoire (Inventor)

    2011-01-01

    The invention relates to the use of model checkers to generate efficient test sets for hardware and software systems. The method provides for extending existing tests to reach new coverage targets; searching *to* some or all of the uncovered targets in parallel; searching in parallel *from* some or all of the states reached in previous tests; and slicing the model relative to the current set of coverage targets. The invention provides efficient test case generation and test set formation. Deep regions of the state space can be reached within allotted time and memory. The approach has been applied to use of the model checkers of SRI's SAL system and to model-based designs developed in Stateflow. Stateflow models achieving complete state and transition coverage in a single test case are reported.

  3. Central respiratory pattern generation in the bullfrog, Rana catesbeiana.

    PubMed

    Milsom, W K; Reid, S G; Meier, J T; Kinkead, R

    1999-11-01

    There are two components to breathing pattern generation the production of the pattern of neural discharge associated with individual breaths, and the pattern in which breaths are produced to effect ventilation. Bullfrogs typically breathe with randomly distributed breaths. When respiratory drive is elevated, breathing becomes more regular and often episodic. Studies on in vitro brainstem-spinal cord preparations of the adult bullfrog and in situ preparations of decerebrate, paralyzed, unidirectionally ventilated animals suggest that output from the central rhythm generator in frogs is conditional on receiving some input and that a host of central inputs remain even in the most reduced preparations. There appear to be descending inputs from sites in the dorsal brainstem just caudal to the optic chiasma that cluster breaths into episodes, a strong excitatory input caudal to this site but rostral to the origin of the Vth cranial nerve and, possibly, segmental rhythm generators throughout the medulla that are normally entrained to produce the normal breathing pattern. The data also suggest that the shape of the discharge pattern (augmenting, decrementing) and timing of outputs (alternating vs synchronous) associated with motor outflow during each breath are also dependent on the interconnections between these various sites. PMID:10665378

  4. Central pattern generator for vocalization: Is there a vertebrate morphotype?

    PubMed Central

    Bass, Andrew H.

    2014-01-01

    Animals that generate acoustic signals for social communication are faced with two essential tasks: generate a temporally precise signal and inform the auditory system about the occurrence of one’s own sonic signal. Recent studies of sound producing fishes delineate a hindbrain network comprised of anatomically distinct compartments coding equally distinct neurophysiological properties that allow an organism to meet these behavioral demands. A set of neural characters comprising a vocal-sonic central pattern generator (CPG) morphotype is proposed for fishes and tetrapods that shares evolutionary developmental origins with pectoral appendage motor systems. PMID:25050813

  5. Downhole steam generator subject of Sandia tests

    SciTech Connect

    Not Available

    1981-05-01

    The first field test of a down-hole steam generator developed to inject hot steam directly into deeply buried heavy oil reservoirs began in mid-April near Long Beach, CA. The 23-ft-long, 6-in.-diameter generator, developed by Sandia National Laboratories, will produce up to 800 cu ft of 500 F steam a minute (1.2 MW thermal) at the bottom of a 2500-ft well. Goals of the test are to demonstrate the feasibility of operating the generator at realistic depths and to determine its overall performance and environmental impact. Development of the generator is part of the US Department of Energy's Project Deep Steam to identify techniques for recovering heavy oil from deeply buried (greater than 2500 ft) reservoirs.

  6. Generating Coherent Patterns of Activity from Chaotic Neural Networks

    PubMed Central

    Sussillo, David; Abbott, L. F.

    2009-01-01

    Neural circuits display complex activity patterns both spontaneously and when responding to a stimulus or generating a motor output. How are these two forms of activity related? We develop a procedure called FORCE learning for modifying synaptic strengths either external to or within a model neural network to change chaotic spontaneous activity into a wide variety of desired activity patterns. FORCE learning works even though the networks we train are spontaneously chaotic and we leave feedback loops intact and unclamped during learning. Using this approach, we construct networks that produce a wide variety of complex output patterns, input-output transformations that require memory, multiple outputs that can be switched by control inputs, and motor patterns matching human motion capture data. Our results reproduce data on pre-movement activity in motor and premotor cortex, and suggest that synaptic plasticity may be a more rapid and powerful modulator of network activity than generally appreciated. PMID:19709635

  7. Modeling Scalable Pattern Generation in DNA Reaction Networks

    PubMed Central

    Allen, Peter B.; Chen, Xi; Simpson, Zack B.; Ellington, Andrew D.

    2013-01-01

    We have developed a theoretical framework for developing patterns in multiple dimensions using controllable diffusion and designed reactions implemented in DNA. This includes so-called strand displacement reactions in which one single-stranded DNA hybridizes to a hemi-duplex DNA and displaces another single-stranded DNA, reversibly or irreversibly. These reactions can be designed to proceed with designed rate and molecular specificity. By also controlling diffusion by partial complementarity to a stationary, cross-linked DNA, we can generate predictable patterns. We demonstrate this with several simulations showing deterministic, predictable shapes in space. PMID:25506295

  8. Order parameter for bursting polyrhythms in multifunctional central pattern generators

    NASA Astrophysics Data System (ADS)

    Wojcik, Jeremy; Clewley, Robert; Shilnikov, Andrey

    2011-05-01

    We examine multistability of several coexisting bursting patterns in a central pattern generator network composed of three Hodgkin-Huxley type cells coupled reciprocally by inhibitory synapses. We establish that the control of switching between bursting polyrhythms and their bifurcations are determined by the temporal characteristics, such as the duty cycle, of networked interneurons and the coupling strength asymmetry. A computationally effective approach to the reduction of dynamics of the nine-dimensional network to two-dimensional Poincaré return mappings for phase lags between the interneurons is presented.

  9. Next Generation Drivetrain Development and Test Program

    SciTech Connect

    Keller, Jonathan; Erdman, Bill; Blodgett, Doug; Halse, Chris; Grider, Dave

    2015-11-03

    This presentation was given at the Wind Energy IQ conference in Bremen, Germany, November 30 through December 2, 2105. It focused on the next-generation drivetrain architecture and drivetrain technology development and testing (including gearbox and inverter software and medium-voltage inverter modules.

  10. Computer-Based Arithmetic Test Generation

    ERIC Educational Resources Information Center

    Trocchi, Robert F.

    1973-01-01

    The computer can be a welcome partner in the instructional process, but only if there is man-machine interaction. Man should not compromise system design because of available hardware; the computer must fit the system design for the result to represent an acceptable solution to instructional technology. The Arithmetic Test Generator system fits…

  11. THE IDENTIFICATION AND TESTING OF INTERACTION PATTERNS

    EPA Science Inventory

    This paper presents a method for identifying and assessing the significance of interaction patterns among various chemicals and chemical classes of importance to regulatory toxicologists. To this end, efforts were made to assemble and evaluate experimental data on toxicologically...

  12. Neural Sequence Generation Using Spatiotemporal Patterns of Inhibition.

    PubMed

    Cannon, Jonathan; Kopell, Nancy; Gardner, Timothy; Markowitz, Jeffrey

    2015-11-01

    Stereotyped sequences of neural activity are thought to underlie reproducible behaviors and cognitive processes ranging from memory recall to arm movement. One of the most prominent theoretical models of neural sequence generation is the synfire chain, in which pulses of synchronized spiking activity propagate robustly along a chain of cells connected by highly redundant feedforward excitation. But recent experimental observations in the avian song production pathway during song generation have shown excitatory activity interacting strongly with the firing patterns of inhibitory neurons, suggesting a process of sequence generation more complex than feedforward excitation. Here we propose a model of sequence generation inspired by these observations in which a pulse travels along a spatially recurrent excitatory chain, passing repeatedly through zones of local feedback inhibition. In this model, synchrony and robust timing are maintained not through redundant excitatory connections, but rather through the interaction between the pulse and the spatiotemporal pattern of inhibition that it creates as it circulates the network. These results suggest that spatially and temporally structured inhibition may play a key role in sequence generation. PMID:26536029

  13. Neural Sequence Generation Using Spatiotemporal Patterns of Inhibition

    PubMed Central

    Cannon, Jonathan; Kopell, Nancy; Gardner, Timothy; Markowitz, Jeffrey

    2015-01-01

    Stereotyped sequences of neural activity are thought to underlie reproducible behaviors and cognitive processes ranging from memory recall to arm movement. One of the most prominent theoretical models of neural sequence generation is the synfire chain, in which pulses of synchronized spiking activity propagate robustly along a chain of cells connected by highly redundant feedforward excitation. But recent experimental observations in the avian song production pathway during song generation have shown excitatory activity interacting strongly with the firing patterns of inhibitory neurons, suggesting a process of sequence generation more complex than feedforward excitation. Here we propose a model of sequence generation inspired by these observations in which a pulse travels along a spatially recurrent excitatory chain, passing repeatedly through zones of local feedback inhibition. In this model, synchrony and robust timing are maintained not through redundant excitatory connections, but rather through the interaction between the pulse and the spatiotemporal pattern of inhibition that it creates as it circulates the network. These results suggest that spatially and temporally structured inhibition may play a key role in sequence generation. PMID:26536029

  14. Generating patterns from fields of cells. Examples from Drosophila segmentation.

    PubMed

    Sanson, B

    2001-12-01

    In Drosophila, a cascade of maternal, gap, pair-rule and segment polarity genes subdivides the antero/posterior axis of the embryo into repeating segmental stripes. This review summarizes what happens next, i.e. how an intrasegmental pattern is generated and controls the differentiation of specific cell types in the epidermis. Within each segment, cells secreting the signalling molecules Wingless (the homologue of vertebrate Wnt-1) and Hedgehog are found in narrow stripes on both sides of the parasegmental boundary. The Wingless and Hedgehog organizing activities help to establish two more stripes per segment that localize ligands for the Epidermal Growth Factor and the Notch signalling pathways, respectively. These four signals then act at short range and in concert to control epidermal differentiation at the single cell level across the segment. This example from Drosophila provides a paradigm for how organizers generate precise patterns, and ultimately different cell types, in a naïve field of cells. PMID:11743020

  15. Override of spontaneous respiratory pattern generator reduces cardiovascular parasympathetic influence

    NASA Technical Reports Server (NTRS)

    Patwardhan, A. R.; Vallurupalli, S.; Evans, J. M.; Bruce, E. N.; Knapp, C. F.

    1995-01-01

    We investigated the effects of voluntary control of breathing on autonomic function in cardiovascular regulation. Variability in heart rate was compared between 5 min of spontaneous and controlled breathing. During controlled breathing, for 5 min, subjects voluntarily reproduced their own spontaneous breathing pattern (both rate and volume on a breath-by-breath basis). With the use of this experimental design, we could unmask the effects of voluntary override of the spontaneous respiratory pattern generator on autonomic function in cardiovascular regulation without the confounding effects of altered respiratory pattern. Results from 10 subjects showed that during voluntary control of breathing, mean values of heart rate and blood pressure increased, whereas fractal and spectral powers in heart rate in the respiratory frequency region decreased. End-tidal PCO2 was similar during spontaneous and controlled breathing. These results indicate that the act of voluntary control of breathing decreases the influence of the vagal component, which is the principal parasympathetic influence in cardiovascular regulation.

  16. Continuities and changes in infant attachment patterns across two generations.

    PubMed

    Raby, K Lee; Steele, Ryan D; Carlson, Elizabeth A; Sroufe, L Alan

    2015-01-01

    This study examined the intergenerational continuities and changes in infant attachment patterns within a higher-risk longitudinal sample of 55 female participants born into poverty. Infant attachment was assessed using the Strange Situation when participants were 12 and 18 months as well as several decades later with participants' children. Paralleling earlier findings from this sample on the stability of attachment patterns from infancy to young adulthood, results provided evidence for intergenerational continuities in attachment disorganization but not security. Children of adults with histories of infant attachment disorganization were at an increased risk of forming disorganized attachments. Although changes in infant attachment patterns across the two generations were not correlated with individuals' caregiving experiences or interpersonal stresses and supports during childhood and adolescence, higher quality social support during adulthood was associated with intergenerational changes from insecure to secure infant-caregiver attachment relationships. PMID:26213155

  17. Continuities and Changes in Infant Attachment Patterns Across Two Generations

    PubMed Central

    Raby, K. Lee; Steele, Ryan D.; Carlson, Elizabeth A.; Sroufe, L. Alan

    2015-01-01

    This study examined the intergenerational continuities and changes in infant attachment patterns within a higher-risk longitudinal sample of 55 female participants born into poverty. Infant attachment was assessed using the Strange Situation when participants were 12 and 18 months as well as several decades later with participants’ children. Paralleling earlier findings from this sample on the stability of attachment patterns from infancy to young adulthood, results provided evidence for intergenerational continuities in attachment disorganization but not security. Children of adults with histories of infant attachment disorganization were at an increased risk of forming disorganized attachments. Although changes in infant attachment patterns across the two generations were not correlated with individuals’ caregiving experiences or interpersonal stresses and supports during childhood and adolescence, higher quality social support during adulthood was associated with intergenerational changes from insecure to secure infant-caregiver attachment relationships. PMID:26213155

  18. Electron beam pattern generator sensitivity to target potentials

    NASA Astrophysics Data System (ADS)

    Ruan, Junru; Hartley, John

    2005-11-01

    Electrostatic chucking is the plan of record for mask clamping in Extreme Ultraviolet (EUV) lithography. In order to minimize mask distortion it is recommended by the EUV lithography community that identical electrostatic chucks be used in the mask patterning and metrology tools. The high voltages used in electrostatic chucking have the potential to establish voltages on the mask surface, which may influence the electron optical characteristics of the pattern generator to the detrimental imaging of the pattern. To understand the relationship between image degradation and mask surface voltages, we are modeling the interaction between mask potential and electron beam columns. The first system modeled consists entirely of electrostatic elements, and the second one is a more traditional electron beam lithography system with electrostatic and magnetic components. All of the working parameters of the systems were fixed to establish optimal imaging on the grounded mask. We then altered the potential on the mask surface and determined the impact on focus and deflection errors. The simulation results establish the relationship between the mask potential, focus and deflection errors. Detailed data of focus deflection error versus mask potential will be presented for these electron beam column configurations. When combined with ITRS roadmap specifications, these results set boundaries on mask and chuck configurations as well as grounding schemes. The results are also applicable to charged particle maskless lithography schemes as well as issues of substrate charging in both pattern generators and metrology tools.

  19. Use of design pattern layout for automatic metrology recipe generation

    NASA Astrophysics Data System (ADS)

    Tabery, Cyrus; Page, Lorena

    2005-05-01

    As critical dimension control requirements become more challenging, due to complex designs, aggressive lithography, and the constant need to shrink,metrology recipe generation and design evaluation have also become very complex. Hundreds of unique sites must be measured and monitored to ensure good device performance and high yield. The use of the design and layout for automated metrology recipe generation will be critical to that challenge. The DesignGauge from Hitachi implements a system enabling arbitrary recipe generation and control of SEM observations performed on the wafer, based only on the design information. This concept for recipe generation can reduce the time to develop a technology node from RET and design rule selection, through OPC model calibration and verification, and all the way to high volume manufacturing. Conventional recipe creation for a large number of measurement targets requires a significant amount of engineering time. Often these recipes are used only once or twice during mask and process verification or OPC calibration data acquisition. This process of manual setup and analysis is also potentially error prone. CD-SEM recipe creation typically requires an actual wafer, so the recipe creation cannot occur until the scanner and reticle are in house. All of these problems with conventional CD SEM lead to increased development time and reduced final process quality. The new model of CD-SEM recipe generation and management utilizes design-to-SEM matching technology. This new technology extracts an idealized shape from the designed pattern, and utilizes the shape information for pattern matching. As a result, the designed pattern is used as basis for the template instead of the actual SEM image. Recipe creation can be achieved in a matter of seconds once the target site list is finalized. The sequence of steps for creating a recipe are: generate a target site list, pass the design polygons (GDS) and site list to the CD SEM, define references

  20. Stochastic Generation of Wind Patterns over Lake Geneva

    NASA Astrophysics Data System (ADS)

    Barry, D. A.; Barry, C. E.; Razmi, A. M.; Lemmin, U.; Le Dantec, N.

    2011-12-01

    stochastic generator of wind-pattern indices, i.e., the INAR(1) model produces a sequence of integers, each of which corresponds to a wind pattern. For a given index, the aforementioned binned COSMO wind fields were sampled randomly to produce the stochastic wind-field sequence.

  1. Pattern Recognition on Read Positioning in Next Generation Sequencing

    PubMed Central

    Byeon, Boseon; Kovalchuk, Igor

    2016-01-01

    The usefulness and the utility of the next generation sequencing (NGS) technology are based on the assumption that the DNA or cDNA cleavage required to generate short sequence reads is random. Several previous reports suggest the existence of sequencing bias of NGS reads. To address this question in greater detail, we analyze NGS data from four organisms with different GC content, Plasmodium falciparum (19.39%), Arabidopsis thaliana (36.03%), Homo sapiens (40.91%) and Streptomyces coelicolor (72.00%). Using machine learning techniques, we recognize the pattern that the NGS read start is positioned in the local region where the nucleotide distribution is dissimilar from the global nucleotide distribution. We also demonstrate that the mono-nucleotide distribution underestimates sequencing bias, and the recognized pattern is explained largely by the distribution of multi-nucleotides (di-, tri-, and tetra- nucleotides) rather than mono-nucleotides. This implies that the correction of sequencing bias needs to be performed on the basis of the multi-nucleotide distribution. Providing companion software to quantify the effect of the recognized pattern on read positioning, we exemplify that the bias correction based on the mono-nucleotide distribution may not be sufficient to clean sequencing bias. PMID:27299343

  2. Generation of Viable Cell and Biomaterial Patterns by Laser Transfer

    NASA Astrophysics Data System (ADS)

    Ringeisen, Bradley

    2001-03-01

    In order to fabricate and interface biological systems for next generation applications such as biosensors, protein recognition microarrays, and engineered tissues, it is imperative to have a method of accurately and rapidly depositing different active biomaterials in patterns or layered structures. Ideally, the biomaterial structures would also be compatible with many different substrates including technologically relevant platforms such as electronic circuits or various detection devices. We have developed a novel laser-based technique, termed matrix assisted pulsed laser evaporation direct write (MAPLE DW), that is able to direct write patterns and three-dimensional structures of numerous biologically active species ranging from proteins and antibodies to living cells. Specifically, we have shown that MAPLE DW is capable of forming mesoscopic patterns of living prokaryotic cells (E. coli bacteria), living mammalian cells (Chinese hamster ovaries), active proteins (biotinylated bovine serum albumin, horse radish peroxidase), and antibodies specific to a variety of classes of cancer related proteins including intracellular and extracellular matrix proteins, signaling proteins, cell cycle proteins, growth factors, and growth factor receptors. In addition, patterns of viable cells and active biomolecules were deposited on different substrates including metals, semiconductors, nutrient agar, and functionalized glass slides. We will present an explanation of the laser-based transfer mechanism as well as results from our recent efforts to fabricate protein recognition microarrays and tissue-based microfluidic networks.

  3. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern...

  4. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern...

  5. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern...

  6. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern...

  7. Evolution of central pattern generators and rhythmic behaviours.

    PubMed

    Katz, Paul S

    2016-01-01

    Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization. PMID:26598733

  8. Temperature-dependent regulation of vocal pattern generator.

    PubMed

    Yamaguchi, Ayako; Gooler, David; Herrold, Amy; Patel, Shailja; Pong, Winnie W

    2008-12-01

    Vocalizations of Xenopus laevis are generated by central pattern generators (CPGs). The advertisement call of male X. laevis is a complex biphasic motor rhythm consisting of fast and slow trills (a train of clicks). We found that the trill rate of these advertisement calls is sensitive to temperature and that this rate modification of the vocal rhythms originates in the central pattern generators. In vivo the rates of fast and slow trills increased linearly with an increase in temperature. In vitro a similar linear relation between temperature and compound action potential frequency in the laryngeal nerve was found when fictive advertisement calls were evoked in the isolated brain. Temperature did not limit the contractile properties of laryngeal muscles within the frequency range of vocalizations. We next took advantage of the temperature sensitivity of the vocal CPG in vitro to localize the source of the vocal rhythms. We focused on the dorsal tegmental area of the medulla (DTAM), a brain stem nucleus that is essential for vocal production. We found that bilateral cooling of DTAM reduced both fast and slow trill rates. Thus we conclude that DTAM is a source of biphasic vocal rhythms. PMID:18829853

  9. The generation of vertebral segmental patterning in the chick embryo

    PubMed Central

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-01-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline. PMID:22458512

  10. Fault Simulation and Test Generation for Transistor Shorts Using Stuck-at Test Tools

    NASA Astrophysics Data System (ADS)

    Higami, Yoshinobu; Saluja, Kewal K.; Takahashi, Hiroshi; Kobayashi, Shin-Ya; Takamatsu, Yuzo

    This paper presents methods for detecting transistor short faults using logic level fault simulation and test generation. The paper considers two types of transistor level faults, namely strong shorts and weak shorts, which were introduced in our previous research. These faults are defined based on the values of outputs of faulty gates. The proposed fault simulation and test generation are performed using gate-level tools designed to deal with stuck-at faults, and no transistor-level tools are required. In the test generation process, a circuit is modified by inserting inverters, and a stuck-at test generator is used. The modification of a circuit does not mean a design-for-testability technique, as the modified circuit is used only during the test generation process. Further, generated test patterns are compacted by fault simulation. Also, since the weak short model involves uncertainty in its behavior, we define fault coverage and fault efficiency in three different way, namely, optimistic, pessimistic and probabilistic and assess them. Finally, experimental results for ISCAS benchmark circuits are used to demonstrate the effectiveness of the proposed methods.

  11. Custom pulse generator for RPC testing

    NASA Astrophysics Data System (ADS)

    Gil, A.; Castro, E.; Díaz, J.; Fonte, P.; Garzón, J. A.; Montes, N.; Zapata, M.

    2009-05-01

    We present a pulse generator able to generate pulses statistically similar to the ones produced by RPC cells. The device generates up to four arrays of fast and narrow random-like pulses. Polarity, maximum amplitudes, widths and pulse rate in each channel may be modified independently in order to simulate different RPC setups and environments. This portable and cost-effective pulse generator is a versatile instrument for testing FE-Electronics and different real detector features related with the signal propagation inside the detector. It has been developed in the framework of the ESTRELA project of the HADES experiment at GSI. ESTRELA (Electrically Shielded Timing RPC Ensemble for Low Angles) is part of the upgrade of the HADES experiment at GSI with the aim of constructing an RPC-based time-of-flight wall that will cover around 8 m 2 in order to cope with the high particle multiplicities expected for heavy nuclei collision systems such as Au+Au.

  12. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Steam generator inspections and tests. 229.114... Generators § 229.114 Steam generator inspections and tests. (a) Periodic steam generator inspection. Except as provided in § 229.33, each steam generator shall be inspected and tested in accordance...

  13. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Steam generator inspections and tests. 229.114... Generators § 229.114 Steam generator inspections and tests. (a) Periodic steam generator inspection. Except as provided in § 229.33, each steam generator shall be inspected and tested in accordance...

  14. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Steam generator inspections and tests. 229.114... Generators § 229.114 Steam generator inspections and tests. (a) Periodic steam generator inspection. Except as provided in § 229.33, each steam generator shall be inspected and tested in accordance...

  15. Central Pattern Generator for Locomotion: Anatomical, Physiological, and Pathophysiological Considerations

    PubMed Central

    Guertin, Pierre A.

    2013-01-01

    This article provides a perspective on major innovations over the past century in research on the spinal cord and, specifically, on specialized spinal circuits involved in the control of rhythmic locomotor pattern generation and modulation. Pioneers such as Charles Sherrington and Thomas Graham Brown have conducted experiments in the early twentieth century that changed our views of the neural control of locomotion. Their seminal work supported subsequently by several decades of evidence has led to the conclusion that walking, flying, and swimming are largely controlled by a network of spinal neurons generally referred to as the central pattern generator (CPG) for locomotion. It has been subsequently demonstrated across all vertebrate species examined, from lampreys to humans, that this CPG is capable, under some conditions, to self-produce, even in absence of descending or peripheral inputs, basic rhythmic, and coordinated locomotor movements. Recent evidence suggests, in turn, that plasticity changes of some CPG elements may contribute to the development of specific pathophysiological conditions associated with impaired locomotion or spontaneous locomotor-like movements. This article constitutes a comprehensive review summarizing key findings on the CPG as well as on its potential role in Restless Leg Syndrome, Periodic Leg Movement, and Alternating Leg Muscle Activation. Special attention will be paid to the role of the CPG in a recently identified, and uniquely different neurological disorder, called the Uner Tan Syndrome. PMID:23403923

  16. Sequentially firing neurons confer flexible timing in neural pattern generators

    SciTech Connect

    Urban, Alexander; Ermentrout, Bard

    2011-05-15

    Neuronal networks exhibit a variety of complex spatiotemporal patterns that include sequential activity, synchrony, and wavelike dynamics. Inhibition is the primary means through which such patterns are implemented. This behavior is dependent on both the intrinsic dynamics of the individual neurons as well as the connectivity patterns. Many neural circuits consist of networks of smaller subcircuits (motifs) that are coupled together to form the larger system. In this paper, we consider a particularly simple motif, comprising purely inhibitory interactions, which generates sequential periodic dynamics. We first describe the dynamics of the single motif both for general balanced coupling (all cells receive the same number and strength of inputs) and then for a specific class of balanced networks: circulant systems. We couple these motifs together to form larger networks. We use the theory of weak coupling to derive phase models which, themselves, have a certain structure and symmetry. We show that this structure endows the coupled system with the ability to produce arbitrary timing relationships between symmetrically coupled motifs and that the phase relationships are robust over a wide range of frequencies. The theory is applicable to many other systems in biology and physics.

  17. Spatial patterns of nonstationarity: does the statistical test matter?

    NASA Astrophysics Data System (ADS)

    Cahill, A. T.; Faloon, A.; Brumbelow, J. K.

    2012-12-01

    In many regions, extreme rainfalls are generated by large-scale weather features which are significantly larger than the separation among the set of rain gages in the region; it would be expected therefore that these rain gages would exhibit similar statistical behavior. When time series of extreme rainfalls measured at these gages are tested individually for nonstationarity, however, it is often found that any spatial pattern of the nonstationarity is poorly defined. The fact that extremes of rainfall at one location are increasing in time is not strongly predictive of the behavior of the extreme rainfall at neighboring rain gages, which may be increasing, decreasing or unchanging, when the individual time series are considered by themselves. Using rainfall data sets from the southern United States as a test case, we present work on detection of nonstationarity in rainfall extremes which takes into account the disparate answers individual tests of nonstationarity can give, given our assumption of larger-scale precipitation fields driving the behavior of point observations.

  18. Optimal Test Design with Rule-Based Item Generation

    ERIC Educational Resources Information Center

    Geerlings, Hanneke; van der Linden, Wim J.; Glas, Cees A. W.

    2013-01-01

    Optimal test-design methods are applied to rule-based item generation. Three different cases of automated test design are presented: (a) test assembly from a pool of pregenerated, calibrated items; (b) test generation on the fly from a pool of calibrated item families; and (c) test generation on the fly directly from calibrated features defining…

  19. Improved photomask accuracy with a high-productivity DUV laser pattern generator

    NASA Astrophysics Data System (ADS)

    Öström, Thomas; Måhlén, Jonas; Karawajczyk, Andrzej; Rosling, Mats; Carlqvist, Per; Askebjer, Per; Karlin, Tord; Sallander, Jesper; Österberg, Anders

    2006-10-01

    A strategy for sub-100 nm technology nodes is to maximize the use of high-speed deep-UV laser pattern generators, reserving e-beam tools for the most critical photomask layers. With a 248 nm excimer laser and 0.82 NA projection optics, the Sigma7500 increases the application space of laser pattern generators. A programmable spatial light modulator (SLM) is imaged with partially coherent optics to compose the photomask pattern. Image profiles are enhanced with phase shifting in the pattern generator, and features below 200 nm are reliably printed. The Sigma7500 extends the SLM-based architecture with improvements to CD uniformity and placement accuracy, resulting from an error budget-based methodology. Among these improvements is a stiffer focus stage design with digital servos, resulting in improved focus stability. Tighter climate controls and improved dose control reduce drift during mask patterning. As a result, global composite CD uniformity below 5 nm (3σ) has been demonstrated, with placement accuracy below 10 nm (3σ) across the mask. Self-calibration methods are used to optimize and monitor system performance, reducing the need to print test plates. The SLM calibration camera views programmed test patterns, making it possible to evaluate image metrics such as CD uniformity and line edge roughness. The camera is also used to characterize image placement over the optical field. A feature called ProcessEqualizer TM has been developed to correct long-range CD errors arising from process effects on production photomasks. Mask data is sized in real time to compensate for pattern-dependent errors related to local pattern density, as well as for systematic pattern-independent errors such as radial CD signatures. Corrections are made in the pixel domain in the advanced adjustments processor, which also performs global biasing, stamp distortion compensation, and corner enhancement. In the Sigma7500, the mask pattern is imaged with full edge addressability in each

  20. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of radiopaque or radioactive material sealed in a solid pattern intended to serve as a test for a performance characteristic of a nuclear medicine imaging device. (b) Classification. Class I (general...

  1. Validation Testing of Hydrogen Generation Technology

    SciTech Connect

    Smith, Barton; Toops, Todd J

    2007-12-01

    This report describes the results of testing performed by ORNL for Photech Energies, Inc. The objective of the testing was to evaluate the efficacy of Photech's hydrogen generation reactor technology, which produces gaseous hydrogen through electrolysis. Photech provided several prototypes of their proprietary reactor for testing and the ancillary equipment, such as power supplies and electrolyte solutions, required for proper operation of the reactors. ORNL measured the production of hydrogen gas (volumetric flow of hydrogen at atmospheric pressure) as a function of input power and analyzed the composition of the output stream to determine the purity of the hydrogen content. ORNL attempted measurements on two basic versions of the prototype reactors-one version had a clear plastic outer cylinder, while another version had a stainless steel outer cylinder-but was only able to complete measurements on reactors in the plastic version. The problem observed in the stainless steel reactors was that in these reactors most of the hydrogen was produced near the anodes along with oxygen and the mixed gases made it impossible to determine the amount of hydrogen produced. In the plastic reactors the production of hydrogen gas increased monotonically with input power, and the flow rates increased faster at low input powers than they did at higher input powers. The maximum flow rate from the cathode port measured during the tests was 0.85 LPM at an input power of about 1100 W, an electrolyte concentration of 20%. The composition of the flow from the cathode port was primarily hydrogen and water vapor, with some oxygen and trace amounts of carbon dioxide. An operational mode that occurs briefly during certain operating conditions, and is characterized by flashes of light and violent bubbling near the cathode, might be attributable to the combustion of hydrogen and oxygen in the electrolyte solution.

  2. Sexually differentiated central pattern generators in Xenopus laevis.

    PubMed

    Zornik, Erik; Yamaguchi, Ayako

    2008-06-01

    Understanding the neural mechanisms that underlie the function of central pattern generators (CPGs) presents a formidable challenge requiring sophisticated tools and well-chosen model systems. In this article, we describe recent work on vocalizations of the African clawed frog Xenopus laevis. These behaviors are driven by sexually differentiated CPGs and are exceptionally well suited to this objective. In particular, a simplified mechanism of vocal production (independent of respiratory musculature) allows straightforward interpretations of nerve activity with respect to behavior. Furthermore, the development of a fictively vocalizing isolated brain, together with the finding of rapid androgen-induced masculinization of female vocalizations, provides an invaluable tool for determining how new behaviors arise from existing circuits. PMID:18471902

  3. Analog electronic model of the lobster pyloric central pattern generator

    NASA Astrophysics Data System (ADS)

    Volkovskii, A.; Brugioni, S.; Levi, R.; Rabinovich, M.; Selverston, A.; Abarbane, H. D. I.

    2005-01-01

    An electronic circuit intended to simulate the nonlinear dynamics of a simplified 3-cell model of the pyloric central pattern generator in California spiny lobster stomato gastric ganglion is presented. The model employs the synaptic phase locked loop (SPLL) concept where the frequency of oscillations of a postsynaptic cell is mainly controlled by the synaptic current which depends on the phase shift between the oscillations. The theoretical study showed that the system has a stable steady state with correct phase shifts between the oscillations and that this regime is stable when the frequency of the pacemaker cell is varied over a wide range. The main bifurcations in the system were studied analytically, in computer simulations, and in experiments with the electronic circuit. The experimental measurements are in good agreement with the expectations of the theoretical model.

  4. Neural Patterns of the Implicit Association Test

    PubMed Central

    Healy, Graham F.; Boran, Lorraine; Smeaton, Alan F.

    2015-01-01

    The Implicit Association Test (IAT) is a reaction time based categorization task that measures the differential associative strength between bipolar targets and evaluative attribute concepts as an approach to indexing implicit beliefs or biases. An open question exists as to what exactly the IAT measures, and here EEG (Electroencephalography) has been used to investigate the time course of ERPs (Event-related Potential) indices and implicated brain regions in the IAT. IAT-EEG research identifies a number of early (250–450 ms) negative ERPs indexing early-(pre-response) processing stages of the IAT. ERP activity in this time range is known to index processes related to cognitive control and semantic processing. A central focus of these efforts has been to use IAT-ERPs to delineate the implicit and explicit factors contributing to measured IAT effects. Increasing evidence indicates that cognitive control (and related top-down modulation of attention/perceptual processing) may be components in the effective measurement of IAT effects, as factors such as physical setting or task instruction can change an IAT measurement. In this study we further implicate the role of proactive cognitive control and top-down modulation of attention/perceptual processing in the IAT-EEG. We find statistically significant relationships between D-score (a reaction-time based measure of the IAT-effect) and early ERP-time windows, indicating where more rapid word categorizations driving the IAT effect are present, they are at least partly explainable by neural activity not significantly correlated with the IAT measurement itself. Using LORETA, we identify a number of brain regions driving these ERP-IAT relationships notably involving left-temporal, insular, cingulate, medial frontal and parietal cortex in time regions corresponding to the N2- and P3-related activity. The identified brain regions involved with reduced reaction times on congruent blocks coincide with those of previous studies

  5. Two-stage Turing model for generating pigment patterns on the leopard and the jaguar

    NASA Astrophysics Data System (ADS)

    Liu, R. T.; Liaw, S. S.; Maini, P. K.

    2006-07-01

    Based on the results of phylogenetic analysis, which showed that flecks are the primitive pattern of the felid family and all other patterns including rosettes and blotches develop from it, we construct a Turing reaction-diffusion model which generates spot patterns initially. Starting from this spotted pattern, we successfully generate patterns of adult leopards and jaguars by tuning parameters of the model in the subsequent phase of patterning.

  6. Generational Patterns in Mexican Americans' Academic Performance in an Unwelcoming Political Context

    PubMed Central

    Moosmann, Danyel A. V.; Roosa, Mark W.; Knight, George P.

    2014-01-01

    Research has shown that immigrant students often do better academically than their U.S.-born peers from the same ethnic group but it is unclear whether this pattern holds for Mexican Americans. We examined the academic performance of four generations of Mexican American students from fifth to 10th grade looking for generation differences and explanations for them. Using data from 749 families, we tested a model with fifth grade variables that differed by generation as potential mediators linking student generation to 10th grade academic performance. Results showed that immigrants were academically behind at fifth grade but caught up by seventh. Only economic hardship mediated the long term relationship between student generation and 10th grade academic performance; maternal educational expectations and child language hassles, English usage, discrimination, and mainstream values helped explained the early academic deficit of immigrant children. The results identified potential targets for interventions to improve Mexican American students' academic performance. PMID:24578588

  7. Generation of Earth's First-Order Biodiversity Pattern

    NASA Astrophysics Data System (ADS)

    Krug, Andrew Z.; Jablonski, David; Valentine, James W.; Roy, Kaustuv

    2009-02-01

    The first-order biodiversity pattern on Earth today and at least as far back as the Paleozoic is the latitudinal diversity gradient (LDG), a decrease in richness of species and higher taxa from the equator to the poles. LDGs are produced by geographic trends in origination, extinction, and dispersal over evolutionary timescales, so that analyses of static patterns will be insufficient to reveal underlying processes. The fossil record of marine bivalve genera, a model system for the analysis of biodiversity dynamics over large temporal and spatial scales, shows that an origination and range-expansion gradient plays a major role in generating the LDG. Peak origination rates and peak diversities fall within the tropics, with range expansion out of the tropics the predominant spatial dynamic thereafter. The origination-diversity link occurs even in a "contrarian" group whose diversity peaks at midlatitudes, an exception proving the rule that spatial variations in origination are key to latitudinal diversity patterns. Extinction rates are lower in polar latitudes (≥60°) than in temperate zones and thus cannot create the observed gradient alone. They may, however, help to explain why origination and immigration are evidently damped in higher latitudes. We suggest that species require more resources in higher latitudes, for the seasonality of primary productivity increases by more than an order of magnitude from equatorial to polar regions. Higher-latitude species are generalists that, unlike potential immigrants, are adapted to garner the large share of resources required for incumbency in those regions. When resources are opened up by extinctions, lineages spread chiefly poleward and chiefly through speciation.

  8. A rule-based software test data generator

    NASA Technical Reports Server (NTRS)

    Deason, William H.; Brown, David B.; Chang, Kai-Hsiung; Cross, James H., II

    1991-01-01

    Rule-based software test data generation is proposed as an alternative to either path/predicate analysis or random data generation. A prototype rule-based test data generator for Ada programs is constructed and compared to a random test data generator. Four Ada procedures are used in the comparison. Approximately 2000 rule-based test cases and 100,000 randomly generated test cases are automatically generated and executed. The success of the two methods is compared using standard coverage metrics. Simple statistical tests showing that even the primitive rule-based test data generation prototype is significantly better than random data generation are performed. This result demonstrates that rule-based test data generation is feasible and shows great promise in assisting test engineers, especially when the rule base is developed further.

  9. Test Generation Algorithm for Fault Detection of Analog Circuits Based on Extreme Learning Machine

    PubMed Central

    Zhou, Jingyu; Tian, Shulin; Yang, Chenglin; Ren, Xuelong

    2014-01-01

    This paper proposes a novel test generation algorithm based on extreme learning machine (ELM), and such algorithm is cost-effective and low-risk for analog device under test (DUT). This method uses test patterns derived from the test generation algorithm to stimulate DUT, and then samples output responses of the DUT for fault classification and detection. The novel ELM-based test generation algorithm proposed in this paper contains mainly three aspects of innovation. Firstly, this algorithm saves time efficiently by classifying response space with ELM. Secondly, this algorithm can avoid reduced test precision efficiently in case of reduction of the number of impulse-response samples. Thirdly, a new process of test signal generator and a test structure in test generation algorithm are presented, and both of them are very simple. Finally, the abovementioned improvement and functioning are confirmed in experiments. PMID:25610458

  10. Test generation algorithm for fault detection of analog circuits based on extreme learning machine.

    PubMed

    Zhou, Jingyu; Tian, Shulin; Yang, Chenglin; Ren, Xuelong

    2014-01-01

    This paper proposes a novel test generation algorithm based on extreme learning machine (ELM), and such algorithm is cost-effective and low-risk for analog device under test (DUT). This method uses test patterns derived from the test generation algorithm to stimulate DUT, and then samples output responses of the DUT for fault classification and detection. The novel ELM-based test generation algorithm proposed in this paper contains mainly three aspects of innovation. Firstly, this algorithm saves time efficiently by classifying response space with ELM. Secondly, this algorithm can avoid reduced test precision efficiently in case of reduction of the number of impulse-response samples. Thirdly, a new process of test signal generator and a test structure in test generation algorithm are presented, and both of them are very simple. Finally, the abovementioned improvement and functioning are confirmed in experiments. PMID:25610458

  11. HIV Testing Patterns among Urban YMSM of Color

    ERIC Educational Resources Information Center

    Leonard, Noelle R.; Rajan, Sonali; Gwadz, Marya V.; Aregbesola, Temi

    2014-01-01

    The heightened level of risk for HIV infection among Black and Latino young men who have sex with men (YMSM) is driven by multilevel influences. Using cross-sectional data, we examined HIV testing patterns among urban YMSM of color in a high-HIV seroprevalence area (ages 16 to 21 years). Self-reported frequency of testing was high, with 42% of…

  12. Caregiving Practice Patterns of Asian, Hispanic, and Non-Hispanic White American Family Caregivers of Older Adults Across Generations.

    PubMed

    Miyawaki, Christina E

    2016-03-01

    This study is a cross-sectional investigation of caregiving practice patterns among Asian, Hispanic and non-Hispanic White American family caregivers of older adults across three immigrant generations. The 2009 California Health Interview Survey (CHIS) dataset was used, and 591 Asian, 989 Hispanic and 6537 non-Hispanic White American caregivers of older adults were selected. First, descriptive analyses of caregivers' characteristics, caregiving situations and practice patterns were examined by racial/ethnic groups and immigrant generations. Practice patterns measured were respite care use, hours and length of caregiving. Three hypotheses on caregiving patterns based on assimilation theory were tested and analyzed using logistic regression and generalized linear models by racial/ethnic groups and generations. Caregiving patterns of non-Hispanic White caregivers supported all three hypotheses regarding respite care use, caregiving hours and caregiving duration, showing less caregiving involvement in later generations. However, Asian and Hispanic counterparts showed mixed results. Third generation Asian and Hispanic caregivers used respite care the least and spent the most caregiving hours per week and had the longest caregiving duration compared to earlier generations. These caregiving patterns revealed underlying cultural values related to filial responsibility, even among later generations of caregivers of color. Findings suggest the importance of considering the cultural values of each racial/ethnic group regardless of generation when working with racially and ethnically diverse populations of family caregivers of older adults. PMID:26810575

  13. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and...

  14. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and...

  15. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and...

  16. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is...

  17. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is...

  18. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is...

  19. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is...

  20. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electroencephalograph test signal generator. 882.1430 Section 882.1430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is...

  1. Electronic Tongue Generating Continuous Recognition Patterns for Protein Analysis

    PubMed Central

    Hou, Yanxia; Genua, Maria; Garçon, Laurie-Amandine; Buhot, Arnaud; Calemczuk, Roberto; Bonnaffé, David; Lortat-Jacob, Hugues; Livache, Thierry

    2014-01-01

    In current protocol, a combinatorial approach has been developed to simplify the design and production of sensing materials for the construction of electronic tongues (eT) for protein analysis. By mixing a small number of simple and easily accessible molecules with different physicochemical properties, used as building blocks (BBs), in varying and controlled proportions and allowing the mixtures to self-assemble on the gold surface of a prism, an array of combinatorial surfaces featuring appropriate properties for protein sensing was created. In this way, a great number of cross-reactive receptors can be rapidly and efficiently obtained. By combining such an array of combinatorial cross-reactive receptors (CoCRRs) with an optical detection system such as surface plasmon resonance imaging (SPRi), the obtained eT can monitor the binding events in real-time and generate continuous recognition patterns including 2D continuous evolution profile (CEP) and 3D continuous evolution landscape (CEL) for samples in liquid. Such an eT system is efficient for discrimination of common purified proteins. PMID:25286325

  2. Electronic tongue generating continuous recognition patterns for protein analysis.

    PubMed

    Hou, Yanxia; Genua, Maria; Garçon, Laurie-Amandine; Buhot, Arnaud; Calemczuk, Roberto; Bonnaffé, David; Lortat-Jacob, Hugues; Livache, Thierry

    2014-01-01

    In current protocol, a combinatorial approach has been developed to simplify the design and production of sensing materials for the construction of electronic tongues (eT) for protein analysis. By mixing a small number of simple and easily accessible molecules with different physicochemical properties, used as building blocks (BBs), in varying and controlled proportions and allowing the mixtures to self-assemble on the gold surface of a prism, an array of combinatorial surfaces featuring appropriate properties for protein sensing was created. In this way, a great number of cross-reactive receptors can be rapidly and efficiently obtained. By combining such an array of combinatorial cross-reactive receptors (CoCRRs) with an optical detection system such as surface plasmon resonance imaging (SPRi), the obtained eT can monitor the binding events in real-time and generate continuous recognition patterns including 2D continuous evolution profile (CEP) and 3D continuous evolution landscape (CEL) for samples in liquid. Such an eT system is efficient for discrimination of common purified proteins. PMID:25286325

  3. The Network Spinal Wave as a Central Pattern Generator

    PubMed Central

    Epstein, Donald M.; Lemberger, Daniel

    2016-01-01

    Abstract Objectives: This article explains the research on a unique spinal wave visibly observed in association with network spinal analysis care. Since 1997, the network wave has been studied using surface electromyography (sEMG), characterized mathematically, and determined to be a unique and repeatable phenomenon. Methods: The authors provide a narrative review of the research and a context for the network wave's development. Results: The sEMG research demonstrates that the movement of the musculature of the spine during the wave phenomenon is electromagnetic and mechanical. The changes running along the spine were characterized mathematically at three distinct levels of care. Additionally, the wave has the mathematical properties of a central pattern generator (CPG). Conclusions: The network wave may be the first CPG discovered in the spine unrelated to locomotion. The mathematical characterization of the signal also demonstrates coherence at a distance between the sacral to cervical spine. According to mathematical engineers, based on studies conducted a decade apart, the wave itself is a robust phenomenon and the detection methods for this coherence may represent a new measure for central nervous system health. This phenomenon has implications for recovery from spinal cord injury and for reorganizational healing development. PMID:27243963

  4. Mutual synchronization between structure and central pattern generator

    NASA Astrophysics Data System (ADS)

    Hongu, Junichi; Iba, Daisuke

    2012-04-01

    This paper shows an evaluating method of synchronization between a structure and Central Pattern Generators (CPGs), which are embedded in a controller designed for an active mass damper. A neural oscillator composing the CPGs has nonlinear and entrainment properties. Therefore, the proposed controller has possibility to exhibit the characteristic of robustness, when the structural parameters, i.e. stiffness or damping, are changed by earthquakes and the like. Our earlier studies have proposed the new controller and ascertained the efficacy of vibration suppression. However, there has been no study to evaluate the controller's above-mentioned properties. For tuning into practical application, the reliability and robustness along with the controller's vibration mitigation performance must be analyzed. In this paper, phase reduction theory is tried to appraise the synchronization between a structure and the CPGs. In this case, the synchronization between the target structure and a single neural oscillator constituting the CPGs is required to be investigated. Therefore, the single neural oscillator's the harmonization characteristic with sinusoidal input is firstly examined, and the synchronization region is expressed using phase response curves. In addition, the mutual synchronization between the structure and the single neural oscillator is studied under sinusoidal input using the result of the harmonization characteristic.

  5. Cellular basis for singing motor pattern generation in the field cricket (Gryllus bimaculatus DeGeer)

    PubMed Central

    Schöneich, Stefan; Hedwig, Berthold

    2012-01-01

    The singing behavior of male crickets allows analyzing a central pattern generator (CPG) that was shaped by sexual selection for reliable production of species-specific communication signals. After localizing the essential ganglia for singing in Gryllus bimaculatus, we now studied the calling song CPG at the cellular level. Fictive singing was initiated by pharmacological brain stimulation. The motor pattern underlying syllables and chirps was recorded as alternating spike bursts of wing-opener and wing-closer motoneurons in a truncated wing nerve; it precisely reflected the natural calling song. During fictive singing, we intracellularly recorded and stained interneurons in thoracic and abdominal ganglia and tested their impact on the song pattern by intracellular current injections. We identified three interneurons of the metathoracic and first unfused abdominal ganglion that rhythmically de- and hyperpolarized in phase with the syllable pattern and spiked strictly before the wing-opener motoneurons. Depolarizing current injection in two of these opener interneurons caused additional rhythmic singing activity, which reliably reset the ongoing chirp rhythm. The closely intermeshing arborizations of the singing interneurons revealed the dorsal midline neuropiles of the metathoracic and three most anterior abdominal neuromeres as the anatomical location of singing pattern generation. In the same neuropiles, we also recorded several closer interneurons that rhythmically hyper- and depolarized in the syllable rhythm and spiked strictly before the wing-closer motoneurons. Some of them received pronounced inhibition at the beginning of each chirp. Hyperpolarizing current injection in the dendrite revealed postinhibitory rebound depolarization as one functional mechanism of central pattern generation in singing crickets. PMID:23170234

  6. Neural basis of singing in crickets: central pattern generation in abdominal ganglia

    NASA Astrophysics Data System (ADS)

    Schöneich, Stefan; Hedwig, Berthold

    2011-12-01

    The neural mechanisms underlying cricket singing behavior have been the focus of several studies, but the central pattern generator (CPG) for singing has not been localized conclusively. To test if the abdominal ganglia contribute to the singing motor pattern and to analyze if parts of the singing CPG are located in these ganglia, we systematically truncated the abdominal nerve cord of fictively singing crickets while recording the singing motor pattern from a front-wing nerve. Severing the connectives anywhere between terminal ganglion and abdominal ganglion A3 did not preclude singing, although the motor pattern became more variable and failure-prone as more ganglia were disconnected. Singing terminated immediately and permanently after transecting the connectives between the metathoracic ganglion complex and the first unfused abdominal ganglion A3. The contribution of abdominal ganglia for singing pattern generation was confirmed by intracellular interneuron recordings and current injections. During fictive singing, an ascending interneuron with its soma and dendrite in A3 depolarized rhythmically. It spiked 10 ms before the wing-opener activity and hyperpolarized in phase with the wing-closer activity. Depolarizing current injection elicited rhythmic membrane potential oscillations and spike bursts that elicited additional syllables and reliably reset the ongoing chirp rhythm. Our results disclose that the abdominal ganglion A3 is directly involved in generating the singing motor pattern, whereas the more posterior ganglia seem to provide only stabilizing feedback to the CPG circuit. Localizing the singing CPG in the anterior abdominal neuromeres now allows analyzing its circuitry at the level of identified interneurons in subsequent studies.

  7. The NIH Toolbox Pattern Comparison Processing Speed Test: Normative Data.

    PubMed

    Carlozzi, Noelle E; Beaumont, Jennifer L; Tulsky, David S; Gershon, Richard C

    2015-08-01

    The NIH Toolbox Pattern Comparison Processing Speed Test was developed to assess processing speed. While initial validation work provides preliminary support for this test in both children and adults, more work is needed to ensure dependability and generalizability. Thus, this replication study examines descriptive data (including age effects), test-retest reliability, and construct validity in n = 4,859 participants ages 3-85 years (matched to 2010 census data). Although the Pattern Comparison was not appropriate for all 3 and 4 years old, by ages 5 and 6, more meaningful scores were apparent. There was evidence for convergent and discriminant validity. There was also a moderate practice effect (i.e., increase of 5.5 points) over a 1-week time frame. Pattern Comparison exhibits a number of strengths: it is appropriate for use across the lifespan (ages 5-85), it is short and easy to administer, and there is support for construct validity. PMID:26025230

  8. "MSTGen": Simulated Data Generator for Multistage Testing

    ERIC Educational Resources Information Center

    Han, Kyung T.

    2013-01-01

    Multistage testing, or MST, was developed as an alternative to computerized adaptive testing (CAT) for applications in which it is preferable to administer a test at the level of item sets (i.e., modules). As with CAT, the simulation technique in MST plays a critical role in the development and maintenance of tests. "MSTGen," a new MST…

  9. CATGEN: A Computer Assisted Test Generator.

    ERIC Educational Resources Information Center

    McCallum, L. W.

    1985-01-01

    Procedures for generating multiple-choice exams in psychology using the Apple IIe computer and the Applewriter II text editing software are described. The model is simple to use and provides flexibility in sequencing the choice of items from an instructor generated pool. (Author/RM)

  10. Positive Selection Linked with Generation of Novel Mammalian Dentition Patterns.

    PubMed

    Machado, João Paulo; Philip, Siby; Maldonado, Emanuel; O'Brien, Stephen J; Johnson, Warren E; Antunes, Agostinho

    2016-01-01

    A diverse group of genes are involved in the tooth development of mammals. Several studies, focused mainly on mice and rats, have provided a detailed depiction of the processes coordinating tooth formation and shape. Here we surveyed 236 tooth-associated genes in 39 mammalian genomes and tested for signatures of selection to assess patterns of molecular adaptation in genes regulating mammalian dentition. Of the 236 genes, 31 (∼13.1%) showed strong signatures of positive selection that may be responsible for the phenotypic diversity observed in mammalian dentition. Mammalian-specific tooth-associated genes had accelerated mutation rates compared with older genes found across all vertebrates. More recently evolved genes had fewer interactions (either genetic or physical), were associated with fewer Gene Ontology terms and had faster evolutionary rates compared with older genes. The introns of these positively selected genes also exhibited accelerated evolutionary rates, which may reflect additional adaptive pressure in the intronic regions that are associated with regulatory processes that influence tooth-gene networks. The positively selected genes were mainly involved in processes like mineralization and structural organization of tooth specific tissues such as enamel and dentin. Of the 236 analyzed genes, 12 mammalian-specific genes (younger genes) provided insights on diversification of mammalian teeth as they have higher evolutionary rates and exhibit different expression profiles compared with older genes. Our results suggest that the evolution and development of mammalian dentition occurred in part through positive selection acting on genes that previously had other functions. PMID:27613398

  11. Testing the Generation of Jets in Young Stars with ALMA

    NASA Astrophysics Data System (ADS)

    Bacciotti, F.; Podio, L.; Codella, C.; Coffey, D.

    2015-12-01

    Jets are a crucial element in the star formation process, as they are thought to remove the excess angular momentum from the system. A firm detection of jet rotation could lend support to this statement. Jet rotation studies, however, are hindered by the requirement of simultaneous high spatial and spectral resolution, and as a matter of fact, the rotation interpretation is still debated. Soon, however, the improved spatial resolution of ALMA will allow us to firmly establish rotation patterns. At the same time the new ALMA polarimetric capabilities will permit the determination of the magnetic configuration in the system. The ALMA combined search for rotation properties and magnetic fields will be a powerful test of the proposed jet generation mechanisms.

  12. The generation of antiphase oscillations and synchrony by a rebound-based vertebrate central pattern generator.

    PubMed

    Li, Wen-Chang; Merrison-Hort, Robert; Zhang, Hong-Yan; Borisyuk, Roman

    2014-04-23

    Many neural circuits are capable of generating multiple stereotyped outputs after different sensory inputs or neuromodulation. We have previously identified the central pattern generator (CPG) for Xenopus tadpole swimming that involves antiphase oscillations of activity between the left and right sides. Here we analyze the cellular basis for spontaneous left-right motor synchrony characterized by simultaneous bursting on both sides at twice the swimming frequency. Spontaneous synchrony bouts are rare in most tadpoles, and they instantly emerge from and switch back to swimming, most frequently within the first second after skin stimulation. Analyses show that only neurons that are active during swimming fire action potentials in synchrony, suggesting both output patterns derive from the same neural circuit. The firing of excitatory descending interneurons (dINs) leads that of other types of neurons in synchrony as it does in swimming. During synchrony, the time window between phasic excitation and inhibition is 7.9 ± 1 ms, shorter than that in swimming (41 ± 2.3 ms). The occasional, extra midcycle firing of dINs during swimming may initiate synchrony, and mismatches of timing in the left and right activity can switch synchrony back to swimming. Computer modeling supports these findings by showing that the same neural network, in which reciprocal inhibition mediates rebound firing, can generate both swimming and synchrony without circuit reconfiguration. Modeling also shows that lengthening the time window between phasic excitation and inhibition by increasing dIN synaptic/conduction delay can improve the stability of synchrony. PMID:24760866

  13. The NIH Toolbox Pattern Comparison Processing Speed Test: Normative Data

    PubMed Central

    Carlozzi, Noelle E.; Beaumont, Jennifer L.; Tulsky, David S.; Gershon, Richard C.

    2015-01-01

    The NIH Toolbox Pattern Comparison Processing Speed Test was developed to assess processing speed. While initial validation work provides preliminary support for this test in both children and adults, more work is needed to ensure dependability and generalizability. Thus, this replication study examines descriptive data (including age effects), test–retest reliability, and construct validity in n = 4,859 participants ages 3–85 years (matched to 2010 census data). Although the Pattern Comparison was not appropriate for all 3 and 4 years old, by ages 5 and 6, more meaningful scores were apparent. There was evidence for convergent and discriminant validity. There was also a moderate practice effect (i.e., increase of 5.5 points) over a 1-week time frame. Pattern Comparison exhibits a number of strengths: it is appropriate for use across the lifespan (ages 5–85), it is short and easy to administer, and there is support for construct validity. PMID:26025230

  14. Discovering Visual Scanning Patterns in a Computerized Cancellation Test

    ERIC Educational Resources Information Center

    Huang, Ho-Chuan; Wang, Tsui-Ying

    2013-01-01

    The purpose of this study was to develop an attention sequential mining mechanism for investigating the sequential patterns of children's visual scanning process in a computerized cancellation test. Participants had to locate and cancel the target amongst other non-targets in a structured form, and a random form with Chinese stimuli. Twenty-three…

  15. Status of the integrated topping cycle and MHD generator testing

    SciTech Connect

    Pian, C.C.P.; Dunton, A.W.; Schmitt, E.W.; Morrison, D.J.

    1993-12-31

    The status of the Integrated Topping Cycle (ITC) MHD generator testing is presented. This generator is part of a 50 MW{sub t} prototypic powertrain that is currently undergoing proof-of-concept (POC) testing at the U.S. Department of Energy`s Component Development and Integration Facility in Butte, Montana. Test objectives are to establish component lifetimes at prototypic operating conditions and to verify the design performance parameters. The ITC generator has completed Design Verification Testing and is now well into the POC duration test. To date (May 1, 1993), over 360 hours of the planned 1000 hours of testing has been completed. Generator testing is being performed at conditions representative of commercial power plant operating conditions. Prototypic generator channel hardware is performing very well. Based on test results obtained thus far, the prognosis is excellent for meeting all of the POC test objectives.

  16. Adding Test Generation to the Teaching Machine

    ERIC Educational Resources Information Center

    Bruce-Lockhart, Michael; Norvell, Theodore; Crescenzi, Pierluigi

    2009-01-01

    We propose an extension of the Teaching Machine project, called Quiz Generator, that allows instructors to produce assessment quizzes in the field of algorithm and data structures quite easily. This extension makes use of visualization techniques and is based on new features of the Teaching Machine that allow third-party visualizers to be added as…

  17. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Transient test cycle generation. 86...) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for...

  18. Study on Noncontact Pulmonary Function Test Using Pattern Light Projection

    NASA Astrophysics Data System (ADS)

    Aoki, Hirooki; Koshiji, Kohji

    The pulmonary function test by spirometer is generally conducted. The test subjects, especially children, women and older people, feel uncomfortable as the mouthpiece and nasal plug must be attached to the face of them. We have studied the nonrestraint pulmonary function test using the dot matrix pattern projection in order to decrease the burden to the examinee. In our proposed system, the pattern light projector illuminates the thorax with the dot matrix pattern light. And the CCD camera takes a series of images of the dot matrix pattern. The three dimensional shape of the thorax surface can be calculated by the distribution of light dots. And the respiratory waveform is calculated by the time-series change of the three dimensional shape. The respiratory waveform of our system was similar to one of spirometer. Therefore, we clarified that our proposed system can equivalently measure the respiration with spirometer. And we compared the volume change of the three dimensional shape calculated by our system with the expired tidal volume measured by the expiration gas analyzer. And we examined the relationship between the expired tidal volume and the volume change of the thorax surface.

  19. Test-Aerosol Generator For Calibrating Particle Counters

    NASA Technical Reports Server (NTRS)

    Mogan, Paul A.; Adams, Alois J.; Schwindt, Christian J.; Hodge, Timothy R.; Mallow, Tim J.; Duong, Anh A.; Bukauskas, Vyto V.

    1996-01-01

    Apparatus generates clean, stable aerosol stream for use in testing and calibrating laser-based aerosol-particle counter. Size and concentration of aerosol particles controlled to ensure accurate calibration. Cheap, widely available medical nebulizers used to generate aerosols.

  20. A Compartmental Lateral Inhibition System to Generate Contrasting Patterns

    PubMed Central

    Rufino Ferreira, Ana S.; Hsia, Justin; Arcak, Murat

    2015-01-01

    We propose a lateral inhibition system and analyze contrasting patterns of gene expression. The system consists of a set of compartments interconnected by channels. Each compartment contains a colony of cells that produce diffusible molecules to be detected by the neighboring colonies. Each cell is equipped with an inhibitory circuit that reduces its production when the detected signal is sufficiently strong. We characterize the parameter range in which steady-state patterns emerge. PMID:26665158

  1. Penetration tests in next generation networks

    NASA Astrophysics Data System (ADS)

    Rezac, Filip; Voznak, Miroslav

    2012-06-01

    SIP proxy server is without any doubts centerpiece of any SIP IP telephony infrastructure. It also often provides other services than those related to VoIP traffic. These softswitches are, however, very often become victims of attacks and threats coming from public networks. The paper deals with a system that we developed as an analysis and testing tool to verify if the target SIP server is adequately secured and protected against any real threats. The system is designed as an open-source application, thus allowing independent access and is fully extensible to other test modules.

  2. Electronic speckle pattern interferometry for mechanical testing of thin films

    NASA Astrophysics Data System (ADS)

    Augulis, L.; Tamulevic̆ius, S.; Augulis, R.; Bonneville, J.; Goudeau, P.; Templier, C.

    2004-07-01

    The design, performance and principles of computerised control of an optical micro-electro-mechanical device combining microtensile device and electronic speckle pattern interferometry (ESPI) to test both elastic and plastic properties of thin metallic, dielectric as well as multilayered freestanding films are presented. A piezo-actuated microtensile set up is synchronised with an ESPI to measure film elongation up to 70 μm in length with an accuracy of nearly 50 nm. No patterning or marking of the specimen surface is needed when using the ESPI and displacements can be measured at various points of the films. Tensile force is directly measured using a miniature load cell. Tensile tests of 10 μm aluminium and 50 μm polymer (Kapton ®) foils have been performed. The Young's moduli are calculated for both materials from the stress-strain curves.

  3. Spin wave excitation patterns generated by spin torque oscillators

    NASA Astrophysics Data System (ADS)

    Macià, F.; Hoppensteadt, F. C.; Kent, A. D.

    2014-01-01

    Spin torque nano-oscillators (STNO) are nanoscale devices that can convert a direct current into short wavelength spin wave excitations in a ferromagnetic layer. We show that arrays of STNO can be used to create directional spin wave radiation similarly to electromagnetic antennas. Combining STNO excitations with planar spin waves also creates interference patterns. We show that these interference patterns are static and have information on the wavelength and phase of the spin waves emitted from the STNO. We describe a means of actively controlling spin wave radiation patterns with the direct current flowing through STNO, which is useful in on-chip communication and information processing and could be a promising technique for studying short wavelength spin waves in different materials.

  4. SSME seal test program: Test results for hole-pattern damper seals

    NASA Technical Reports Server (NTRS)

    Childs, D. W.

    1985-01-01

    The results consisting of direct and transverse force coefficients are presented for thirteen, hole-pattern, damper-seal configurations. The designation damper seal refers to a seal which uses a deliberately roughened stator nd smooth rotor, to increase the net damping force developed by a seal. The designation hole-pattern refers to a stator roughness pattern which is developed by a pattern of round holes while are milled into the stator. All seals tested use the same smooth rotor and have the same constant minimum clearance. The seal tests examined the following major design options: (1) hole-area density, i.e., the proportion of stator surface area consumed by holes; and (2) hole depth, particularly the ratio of hole depth to minimum clearance. In addition, limited data were taken to examine the influence of in-line versus staggered hole patterns and flat-bottomed versus spherical-bottomed holes.

  5. Improving physician practice efficiency by learning lab test ordering pattern.

    PubMed

    Cai, Peng; Cao, Feng; Ni, Yuan; Shen, Weijia; Zheng, Tao

    2013-01-01

    The system of electronic medical records (EMR) has been widely used in physician practice. In China, physicians have the time pressure to provide care to many patients in a short period. Improving practice efficiency is a promising direction to mitigate this predicament. During the encounter, ordering lab test is one of the most frequent actions in EMR system. In this paper, our motivation is to save physician's time by providing lab test ordering list to facilitate physician practice. To this end, we developed weight based multi-label classification framework to learn to order lab test for the current encounter according to the historical EMR. Particularly, we propose to learn the physician-specific lab test ordering pattern as different physicians may have different practice behavior on the same population. Experimental results on the real data set demonstrate that physician-specific models can outperform the baseline. PMID:23920762

  6. 40 CFR 86.1333 - Transient test cycle generation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... The generation of the maximum torque curve is described in 40 CFR part 1065. (b) Example of the...: ER28AP14.006 Where: Max Test Speed = the maximum test speed as calculated in 40 CFR part 1065. (ii) For Otto-cycle engines: ER28AP14.007 Where: Max Test Speed = the maximum test speed as calculated in 40...

  7. SSME seal test program: Test results for smooth, hole-pattern and helically-grooved stators

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.

    1987-01-01

    All of the listed seals were tested in a liquid Halon test facility at high Reynolds numbers. In addition, a helically-grooved-stator seal was tested in an air seal facility. An analysis of the test results with comparisons to theoretical predictions supports the following conclusions: (1) For small seals, the Hirs' friction-factor model is more restricted than had been thought; (2) For smooth seals, predictions of stiffness and damping improve markedly as the radical clearance is reduced; (3) Friction-factor data for hole-pattern-seal stators frequently deviates from the Hirs model; (4) Predictions of stiffness and damping coefficients for hole-pattern-stator seals is generally reasonable; (5) Tests for the hole-pattern stators at reduced clearances show no clear optimum for hole-pattern seals with respect to either hole-area ratio or hole depth to minimum clearance ratios; (6) Tests of these hole-pattern stators show no significant advantage in net damping over smooth seals; (7) Tests of helically-grooved seal stators in Halon show reasonable agreement between theory and prediction for leakage and direct stiffness but poor agreement for the net damping coefficient.

  8. Polychromatic Optical Vortex Generation from Patterned Cholesteric Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Kobashi, Junji; Yoshida, Hiroyuki; Ozaki, Masanori

    2016-06-01

    Generation of optical vortices is described in cholesteric liquid crystals with a singular point in the spatial distribution of a helix phase. The phenomenon uses the fact that a Bragg reflected light phase varies in proportion to the spatial phase of the helix, both at normal and oblique incidences. Our proposal enables high-efficiency, polychromatic generation of optical vortices without the need of a cumbersome fabrication process and fine-tuning.

  9. Polychromatic Optical Vortex Generation from Patterned Cholesteric Liquid Crystals.

    PubMed

    Kobashi, Junji; Yoshida, Hiroyuki; Ozaki, Masanori

    2016-06-24

    Generation of optical vortices is described in cholesteric liquid crystals with a singular point in the spatial distribution of a helix phase. The phenomenon uses the fact that a Bragg reflected light phase varies in proportion to the spatial phase of the helix, both at normal and oblique incidences. Our proposal enables high-efficiency, polychromatic generation of optical vortices without the need of a cumbersome fabrication process and fine-tuning. PMID:27391724

  10. HIV testing patterns among urban YMSM of color.

    PubMed

    Leonard, Noelle R; Rajan, Sonali; Gwadz, Marya V; Aregbesola, Temi

    2014-12-01

    The heightened level of risk for HIV infection among Black and Latino young men who have sex with men (YMSM) is driven by multilevel influences. Using cross-sectional data, we examined HIV testing patterns among urban YMSM of color in a high-HIV seroprevalence area (ages 16 to 21 years). Self-reported frequency of testing was high, with 42% of youth reporting testing at a greater frequency than recommended guidelines. There were no differences between less frequent and more frequent testers on sexual risk behaviors. Most (80%) youth cited reassurance of HIV-negative status as a reason for testing. Further, over half of the sample reported numerous other reasons for HIV testing, which spanned individual, partner, social, and structural levels of influence. Approximately half of respondents indicated that peers, family members, and counselors influenced their motivation to get tested. Of concern, their first HIV test occurred approximately 2 years after their first sexual experience with another male. These results indicate the need to consider developmental issues as well as comprehensive, multilevel efforts to ensure that YMSM of color test at the Centers for Disease Control and Prevention-recommended frequency but not less than this or too frequently. PMID:24973260

  11. Model Based Analysis and Test Generation for Flight Software

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.; Schumann, Johann M.; Mehlitz, Peter C.; Lowry, Mike R.; Karsai, Gabor; Nine, Harmon; Neema, Sandeep

    2009-01-01

    We describe a framework for model-based analysis and test case generation in the context of a heterogeneous model-based development paradigm that uses and combines Math- Works and UML 2.0 models and the associated code generation tools. This paradigm poses novel challenges to analysis and test case generation that, to the best of our knowledge, have not been addressed before. The framework is based on a common intermediate representation for different modeling formalisms and leverages and extends model checking and symbolic execution tools for model analysis and test case generation, respectively. We discuss the application of our framework to software models for a NASA flight mission.

  12. Testing to Characterize the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward; Schreiber, Jeffrey

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. Lockheed Martin designed and fabricated an engineering unit (EU), the ASRG EU, under contract to the Department of Energy. This unit is currently undergoing extended operation testing at the NASA Glenn Research Center to generate performance data and validate life and reliability predictions for the generator and the Stirling convertors. It has also undergone performance tests to characterize generator operation while varying control parameters and system inputs. This paper summarizes and explains test results in the context of designing operating strategies for the generator during a space mission and notes expected differences between the EU performance and future generators.

  13. Microstencils to generate defined, multi-species patterns of bacteria

    SciTech Connect

    Doktycz, Mitchel J.; Retterer, Scott T.; Pelletier, Dale A.; Timm, Collin M.; Hansen, Ryan R.

    2015-11-12

    Microbial communities are complex heterogeneous systems that are influenced by physical and chemical interactions with their environment, host, and community members. Techniques that facilitate the quantitative evaluation of how microscale organization influences the morphogenesis of multispecies communities could provide valuable insights into the dynamic behavior and organization of natural communities, the design of synthetic environments for multispecies culture, and the engineering of artificial consortia. In this work, we demonstrate a method for patterning microbes into simple arrangements that allow the quantitative measurement of growth dynamics as a function of their proximity to one another. The method combines parylene-based liftoff techniques with microfluidic delivery to simultaneously pattern multiple bacterial species with high viability using low-cost, customizable methods. Furthermore, quantitative measurements of bacterial growth for two competing isolates demonstrate that spatial coordination can play a critical role in multispecies growth and structure.

  14. Microstencils to generate defined, multi-species patterns of bacteria

    DOE PAGESBeta

    Doktycz, Mitchel J.; Retterer, Scott T.; Pelletier, Dale A.; Timm, Collin M.; Hansen, Ryan R.

    2015-11-12

    Microbial communities are complex heterogeneous systems that are influenced by physical and chemical interactions with their environment, host, and community members. Techniques that facilitate the quantitative evaluation of how microscale organization influences the morphogenesis of multispecies communities could provide valuable insights into the dynamic behavior and organization of natural communities, the design of synthetic environments for multispecies culture, and the engineering of artificial consortia. In this work, we demonstrate a method for patterning microbes into simple arrangements that allow the quantitative measurement of growth dynamics as a function of their proximity to one another. The method combines parylene-based liftoff techniquesmore » with microfluidic delivery to simultaneously pattern multiple bacterial species with high viability using low-cost, customizable methods. Furthermore, quantitative measurements of bacterial growth for two competing isolates demonstrate that spatial coordination can play a critical role in multispecies growth and structure.« less

  15. 32 nm imprint masks using variable shape beam pattern generators

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta; Thompson, Ecron; Schmid, Gerard; Stacey, Nick; Perez, Joseph; Maltabes, John; Resnick, Douglas J.; Yeo, Jeongho; Kim, Hoyeon; Eynon, Ben

    2008-05-01

    Imprint lithography has been included on the ITRS Lithography Roadmap at the 32, 22 and 16 nm nodes. Step and Flash Imprint Lithography (S-FIL ®) is a unique method that has been designed from the beginning to enable precise overlay for creating multilevel devices. A photocurable low viscosity monomer is dispensed dropwise to meet the pattern density requirements of the device, thus enabling imprint patterning with a uniform residual layer across a field and across entire wafers. Further, S-FIL provides sub-100 nm feature resolution without the significant expense of multi-element, high quality projection optics or advanced illumination sources. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. For sub-32 nm device manufacturing, one of the major technical challenges remains the fabrication of full-field 1x templates with commercially viable write times. Recent progress in the writing of sub-40 nm patterns using commercial variable shape e-beam tools and non-chemically amplified resists has demonstrated a very promising route to realizing these objectives, and in doing so, has considerably strengthened imprint lithography as a competitive manufacturing technology for the sub 32nm node. Here we report the first imprinting results from sub-40 nm full-field patterns, using Samsung's current flash memory production device design. The fabrication of the template is discussed and the resulting critical dimension control and uniformity are discussed, along with image placement results. The imprinting results are described in terms of CD uniformity, etch results, and overlay.

  16. A random approach of test macro generation for early detection of hotspots

    NASA Astrophysics Data System (ADS)

    Lee, Jong-hyun; Kim, Chin; Kang, Minsoo; Hwang, Sungwook; Yang, Jae-seok; Harb, Mohammed; Al-Imam, Mohamed; Madkour, Kareem; ElManhawy, Wael; Kwan, Joe

    2016-03-01

    Multiple-Patterning Technology (MPT) is still the preferred choice over EUV for the advanced technology nodes, starting the 20nm node. Down the way to 7nm and 5nm nodes, Self-Aligned Multiple Patterning (SAMP) appears to be one of the effective multiple patterning techniques in terms of achieving small pitch of printed lines on wafer, yet its yield is in question. Predicting and enhancing the yield in the early stages of technology development are some of the main objectives for creating test macros on test masks. While conventional yield ramp techniques for a new technology node have relied on using designs from previous technology nodes as a starting point to identify patterns for Design of Experiment (DoE) creation, these techniques are challenging to apply in the case of introducing an MPT technique like SAMP that did not exist in previous nodes. This paper presents a new strategy for generating test structures based on random placement of unit patterns that can construct more meaningful bigger patterns. Specifications governing the relationships between those unit patterns can be adjusted to generate layout clips that look like realistic SAMP designs. A via chain can be constructed to connect the random DoE of SAMP structures through a routing layer to external pads for electrical measurement. These clips are decomposed according to the decomposition rules of the technology into the appropriate mandrel and cut masks. The decomposed clips can be tested through simulations, or electrically on silicon to discover hotspots. The hotspots can be used in optimizing the fabrication process and models to fix them. They can also be used as learning patterns for DFM deck development. By expanding the size of the randomly generated test structures, more hotspots can be detected. This should provide a faster way to enhance the yield of a new technology node.

  17. A central pattern generator producing alternative outputs: pattern, strength, and dynamics of premotor synaptic input to leech heart motor neurons.

    PubMed

    Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

    2007-11-01

    The central pattern generator (CPG) for heartbeat in medicinal leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. Using extracellular recordings from premotor interneurons and voltage-clamp recordings of ipsilateral segmental motor neurons in 69 isolated nerve cords, we assessed the strength and dynamics of premotor inhibitory synaptic output onto the entire ensemble of heart motor neurons and the associated conduction delays in both coordination modes. We conclude that premotor interneurons establish a stereotypical pattern of intersegmental synaptic connectivity, strengths, and dynamics that is invariant across coordination modes, despite wide variations among preparations. These data coupled with a previous description of the temporal pattern of premotor interneuron activity and relative phasing of motor neuron activity in the two coordination modes enable a direct assessment of how premotor interneurons through their temporal pattern of activity and their spatial pattern of synaptic connectivity, strengths, and dynamics coordinate segmental motor neurons into a functional pattern of activity. PMID:17804574

  18. Model-Driven Test Generation of Distributed Systems

    NASA Technical Reports Server (NTRS)

    Easwaran, Arvind; Hall, Brendan; Schweiker, Kevin

    2012-01-01

    This report describes a novel test generation technique for distributed systems. Utilizing formal models and formal verification tools, spe cifically the Symbolic Analysis Laboratory (SAL) tool-suite from SRI, we present techniques to generate concurrent test vectors for distrib uted systems. These are initially explored within an informal test validation context and later extended to achieve full MC/DC coverage of the TTEthernet protocol operating within a system-centric context.

  19. Results of the integrated topping cycle MHD generator testing

    SciTech Connect

    Pian, C.C.P.; Schmitt, E.W.

    1994-12-31

    The results of the Integrated Topping Cycle (ITC) MHD generator tests are presented. This generator is part of a 50 MW{sub t} prototypic powertrain which recently completed proof-of-concept (POC) testing at the U.S. Department of Energy`s Component Development and Integration Facility (CDIF) in Butte, Montana. POC duration testing was carried out at conditions representative of commercial power plant operation, in order to establish component lifetimes and to verify the design performance parameters. Over 500 hours of thermal and power testing was cumulated with the generator hardware before the program funding was terminated. A summary of the MHD generator performance characteristics and hardware evaluations is provided in the paper. A summary of the generator performance throughout the POC test series is presented. Included are comparisons of: (1) plasma electrical conductivities measured early in the Design Verification Test series and during the POC series, (2) measured generator performance with analytical predictions, and (3) internal wall leakage characteristics of the generator channel with and without iron oxide addition. The performance requirement of the ITC program, i.e., the demonstration of 1.5 MW{sub e} power output, was easily achieved. The ITC generator channel, nozzle, and diffuser accumulated more than 300 hours at nominal power conditions. The prototypic hardware performed well throughout the POC test series. Some problems did arise during the tests. but they were not life-threatening to the MHD generator. Corrective measures were implemented; they will be discussed in the full paper. The physical condition of the overall generator channel at the end of POC tests is good.

  20. GENERATING FRACTAL PATTERNS BY USING p-CIRCLE INVERSION

    NASA Astrophysics Data System (ADS)

    Ramírez, José L.; Rubiano, Gustavo N.; Zlobec, Borut Jurčič

    2015-10-01

    In this paper, we introduce the p-circle inversion which generalizes the classical inversion with respect to a circle (p = 2) and the taxicab inversion (p = 1). We study some basic properties and we also show the inversive images of some basic curves. We apply this new transformation to well-known fractals such as Sierpinski triangle, Koch curve, dragon curve, Fibonacci fractal, among others. Then we obtain new fractal patterns. Moreover, we generalize the method called circle inversion fractal be means of the p-circle inversion.

  1. Pattern generation with cesium atomic beams at nanometer scales

    NASA Astrophysics Data System (ADS)

    Kreis, M.; Lison, F.; Haubrich, D.; Meschede, D.; Nowak, S.; Pfau, T.; Mlynek, J.

    1996-12-01

    We have demonstrated that a cesium atomic beam can be used to pattern a gold surface using a self assembling monolayer (SAM) as a resist. A 12.5 μm period mesh was used as a proximity mask for the atomic beam. The cesium atoms locally change the wetability of the SAM, which allows a wet etching reagent to remove the underlying gold in the exposed regions. An edge resolution of better than 100 nm was obtained. The experiment suggests that this method can either be used as a sensitive position detector with nanometer resolution in atom optics, or for nanostructuring in a resist technique.

  2. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM 10 § 53.42 Generation of test atmospheres for wind... of multiplets (doublets and triplets) in a test particle atmosphere shall not exceed 10 percent....

  3. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... of multiplets (doublets and triplets) in a test particle atmosphere shall not exceed 10 percent....

  4. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM 10 § 53.42 Generation of test atmospheres for wind... of multiplets (doublets and triplets) in a test particle atmosphere shall not exceed 10 percent....

  5. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... of multiplets (doublets and triplets) in a test particle atmosphere shall not exceed 10 percent....

  6. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... of multiplets (doublets and triplets) in a test particle atmosphere shall not exceed 10 percent....

  7. Tests and evaluation of multihundred watt thermoelectric generators at JPL

    NASA Technical Reports Server (NTRS)

    Rouklove, P.

    1977-01-01

    The multihundred watt (MHW) thermoelectric generator, based on silicon-germanium thermoelectric technology, delivers a nominal power output of 150 watts with an efficiency of about 6%. The two Voyager space probes each use three such generators assembled in tandem on a boom. A total of seven MHW type thermoelectric generators were tested at JPL in support of the Voyager project. The tests consisted of: (1) parametric evaluation of the electrical characteristics of the devices over a wide range of output voltage for different values of input power, different operating ambients (air, vacuum), and different internal environments (argon, helium, xenon, mixture of these gases, and vacuum) at different pressures to allow evaluation of the influences of both gas and pressure on the performance of the generator; (2) tests to determine the transient behavior of the generators; and (3) operation of the generator in conjunction with the Voyager spacecraft.

  8. Testing of a direct drive generator for wind turbines

    SciTech Connect

    Sondergaard, L.M.

    1996-12-31

    The normal drive train of a wind turbine consists a gearbox and a 4 to 8 poles asynchronous generator. The gearbox is an expensive and unreliable components and this paper deals with testing of a direct drive synchronous generator for a gearless wind turbine. The Danish company Belt Electric has constructed and manufactured a 27 kW prototype radial flux PM-generator (DD600). They have used cheap hard ferrite magnets in the rotor of this PM-generator. This generator has been tested at Riso and the test results are investigated and analyzed in this paper. The tests have been done with three different load types (1: resistance; 2: diode rectifier, DC-capacitor, resistance; 3: AC-capacitor, diode rectifier, DC-capacitor, resistance). 1 ref., 9 figs., 5 tabs.

  9. Design driven test patterns for OPC models calibration

    NASA Astrophysics Data System (ADS)

    Al-Imam, Mohamed

    2009-03-01

    In the modern photolithography process for manufacturing integrated circuits, geometry dimensions need to be realized on silicon which are much smaller than the exposure wavelength. Thus Resolution Enhancement Techniques have an indispensable role towards the implementation of a successful technology process node. Finding an appropriate RET recipe, that answers the needs of a certain fabrication process, usually involves intensive computational simulations. These simulations have to reflect how different elements in the lithography process under study will behave. In order to achieve this, accurate models are needed that truly represent the transmission of patterns from mask to silicon. A common practice in calibrating lithography models is to collect data for the dimensions of some test structures created on the exposure mask along with the corresponding dimensions of these test structures on silicon after exposure. This data is used to tune the models for good predictions. The models will be guaranteed to accurately predict the test structures that has been used in its tuning. However, real designs might have a much greater variety of structures that might not have been included in the test structures. This paper explores a method for compiling the test structures to be used in the model calibration process using design layouts as an input. The method relies on reducing structures in the design layout to the essential unique structure from the lithography models point of view, and thus ensuring that the test structures represent what the model would actually have to predict during the simulations.

  10. Patterns of rock fragment cover generated by tillage erosion

    NASA Astrophysics Data System (ADS)

    Poesen, Jean; Wesemael, Bas van; Govers, Gerard; Martinez-Fernandez, José; Desmet, Philippe; Vandaele, Karel; Quine, Timothy; Degraer, Greet

    1997-03-01

    Intensively cultivated areas in the upper part of the Guadalentin catchment (southeast Spain) show a systematic spatial pattern of surface rock fragment cover ( Rc). The objective of this paper is to quantify and to explain this spatial rock fragment cover pattern. Therefore, a map of an intensively cultivated area of 5 km 2 was digitised, and for each pixel total topographic curvature was calculated. Next, rock fragment cover was determined photographically at 35 sites with a range of total slope curvatures. A linear relation between total curvature and rock fragment cover was found, except for narrow concavities. It was hypothesised that this pattern can be explained by a significant net downslope movement of rock fragments and fine earth by tillage. The displacement distances of rock fragments by tillage with a duckfoot chisel were measured by monitoring the displacement of tracers (painted rock fragments and aluminium cubes) on 5 sites having different slopes. The rare of tillage erosion for one tillage pass with a duckfoot chisel, expressed by the diffusion constant ( k), equals 282 kg/m for up and downslope tillage and only 139 kg/m for contour tillage. Nomograms indicate that mean denudation rates in almond groves due to tillage erosion (3 to 5 tillage passes per year) can easily amount to 1.5-2.6 mm/year for contour tillage and up to 3.6-5.9 mm/year for up- and downslope tillage for a field, 50 m long and having a slope of 20%. These figures are at least one order of magnitude larger than reported denudation rates caused by water erosion in similar environments. Hence tillage erosion contributes significantly to land degradation. The downslope soil flux induced by tillage not only causes considerable denudation on topographic convexities (hill tops and spurs) and upper field boundaries but also an important sediment accumulation in topographic concavities (hollows and valley bottoms) and at lower field boundaries. Kinetic sieving (i.e. the upward migration

  11. Gas Generation Testing of Neptunium Oxide at Elevated Temperature

    SciTech Connect

    Duffey, JM

    2004-01-30

    Elevated temperature gas generation tests have been conducted using neptunium dioxide produced on a laboratory scale using the HB-Line Phase II flowsheet. These tests were performed to determine what effect elevated temperatures would have on the neptunium dioxide in comparison to neptunium dioxide tested at ambient temperature. The headspace gas compositions following storage at elevated temperatures associated with normal conditions of transport (NCT) have been measured. These test results show an increase in hydrogen generation rate at elevated temperature and significant removal of oxygen from the headspace gas. The elevated temperature gas generation tests described in this report involved heating small test vessels containing neptunium dioxide and measuring the headspace gas pressure and composition at the end of the test period. Four samples were used in these tests to evaluate the impact of process variables on the gas generation rate. Two samples were calcined to 600 degrees Celsius and two were calcined to 650 degrees Celsius. Each test vessel contained approximately 9.5 g of neptunium dioxide. Following exposure to 75 per cent relative humidity (RH) for five days, these samples were loaded in air and then heated to between 105 and 115 degrees Celsius for about one month. At the conclusion of the test period, the headspace gas of each container was analyzed using a micro-gas chromatograph installed in the glovebox where the experiments were conducted. The pressure, volume, and composition data for the headspace gas samples were used to calculate average H2 generation rates.

  12. Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation.

    PubMed

    Souza, G S; Schakelford, H B; Moura, A L A; Gomes, B D; Ventura, D F; Fitzgerald, M E C; Silveira, L C L

    2012-10-01

    This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation modes. At the periphery, pattern reversal showed a larger number of reliable responses. Pattern pulse stimuli performed similarly to pattern reversal stimuli to generate reliable waveforms in R1 and R2. The advantage of using both protocols to study mfVEP responses is their complementarity: in some patients, reliable waveforms in specific sectors may be obtained with only one of the two methods. The joint analysis of pattern reversal and pattern pulse stimuli increased the rate of reliability for central sectors by 7.14% in R1, 5.35% in R2, 4.76% in R3, 3.57% in R4, 2.97% in R5, and 1.78% in R6. From R1 to R4 the reliability to generate mfVEPs was above 70% when using both protocols. Thus, for a very high reliability and thorough examination of visual performance, it is recommended to use both stimulation protocols. PMID:22782556

  13. Morphodynamics and anabranching patterns generated in the Madeira River, Brazil

    NASA Astrophysics Data System (ADS)

    Latrubesse, E. M.; Bonthius, C.; Abad, J. D.; Stevaux, J.; Filizola, N.; Frias, C. E.

    2013-12-01

    The Madeira River is the largest tributary in water discharge and sediment transport of the Amazon River. At present, this river is at the center of a controversial political discussion because the Brazilian government is building two hydroelectric plants on the Bolivia-Brazil border, flooding a long reach from near Cachuela Esperanza in the tributary Beni River, close to the Brazil-Bolivia border, up to Porto Velho. We present results from three field expeditions carried out in July-August 2011, December 2012 and March 2013. The main scope of this article is to disseminate the environmental threat suffered by the Madeira from regulation/disruption, and to present preliminary results on the geomorphologic characteristics of the Madeira channel and floodplain. Using historical radar and satellite imagery, the floodplain morpho-sedimentary units and morphology of the channel were assessed and quantified. Sediment bed and bank sampling, bathymetric surveys and velocity measurements were recorded using a single beam echo sounder and an acoustic Doppler current profiler (ADCP), respectively. Velocity data were analyzed using TRDI's WinRiverII and a MATLAB-based software package Velocity Mapping Tool. We consider that the Madeira River offers some ideal conditions to provide information on critical conditions and geomorphologic thresholds in mega-rivers. The Madeira River has been classified as a simple to moderate anabranching low-sinuosity river. The Madeira flows through a relatively simple pattern, alternating straight reaches with others that exhibit an incipient tendency to anabranch. Single beam and ADCP data yields insight into the bathymetry and flow characteristics in the channel through straight, pseudo-meandering, and anabranching stretches. We studied in detail three selected three reaches zones where three primary mechanisms for anabranching were identified: a) branches upstream and downstream in box shape pseudo-meanders; b) simple branch patterns

  14. Computer-Assisted Generation of Patterns and Virtual Reality Techniques for Fashion Design

    NASA Astrophysics Data System (ADS)

    Naud, Mickael; Richard, Paul; Chapeau-Blondeau, François

    2009-03-01

    We present a methodology for the design of aesthetic patterns and their visualization on virtual clothes. Generated patterns are directly mapped on the dress of a virtual mannequin. Furthermore, patterns sets may be interactively mapped on the virtual dress using a specific 3D interaction technique called Back-and-Forth. Pattern generation involves different mathematical approaches such as iterated function systems (IFS) and nonlinear trajectory models. Both model parameters and color space exploration is performed through a simple user interface. This work contributes to promote both computer assistance in the context of mass customization for fashion design.

  15. Statistical Tests of the Apple IIe Random Number Generator Yield Suggestions from Generator Seeding.

    ERIC Educational Resources Information Center

    Gleason, John M.

    1988-01-01

    Discusses flaws in the Apple IIe Applesoft random number generator, RND, and reports results of frequency and serial correlation tests of the generator. Suggestions of seeds that yield sequences of numbers which pass fundamental screening tests for randomness are presented. (Author/LRW)

  16. Topology-generating interfacial pattern formation during liquid metal dealloying

    PubMed Central

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-01-01

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Moreover, we deduce scaling laws governing microstructural length scales and dealloying kinetics. PMID:26582248

  17. Topology-generating interfacial pattern formation during liquid metal dealloying.

    PubMed

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-01-01

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Moreover, we deduce scaling laws governing microstructural length scales and dealloying kinetics. PMID:26582248

  18. Topology-generating interfacial pattern formation during liquid metal dealloying

    NASA Astrophysics Data System (ADS)

    Geslin, Pierre-Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-01

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Moreover, we deduce scaling laws governing microstructural length scales and dealloying kinetics.

  19. Topology-generating interfacial pattern formation during liquid metal dealloying

    DOE PAGESBeta

    Geslin, Pierre -Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-19

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growthmore » of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.« less

  20. Topology-generating interfacial pattern formation during liquid metal dealloying

    SciTech Connect

    Geslin, Pierre -Antoine; McCue, Ian; Gaskey, Bernard; Erlebacher, Jonah; Karma, Alain

    2015-11-19

    Liquid metal dealloying has emerged as a novel technique to produce topologically complex nanoporous and nanocomposite structures with ultra-high interfacial area and other unique properties relevant for diverse material applications. This process is empirically known to require the selective dissolution of one element of a multicomponent solid alloy into a liquid metal to obtain desirable structures. However, how structures form is not known. Here we demonstrate, using mesoscale phase-field modelling and experiments, that nano/microstructural pattern formation during dealloying results from the interplay of (i) interfacial spinodal decomposition, forming compositional domain structures enriched in the immiscible element, and (ii) diffusion-coupled growth of the enriched solid phase and the liquid phase into the alloy. We highlight how those two basic mechanisms interact to yield a rich variety of topologically disconnected and connected structures. Furthermore, we deduce scaling laws governing microstructural length scales and dealloying kinetics.

  1. Test Input Generation for Red-Black Trees using Abstraction

    NASA Technical Reports Server (NTRS)

    Visser, Willem; Pasareanu, Corina S.; Pelanek, Radek

    2005-01-01

    We consider the problem of test input generation for code that manipulates complex data structures. Test inputs are sequences of method calls from the data structure interface. We describe test input generation techniques that rely on state matching to avoid generation of redundant tests. Exhaustive techniques use explicit state model checking to explore all the possible test sequences up to predefined input sizes. Lossy techniques rely on abstraction mappings to compute and store abstract versions of the concrete states; they explore under-approximations of all the possible test sequences. We have implemented the techniques on top of the Java PathFinder model checker and we evaluate them using a Java implementation of red-black trees.

  2. MINET validation study using steam generator test data

    SciTech Connect

    Van Tuyle, G.J.; Guppy, J.G.

    1984-01-01

    Three steam generator transient test cases that were simulated using the MINET computer code are described, with computed results compared against experimental data. The MINET calculations closely agreed with the experiment for both the once-through and the U-tube steam generator test cases. The effort is part of an ongoing effort to validate the MINET computer code for thermal-hydraulic plant systems transient analysis, and strongly supports the validity of the MINET models.

  3. CFFF testing of ceramic elements for MHD generators

    SciTech Connect

    Lineberry, J.T.; Christiansen, P.J.

    1994-12-31

    In September 1992, the POC test LMF5-J was concluded at the CFFF in accordance with the objectives as set for the western coal POC test program. During this activity, a {open_quotes}piggyback{close_quotes} type test was conducted for the Busek Company in partial fulfillment of a DOE Phase II SBIR. A near prototypical design, generator module that was designed and constructed by the Busek Co. was installed in the LMF upstream test train of the CFFF for this test. The module incorporated AlN{sub 2} (ceramic) sidebar elements. The objective of the SBIR Phase II was to evaluate the integrity of this material subject to long duration operation under typical coal-fired MHD generator conditions. A summary of the LMF5-J test at the CFFF and activities and test results relevant to the SBIR Phase II related to the Busek SBIR project are provided.

  4. Mechanisms of Left-Right Coordination in Mammalian Locomotor Pattern Generation Circuits: A Mathematical Modeling View

    PubMed Central

    Talpalar, Adolfo E.; Rybak, Ilya A.

    2015-01-01

    The locomotor gait in limbed animals is defined by the left-right leg coordination and locomotor speed. Coordination between left and right neural activities in the spinal cord controlling left and right legs is provided by commissural interneurons (CINs). Several CIN types have been genetically identified, including the excitatory V3 and excitatory and inhibitory V0 types. Recent studies demonstrated that genetic elimination of all V0 CINs caused switching from a normal left-right alternating activity to a left-right synchronized “hopping” pattern. Furthermore, ablation of only the inhibitory V0 CINs (V0D subtype) resulted in a lack of left-right alternation at low locomotor frequencies and retaining this alternation at high frequencies, whereas selective ablation of the excitatory V0 neurons (V0V subtype) maintained the left–right alternation at low frequencies and switched to a hopping pattern at high frequencies. To analyze these findings, we developed a simplified mathematical model of neural circuits consisting of four pacemaker neurons representing left and right, flexor and extensor rhythm-generating centers interacting via commissural pathways representing V3, V0D, and V0V CINs. The locomotor frequency was controlled by a parameter defining the excitation of neurons and commissural pathways mimicking the effects of N-methyl-D-aspartate on locomotor frequency in isolated rodent spinal cord preparations. The model demonstrated a typical left-right alternating pattern under control conditions, switching to a hopping activity at any frequency after removing both V0 connections, a synchronized pattern at low frequencies with alternation at high frequencies after removing only V0D connections, and an alternating pattern at low frequencies with hopping at high frequencies after removing only V0V connections. We used bifurcation theory and fast-slow decomposition methods to analyze network behavior in the above regimes and transitions between them. The model

  5. Mechanisms of left-right coordination in mammalian locomotor pattern generation circuits: a mathematical modeling view.

    PubMed

    Molkov, Yaroslav I; Bacak, Bartholomew J; Talpalar, Adolfo E; Rybak, Ilya A

    2015-05-01

    The locomotor gait in limbed animals is defined by the left-right leg coordination and locomotor speed. Coordination between left and right neural activities in the spinal cord controlling left and right legs is provided by commissural interneurons (CINs). Several CIN types have been genetically identified, including the excitatory V3 and excitatory and inhibitory V0 types. Recent studies demonstrated that genetic elimination of all V0 CINs caused switching from a normal left-right alternating activity to a left-right synchronized "hopping" pattern. Furthermore, ablation of only the inhibitory V0 CINs (V0D subtype) resulted in a lack of left-right alternation at low locomotor frequencies and retaining this alternation at high frequencies, whereas selective ablation of the excitatory V0 neurons (V0V subtype) maintained the left-right alternation at low frequencies and switched to a hopping pattern at high frequencies. To analyze these findings, we developed a simplified mathematical model of neural circuits consisting of four pacemaker neurons representing left and right, flexor and extensor rhythm-generating centers interacting via commissural pathways representing V3, V0D, and V0V CINs. The locomotor frequency was controlled by a parameter defining the excitation of neurons and commissural pathways mimicking the effects of N-methyl-D-aspartate on locomotor frequency in isolated rodent spinal cord preparations. The model demonstrated a typical left-right alternating pattern under control conditions, switching to a hopping activity at any frequency after removing both V0 connections, a synchronized pattern at low frequencies with alternation at high frequencies after removing only V0D connections, and an alternating pattern at low frequencies with hopping at high frequencies after removing only V0V connections. We used bifurcation theory and fast-slow decomposition methods to analyze network behavior in the above regimes and transitions between them. The model

  6. The generation effect: a test between single- and multifactor theories.

    PubMed

    Burns, D J

    1990-11-01

    Single- and multifactor accounts of the generation effect (better memory for internally generated items than for externally presented items) were tested. Single-factor theories suggest that generation induces either stimulus-response relational processing or response-oriented processing. Multifactor theories suggest that generation induces both types of processing. In the first three experiments subjects either read or generated responses, and the degree of categorical structure within the list was manipulated. When categorical structure was minimal, large generation effects were observed for free recall and recognition, but not for cued recall. When categorical structure was high, however, a generation effect was observed for cued recall but not for recognition or free recall. A fourth experiment was performed to eliminate an uninteresting interpretation of the results. It is argued that a multifactor account is needed to explain these findings. PMID:2148579

  7. Generation of nearly hemispherical and high gain azimuthally symmetric patterns with printed circuit antennas

    NASA Astrophysics Data System (ADS)

    Yang, Hung Yu; Alexopoulos, Nicolaos G.

    1987-08-01

    Patttern shaping techniques are discussed for printed circuit antennas such as microstrip dipoles and slot elements. Crossed printed circuit dipoles or a combination of a printed circuit dipole and a slot are employed. It is demonstrated that with the proper choice of substrate or substrate-superstrate parameters it is possible to generate: (1) nearly hemispherical patterns, (2) high-gain azimuthally symmetric patterns, and (3) nearly sec theta patterns.

  8. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    NASA Astrophysics Data System (ADS)

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-02-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment.

  9. Generation of Customizable Micro-wavy Pattern through Grayscale Direct Image Lithography

    PubMed Central

    He, Ran; Wang, Shunqiang; Andrews, Geoffrey; Shi, Wentao; Liu, Yaling

    2016-01-01

    With the increasing amount of research work in surface studies, a more effective method of producing patterned microstructures is highly desired due to the geometric limitations and complex fabricating process of current techniques. This paper presents an efficient and cost-effective method to generate customizable micro-wavy pattern using direct image lithography. This method utilizes a grayscale Gaussian distribution effect to model inaccuracies inherent in the polymerization process, which are normally regarded as trivial matters or errors. The measured surface profiles and the mathematical prediction show a good agreement, demonstrating the ability of this method to generate wavy patterns with precisely controlled features. An accurate pattern can be generated with customizable parameters (wavelength, amplitude, wave shape, pattern profile, and overall dimension). This mask-free photolithography approach provides a rapid fabrication method that is capable of generating complex and non-uniform 3D wavy patterns with the wavelength ranging from 12 μm to 2100 μm and an amplitude-to-wavelength ratio as large as 300%. Microfluidic devices with pure wavy and wavy-herringbone patterns suitable for capture of circulating tumor cells are made as a demonstrative application. A completely customized microfluidic device with wavy patterns can be created within a few hours without access to clean room or commercial photolithography equipment. PMID:26902520

  10. Central Pattern Generation and the Motor Infrastructure for Suck, Respiration, and Speech

    ERIC Educational Resources Information Center

    Barlow, Steven M.; Estep, Meredith

    2006-01-01

    The objective of the current report is to review experimental findings on centrally patterned movements and sensory and descending modulation of central pattern generators (CPGs) in a variety of animal and human models. Special emphasis is directed toward speech production muscle systems, including the chest wall and orofacial complex during…

  11. From Central Pattern Generator to Sensory Template in the Evolution of Birdsong

    ERIC Educational Resources Information Center

    Konishi, Masakazu

    2010-01-01

    Central nervous networks, be they a part of the human brain or a group of neurons in a snail, may be designed to produce distinct patterns of movement. Central pattern generators can account for the development and production of normal vocal signals without auditory feedback in non-songbirds. Songbirds need auditory feedback to develop and…

  12. Performance testing of thermoelectric generators at JPL. [for space applications

    NASA Technical Reports Server (NTRS)

    Rouklove, P.; Truscello, V. C.

    1975-01-01

    Several thermoelectric generators, ranging in output power from 170 watts to microwatts, are undergoing testing at JPL. They represent a wide range of technologies using advanced PbTe, SiGe and cascaded PbTe and BiTe thermoelectric materials. Several of these generators are of an advanced concept while others are representative of the Nimbus, Transit, Viking and the multi-hundred-watt (MHW) technology. Of interest is the behavior of generators which have been tested for times in excess of 60,000 hours.

  13. Automatic generation of primary sequence patterns from sets of related protein sequences.

    PubMed

    Smith, R F; Smith, T F

    1990-01-01

    We have developed a computer algorithm that can extract the pattern of conserved primary sequence elements common to all members of a homologous protein family. The method involves clustering the pairwise similarity scores among a set of related sequences to generate a binary dendrogram (tree). The tree is then reduced in a stepwise manner by progressively replacing the node connecting the two most similar termini by one common pattern until only a single common "root" pattern remains. A pattern is generated at a node by (i) performing a local optimal alignment on the sequence/pattern pair connected by the node with the use of an extended dynamic programming algorithm and then (ii) constructing a single common pattern from this alignment with a nested hierarchy of amino acid classes to identify the minimal inclusive amino acid class covering each paired set of elements in the alignment. Gaps within an alignment are created and/or extended using a "pay once" gap penalty rule, and gapped positions are converted into gap characters that function as 0 or 1 amino acid of any type during subsequent alignment. This method has been used to generate a library of covering patterns for homologous families in the National Biomedical Research Foundation/Protein Identification Resource protein sequence data base. We show that a covering pattern can be more diagnostic for sequence family membership than any of the individual sequences used to construct the pattern. PMID:2296575

  14. Measurement resolution of noise directivity patterns from acoustic flight tests

    NASA Technical Reports Server (NTRS)

    Conner, David A.

    1989-01-01

    The measurement resolution of noise directivity patterns from acoustic flight tests was investigated. Directivity angle resolution is affected by the data reduction parameters, the aircraft velocity and flyover altitude, and by deviations of the aircraft from the desired flight path. Equations are developed which determine bounds for the lateral and longitudinal directivity angle resolution as a function of the nominal directivity angle. The equations are applied to a flight test data base and the effects of several flight conditions and data reduction parameters on the directivity angle resolution are presented. The maximum directivity angle resolution typically occurs when the aircraft is at or near the overhead position. In general, directivity angle resolution improves with decreasing velocity, increasing altitude, increasing sampling rate, decreasing block size, and decreasing block averages. Deviations from the desired ideal flight path will increase the resolution. For the flight experiment considered in this study, an average of two flyovers were required at each test condition to obtain an acceptable flight path. The ability of the pilot to maintain the flight track improved with decreasing altitude, decreasing velocity, and practice. Due to the prevailing wind conditions, yaw angles of as much as 20 deg were required to maintain the desired flight path.

  15. 40 CFR 86.1333-2010 - Transient test cycle generation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 1065. (2) Torque is normalized to the maximum torque at the rpm listed with it. Therefore, to.... The generation of the maximum torque curve is described in 40 CFR part 1065. (b) Example of the... engines: ER13JY05.001 Where: MaxTestSpeed = the maximum test speed as calculated in 40 CFR part 1065....

  16. 40 CFR 86.1333-2010 - Transient test cycle generation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 1065. (2) Torque is normalized to the maximum torque at the rpm listed with it. Therefore, to.... The generation of the maximum torque curve is described in 40 CFR part 1065. (b) Example of the... engines: ER13JY05.001 Where: MaxTestSpeed = the maximum test speed as calculated in 40 CFR part 1065....

  17. 40 CFR 86.1333-2010 - Transient test cycle generation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 1065. (2) Torque is normalized to the maximum torque at the rpm listed with it. Therefore, to.... The generation of the maximum torque curve is described in 40 CFR part 1065. (b) Example of the... engines: ER13JY05.001 Where: MaxTestSpeed = the maximum test speed as calculated in 40 CFR part 1065....

  18. Long term tests of a SNAP-19 thermoelectric generator.

    NASA Technical Reports Server (NTRS)

    Rouklove, P.; Truscello, V.

    1972-01-01

    Results of tests performed on a SNAP 19 thermoelectric generator, SN-20. The SN-20 generator was tested for approximately 37,000 hours using electrical heating to simulate the heat released by isotope decay. After 27,000 hours of operation the output power from the generator decreased to approximately 1/3 of the beginning of life value while the internal resistance increased by a factor of 5. Analysis of the test results, confirmed by preliminary metallographic examination, indicated that the output power degradation was the result of excessive sublimation of the thermoelectric material and loss of the hot junction bond due to the depletion of the internal cover gas. This also resulted in excessive junction temperatures. Comparison is made with the behavior observed from the two flight generators and a tentative conclusion is advanced as to the reason for their failure.

  19. A versatile waveform generator for testing neuroelectric signal processors.

    PubMed

    Kohn, A F

    1989-08-01

    A multi-channel waveform generator was designed for testing neuroelectric signal processors. Smooth transient signals that resemble action potentials or evoked potentials are generated by a second order switched capacitor filter excited by brief rectangular pulses. The choice of an integrated circuit switched capacitor filter simplified the design by circumventing some of the disadvantages of conventional active filters. The waveform generator is versatile, with several signal parameters being independently adjustable from front panel controls: duration, waveshape, latency, amplitude and signal-to-noise ratio. The generator has been used for testing evoked potential acquisition and processing systems, for evaluating the effects of analog filters on evoked potentials and for testing systems designed to detect and classify trains of multi-unit action potentials. PMID:2770339

  20. Performance results of a digital test signal generator

    NASA Technical Reports Server (NTRS)

    Gutierrez-Luaces, B. O.; Marina, M.; Parham, B.

    1993-01-01

    Performance results of a digital test signal-generator hardware-demonstration unit are reported. Capabilities available include baseband and intermediate frequency (IF) spectrum generation, for which test results are provided. Repeatability in the setting of a given signal-to-noise ratio (SNR) when a baseband or an IF spectrum is being generated ranges from 0.01 dB at high SNR's or high data rates to 0.3 dB at low data rates or low SNR's. Baseband symbol SNR and carrier SNR (Pc/No) accuracies of 0.1 dB were verified with the built-in statistics circuitry. At low SNR's that accuracy remains to be fully verified. These results were confirmed with measurements from a demodulator synchronizer assembly for the baseband spectrum generation, and with a digital receiver (Pioneer 10 receiver) for the IF spectrum generation.

  1. Development and Test of a Prototype 100MVA Superconducting Generator

    SciTech Connect

    Fogarty, James M.; Bray, James W.

    2007-05-25

    In 2002, General Electric and the US Department of Energy (DOE) entered into a cooperative agreement for the development of a commercialized 100 MVA generator using high temperature superconductors (HTS) in the field winding. The intent of the program was to: • Identify and develop technologies that would be needed for such a generator. • Develop conceptual designs for generators with ratings of 100 MVA and higher using HTS technology. • Perform proof of concept tests at the 1.5 MW level for GE’s proprietary warm iron rotor HTS generator concept. • Design, build, and test a prototype of a commercially viable 100 MVA generator that could be placed on the power grid. This report summarizes work performed during the program and is provided as one of the final program deliverables.

  2. A Test Generation Framework for Distributed Fault-Tolerant Algorithms

    NASA Technical Reports Server (NTRS)

    Goodloe, Alwyn; Bushnell, David; Miner, Paul; Pasareanu, Corina S.

    2009-01-01

    Heavyweight formal methods such as theorem proving have been successfully applied to the analysis of safety critical fault-tolerant systems. Typically, the models and proofs performed during such analysis do not inform the testing process of actual implementations. We propose a framework for generating test vectors from specifications written in the Prototype Verification System (PVS). The methodology uses a translator to produce a Java prototype from a PVS specification. Symbolic (Java) PathFinder is then employed to generate a collection of test cases. A small example is employed to illustrate how the framework can be used in practice.

  3. Interactions between zebrafish pigment cells responsible for the generation of Turing patterns.

    PubMed

    Nakamasu, Akiko; Takahashi, Go; Kanbe, Akio; Kondo, Shigeru

    2009-05-26

    The reaction-diffusion system is one of the most studied nonlinear mechanisms that generate spatially periodic structures autonomous. On the basis of many mathematical studies using computer simulations, it is assumed that animal skin patterns are the most typical examples of the Turing pattern (stationary periodic pattern produced by the reaction-diffusion system). However, the mechanism underlying pattern formation remains unknown because the molecular or cellular basis of the phenomenon has yet to be identified. In this study, we identified the interaction network between the pigment cells of zebrafish, and showed that this interaction network possesses the properties necessary to form the Turing pattern. When the pigment cells in a restricted region were killed with laser treatment, new pigment cells developed to regenerate the striped pattern. We also found that the development and survival of the cells were influenced by the positioning of the surrounding cells. When melanophores and xanthophores were located at adjacent positions, these cells excluded one another. However, melanophores required a mass of xanthophores distributed in a more distant region for both differentiation and survival. Interestingly, the local effect of these cells is opposite to that of their effects long range. This relationship satisfies the necessary conditions required for stable pattern formation in the reaction-diffusion model. Simulation calculations for the deduced network generated wild-type pigment patterns as well as other mutant patterns. Our findings here allow further investigation of Turing pattern formation within the context of cell biology. PMID:19433782

  4. Dynamic test input generation for multiple-fault isolation

    NASA Technical Reports Server (NTRS)

    Schaefer, Phil

    1990-01-01

    Recent work is Causal Reasoning has provided practical techniques for multiple fault diagnosis. These techniques provide a hypothesis/measurement diagnosis cycle. Using probabilistic methods, they choose the best measurements to make, then update fault hypotheses in response. For many applications such as computers and spacecraft, few measurement points may be accessible, or values may change quickly as the system under diagnosis operates. In these cases, a hypothesis/measurement cycle is insufficient. A technique is presented for a hypothesis/test-input/measurement diagnosis cycle. In contrast to generating tests a priori for determining device functionality, it dynamically generates tests in response to current knowledge about fault probabilities. It is shown how the mathematics previously used for measurement specification can be applied to the test input generation process. An example from an efficient implementation called Multi-Purpose Causal (MPC) is presented.

  5. Mosquito noise in MPEG-compressed video: test patterns and metrics

    NASA Astrophysics Data System (ADS)

    Fenimore, Charles P.; Libert, John M.; Roitman, Peter

    2000-06-01

    Mosquito noise is a time dependent video compression impairment in which the high frequency spatial detail in video images having crisp edges is aliased intermittently. A new synthetic test pattern of moving spirals or circles is described which generates mosquito noise (MN) under Motion Pictures Expert Group (MPEG) compression. The spiral pattern is one of several NIST-developed patterns designed to stress specific features of compression based on motion estimation and quantization. The 'Spirals' pattern has several spirals or circles superimposed on a uniform background. The frames are filtered to avoid interline flicker which may be confounded with MN. Motion of the spirals and changing luminance of the background can be included to reduce the correlation between successive frames. Unexpectedly, even a static pattern of spirals can induce mosquito noise due to the stochastic character of the encoder. We consider metrics which are specific to the impairment being measured. For mosquito noise, we examine two separable detectors: each consists of a temporal (frame-to-frame) computation applied to the output of a spatial impairment detector which is applied to each frame. The two spatial detectors are: FLATS, which detects level 8 X 8 pixel image blocks; and the root-mean-square (RMS) applied to the image differences between original and compressed frames. The test patterns are encoded at low bit rates. We examine the measured mosquito noise as a function of the Group-of-Pictures (GOP) pattern in the MPEG-2 encoding and find that the GOP structure defines the periodicities of the MN.

  6. Alcohol Consumption Patterns in Immigrant and Later Generation Mexican American Women.

    ERIC Educational Resources Information Center

    Gilbert, M. Jean

    1987-01-01

    Immigrant Mexican women's drinking patterns were compared with those of Mexican women in Mexico, other United States Latinas, later-generation Mexican-American women, and male immigrants. Changes in the direction of greater permissiveness and rationalization of alcohol use among later-generation Mexican-American women are demonstrated. (JMM)

  7. Effects of Differences in Working Memory Capacity on Patterns of Word Generation

    ERIC Educational Resources Information Center

    Kawamura, Mimpei; Kobayashi, Yasutaka; Morioka, Shu

    2012-01-01

    In recent years, it has been reported that WM (working memory) is concerned with word generation, but many points regarding the relationship between the individual differences of WM capacity and the patterns of word generation remain unclear. This study is to investigate these unclear points by using three types of word fluency task with different…

  8. Optical testing of cylindrical surfaces with computer-generated holograms

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Guo, Pei-ji

    2013-08-01

    Increasing demands for highly accurate cylinders require more high-precision testing techniques. The existing methods of testing cylindrical surfaces can not ensure the highly-accuracy, efficiency, convenience and the overall cost. In order to acquire highly accurate cylindrical surfaces conveniently at a low cost, a new Fizeau interferometric optical testing utilizing CGH which is fabricated onto a wedge-shaped substrate is designed. In this test, a slit filter is placed in the center of the cylindrical curvature to filter out the undesired diffraction orders which occur when the beam hits the CGH. Meanwhile, the front side of the wedge-shaped substrate is as the reference flat, and the CGH is written onto the inclined surface, so that the real fringe pattern can not be affected by its reflected beam. Moreover, the design of cylindrical surfaces under test tilting and off-center relative to the diffraction surface of the CGH results that the required rays for interference can be obtained effectively from the pinhole filter in the interferometer. Furthermore, high-accuracy CGH in this test can be processed by conventional microlithography equipments. Corresponding to a cylindrical surface with 60mm in diameter and f-number of 1/7, the test has been successfully designed and optimized in Zemax whose testing accuracy is prior to 0.0019λ. Better interference pattern can be obtained because all the other disturbing rays image outside of aperture in a radius of 2mm. Experiment shows the method is efficient and predominant.

  9. Automated Generation and Assessment of Autonomous Systems Test Cases

    NASA Technical Reports Server (NTRS)

    Barltrop, Kevin J.; Friberg, Kenneth H.; Horvath, Gregory A.

    2008-01-01

    This slide presentation reviews some of the issues concerning verification and validation testing of autonomous spacecraft routinely culminates in the exploration of anomalous or faulted mission-like scenarios using the work involved during the Dawn mission's tests as examples. Prioritizing which scenarios to develop usually comes down to focusing on the most vulnerable areas and ensuring the best return on investment of test time. Rules-of-thumb strategies often come into play, such as injecting applicable anomalies prior to, during, and after system state changes; or, creating cases that ensure good safety-net algorithm coverage. Although experience and judgment in test selection can lead to high levels of confidence about the majority of a system's autonomy, it's likely that important test cases are overlooked. One method to fill in potential test coverage gaps is to automatically generate and execute test cases using algorithms that ensure desirable properties about the coverage. For example, generate cases for all possible fault monitors, and across all state change boundaries. Of course, the scope of coverage is determined by the test environment capabilities, where a faster-than-real-time, high-fidelity, software-only simulation would allow the broadest coverage. Even real-time systems that can be replicated and run in parallel, and that have reliable set-up and operations features provide an excellent resource for automated testing. Making detailed predictions for the outcome of such tests can be difficult, and when algorithmic means are employed to produce hundreds or even thousands of cases, generating predicts individually is impractical, and generating predicts with tools requires executable models of the design and environment that themselves require a complete test program. Therefore, evaluating the results of large number of mission scenario tests poses special challenges. A good approach to address this problem is to automatically score the results

  10. Gas Generation from K East Basin Sludges - Series II Testing

    SciTech Connect

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2001-03-14

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focused on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report will present results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge.

  11. Pigment cell movement is not required for generation of Turing patterns in zebrafish skin

    PubMed Central

    Bullara, D.; De Decker, Y.

    2015-01-01

    The zebrafish is a model organism for pattern formation in vertebrates. Understanding what drives the formation of its coloured skin motifs could reveal pivotal to comprehend the mechanisms behind morphogenesis. The motifs look and behave like reaction–diffusion Turing patterns, but the nature of the underlying physico-chemical processes is very different, and the origin of the patterns is still unclear. Here we propose a minimal model for such pattern formation based on a regulatory mechanism deduced from experimental observations. This model is able to produce patterns with intrinsic wavelength, closely resembling the experimental ones. We mathematically prove that their origin is a Turing bifurcation occurring despite the absence of cell motion, through an effect that we call differential growth. This mechanism is qualitatively different from the reaction–diffusion originally proposed by Turing, although they both generate the short-range activation and the long-range inhibition required to form Turing patterns. PMID:25959141

  12. Pigment cell movement is not required for generation of Turing patterns in zebrafish skin

    NASA Astrophysics Data System (ADS)

    Bullara, D.; de Decker, Y.

    2015-05-01

    The zebrafish is a model organism for pattern formation in vertebrates. Understanding what drives the formation of its coloured skin motifs could reveal pivotal to comprehend the mechanisms behind morphogenesis. The motifs look and behave like reaction-diffusion Turing patterns, but the nature of the underlying physico-chemical processes is very different, and the origin of the patterns is still unclear. Here we propose a minimal model for such pattern formation based on a regulatory mechanism deduced from experimental observations. This model is able to produce patterns with intrinsic wavelength, closely resembling the experimental ones. We mathematically prove that their origin is a Turing bifurcation occurring despite the absence of cell motion, through an effect that we call differential growth. This mechanism is qualitatively different from the reaction-diffusion originally proposed by Turing, although they both generate the short-range activation and the long-range inhibition required to form Turing patterns.

  13. Integrated circuit test-port architecture and method and apparatus of test-port generation

    DOEpatents

    Teifel, John

    2016-04-12

    A method and apparatus are provided for generating RTL code for a test-port interface of an integrated circuit. In an embodiment, a test-port table is provided as input data. A computer automatically parses the test-port table into data structures and analyzes it to determine input, output, local, and output-enable port names. The computer generates address-detect and test-enable logic constructed from combinational functions. The computer generates one-hot multiplexer logic for at least some of the output ports. The one-hot multiplexer logic for each port is generated so as to enable the port to toggle between data signals and test signals. The computer then completes the generation of the RTL code.

  14. NASA Fastrac Engine Gas Generator Component Test Program and Results

    NASA Technical Reports Server (NTRS)

    Dennis, Henry J., Jr.; Sanders, Tim; Turner, James E. (Technical Monitor)

    2000-01-01

    This presentation consists of viewgraph which review the test program and the results of the tests for the Gas Generator (GG) component for the Fastrac Engine. Included are pictures of the Fastrac (MC-1) Engine and the GG, diagrams of the flight configuration, and schematics of the LOX, and the RP-1 systems and the injector assembly. The normal operating parameters are reviewed, as are the test instrumentation. Also shown are graphs of the hot gas temperature, and the test temperature profiles. The results are summarized.

  15. Generating realistic environments for cyber operations development, testing, and training

    NASA Astrophysics Data System (ADS)

    Berk, Vincent H.; Gregorio-de Souza, Ian; Murphy, John P.

    2012-06-01

    Training eective cyber operatives requires realistic network environments that incorporate the structural and social complexities representative of the real world. Network trac generators facilitate repeatable experiments for the development, training and testing of cyber operations. However, current network trac generators, ranging from simple load testers to complex frameworks, fail to capture the realism inherent in actual environments. In order to improve the realism of network trac generated by these systems, it is necessary to quantitatively measure the level of realism in generated trac with respect to the environment being mimicked. We categorize realism measures into statistical, content, and behavioral measurements, and propose various metrics that can be applied at each level to indicate how eectively the generated trac mimics the real world.

  16. From social behavior to neural circuitry: steroid hormones rapidly modulate advertisement calling via a vocal pattern generator.

    PubMed

    Remage-Healey, Luke; Bass, Andrew H

    2006-09-01

    Across vertebrates, androgens are rapidly elevated within minutes in response to aggressive or reproductive stimuli, yet it is unclear what the causal relationship is between fast androgen elevation and the ongoing (minute-by-minute) expression of behavior. This study tested the hypothesis that rapid increases in plasma steroid levels induce similarly rapid increases in both vocal behavior and the neurophysiological output of a central pattern generator that governs vocal behavior. In Gulf toadfish (Opsanus beta), males call to attract females to their nesting sites, and both males and females vocalize in aggressive interactions. Previous field experiments with males showed that simulated territorial challenges produce rapid and concurrent elevations in ongoing calling behavior and circulating levels of the teleost-specific androgen 11-ketotestosterone (11kT), but not the glucocorticoid cortisol. The current field experiments showed that non-invasive (food) delivery of 11kT, but not cortisol, induced an elevation within 10 min in the ongoing calling behavior of males. Electrophysiological experiments revealed that intramuscular injections of either 11kT or cortisol, but neither testosterone nor 17-beta-estradiol, induced increases within 5 min in the output of the vocal pattern generator in males, whereas only cortisol had similarly fast effects in females. The field behavioral results support predictions generated by the challenge hypothesis and also parallel the 11kT-dependent modulation of the vocal pattern generator in males. The cortisol effect on the vocal pattern generator in both sexes predicts that glucocorticoids regulate vocalizations in non-advertisement contexts. Together, these experiments provide strong support for the hypothesis that surges in circulating steroid levels play a causal role in shaping rapid changes in social behavior (vocalizations) through non-genomic-like actions on neural (vocal motor) circuits that directly encode behavioral

  17. Generating Reduced Tests for FSMs with Extra States

    NASA Astrophysics Data System (ADS)

    Simão, Adenilso; Petrenko, Alexandre; Yevtushenko, Nina

    We address the problem of generating tests from a deterministic Finite State Machine to provide full fault coverage even if the faults may introduce extra states in the implementations. It is well-known that such tests should include the sequences in the so-called traversal set, which contains all sequences of length defined by the number of extra states. Therefore, the only apparent opportunity to produce shorter tests is to find within a test suite a suitable arrangement of the sequences in the inescapable traversal set. We observe that the direct concatenation of the traversal set to a given state cover, suggested by all existing generation methods with full fault coverage, results in extensive test branching, when a test has to be repeatedly executed to apply all the sequences of the traversal set. In this paper, we state conditions which allow distributing these sequences over several tests. We then utilize these conditions to elaborate a method, called SPY-method, which shortens tests by avoiding test branching as much as possible. We present the results of the experimental comparison of the proposed method with an existing method which indicate that the resulting save can be up to 40%.

  18. Flow generation in a novel centrifugal diffuser test device

    NASA Astrophysics Data System (ADS)

    Vidos, P.

    1983-09-01

    Recognition of the need to develop optimum diffusers for advanced centrifugal compressors, resulted in the design and manufacture of a novel low-speed test facility for centrifugal diffuser testing. The CDTD was designed to allow the flow angle and wall boundary profiles into the test diffuser to be controlled by variable geometry in the flow generator. The present study reports on the design of the flow generator and the analysis of the internal flow using a NASA computer code (MERIDL). First test results are given and are compared with the results of a control volume analysis. The flow angle control technique was found to work effectively but to give somewhat smaller angles (by 4 deg) than were predicted. It was concluded that the information obtained would allow scaling of the device; however, an analysis code was needed which would accept the real physical boundary conditions.

  19. Experiments with Test Case Generation and Runtime Analysis

    NASA Technical Reports Server (NTRS)

    Artho, Cyrille; Drusinsky, Doron; Goldberg, Allen; Havelund, Klaus; Lowry, Mike; Pasareanu, Corina; Rosu, Grigore; Visser, Willem; Koga, Dennis (Technical Monitor)

    2003-01-01

    Software testing is typically an ad hoc process where human testers manually write many test inputs and expected test results, perhaps automating their execution in a regression suite. This process is cumbersome and costly. This paper reports preliminary results on an approach to further automate this process. The approach consists of combining automated test case generation based on systematically exploring the program's input domain, with runtime analysis, where execution traces are monitored and verified against temporal logic specifications, or analyzed using advanced algorithms for detecting concurrency errors such as data races and deadlocks. The approach suggests to generate specifications dynamically per input instance rather than statically once-and-for-all. The paper describes experiments with variants of this approach in the context of two examples, a planetary rover controller and a space craft fault protection system.

  20. Next Generation Advanced Video Guidance Sensor Development and Test

    NASA Technical Reports Server (NTRS)

    Howard, Richard T.; Bryan, Thomas C.; Lee, Jimmy; Robertson, Bryan

    2009-01-01

    The Advanced Video Guidance Sensor (AVGS) was the primary docking sensor for the Orbital Express mission. The sensor performed extremely well during the mission, and the technology has been proven on orbit in other flights too. Parts obsolescence issues prevented the construction of more AVGS units, so the next generation of sensor was designed with current parts and updated to support future programs. The Next Generation Advanced Video Guidance Sensor (NGAVGS) has been tested as a breadboard, two different brassboard units, and a prototype. The testing revealed further improvements that could be made and demonstrated capability beyond that ever demonstrated by the sensor on orbit. This paper presents some of the sensor history, parts obsolescence issues, radiation concerns, and software improvements to the NGAVGS. In addition, some of the testing and test results are presented. The NGAVGS has shown that it will meet the general requirements for any space proximity operations or docking need.

  1. Localization of Motor Neurons and Central Pattern Generators for Motor Patterns Underlying Feeding Behavior in Drosophila Larvae.

    PubMed

    Hückesfeld, Sebastian; Schoofs, Andreas; Schlegel, Philipp; Miroschnikow, Anton; Pankratz, Michael J

    2015-01-01

    Motor systems can be functionally organized into effector organs (muscles and glands), the motor neurons, central pattern generators (CPG) and higher control centers of the brain. Using genetic and electrophysiological methods, we have begun to deconstruct the motor system driving Drosophila larval feeding behavior into its component parts. In this paper, we identify distinct clusters of motor neurons that execute head tilting, mouth hook movements, and pharyngeal pumping during larval feeding. This basic anatomical scaffold enabled the use of calcium-imaging to monitor the neural activity of motor neurons within the central nervous system (CNS) that drive food intake. Simultaneous nerve- and muscle-recordings demonstrate that the motor neurons innervate the cibarial dilator musculature (CDM) ipsi- and contra-laterally. By classical lesion experiments we localize a set of CPGs generating the neuronal pattern underlying feeding movements to the subesophageal zone (SEZ). Lesioning of higher brain centers decelerated all feeding-related motor patterns, whereas lesioning of ventral nerve cord (VNC) only affected the motor rhythm underlying pharyngeal pumping. These findings provide a basis for progressing upstream of the motor neurons to identify higher regulatory components of the feeding motor system. PMID:26252658

  2. Localization of Motor Neurons and Central Pattern Generators for Motor Patterns Underlying Feeding Behavior in Drosophila Larvae

    PubMed Central

    Hückesfeld, Sebastian; Schoofs, Andreas; Schlegel, Philipp; Miroschnikow, Anton; Pankratz, Michael J.

    2015-01-01

    Motor systems can be functionally organized into effector organs (muscles and glands), the motor neurons, central pattern generators (CPG) and higher control centers of the brain. Using genetic and electrophysiological methods, we have begun to deconstruct the motor system driving Drosophila larval feeding behavior into its component parts. In this paper, we identify distinct clusters of motor neurons that execute head tilting, mouth hook movements, and pharyngeal pumping during larval feeding. This basic anatomical scaffold enabled the use of calcium-imaging to monitor the neural activity of motor neurons within the central nervous system (CNS) that drive food intake. Simultaneous nerve- and muscle-recordings demonstrate that the motor neurons innervate the cibarial dilator musculature (CDM) ipsi- and contra-laterally. By classical lesion experiments we localize a set of CPGs generating the neuronal pattern underlying feeding movements to the subesophageal zone (SEZ). Lesioning of higher brain centers decelerated all feeding-related motor patterns, whereas lesioning of ventral nerve cord (VNC) only affected the motor rhythm underlying pharyngeal pumping. These findings provide a basis for progressing upstream of the motor neurons to identify higher regulatory components of the feeding motor system. PMID:26252658

  3. Benzene Generation Testing for Tank 48H Waste Disposition

    SciTech Connect

    Peters, T

    2005-05-13

    In support for the Aggregation option1, researchers performed a series of tests using actual Tank 48H slurries. The tests were designed to examine potential benzene generation issues if the Tank 48H slurry is disposed to Saltstone. Personnel used the archived Tank 48H sample (HTF-E-03-127, collected September 17, 2003) for the experiments. The tests included a series of three experiments (Tests A, B, and F) performed in duplicate, giving a total of six experiments. Test A used Tank 48H slurry mixed with {approx}20:1 with Defense Waste Processing Facility (DWPF) Recycle from Tanks 21H and 22H. Test B used Tank 48H slurry mixed with {approx}2.7:1 with DWPF Recycle from Tanks 21H and 22H, while Test F used Tank 48H slurry as-is. Tests A and B occurred at 45 C, while Test F occurred at 55 C. Over a period of 8 weeks, personnel collected samples for analysis, once per week. Each sample was tested with the in-cell gamma counter. The researchers noted a decline in the cesium activity in solution which is attributed to temperature dependence of the complex slurry equilibrium. Selected samples were sent to ADS for potassium, boron, and cesium analysis. The benzene generation rate was inferred from the TPB destruction which is indirectly measured by the in-growth of cesium, potassium or boron. The results of all the analyses reveal no discernible in-growth of radiocesium, potassium or boron, indicating no significant tetraphenylborate (TPB) decomposition in any of the experiments. From boron measurements, the inferred rate of TPB destruction remained less than 0.332 mg/(L-h) implying a maximum benzene generation rate of <0.325 mg/(L-h).

  4. Note: A novel dielectric barrier discharge system for generating stable patterns in wide range

    NASA Astrophysics Data System (ADS)

    Liu, Weibo; Wang, Yongjie; Zhang, Hao; Pan, Yuyang; Dong, Lifang

    2016-05-01

    We develop a novel dielectric barrier discharge (DBD) system with a meshed water electrode to generate stable square superlattice patterns (MSSP) in Ar/air mixture in a wide range of experimental environments. Discharge scenarios with the applied voltage increasing in the meshed DBD and ordinary DBD are presented respectively under the same experimental conditions. It is found that a square pattern and MSSP can be obtained stably and easily in meshed DBD, while no pattern emerges in ordinary DBD. MSSP can be formed when the Ar content is from 0% to 70%, and the corresponding applied voltage decreases with Ar content increasing. Results based on optical methods show that MSSP is generated by artificially designed electrodes together with nonlinear characteristics of DBD, which may account for why patterns in meshed DBD exist in a wide range.

  5. Note: A novel dielectric barrier discharge system for generating stable patterns in wide range.

    PubMed

    Liu, Weibo; Wang, Yongjie; Zhang, Hao; Pan, Yuyang; Dong, Lifang

    2016-05-01

    We develop a novel dielectric barrier discharge (DBD) system with a meshed water electrode to generate stable square superlattice patterns (MSSP) in Ar/air mixture in a wide range of experimental environments. Discharge scenarios with the applied voltage increasing in the meshed DBD and ordinary DBD are presented respectively under the same experimental conditions. It is found that a square pattern and MSSP can be obtained stably and easily in meshed DBD, while no pattern emerges in ordinary DBD. MSSP can be formed when the Ar content is from 0% to 70%, and the corresponding applied voltage decreases with Ar content increasing. Results based on optical methods show that MSSP is generated by artificially designed electrodes together with nonlinear characteristics of DBD, which may account for why patterns in meshed DBD exist in a wide range. PMID:27250476

  6. High-fidelity spherical cholesteric liquid crystal Bragg reflectors generating unclonable patterns for secure authentication

    PubMed Central

    Geng, Yong; Noh, JungHyun; Drevensek-Olenik, Irena; Rupp, Romano; Lenzini, Gabriele; Lagerwall, Jan P. F.

    2016-01-01

    Monodisperse cholesteric liquid crystal microspheres exhibit spherically symmetric Bragg reflection, generating, via photonic cross communication, dynamically tuneable multi-coloured patterns. These patterns, uniquely defined by the particular sphere arrangement, could render cholesteric microspheres very useful in countless security applications, as tags to identify and authenticate their carriers, mainly physical objects or persons. However, the optical quality of the cholesteric droplets studied so far is unsatisfactory, especially after polymerisation, a step required for obtaining durable samples that can be used for object identification. We show that a transition from droplets to shells solves all key problems, giving rise to sharp patterns and excellent optical quality even after polymerisation, the polymerised shells sustaining considerable mechanical deformation. Moreover, we demonstrate that, counter to prior expectation, cross communication takes place even between non-identical shells. This opens additional communication channels that add significantly to the complexity and unique character of the generated patterns. PMID:27230944

  7. High-fidelity spherical cholesteric liquid crystal Bragg reflectors generating unclonable patterns for secure authentication.

    PubMed

    Geng, Yong; Noh, JungHyun; Drevensek-Olenik, Irena; Rupp, Romano; Lenzini, Gabriele; Lagerwall, Jan P F

    2016-01-01

    Monodisperse cholesteric liquid crystal microspheres exhibit spherically symmetric Bragg reflection, generating, via photonic cross communication, dynamically tuneable multi-coloured patterns. These patterns, uniquely defined by the particular sphere arrangement, could render cholesteric microspheres very useful in countless security applications, as tags to identify and authenticate their carriers, mainly physical objects or persons. However, the optical quality of the cholesteric droplets studied so far is unsatisfactory, especially after polymerisation, a step required for obtaining durable samples that can be used for object identification. We show that a transition from droplets to shells solves all key problems, giving rise to sharp patterns and excellent optical quality even after polymerisation, the polymerised shells sustaining considerable mechanical deformation. Moreover, we demonstrate that, counter to prior expectation, cross communication takes place even between non-identical shells. This opens additional communication channels that add significantly to the complexity and unique character of the generated patterns. PMID:27230944

  8. High-fidelity spherical cholesteric liquid crystal Bragg reflectors generating unclonable patterns for secure authentication

    NASA Astrophysics Data System (ADS)

    Geng, Yong; Noh, Junghyun; Drevensek-Olenik, Irena; Rupp, Romano; Lenzini, Gabriele; Lagerwall, Jan P. F.

    2016-05-01

    Monodisperse cholesteric liquid crystal microspheres exhibit spherically symmetric Bragg reflection, generating, via photonic cross communication, dynamically tuneable multi-coloured patterns. These patterns, uniquely defined by the particular sphere arrangement, could render cholesteric microspheres very useful in countless security applications, as tags to identify and authenticate their carriers, mainly physical objects or persons. However, the optical quality of the cholesteric droplets studied so far is unsatisfactory, especially after polymerisation, a step required for obtaining durable samples that can be used for object identification. We show that a transition from droplets to shells solves all key problems, giving rise to sharp patterns and excellent optical quality even after polymerisation, the polymerised shells sustaining considerable mechanical deformation. Moreover, we demonstrate that, counter to prior expectation, cross communication takes place even between non-identical shells. This opens additional communication channels that add significantly to the complexity and unique character of the generated patterns.

  9. Steam generator tube integrity program leak rate tests. Progress report

    SciTech Connect

    Clark, R.A.; Bickford, R.L.

    1984-01-01

    This interim report presents preliminary results on leak rate tests performed on through-wall defected Inconel 600 steam generator tubing. Tube defects included an EDM (electro-discharge machine) notch and IGSCC (intergranular stress corrosion cracks) of various lengths. Tests were conducted at PWR operating temperatures with leakage of hot water/steam into air. A number of IGSCC cracks were unstable under the experiment conditions of these initial tests, continuing to grow until system capacity limitations resulted in decreased pressure differential. However, initial tesing also pointed to a need for reconfiguration of the test apparatus to sustain increased flow and, more importantly, alter the mode of control. The initial test configuration is based on flow control, with pressure differential across the specimen an independent variable. This often results in pressure increases too rapid to establish the initiation of crack instability. A reconfigured system based on pressure control with flow as an independent parameter is being recommended for future tests.

  10. Testing and Functions of the J2X Gas Generator

    NASA Technical Reports Server (NTRS)

    Miller, Nicholas

    2009-01-01

    The Ares I, NASA s new solid rocket based crew launch vehicle, is a two stage in line rocket that has made its waytothe forefront of NASA s endeavors. The Ares I s Upper Stage (US) will be propelled by a J-2X engine which is fueled by liquid hydrogen and liquid oxygen. The J-2X is a variation based on two of its predecessor s, the J-2 and J-2S engines. ET50 is providing the design support for hardware required to run tests on the J-2X Gas Generator (GG) that increases the delivery pressure of the supplied combustion fuels that the engine burns. The test area will be running a series of tests using different lengths and curved segments of pipe and different sized nozzles to determine the configuration that best satisfies the thrust, heat, and stability requirements for the engine. I have had to research the configurations that are being tested and gain an understanding of the purpose of the tests. I then had to research the parts that would be used in the test configurations. I was taken to see parts similar to the ones used in the test configurations and was allowed to review drawings and dimensions used for those parts. My job over this summer has been to use the knowledge I have gained to design, model, and create drawings for the un-fabricated parts that are necessary for the J-2X Workhorse Gas Generator Phase IIcTest.

  11. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Thromboplastin generation test. 864.7900 Section 864.7900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  12. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Thromboplastin generation test. 864.7900 Section 864.7900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  13. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thromboplastin generation test. 864.7900 Section 864.7900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  14. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Thromboplastin generation test. 864.7900 Section 864.7900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  15. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Thromboplastin generation test. 864.7900 Section 864.7900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  16. Testing a Student Generated Hypothesis Using Student Data

    ERIC Educational Resources Information Center

    McGowan, Herle M.; Vaughan, Joel

    2012-01-01

    We describe an activity that allows students to experience the full process of a statistical investigation, from generating the research question, to collecting data and testing a hypothesis. Implementation of the activity is described both with and without use of clickers, handheld remotes that allow instant data collection.

  17. Automatic Generation of Tests from Domain and Multimedia Ontologies

    ERIC Educational Resources Information Center

    Papasalouros, Andreas; Kotis, Konstantinos; Kanaris, Konstantinos

    2011-01-01

    The aim of this article is to present an approach for generating tests in an automatic way. Although other methods have been already reported in the literature, the proposed approach is based on ontologies, representing both domain and multimedia knowledge. The article also reports on a prototype implementation of this approach, which…

  18. When does colonisation of a semi-arid hillslope generate vegetation patterns?

    PubMed

    Sherratt, Jonathan A

    2016-07-01

    Patterned vegetation occurs in many semi-arid regions of the world. Most previous studies have assumed that patterns form from a starting point of uniform vegetation, for example as a response to a decrease in mean annual rainfall. However an alternative possibility is that patterns are generated when bare ground is colonised. This paper investigates the conditions under which colonisation leads to patterning on sloping ground. The slope gradient plays an important role because of the downhill flow of rainwater. One long-established consequence of this is that patterns are organised into stripes running parallel to the contours; such patterns are known as banded vegetation or tiger bush. This paper shows that the slope also has an important effect on colonisation, since the uphill and downhill edges of an isolated vegetation patch have different dynamics. For the much-used Klausmeier model for semi-arid vegetation, the author shows that without a term representing water diffusion, colonisation always generates uniform vegetation rather than a pattern. However the combination of a sufficiently large water diffusion term and a sufficiently low slope gradient does lead to colonisation-induced patterning. The author goes on to consider colonisation in the Rietkerk model, which is also in widespread use: the same conclusions apply for this model provided that a small threshold is imposed on vegetation biomass, below which plant growth is set to zero. Since the two models are quite different mathematically, this suggests that the predictions are a consequence of the basic underlying assumption of water redistribution as the pattern generation mechanism. PMID:26547308

  19. Quantum random number generation for loophole-free Bell tests

    NASA Astrophysics Data System (ADS)

    Mitchell, Morgan; Abellan, Carlos; Amaya, Waldimar

    2015-05-01

    We describe the generation of quantum random numbers at multi-Gbps rates, combined with real-time randomness extraction, to give very high purity random numbers based on quantum events at most tens of ns in the past. The system satisfies the stringent requirements of quantum non-locality tests that aim to close the timing loophole. We describe the generation mechanism using spontaneous-emission-driven phase diffusion in a semiconductor laser, digitization, and extraction by parity calculation using multi-GHz logic chips. We pay special attention to experimental proof of the quality of the random numbers and analysis of the randomness extraction. In contrast to widely-used models of randomness generators in the computer science literature, we argue that randomness generation by spontaneous emission can be extracted from a single source.

  20. Calculation of second-harmonic wave pattern generated by focused cylindrical vector beams

    NASA Astrophysics Data System (ADS)

    Ohtsu, A.; Kozawa, Y.; Sato, S.

    2010-03-01

    We calculated the second-harmonic wave pattern induced by focused cylindrically symmetric, polarized vector beams. The second-order nonlinear polarization was expressed for fundamental electric field components passed through a dielectric interface based on vector diffraction theory. Furthermore, the second-harmonic wave pattern was represented on the basis of the far-field approximate expression derived from the formulation of higher-order harmonic generation including a Green's function. For a (110) zinc selenide crystal, the calculated forward emission patterns of the second-harmonic wave were eight-figure shaped as observed in experiment.

  1. Automated Test Case Generation for an Autopilot Requirement Prototype

    NASA Technical Reports Server (NTRS)

    Giannakopoulou, Dimitra; Rungta, Neha; Feary, Michael

    2011-01-01

    Designing safety-critical automation with robust human interaction is a difficult task that is susceptible to a number of known Human-Automation Interaction (HAI) vulnerabilities. It is therefore essential to develop automated tools that provide support both in the design and rapid evaluation of such automation. The Automation Design and Evaluation Prototyping Toolset (ADEPT) enables the rapid development of an executable specification for automation behavior and user interaction. ADEPT supports a number of analysis capabilities, thus enabling the detection of HAI vulnerabilities early in the design process, when modifications are less costly. In this paper, we advocate the introduction of a new capability to model-based prototyping tools such as ADEPT. The new capability is based on symbolic execution that allows us to automatically generate quality test suites based on the system design. Symbolic execution is used to generate both user input and test oracles user input drives the testing of the system implementation, and test oracles ensure that the system behaves as designed. We present early results in the context of a component in the Autopilot system modeled in ADEPT, and discuss the challenges of test case generation in the HAI domain.

  2. Experimental laboratory system to generate high frequency test environments

    SciTech Connect

    Gregory, D.L.; Paez, T.L.

    1991-01-01

    This is an extension of two previous analytical studies to investigate a technique for generating high frequency, high amplitude vibration environments. These environments are created using a device attached to a common vibration exciter that permits multiple metal on metal impacts driving a test surface. These analytical studies predicted that test environments with an energy content exceeding 10 kHz could be achieved using sinusoidal and random shaker excitations. The analysis predicted that chaotic vibrations yielding random like test environments could be generated from sinusoidal inputs. In this study, a much simplified version of the proposed system was fabricated and tested in the laboratory. Experimental measurements demonstrate that even this simplified system, utilizing a single impacting object, can generate environments on the test surface with significant frequency content in excess of 40 kHz. Results for sinusoidal shaker inputs tuned to create chaotic impact response are shown along with the responses due to random vibration shaker inputs. The experiments and results are discussed. 4 refs., 5 figs.

  3. Developing the Persian version of the homophone meaning generation test

    PubMed Central

    Ebrahimipour, Mona; Motamed, Mohammad Reza; Ashayeri, Hassan; Modarresi, Yahya; Kamali, Mohammad

    2016-01-01

    Background: Finding the right word is a necessity in communication, and its evaluation has always been a challenging clinical issue, suggesting the need for valid and reliable measurements. The Homophone Meaning Generation Test (HMGT) can measure the ability to switch between verbal concepts, which is required in word retrieval. The purpose of this study was to adapt and validate the Persian version of the HMGT. Methods: The first phase involved the adaptation of the HMGT to the Persian language. The second phase concerned the psychometric testing. The word-finding performance was assessed in 90 Persian-speaking healthy individuals (20-50 year old; 45 males and 45 females) through three naming tasks: Semantic Fluency, Phonemic Fluency, and Homophone Meaning Generation Test. The participants had no history of neurological or psychiatric diseases, alcohol abuse, severe depression, or history of speech, language, or learning problems. Results: The internal consistency coefficient was larger than 0.8 for all the items with a total Cronbach’s alpha of 0.80. Interrater and intrarater reliability were also excellent. The validity of all items was above 0.77, and the content validity index (0.99) was appropriate. The Persian HMGT had strong convergent validity with semantic and phonemic switching and adequate divergent validity with semantic and phonemic clustering. Conclusion: The Persian version of the Homophone Meaning Generation Test is an appropriate, valid, and reliable test to evaluate the ability to switch between verbal concepts in the assessment of word-finding performance. PMID:27390705

  4. Oscillatory Pattern Generation of the Olfactory Center Using Pulse-Type Hardware Chaotic Neuron Models

    NASA Astrophysics Data System (ADS)

    Saito, Ken; Hatano, Hirokazu; Saito, Minoru; Sekine, Yoshifumi

    Oscillatory patterns of electrical activity are a ubiquitous feature in nervous systems. Oscillatory patterns play an important role in the processing of sensory information pattern recognition. For example, earlier reports describe that the oscillatory patterns in the olfactory center of the land slug are changed by odor stimuli to the tentacles. Olfactory processing has also been studied in relation to rabbits and land slugs through the construction and use of mathematical neural network models. However, a large-scale model is necessary for the study of a model which has sensory information recognition by the oscillatory pattern. Therefore, the construction of a hardware model that can generate oscillatory patterns is desired because nonlinear operations can be processed at higher speeds than the mathematical model. We are studying about the neural network using hardware neuron models to construct the olfactory center model of the living organisms. In the present study, we discuss about the oscillatory pattern generation of the olfactory center using pulse-type hardware chaotic neuron models. Our model shows periodic, quasi-periodic and chaotic oscillations such as the olfactory center of living organisms by changing the synaptic connection weights.

  5. Improved ant algorithms for software testing cases generation.

    PubMed

    Yang, Shunkun; Man, Tianlong; Xu, Jiaqi

    2014-01-01

    Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to produce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

  6. Solar Stirling power generation - Systems analysis and preliminary tests

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.; Wu, Y.-C.; Moynihan, P. I.; Day, F. D., III

    1977-01-01

    The feasibility of an electric power generation system utilizing a sun-tracking parabolic concentrator and a Stirling engine/linear alternator is being evaluated. Performance predictions and cost analysis of a proposed large distributed system are discussed. Design details and preliminary test results are presented for a 9.5 ft diameter parabolic dish at the Jet Propulsion Laboratory (Caltech) Table Mountain Test Facility. Low temperature calorimetric measurements were conducted to evaluate the concentrator performance, and a helium flow system is being used to test the solar receiver at anticipated working fluid temperatures (up to 650 or 1200 C) to evaluate the receiver thermal performance. The receiver body is designed to adapt to a free-piston Stirling engine which powers a linear alternator assembly for direct electric power generation. During the next phase of the program, experiments with an engine and receiver integrated into the concentrator assembly are planned.

  7. Improved Ant Algorithms for Software Testing Cases Generation

    PubMed Central

    Yang, Shunkun; Xu, Jiaqi

    2014-01-01

    Existing ant colony optimization (ACO) for software testing cases generation is a very popular domain in software testing engineering. However, the traditional ACO has flaws, as early search pheromone is relatively scarce, search efficiency is low, search model is too simple, positive feedback mechanism is easy to porduce the phenomenon of stagnation and precocity. This paper introduces improved ACO for software testing cases generation: improved local pheromone update strategy for ant colony optimization, improved pheromone volatilization coefficient for ant colony optimization (IPVACO), and improved the global path pheromone update strategy for ant colony optimization (IGPACO). At last, we put forward a comprehensive improved ant colony optimization (ACIACO), which is based on all the above three methods. The proposed technique will be compared with random algorithm (RND) and genetic algorithm (GA) in terms of both efficiency and coverage. The results indicate that the improved method can effectively improve the search efficiency, restrain precocity, promote case coverage, and reduce the number of iterations. PMID:24883391

  8. Structural vibration control by tuned mass damper using central pattern generator

    NASA Astrophysics Data System (ADS)

    Iba, Daisuke; Hongu, Junichi

    2011-04-01

    This paper proposes a new control method for active mass dampers using a Central Pattern Generator in vibration mitigation. The active mass dampers (or active dynamic absorbers) have been applied to structural vibration control of high-rise buildings, bridges and so on. In this case, the mass of the active mass damper must oscillate in an appropriate phase in relation to the control object, and generally, the damper has been designed by linear control theory as pole placement method, optimal control method or H infinity control method, and all the rest. On the other hand, on walking of animate beings like mammals or insects, both side feet have appropriate phase relations; moreover, it is possible to keep moving on irregular ground. That is, algorithms for the walking would be embedded into the animate beings to control the complicated and redundant bodies with ease and robustness. In biological study, the Central Pattern Generators in bodies playing a significant role in the walking have been learned over the last few decades, and some studies said that some animate beings are able to control their feet by using the generators without their brains in the walking. Moreover, mathematical models of the pattern generators have been proposed, and some researchers have been studying to realize walking of biped-robots using the pattern generators embedded in a computer. In this study, the algorithm is installed into a controller for the active mass damper; furthermore, validation of the controller is performed by numerical simulation.

  9. Generation of optical crystals and quasicrystal beams: Kaleidoscopic patterns and phase singularity

    SciTech Connect

    Chen, Y. F.; Liang, H. C.; Lin, Y. C.; Tzeng, Y. S.; Su, K. W.; Huang, K. F.

    2011-05-15

    We explore the feasibility of the generation of pseudonondiffracting optical beams related to crystal and quasicrystal structures. It is experimentally confirmed that optical crystal and quasicrystal beams can be remarkably generated with a collimated light to illuminate a high-precision mask with multiple apertures regularly distributed on a ring. We also found that exotic kaleidoscopic patterns can be exhibited with the high-order quasicrystal beams. More importantly, the structures of phase singularities in optical quasicrystal beams are manifested.

  10. Influence of next-generation sequencing and storage conditions on miRNA patterns generated from PAXgene blood.

    PubMed

    Backes, Christina; Leidinger, Petra; Altmann, Gabriela; Wuerstle, Maximilian; Meder, Benjamin; Galata, Valentina; Mueller, Sabine C; Sickert, Daniel; Stähler, Cord; Meese, Eckart; Keller, Andreas

    2015-09-01

    Whole blood derived miRNA signatures determined by Next-Generation Sequencing (NGS) offer themselves as future minimally invasive biomarkers for various human diseases. The PAXgene system is a commonly used blood storage system for miRNA analysis. Central to all miRNA analyses that aim to identify disease specific miRNA signatures, is the question of stability and variability of the miRNA profiles that are generated by NGS. We characterized the influence of five different conditions on the genome wide miRNA expression pattern of human blood isolated in PAXgene RNA tubes. In detail, we analyzed 15 miRNomes from three individuals. The blood was subjected to different numbers of freeze/thaw cycles and analyzed for the influence of storage at -80 or 8 °C. We also determined the influence of blood collection and NGS preparations on the miRNA pattern isolated from a single individual, which has been sequenced 10 times. Here, five PAXGene tubes were consecutively collected that have been split in two replicates, representing two experimental batches. All samples were analyzed by Illumina NGS. For each sample, approximately 20 million NGS reads have been generated. Hierarchical clustering and Principal Component Analysis (PCA) showed an influence of the different conditions on the miRNA patterns. The effects of the different conditions on miRNA abundance are, however, smaller than the differences that are due to interindividual variability. We also found evidence for an influence of the NGS measurement on the miRNA pattern. Specifically, hsa-miR-1271-5p and hsa-miR-182-5p showed coefficients of variation above 100% indicating a strong influence of the NGS protocol on the abundance of these miRNAs. PMID:26207298

  11. Gas Generation from K East Basin Sludges - Series I Testing

    SciTech Connect

    Delegard, Calvin H.; Bryan, Samuel A.; Schmidt, Andrew J.; Bredt, Paul R.; King, Christopher M.; Sell, Rachel L.; Burger, Leland L.; Silvers, Kurt L.

    2000-09-12

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor and canister sludge. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge. The overall goals for this testing were to collect detailed gas generation rate and composition data to ascertain the quantity and reactivity of the metallic uranium (and other reactive species) present in the K Basin sludge. The gas generation evaluation included four large-scale vessels (850 ml) and eight small-scale vessels (30 ml) in an all-metal, leak tight system. The tests were conducted for several thousand hours at ambient and elevated temperatures (32 C, 40 C, 60 C, 80 C, and 95 C) to accelerated the reactions and provide conclusive gas generation data within a reasonable testing period. The sludge used for these tests was collected from the KE Basin floor and canister barrels (containing damaged spent fuel elements) using a consolidated sampling technique (i.e., material from several locations was combined to form ''consolidated samples''). Portions of these samples were sieved to separate particles greater than 250 m (P250) from particle less than 250 m (M250). This separation was performed to mimic the separation operations that are planned during the retrieval of certain K Basin sludge types and to gain a better understanding of how uranium metal is distributed in the sludge. The corrosion rate of the uranium metal particles in the sludge was found to agree reasonably well with corrosion rates reported in the literature.

  12. NASA Fastrac Engine Gas Generator Component Test Program and Results

    NASA Technical Reports Server (NTRS)

    Dennis, Henry J., Jr.; Sanders, T.

    2000-01-01

    Low cost access to space has been a long-time goal of the National Aeronautics and Space Administration (NASA). The Fastrac engine program was begun at NASA's Marshall Space Flight Center to develop a 60,000-pound (60K) thrust, liquid oxygen/hydrocarbon (LOX/RP), gas generator-cycle booster engine for a fraction of the cost of similar engines in existence. To achieve this goal, off-the-shelf components and readily available materials and processes would have to be used. This paper will present the Fastrac gas generator (GG) design and the component level hot-fire test program and results. The Fastrac GG is a simple, 4-piece design that uses well-defined materials and processes for fabrication. Thirty-seven component level hot-fire tests were conducted at MSFC's component test stand #116 (TS116) during 1997 and 1998. The GG was operated at all expected operating ranges of the Fastrac engine. Some minor design changes were required to successfully complete the test program as development issues arose during the testing. The test program data results and conclusions determined that the Fastrac GG design was well on the way to meeting the requirements of NASA's X-34 Pathfinder Program that chose the Fastrac engine as its main propulsion system.

  13. Variation in motor output and motor performance in a centrally generated motor pattern

    PubMed Central

    Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

    2014-01-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

  14. The Development of Group Interaction Patterns: How Groups become Adaptive, Generative, and Transformative Learners

    ERIC Educational Resources Information Center

    London, Manuel; Sessa, Valerie I.

    2007-01-01

    This article integrates the literature on group interaction process analysis and group learning, providing a framework for understanding how patterns of interaction develop. The model proposes how adaptive, generative, and transformative learning processes evolve and vary in their functionality. Environmental triggers for learning, the group's…

  15. Student-Generated Content in College Teaching: Content Quality, Behavioural Pattern and Learning Performance

    ERIC Educational Resources Information Center

    Yang, X.; Guo, X.; Yu, S.

    2016-01-01

    This study investigates the quality of course content, behavioural patterns of students and learning performance in teaching of student-generated content (SGC). A total of 49 third-year university students in educational technology participated in this study. By combining the methods of questionnaire, lag sequence analysis and interview, the study…

  16. Pattern-generating travelling waves in a discrete multicellular system with lateral inhibition

    NASA Astrophysics Data System (ADS)

    Plahte, Erik; Øyehaug, Leiv

    2007-02-01

    On a one-dimensional string of cells, the juxtacrine signalling model for Delta-Notch lateral inhibition by Collier et al. [J.R. Collier, N.A.M. Monk, P.K. Maini, J.H. Lewis, Pattern formation by lateral inhibition with feedback: A mathematical model of Delta-Notch intercellular interaction, J. Theoret. Biol. 183 (1996) 429-446] exhibits a predominant alternating pattern of cells expressing either Delta or Notch, as well as many aperiodic patterns. Despite this multistationarity, in the idealised situation of no noise, travelling waves invading the unstable, homogeneous state only generate the predominant alternating pattern in their wake all over the lattice. However, this robustness is totally lost in the presence of stochastic noise because the invaded, initial state is unstable. Using linear approximations around the initial, homogeneous state and around the final, patterned state, we are able to derive analytically all essential properties of the wave: the shape of the wave front, the unique, alternating pattern generated by the wave, and the asymptotic speed of the wave front. We show that the asymptotic wave speed equals the theoretical minimum wave speed. The latter agrees extremely well with the value estimated from numerical simulations. Thus, in this system travelling waves are pulled by the leading edge of the front.

  17. Synergistic action of nectins and cadherins generates the mosaic cellular pattern of the olfactory epithelium

    PubMed Central

    Katsunuma, Sayaka; Honda, Hisao; Shinoda, Tomoyasu; Ishimoto, Yukitaka; Miyata, Takaki; Kiyonari, Hiroshi; Abe, Takaya; Nibu, Ken-ichi; Takai, Yoshimi

    2016-01-01

    In the olfactory epithelium (OE), olfactory cells (OCs) and supporting cells (SCs), which express different cadherins, are arranged in a characteristic mosaic pattern in which OCs are enclosed by SCs. However, the mechanism underlying this cellular patterning is unclear. Here, we show that the cellular pattern of the OE is established by cellular rearrangements during development. In the OE, OCs express nectin-2 and N-cadherin, and SCs express nectin-2, nectin-3, E-cadherin, and N-cadherin. Heterophilic trans-interaction between nectin-2 on OCs and nectin-3 on SCs preferentially recruits cadherin via α-catenin to heterotypic junctions, and the differential distributions of cadherins between junctions promote cellular intercalations, resulting in the formation of the mosaic pattern. These observations are confirmed by model cell systems, and various cellular patterns are generated by the combinatorial expression of nectins and cadherins. Collectively, the synergistic action of nectins and cadherins generates mosaic pattern, which cannot be achieved by a single mechanism. PMID:26929452

  18. Dynamic mechanisms of generation of oscillatory cluster patterns in a globally coupled chemical system

    NASA Astrophysics Data System (ADS)

    Rotstein, Horacio G.; Wu, Hui

    2012-09-01

    We use simulations and dynamical systems tools to investigate the mechanisms of generation of phase-locked and localized oscillatory cluster patterns in a globally coupled Oregonator model where the activator receives global feedback from the inhibitor, mimicking experimental results observed in the photosensitive Belousov-Zhabotinsky reaction. A homogeneous two-cluster system (two clusters with equal cluster size) displays antiphase patterns. Heterogenous two-cluster systems (two clusters with different sizes) display both phase-locked and localized patterns depending on the parameter values. In a localized pattern the oscillation amplitude of the largest cluster is roughly an order of magnitude smaller than the oscillation amplitude of the smaller cluster, reflecting the effect of self-inhibition exerted by the global feedback term. The transition from phase-locked to localized cluster patterns occurs as the intensity of global feedback increases. Three qualitatively different basic mechanisms, described previously for a globally coupled FitzHugh-Nagumo model, are involved in the generation of the observed patterns. The swing-and-release mechanism is related to the canard phenomenon (canard explosion of limit cycles) in relaxation oscillators. The hold-and-release and hold-and-escape mechanisms are related to the release and escape mechanisms in synaptically connected neural models. The methods we use can be extended to the investigation of oscillatory chemical reactions with other types of non-local coupling.

  19. Dynamic mechanisms of generation of oscillatory cluster patterns in a globally coupled chemical system.

    PubMed

    Rotstein, Horacio G; Wu, Hui

    2012-09-14

    We use simulations and dynamical systems tools to investigate the mechanisms of generation of phase-locked and localized oscillatory cluster patterns in a globally coupled Oregonator model where the activator receives global feedback from the inhibitor, mimicking experimental results observed in the photosensitive Belousov-Zhabotinsky reaction. A homogeneous two-cluster system (two clusters with equal cluster size) displays antiphase patterns. Heterogenous two-cluster systems (two clusters with different sizes) display both phase-locked and localized patterns depending on the parameter values. In a localized pattern the oscillation amplitude of the largest cluster is roughly an order of magnitude smaller than the oscillation amplitude of the smaller cluster, reflecting the effect of self-inhibition exerted by the global feedback term. The transition from phase-locked to localized cluster patterns occurs as the intensity of global feedback increases. Three qualitatively different basic mechanisms, described previously for a globally coupled FitzHugh-Nagumo model, are involved in the generation of the observed patterns. The swing-and-release mechanism is related to the canard phenomenon (canard explosion of limit cycles) in relaxation oscillators. The hold-and-release and hold-and-escape mechanisms are related to the release and escape mechanisms in synaptically connected neural models. The methods we use can be extended to the investigation of oscillatory chemical reactions with other types of non-local coupling. PMID:22979891

  20. Clinch River Breeder Reactor Plant Steam Generator Few Tube Test model post-test examination

    SciTech Connect

    Impellezzeri, J.R.; Camaret, T.L.; Friske, W.H.

    1981-03-11

    The Steam Generator Few Tube Test (FTT) was part of an extensive testing program carried out in support of the Clinch River Breeder Reactor Plant (CRBRP) steam generator design. The testing of full-length seven-tube evaporator and three-tube superheater models of the CRBRP design was conducted to provide steady-state thermal/hydraulic performance data to full power per tube and to verify the absence of multi-year endurance problems. This paper describes the problems encountered with the mechanical features of the FTT model design which led to premature test termination, and the results of the post-test examination. Conditions of tube bowing and significant tube and tube support gouging was observed. An interpretation of the visual and metallurgical observations is also presented. The CRBRP steam generator has undergone design evaluations to resolve observed deficiences found in the FFTM.

  1. Directivity patterns of laser-generated sound in solids: Effects of optical and thermal parameters.

    PubMed

    Krylov, Victor V

    2016-07-01

    In the present paper, directivity patterns of laser-generated sound in solids are investigated theoretically. Two main approaches to the calculation of directivity patterns of laser-generated sound are discussed for the most important case of thermo-optical regime of generation. The first approach, which is widely used in practice, is based on the simple modelling of the equivalent thermo-optical source as a mechanical dipole comprising two horizontal forces applied to the surface in opposite directions. The second approach is based on the rigorous theory that takes into account all acoustical, optical and thermal parameters of a solid material and all geometrical and physical parameters of a laser beam. Directivity patterns of laser-generated bulk longitudinal and shear elastic waves, as well as the amplitudes of generated Rayleigh surface waves, are calculated for different values of physical and geometrical parameters and compared with the directivity patterns calculated in case of dipole-source representation. It is demonstrated that the simple approach using a dipole-source representation of laser-generated sound is rather limited, especially for description of generated longitudinal acoustic waves. A practical criterion is established to define the conditions under which the dipole-source representation gives predictions with acceptable errors. It is shown that, for radiation in the normal direction to the surface, the amplitudes of longitudinal waves are especially sensitive to the values of thermal parameters and of the acoustic reflection coefficient from a free solid surface. A discussion is given on the possibility of using such a high sensitivity to the values of the reflection coefficient for investigation of surface properties of real solids. PMID:26851995

  2. Acceptance Test Plan for Fourth-Generation Corrosion Monitoring Cabinet

    SciTech Connect

    NORMAN, E.C.

    2000-10-23

    This Acceptance Test Plan (ATP) will document the satisfactory operation of the third-generation corrosion monitoring cabinet (Hiline Engineering Part No.0004-CHM-072-C01). This ATP will be performed by the manufacturer of the cabinet prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion monitoring cabinet. The test will consist of a continuity test of the cabinet wiring from the end of cable to be connected to corrosion probe, through the appropriate intrinsic safety barriers and out to the 15 pin D-shell connectors to be connected to the corrosion monitoring instrument. Additional testing will be performed using a constant current and voltage source provided by the corrosion monitoring hardware manufacturer to verify proper operation of corrosion monitoring instrumentation.

  3. A test vector generator for a radar signal processor

    NASA Astrophysics Data System (ADS)

    Robins, C. B.

    1991-02-01

    This report documents the test vector generator (TVG) system developed for the purpose of testing a radar signal processor. This system simulates an eight channel radar receiver by providing input data for testing the signal processor test bed. The TVG system outputs 128-bit wide data samples at variable rates up to and including 10 million samples per second. The VTG memory array is one million samples deep. Variably sized output vectors can be addressed within the memory array and the vectors can be concatenated, repeated, and reshuffled in real time under the control of a single board computer. The TVG is seen having applications on a variety of programs. Discussions of adapting and scaling the system to these other applications are presented.

  4. Wide-field depth-sectioning fluorescence microscopy using projector-generated patterned illumination.

    PubMed

    Delica, Serafin; Blanca, Carlo Mar

    2007-10-10

    We present a simple and cost-effective wide-field, depth-sectioning, fluorescence microscope utilizing a commercial multimedia projector to generate excitation patterns on the sample. Highly resolved optical sections of fluorescent pollen grains at 1.9 microm axial resolution are constructed using the structured illumination technique. This requires grid excitation patterns to be scanned across the sample, which is straightforwardly implemented by creating slideshows of gratings at different phases, projecting them onto the sample, and synchronizing camera acquisition with slide transition. In addition to rapid dynamic pattern generation, the projector provides high illumination power and spectral excitation selectivity. We exploit these properties by imaging mouse neural cells in cultures multistained with Alexa 488 and Cy3. The spectral and structural neural information is effectively resolved in three dimensions. The flexibility and commercial availability of this light source is envisioned to open multidimensional imaging to a broader user base. PMID:17932535

  5. Generation of mask patterns for diffractive optical elements using Mathematica{sup T}{sup M}

    SciTech Connect

    OShea, D.C.

    1996-07-01

    The generation of binary and grayscale masks used in the fabrication of diffractive optical elements is usually performed using a proprietary piece of software or a computer-aided drafting package. Once the pattern is computed or designed, it must be output to a plotting or imaging system that will produce a reticle plate. This article describes a number of short Mathematica modules that can be used to generate binary and grayscale patterns in a PostScript-compatible format. Approaches to ensure that the patterns are directly related to the function of the element and the design wavelength are discussed. A procedure to preserve the scale of the graphic output when it is transferred to another application is given. Examples of surfaces for a 100 mm effective focal length lens and an Alvarez surface are given. {copyright} {ital 1996 American Institute of Physics.}

  6. Identifying Patterns of Appraising Tests in First-Year College Students: Implications for Anxiety and Emotion Regulation during Test Taking

    ERIC Educational Resources Information Center

    Davis, Heather A.; DiStefano, Christine; Schutz, Paul A.

    2008-01-01

    The authors explored patterns of appraising tests in a large sample of 1st-year college students. Cluster analysis was used to identify homogeneous groups of 1st-year students who shared similar patterns of cognitive appraisals about testing. The authors internally validated findings with an independent sample from the same population of students…

  7. Regulation of ventral surface chemoreceptors by the central respiratory pattern generator.

    PubMed

    Guyenet, Patrice G; Mulkey, Daniel K; Stornetta, Ruth L; Bayliss, Douglas A

    2005-09-28

    The rat retrotrapezoid nucleus (RTN) contains neurons described as central chemoreceptors in the adult and respiratory rhythm-generating pacemakers in neonates [parafacial respiratory group (pfRG)]. Here we test the hypothesis that both RTN and pfRG neurons are intrinsically chemosensitive and tonically firing neurons whose respiratory rhythmicity is caused by a synaptic feedback from the central respiratory pattern generator (CPG). In halothane-anesthetized adults, RTN neurons were silent below 4.5% end-expiratory (e-exp) CO2. Their activity increased linearly (3.2 Hz/1% CO2) up to 6.5% (CPG threshold) and then more slowly to peak approximately 10 Hz at 10% CO2. Respiratory modulation of RTN neurons was absent below CPG threshold, gradually stronger beyond, and, like pfRG neurons, typically (42%) characterized by twin periods of reduced activity near phrenic inspiration. After CPG inactivation with kynurenate (KYN), RTN neurons discharged linearly as a function of e-exp CO2 (slope, +1.7 Hz/1% CO2) and arterial pH (threshold, 7.48; slope, 39 Hz/pH unit). In coronal brain slices (postnatal days 7-12), RTN chemosensitive neurons were silent at pH 7.55. Their activity increased linearly with acidification up to pH 7.2 (17 Hz/pH unit at 35 degrees C) and was always tonic. In conclusion, consistent with their postulated central chemoreceptor role, RTN/pfRG neurons encode pH linearly and discharge tonically when disconnected from the rest of the respiratory centers in vivo (KYN treatment) and in vitro. In vivo, RTN neurons receive respiratory synchronous inhibitory inputs that may serve as feedback and impart these neurons with their characteristic respiratory modulation. PMID:16192384

  8. Generation of Simulated Tracking Data for LADEE Operational Readiness Testing

    NASA Technical Reports Server (NTRS)

    Woodburn, James; Policastri, Lisa; Owens, Brandon

    2015-01-01

    Operational Readiness Tests were an important part of the pre-launch preparation for the LADEE mission. The generation of simulated tracking data to stress the Flight Dynamics System and the Flight Dynamics Team was important for satisfying the testing goal of demonstrating that the software and the team were ready to fly the operational mission. The simulated tracking was generated in a manner to incorporate the effects of errors in the baseline dynamical model, errors in maneuver execution and phenomenology associated with various tracking system based components. The ability of the mission team to overcome these challenges in a realistic flight dynamics scenario indicated that the team and flight dynamics system were ready to fly the LADEE mission. Lunar Atmosphere and Dust Environment.

  9. Automatic Generation of Test Oracles - From Pilot Studies to Application

    NASA Technical Reports Server (NTRS)

    Feather, Martin S.; Smith, Ben

    1998-01-01

    There is a trend towards the increased use of automation in V&V. Automation can yield savings in time and effort. For critical systems, where thorough V&V is required, these savings can be substantial. We describe a progression from pilot studies to development and use of V&V automation. We used pilot studies to ascertain opportunities for, and suitability of, automating various analyses whose results would contribute to V&V. These studies culminated in the development of an automatic generator of automated test oracles. This was then applied and extended in the course of testing an Al planning system that is a key component of an autonomous spacecraft.

  10. Facility for generating crew waste water product for ECLSS testing

    NASA Technical Reports Server (NTRS)

    Buitekant, Alan; Roberts, Barry C.

    1990-01-01

    An End-use Equipment Facility (EEF) has been constructed which is used to simulate water interfaces between the Space Station Freedom Environmental Control and Life Support Systems (ECLSS) and man systems. The EEF is used to generate waste water to be treated by ECLSS water recovery systems. The EEF will also be used to close the water recovery loop by allowing test subjects to use recovered hygiene and potable water during several phases of testing. This paper describes the design and basic operation of the EEF.

  11. NREL Next Generation Drivetrain: Mechanical Design and Test Plan (Poster)

    SciTech Connect

    Keller, J.; Halse, C.

    2014-05-01

    The Department of Energy and industry partners are sponsoring a $3m project for design and testing of a 'Next Generation' wind turbine drivetrain at the National Renewable Energy Laboratory (NREL). This poster focuses on innovative aspects of the gearbox design, completed as part of an end-to-end systems engineering approach incorporating innovations that increase drivetrain reliability, efficiency, torque density and minimize capital cost.

  12. Shape matching utilizing indexed hypotheses generation and testing

    NASA Technical Reports Server (NTRS)

    Mehrotra, Rajiv; Grosky, William I.

    1989-01-01

    An indexing mechanism is developed as part of an overall scheme called SMITH (shape matching utilizing indexed hypothesis generation and testing) for two-dimensional model-based object recognition. The approach is based on a dynamic programming implementation of attributed string matching, is computationally efficient, and works effectively for both nonoccluded and occluded shapes. Another advantage of this technique is that models may be inserted or deleted with relatively little cost.

  13. Gas Generation from K East Basin Sludges - Series II Testing

    SciTech Connect

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2004-04-26

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focuses on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report presents results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge. This report was originally published in March 2001. In January 2004, a transcription error was discovered in the value reported for the uranium metal content of KE North Loadout Pit sample FE-3. This revision of the report corrects the U metal content of FE-3 from 0.0013 wt% to 0.013 wt%.

  14. Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites.

    PubMed

    González Pericot, N; Villoria Sáez, P; Del Río Merino, M; Liébana Carrasco, O

    2014-11-01

    The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites. PMID:25081852

  15. The large contour data generation from divided image of photomask pattern of 32 nm and beyond

    NASA Astrophysics Data System (ADS)

    Murakawa, Tsutomu; Ogiso, Yoshiaki; Iwai, Toshimichi; Matsumoto, Jun; Nakamura, Takayuki

    2010-05-01

    The application of Mask CD-SEM for process management of photomask using two dimensional measurements as photomask patterns become smaller and more complex, [1]. Also, WPI technology application using an optical Mask inspection tool simulates wafer plane images using photomask images [2]. In order to simulate the MEEF influence for aggressive OPC and High-end photomask patterns in 32nm node and beyond, a requirement exists for wide Field of View (FOV) GDS data and tone information generated from high precision SEM images. In light of these requirements, we developed a GDS data extraction algorithm with sub-nanometer accuracy using wide FOV images, for example, greater than 10um square. As a result, we over come the difficulty of generating large contour data without the distortion that is normally associated with acquired SEM images. Also, it will be shown that the evaluation result can be effective for 32 nm applications and beyond using Mask CD-SEM E3620 manufactured by Advantest. On the other hand, we investigate the application example of the wide FOV GDS data. In order to easily compare the acquired GDS data with design data, we explain the separate algorithm with three layer structures for Tri-tone (Ternary) photomask pattern, consisting of an outer pattern and another pattern.

  16. Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

    SciTech Connect

    González Pericot, N.; Villoria Sáez, P.; Del Río Merino, M.; Liébana Carrasco, O.

    2014-11-15

    Highlights: • On-site segregation level: 1.80%; training and motivation strategies were not effective. • 70% Cardboard waste: from switches and sockets during the building services stage. • 40% Plastic waste: generated during structures and partition works due to palletizing. • >50% Wood packaging waste, basically pallets, generated during the envelope works. - Abstract: The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.

  17. D0 Experimental Area Emergency Backup Power and Generator Test

    SciTech Connect

    Markley, D.; /Fermilab

    1991-01-24

    The DO experimental area has a generator designated as emergency power. This generator provides power for critical loads and starts automatically upon loss of commercial power. This note concerns the testing of this generator. A list of loads is attached to this note. One of the loads on the emergency power grid is a 10KVA Uninterruptable Power Supply(UPS). The UPS powers the cryogenic controls and Oxygen deficiency hazard equipment(ODH) and has a minimum rating of 20 minutes while on its batteries(to cover the transfer time to/from the emergency generator). Jan 23,1991 at 1640 hrs this system was tested under the supervision of the Terry Ross, Marv Johnson, Dan Markley, Kelly Dixon, and John Urbin. The power feeder to the emergency power grid at DO was disconnected. The generator responded immediately and was supplying power to the emergency power grid in less than 10 seconds. During the 10 seconds that there was no power on the emergency grid the UPS switched on its inverter and provided uninterrupted power to the cryogenic control system and the ODH system. All of the motorized equipment shut off instrument air compressor, vacuum pumps 1 and 2, insulating vacuum blower, glycol cooling pumps, cooling tower fan, and Exhaust Fan 7(EF7). Upon reengagement of power to the grid from the emergency generator, all of the motorized loads started back up with the exception of vacuum pumps 1 and 2, and the UPS inverter turned off. Vacuum pumps 1 and 2 were delay started 20 seconds by the cryogenic control system as not to cause too large of a surge in power by all of the inductive loads starting at once. The DO building elevator which is also on emergency power was test run while the emergency generator was on line with all other emergency loads. The emergency generator current was 140 amps with all loads on line and running except the building elevator. This load of 140 amps is 27% of the generator's capacity. The cryogenic control and ODH system continued to function

  18. Composite axilens-axicon diffractive optical elements for generation of ring patterns with high focal depth

    NASA Astrophysics Data System (ADS)

    Dharmavarapu, Raghu; Vijayakumar, A.; Brunner, R.; Bhattacharya, Shanti

    2016-03-01

    A binary Fresnel Zone Axilens (FZA) is designed for the infinite conjugate mode and the phase profile of a refractive axicon is combined with it to generate a composite Diffractive Optical Element (DOE). The FZA designed for two focal lengths generates a line focus along the propagation direction extending between the two focal planes. The ring pattern generated by the axicon is focused through this distance and the radius of the ring depends on the propagation distance. Hence, the radius of the focused ring pattern can be tuned, during the design process, within the two focal planes. The integration of the two functions was carried out by shifting the location of zones of FZA with respect to the phase profile of the refractive axicon resulting in a binary composite DOE. The FZAs and axicons were designed for different focal depth values and base angles respectively, in order to achieve different ring radii within the focal depth of each element. The elements were simulated using scalar diffraction formula and their focusing characteristics were analyzed. The DOEs were fabricated using electron beam direct writing and evaluated using a fiber coupled diode laser. The tunable ring patterns generated by the DOEs have prospective applications in microdrilling as well as microfabrication of circular diffractive and refractive optical elements.

  19. Vesicular glutamate transporter 2 is required for central respiratory rhythm generation but not for locomotor central pattern generation.

    PubMed

    Wallén-Mackenzie, Asa; Gezelius, Henrik; Thoby-Brisson, Muriel; Nygård, Anna; Enjin, Anders; Fujiyama, Fumino; Fortin, Gilles; Kullander, Klas

    2006-11-22

    Glutamatergic excitatory neurotransmission is dependent on glutamate release from presynaptic vesicles loaded by three members of the solute carrier family, Slc17a6-8, which function as vesicular glutamate transporters (VGLUTs). Here, we show that VGLUT2 (Slc17a6) is required for life ex utero. Vglut2 null mutant mice die immediately after birth because of the absence of respiratory behavior. Investigations at embryonic stages revealed that neural circuits in the location of the pre-Bötzinger (PBC) inspiratory rhythm generator failed to become active. However, neurons with bursting pacemaker properties and anatomical integrity of the PBC area were preserved. Vesicles at asymmetric synapses were fewer and malformed in the Vglut2 null mutant hindbrain, probably causing the complete disruption of AMPA/kainate receptor-mediated synaptic activity in mutant PBC cells. The functional deficit results from an inability of PBC neurons to achieve synchronous activation. In contrast to respiratory rhythm generation, the locomotor central pattern generator of Vglut2 null mutant mice displayed normal rhythmic and coordinated activity, suggesting differences in their operating principles. Hence, the present study identifies VGLUT2-mediated signaling as an obligatory component of the developing respiratory rhythm generator. PMID:17122055

  20. Investigation, Analysis, and Testing of Self-contained Oxygen Generators

    NASA Technical Reports Server (NTRS)

    Keddy, Christopher P.; Haas, Jon P.; Starritt, Larry

    2008-01-01

    Self Contained Oxygen Generators (SCOGs) have widespread use in providing emergency breathing oxygen in a variety of environments including mines, submarines, spacecraft, and aircraft. These devices have definite advantages over storing of gaseous or liquid oxygen. The oxygen is not generated until a chemical briquette containing a chlorate or perchlorate oxidizer and a solid metallic fuel such as iron is ignited starting a thermal decomposition process allowing gaseous oxygen to be produced. These devices are typically very safe to store, easy to operate, and have primarily only a thermal hazard to the operator that can be controlled by barriers or furnaces. Tens of thousands of these devices are operated worldwide every year without major incident. This report examines the rare case of a SCOG whose behavior was both abnormal and lethal. This particular type of SCOG reviewed is nearly identical to a flight qualified version of SCOG slated for use on manned space vehicles. This Investigative Report is a compilation of a NASA effort in conjunction with other interested parties including military and aerospace to understand the causes of the particular SCOG accident and what preventative measures can be taken to ensure this incident is not repeated. This report details the incident and examines the root causes of the observed SCOG behavior from forensic evidence. A summary of chemical and numerical analysis is provided as a background to physical testing of identical SCOG devices. The results and findings of both small scale and full scale testing are documented on a test-by-test basis along with observations and summaries. Finally, conclusions are presented on the findings of this investigation, analysis, and testing along with suggestions on preventative measures for any entity interested in the safe use of these devices.

  1. SOM-based Pattern Generator: Pattern Generation Based on the Backward Projection in a Self-Organizing Map and Its Applications

    NASA Astrophysics Data System (ADS)

    Wakuya, Hiroshi; Ishiguma, Takahiro

    A major feature of the self-organizing map (SOM) is a topology-preserving projection from the input layer to the competitive layer, and it has been used mainly as an analytical tool for discovering underlying rules in the given data set. Even though recent splendid progress in this area, there are few novel ideas to break such a conventional style. On the contrary, based on its distinctive nature, a new method for generating patterns through backward projection from the competitive layer to the input layer is proposed recently. Moreover, a promising technology for producing animation as a series of backward-projected patterns along with any pathways on the competitive layer is presented. Then, in order to carry out further considerations, some computer simulations with a variety of posed stick figures are tried in this paper. After training, four kinds of pathways, which correspond to different movements such as dancing, exercising and walking, are prepared. Though some of them does not contain any training samples, all of them worked well as we have intended in advance. As a result, it is found that the proposed method shows good performance and it is also confirmed its effectiveness.

  2. Effective hydrogen generator testing for on-site small engine

    NASA Astrophysics Data System (ADS)

    Chaiwongsa, Praitoon; Pornsuwancharoen, Nithiroth; Yupapin, Preecha P.

    2009-07-01

    We propose a new concept of hydrogen generator testing for on-site small engine. In general, there is a trade-off between simpler vehicle design and infrastructure issues, for instance, liquid fuels such as gasoline and methanol for small engine use. In this article we compare the hydrogen gases combination the gasoline between normal systems (gasoline only) for small engine. The advantage of the hydrogen combines gasoline for small engine saving the gasoline 25%. Furthermore, the new concept of hydrogen combination for diesel engine, bio-diesel engine, liquid petroleum gas (LPG), natural gas vehicle (NGV), which is discussed in details.

  3. Quantum Statistical Testing of a Quantum Random Number Generator

    SciTech Connect

    Humble, Travis S

    2014-01-01

    The unobservable elements in a quantum technology, e.g., the quantum state, complicate system verification against promised behavior. Using model-based system engineering, we present methods for verifying the opera- tion of a prototypical quantum random number generator. We begin with the algorithmic design of the QRNG followed by the synthesis of its physical design requirements. We next discuss how quantum statistical testing can be used to verify device behavior as well as detect device bias. We conclude by highlighting how system design and verification methods must influence effort to certify future quantum technologies.

  4. International Space Station United States Oxygen Generator Development Testing

    NASA Technical Reports Server (NTRS)

    Erickson, Robert J.; Mason, Richard K.

    2000-01-01

    A life test of a liquid anode feed oxygen generator assembly (OGA) using SPE(R) (United Technologies Corporation, Hamilton Sundstrand Division) membrane technology was terminated in June of 1999. In the total 15,658 hours of operation at MSFC since delivery in 1995, the OGA has produced 2,103 kilograms (kg) (4,632 pounds mass (lbm)) of oxygen, and 263 kg (579 lbm) of hydrogen. Evaluation of cell stack characteristics and oxygen and hydrogen hydrophilic/hydrophobic membrane separators will be discussed.

  5. Biological pattern generation: the cellular and computational logic of networks in motion.

    PubMed

    Grillner, Sten

    2006-12-01

    In 1900, Ramón y Cajal advanced the neuron doctrine, defining the neuron as the fundamental signaling unit of the nervous system. Over a century later, neurobiologists address the circuit doctrine: the logic of the core units of neuronal circuitry that control animal behavior. These are circuits that can be called into action for perceptual, conceptual, and motor tasks, and we now need to understand whether there are coherent and overriding principles that govern the design and function of these modules. The discovery of central motor programs has provided crucial insight into the logic of one prototypic set of neural circuits: those that generate motor patterns. In this review, I discuss the mode of operation of these pattern generator networks and consider the neural mechanisms through which they are selected and activated. In addition, I will outline the utility of computational models in analysis of the dynamic actions of these motor networks. PMID:17145498

  6. Two-phase Flow Patterns in High Temperature Generator of Absorption Chiller / Heater

    NASA Astrophysics Data System (ADS)

    Furukawa, Masahiro; Kanuma, Hitoshi; Sekoguchi, Kotohiko; Takeishi, Masayuki

    There is a lack of information about vapor-liquid two-phase flow patterns determined using void signals in high temperature generator of absorption chiller/heater. Sensing void fraction has been hampered because lithium bromide aqueous solution of strong alkalinity is employed as working fluid at high temperature and high level of vacuum. New void sensor applicable to such difficult conditions was developed. The void Fractions at 48 locations in a high temperature generator were measured simultaneously in both cooling and heating operations. Analysis of void signals detected reveals that the most violent boiling occurs at the upper part of rear plate of combustion chamber and the first line of vertical tubes located in the flue. The flow patterns are strongly affected by the system pressure difference between the cooling and heating operations: there appear bubbly, slug and froth flows in the cooling operation, but only bubbly flow in the heating operation.

  7. A rule-based expert system for automatic control rod pattern generation for boiling water reactors

    SciTech Connect

    Lin, L.S.; Lin, C. )

    1991-07-01

    This paper reports on an expert system for generating control rod patterns that has been developed. The knowledge is transformed into IF-THEN rules. The inference engine uses the Rete pattern matching algorithm to match facts, and rule premises and conflict resolution strategies to make the system function intelligently. A forward-chaining mechanism is adopted in the inference engine. The system is implemented in the Common Lisp programming language. The three-dimensional core simulation model performs the core status and burnup calculations. The system is successfully demonstrated by generating control rod programming for the 2894-MW (thermal) Kuosheng nuclear power plant in Taiwan. The computing time is tremendously reduced compared to programs using mathematical methods.

  8. Experimental observation of multistability and dynamic attractors in silicon central pattern generators

    NASA Astrophysics Data System (ADS)

    Zhao, Le; Nogaret, Alain

    2015-11-01

    We report on the multistability of chaotic networks of silicon neurons and demonstrate how spatiotemporal sequences of voltage oscillations are selected with timed current stimuli. A three neuron central pattern generator was built by interconnecting Hodgkin-Huxley neurons with mutually inhibitory links mimicking gap junctions. By systematically varying the timing of current stimuli applied to individual neurons, we generate the phase lag maps of neuronal oscillators and study their dependence on the network connectivity. We identify up to six attractors consisting of triphasic sequences of unevenly spaced pulses propagating clockwise and anticlockwise. While confirming theoretical predictions, our experiments reveal more complex oscillatory patterns shaped by the ratio of the pulse width to the oscillation period. Our work contributes to validating the command neuron hypothesis.

  9. Photorefractive holographic moiré-like patterns for secure numerical code generation.

    PubMed

    de Oliveira, G N; Oliveira, M E; dos Santos, P A M

    2013-03-15

    In this Letter, low-frequency photorefractive holographic moiré fringe patterns are proposed as secure numerical code generators that could be useful for storage or data transmission. These dynamic moiré patterns are holographically obtained by the superposition of two or more sinusoidal gratings with slightly different pitches. The Bi(12)TiO(20) photorefractive crystal sample is used as holographic medium. An optical numerical base was defined with patterns representing the 0, 1 and -1 digits as bits. Then, the complete set of these optical bits is combined to form bytes, where a numerical sequence is represented. The results show that the proposed numerical code is simple, robust and extremely secure, then could be used efficiently as standard numerical identification in robotic vision or eventually in storage or transmission of secure numerical data. PMID:23503288

  10. Effects of Scoring by Section and Independent Scorers' Patterns on Scorer Reliability in Biology Essay Tests

    ERIC Educational Resources Information Center

    Ebuoh, Casmir N.; Ezeudu, S. A.

    2015-01-01

    The study investigated the effects of scoring by section, use of independent scorers and conventional patterns on scorer reliability in Biology essay tests. It was revealed from literature review that conventional pattern of scoring all items at a time in essay tests had been criticized for not being reliable. The study was true experimental study…

  11. End-on radioisotope thermoelectric generator impact tests

    NASA Astrophysics Data System (ADS)

    Reimus, M. A. H.; Hinckley, J. E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  12. End-on radioisotope thermoelectric generator impact tests

    SciTech Connect

    Reimus, M.A.; Hinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure. {copyright} {ital 1997 American Institute of Physics.}

  13. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M. A. H.; Hinckley, J. E.

    1998-01-15

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  14. Radioisotope thermoelectric generator/thin fragment impact test

    NASA Astrophysics Data System (ADS)

    Reimus, M. A. H.; Hinckley, J. E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  15. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.; Hinckley, J.E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel. {copyright} {ital 1998 American Institute of Physics.}

  16. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel.

  17. End-on radioisotope thermoelectric generator impact tests

    SciTech Connect

    Reimus, M.A.H.; Hhinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  18. Phase relationships between segmentally organized oscillators in the leech heartbeat pattern generating network.

    PubMed

    Masino, Mark A; Calabrese, Ronald L

    2002-03-01

    Motor pattern generating networks that produce segmentally distributed motor outflow are often portrayed as a series of coupled segmental oscillators that produce a regular progression (constant phase differences) in their rhythmic activity. The leech heartbeat central pattern generator is paced by a core timing network, which consists of two coupled segmental oscillators in segmental ganglia 3 and 4. The segmental oscillators comprise paired mutually inhibitory oscillator interneurons and the processes of intersegmental coordinating interneurons. As a first step in understanding the coordination of segmental motor outflow by this pattern generator, we describe the functional synaptic interactions, and activity and phase relationships of the heart interneurons of the timing network, in isolated nerve cord preparations. In the timing network, most (approximately 75%) of the coordinating interneuron action potentials were generated at a primary spike initiation site located in ganglion 4 (G4). A secondary spike initiation site in ganglion 3 (G3) became active in the absence of activity at the primary site. Generally, the secondary site was characterized by a reluctance to burst and a lower spike frequency, when compared with the primary site. Oscillator interneurons in G3 inhibited spike activity at both initiation sites, whereas oscillator interneurons in G4 inhibited spike activity only at the primary initiation site. This asymmetry in the control of spike activity in the coordinating interneurons may account for the observation that the phase of the coordinating interneurons is more tightly linked to the G3 than G4 oscillator interneurons. The cycle period of the timing network and the phase difference between the ipsilateral G3 and G4 oscillator interneurons were regular within individual preparations, but varied among preparations. This variation in phase differences observed across preparations implies that modulated intrinsic membrane and synaptic properties

  19. Key Bifurcations of Bursting Polyrhythms in 3-Cell Central Pattern Generators

    PubMed Central

    Wojcik, Jeremy; Schwabedal, Justus; Clewley, Robert; Shilnikov, Andrey L.

    2014-01-01

    We identify and describe the key qualitative rhythmic states in various 3-cell network motifs of a multifunctional central pattern generator (CPG). Such CPGs are neural microcircuits of cells whose synergetic interactions produce multiple states with distinct phase-locked patterns of bursting activity. To study biologically plausible CPG models, we develop a suite of computational tools that reduce the problem of stability and existence of rhythmic patterns in networks to the bifurcation analysis of fixed points and invariant curves of a Poincaré return maps for phase lags between cells. We explore different functional possibilities for motifs involving symmetry breaking and heterogeneity. This is achieved by varying coupling properties of the synapses between the cells and studying the qualitative changes in the structure of the corresponding return maps. Our findings provide a systematic basis for understanding plausible biophysical mechanisms for the regulation of rhythmic patterns generated by various CPGs in the context of motor control such as gait-switching in locomotion. Our analysis does not require knowledge of the equations modeling the system and provides a powerful qualitative approach to studying detailed models of rhythmic behavior. Thus, our approach is applicable to a wide range of biological phenomena beyond motor control. PMID:24739943

  20. Removal of spike frequency adaptation via neuromodulation intrinsic to the Tritonia escape swim central pattern generator.

    PubMed

    Katz, P S; Frost, W N

    1997-10-15

    For the mollusc Tritonia diomedea to generate its escape swim motor pattern, interneuron C2, a crucial member of the central pattern generator (CPG) for this rhythmic behavior, must fire repetitive bursts of action potentials. Yet, before swimming, repeated depolarizing current pulses injected into C2 at periods similar those in the swim motor program are incapable of mimicking the firing rate attained by C2 on each cycle of a swim motor program. This resting level of C2 inexcitability is attributable to its own inherent spike frequency adaptation (SFA). Clearly, this property must be altered for the swim behavior to occur. The pathway for initiation of the swimming behavior involves activation of the serotonergic dorsal swim interneurons (DSIs), which are also intrinsic members of the swim CPG. Physiologically appropriate DSI stimulation transiently decreases C2 SFA, allowing C2 to fire at higher rates even when repeatedly depolarized at short intervals. The increased C2 excitability caused by DSI stimulation is mimicked and occluded by serotonin application. Furthermore, the change in excitability is not caused by the depolarization associated with DSI stimulation or serotonin application but is correlated with a decrease in C2 spike afterhyperpolarization. This suggests that the DSIs use serotonin to evoke a neuromodulatory action on a conductance in C2 that regulates its firing rate. This modulatory action of one CPG neuron on another is likely to play a role in configuring the swim circuit into its rhythmic pattern-generating mode and maintaining it in that state. PMID:9315892

  1. Towards pattern generation and chaotic series prediction with photonic reservoir computers

    NASA Astrophysics Data System (ADS)

    Antonik, Piotr; Hermans, Michiel; Duport, François; Haelterman, Marc; Massar, Serge

    2016-03-01

    Reservoir Computing is a bio-inspired computing paradigm for processing time dependent signals that is particularly well suited for analog implementations. Our team has demonstrated several photonic reservoir computers with performance comparable to digital algorithms on a series of benchmark tasks such as channel equalisation and speech recognition. Recently, we showed that our opto-electronic reservoir computer could be trained online with a simple gradient descent algorithm programmed on an FPGA chip. This setup makes it in principle possible to feed the output signal back into the reservoir, and thus highly enrich the dynamics of the system. This will allow to tackle complex prediction tasks in hardware, such as pattern generation and chaotic and financial series prediction, which have so far only been studied in digital implementations. Here we report simulation results of our opto-electronic setup with an FPGA chip and output feedback applied to pattern generation and Mackey-Glass chaotic series prediction. The simulations take into account the major aspects of our experimental setup. We find that pattern generation can be easily implemented on the current setup with very good results. The Mackey-Glass series prediction task is more complex and requires a large reservoir and more elaborate training algorithm. With these adjustments promising result are obtained, and we now know what improvements are needed to match previously reported numerical results. These simulation results will serve as basis of comparison for experiments we will carry out in the coming months.

  2. From spinal central pattern generators to cortical network: integrated BCI for walking rehabilitation.

    PubMed

    Cheron, G; Duvinage, M; De Saedeleer, C; Castermans, T; Bengoetxea, A; Petieau, M; Seetharaman, K; Hoellinger, T; Dan, B; Dutoit, T; Sylos Labini, F; Lacquaniti, F; Ivanenko, Y

    2012-01-01

    Success in locomotor rehabilitation programs can be improved with the use of brain-computer interfaces (BCIs). Although a wealth of research has demonstrated that locomotion is largely controlled by spinal mechanisms, the brain is of utmost importance in monitoring locomotor patterns and therefore contains information regarding central pattern generation functioning. In addition, there is also a tight coordination between the upper and lower limbs, which can also be useful in controlling locomotion. The current paper critically investigates different approaches that are applicable to this field: the use of electroencephalogram (EEG), upper limb electromyogram (EMG), or a hybrid of the two neurophysiological signals to control assistive exoskeletons used in locomotion based on programmable central pattern generators (PCPGs) or dynamic recurrent neural networks (DRNNs). Plantar surface tactile stimulation devices combined with virtual reality may provide the sensation of walking while in a supine position for use of training brain signals generated during locomotion. These methods may exploit mechanisms of brain plasticity and assist in the neurorehabilitation of gait in a variety of clinical conditions, including stroke, spinal trauma, multiple sclerosis, and cerebral palsy. PMID:22272380

  3. Thermal vacuum life test facility for radioisotope thermoelectric generators

    SciTech Connect

    Deaton, R.L.; Goebel, C.J.; Amos, W.R.

    1990-01-01

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al. (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met. 4 refs., 3 figs.

  4. Thermal vacuum life test facility for radioisotope thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Deaton, R. L.; Goebel, C. J.; Amos, W. R.

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG and G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al., (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met.

  5. Mobile testing complex based on an explosive magnetic generator

    NASA Astrophysics Data System (ADS)

    Shurupov, A. V.; Kozlov, A. V.; Gusev, A. N.; Shurupova, N. P.; Zavalova, V. E.; Chulkov, A. N.; Bazelyan, E. M.

    2015-01-01

    A mobile testing complex prototype on the basis of an explosive magnetic generator (MTC EMG) is developed to simulate a lightning current pulse. The main element of this complex is a current pulse generator comprising a EMG with a pulse transformer for energy release into the load. The electric chain of the MTC EMG is theoretically analyzed taking into consideration energy losses in active resistances in the primary circuit of the transformer and the inductive-resistive nature of the load, which resulted in the minimization of energy losses in the primary circuit depending on the electric chain parameters. It was found that, if the energy losses are minimized, the efficiency of transferring the EMG energy into the load exceeds 50%. As a result of the field tests of the MTC EMG, its basic characteristics were determined and the waveforms of the current pulses and voltages in the load were obtained. It is shown that the results of the mathematical simulation of current pulses in the load are in good agreement with the experimental data.

  6. NeuroPG: open source software for optical pattern generation and data acquisition

    PubMed Central

    Avants, Benjamin W.; Murphy, Daniel B.; Dapello, Joel A.; Robinson, Jacob T.

    2015-01-01

    Patterned illumination using a digital micromirror device (DMD) is a powerful tool for optogenetics. Compared to a scanning laser, DMDs are inexpensive and can easily create complex illumination patterns. Combining these complex spatiotemporal illumination patterns with optogenetics allows DMD-equipped microscopes to probe neural circuits by selectively manipulating the activity of many individual cells or many subcellular regions at the same time. To use DMDs to study neural activity, scientists must develop specialized software to coordinate optical stimulation patterns with the acquisition of electrophysiological and fluorescence data. To meet this growing need we have developed an open source optical pattern generation software for neuroscience—NeuroPG—that combines, DMD control, sample visualization, and data acquisition in one application. Built on a MATLAB platform, NeuroPG can also process, analyze, and visualize data. The software is designed specifically for the Mightex Polygon400; however, as an open source package, NeuroPG can be modified to incorporate any data acquisition, imaging, or illumination equipment that is compatible with MATLAB’s Data Acquisition and Image Acquisition toolboxes. PMID:25784873

  7. Health Care Waste generation rates and patterns: The case of Lebanon.

    PubMed

    Maamari, Olivia; Brandam, Cedric; Lteif, Roger; Salameh, Dominique

    2015-09-01

    The objective of this study is to analyze Infectious Health Care Waste generation rates and patterns in Lebanon. Therefore, the quantities generated during five years by 57 hospitals from a total of 163 in the country have been analyzed. The seasonal evolution of Infectious Health Care Waste production and the evolution of the evaluation of the trends over years have been studied. Besides, the generation per capita have been estimated and compared to other countries. The variance between categories and the correlation between number of beds and Infectious Health Care Waste generation have been analyzed. The obtained results showed that the large private hospitals (over 200 beds) are characterized by their high generation rate: an average of 2.45kg per occupied bed(-1)day(-1), whereas the average generation rate for other categories is 0.94kg per occupied bed(-1)day(-1). The weighted mean is 1.14 per occupied kgbed(-1)day(-1). Small public hospitals (i.e. less than 100 beds) have the smallest standard deviation: 0.13, whereas large private hospitals (i.e. over than 200 beds) have the highest standard deviation: 0.40. Infectious Health Care Waste generation has been estimated to 1.42kg/capita/year. The correlation between the numbers of hospitals beds in hospitals and the generation rate per bed is weak. The correlation between Infectious Health Care Waste generation per day and beds number is stronger. The total quantity produced by hospitals has increased over the five past years. These results suggest that the quantities of medical waste are not well controlled, and that hospitals have a defective monitoring management system of their waste. Annual peaks are observed in June, July, and December. Thus, this study, for the first time in Lebanon, has provided information on the infectious waste generation, allowing benchmarking between hospitals and between countries. PMID:26049204

  8. Advanced E-O test capability for Army Next-Generation Automated Test System (NGATS)

    NASA Astrophysics Data System (ADS)

    Errea, S.; Grigor, J.; King, D. F.; Matis, G.; McHugh, S.; McKechnie, J.; Nehring, B.

    2015-05-01

    The Future E-O (FEO) program was established to develop a flexible, modular, automated test capability as part of the Next Generation Automatic Test System (NGATS) program to support the test and diagnostic needs of currently fielded U.S. Army electro-optical (E-O) devices, as well as being expandable to address the requirements of future Navy, Marine Corps and Air Force E-O systems. Santa Barbara infrared (SBIR) has designed, fabricated, and delivered three (3) prototype FEO for engineering and logistics evaluation prior to anticipated full-scale production beginning in 2016. In addition to presenting a detailed overview of the FEO system hardware design, features and testing capabilities, the integration of SBIR's EO-IR sensor and laser test software package, IRWindows 4™, into FEO to automate the test execution, data collection and analysis, archiving and reporting of results is also described.

  9. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    SciTech Connect

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  10. Generation, Language, Body Mass Index, and Activity Patterns in Hispanic Children

    PubMed Central

    Taverno, Sharon E.; Rollins, Brandi Y.; Francis, Lori A.

    2010-01-01

    Background The acculturation hypothesis proposes an overall disadvantage in health outcomes for Hispanic immigrants with more time spent living in the U.S., but little is known about how generational status and language may influence Hispanic children’s relative weight and activity patterns. Purpose The association between generation and language was investigated with relative weight (BMI z-scores), physical activity, screen time, and participation in extracurricular activities (e.g., sports, clubs) in a U.S.-based, nationally representative sample of Hispanic children. Methods Participants included 2,012 Hispanic children aged 6–11 years from the cross-sectional, 2003 National Survey of Children’s Health. Children were grouped according to generational status (1st, 2nd or 3rd), and the primary language spoken in the home (English vs non-English). Primary analyses included adjusted logistic and multinomial logistic regression to examine the relationships among variables; all analyses were conducted between 2008 and 2009. Results Compared to 3rd generation, English speakers, 1st and 2nd generation, non-English speakers were over two times more likely to be obese. Moreover, 1st generation, non-English speakers were half as likely to engage in regular physical activity and sports. Both 1st and 2nd generation, non-English speakers were less likely to participate in clubs compared to 2nd and 3rd generation, English speakers. Overall, all non–English speaking groups reported less screen time compared to 3rd generation, English speakers. Conclusions The hypothesis that Hispanics lose their health protection with more time spent in the U.S. was not supported in this sample of Hispanic children. PMID:20117570

  11. Capacitive charge generation apparatus and method for testing circuits

    DOEpatents

    Cole, Jr., Edward I.; Peterson, Kenneth A.; Barton, Daniel L.

    1998-01-01

    An electron beam apparatus and method for testing a circuit. The electron beam apparatus comprises an electron beam incident on an outer surface of an insulating layer overlying one or more electrical conductors of the circuit for generating a time varying or alternating current electrical potential on the surface; and a measurement unit connected to the circuit for measuring an electrical signal capacitively coupled to the electrical conductors to identify and map a conduction state of each of the electrical conductors, with or without an electrical bias signal being applied to the circuit. The electron beam apparatus can further include a secondary electron detector for forming a secondary electron image for registration with a map of the conduction state of the electrical conductors. The apparatus and method are useful for failure analysis or qualification testing to determine the presence of any open-circuits or short-circuits, and to verify the continuity or integrity of electrical conductors buried below an insulating layer thickness of 1-100 .mu.m or more without damaging or breaking down the insulating layer. The types of electrical circuits that can be tested include integrated circuits, multi-chip modules, printed circuit boards and flexible printed circuits.

  12. Capacitive charge generation apparatus and method for testing circuits

    DOEpatents

    Cole, E.I. Jr.; Peterson, K.A.; Barton, D.L.

    1998-07-14

    An electron beam apparatus and method for testing a circuit are disclosed. The electron beam apparatus comprises an electron beam incident on an outer surface of an insulating layer overlying one or more electrical conductors of the circuit for generating a time varying or alternating current electrical potential on the surface; and a measurement unit connected to the circuit for measuring an electrical signal capacitively coupled to the electrical conductors to identify and map a conduction state of each of the electrical conductors, with or without an electrical bias signal being applied to the circuit. The electron beam apparatus can further include a secondary electron detector for forming a secondary electron image for registration with a map of the conduction state of the electrical conductors. The apparatus and method are useful for failure analysis or qualification testing to determine the presence of any open-circuits or short-circuits, and to verify the continuity or integrity of electrical conductors buried below an insulating layer thickness of 1-100 {micro}m or more without damaging or breaking down the insulating layer. The types of electrical circuits that can be tested include integrated circuits, multi-chip modules, printed circuit boards and flexible printed circuits. 7 figs.

  13. Generation of spatially periodic patterns by a mechanical instability: a mechanical alternative to the Turing model.

    PubMed

    Harris, A K; Stopak, D; Warner, P

    1984-04-01

    We have studied the generation of spatial patterns created by mechanical (rather than chemical) instabilities. When dissociated fibroblasts are suspended in a gel of reprecipitated collagen, and the contraction of the gel as a whole is physically restrained by attachment of its margin to a glass fibre meshwork, then the effect of the fibroblasts' traction is to break up the cell-matrix mixture into a series of clumps or aggregations of cells and compressed matrix. These aggregations are interconnected by linear tracts of collagen fibres aligned under the tensile stress exerted by fibroblast traction. The patterns generated by this mechanical instability vary depending upon cell population density and other factors. Over a certain range of cell concentrations, this mechanical instability yields geometric patterns which resemble but are usually much less regular than the patterns which develop normally in the dermis of developing bird skin. We propose that an equivalent mechanical instability, occurring during the embryonic development of this skin, could be the cause not only of the clumping of dermal fibroblasts to form the feather papillae, but also of the alignment of collagen fibres into the characteristic polygonal network of fibre bundles - which interconnect these papillae and which presage the subsequent pattern of the dermal muscles serving to control feather movements. More generally, we suggest that this type of mechanical instability can serve the morphogenetic functions for which Turing's chemical instability and other reaction-diffusion systems have been proposed. Mechanical instabilities can create physical structures directly, in one step, in contrast to the two or more steps which would be required if positional information first had to be specified by chemical gradients and then only secondarily implemented in physical form. In addition, physical forces can act more quickly and at much longer range than can diffusing chemicals and can generate a

  14. Toward robust phase-locking in Melibe swim central pattern generator models

    NASA Astrophysics Data System (ADS)

    Jalil, Sajiya; Allen, Dane; Youker, Joseph; Shilnikov, Andrey

    2013-12-01

    Small groups of interneurons, abbreviated by CPG for central pattern generators, are arranged into neural networks to generate a variety of core bursting rhythms with specific phase-locked states, on distinct time scales, which govern vital motor behaviors in invertebrates such as chewing and swimming. These movements in lower level animals mimic motions of organs in higher animals due to evolutionarily conserved mechanisms. Hence, various neurological diseases can be linked to abnormal movement of body parts that are regulated by a malfunctioning CPG. In this paper, we, being inspired by recent experimental studies of neuronal activity patterns recorded from a swimming motion CPG of the sea slug Melibe leonina, examine a mathematical model of a 4-cell network that can plausibly and stably underlie the observed bursting rhythm. We develop a dynamical systems framework for explaining the existence and robustness of phase-locked states in activity patterns produced by the modeled CPGs. The proposed tools can be used for identifying core components for other CPG networks with reliable bursting outcomes and specific phase relationships between the interneurons. Our findings can be employed for identifying or implementing the conditions for normal and pathological functioning of basic CPGs of animals and artificially intelligent prosthetics that can regulate various movements.

  15. TESTING OF THE SECOND GENERATION SPINTEK ROTARY FILTER -11357

    SciTech Connect

    Herman, D.; Poirier, M.; Fowley, M.; Keefer, M.; Huff, T.

    2011-02-02

    The SpinTek rotary microfilter has been developed under the Department of Energy (DOE) Office of Environmental Management (EM) for the purpose of deployment in radioactive service in the DOE complex. The unit that was fabricated and tested is the second generation of the filter that incorporates recommended improvements from previous testing. The completion of this test satisfied a key milestone for the EM technology development program and technology readiness for deployment by Savannah River Remediation in the Small Column Ion Exchange and Sludge Washing processes at the Savannah River Site (SRS). The Savannah River National Laboratory (SRNL) contracted SpinTek Filtration to fabricate a full scale 25 disk rotary filter and perform a 1000 hour endurance test with a simulated SRS sludge. Over 1500 hours of operation have been completed with the filter. SpinTek Filtration fabricated a prototypic 25 disk rotary filter including updates to manufacturing tolerances, an updated design to the rotary joint, improved cooling to the bottom journal, decreases in disk and filter shaft hydraulic resistances. The filter disks were fabricated with 0.5 {micro} pore size, sintered-metal filter media manufactured by Pall Corporation (M050). After fabrication was complete, the filter passed acceptance tests demonstrating rejection of solids and clean water flux with a 50% improvement over the previous filters. Once the acceptance test was complete, a 1000 hour endurance test was initiated simulating a sludge washing process. The test used a simulated SRS Sludge Batch 6 recipe. The insoluble solids started at 5 wt% and were raised to 10 and 15 wt% insoluble solids to simulate the concentration of a large volume tank. The filter system was automated and set up for 24 hour unattended operation. To facilitate this, process control logic was written to operate the filter. During the development it was demonstrated that the method of starting and stopping the filter can affect the build

  16. 21 CFR 874.1120 - Electronic noise generator for audiometric testing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electronic noise generator for audiometric testing... noise generator for audiometric testing. (a) Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an...

  17. 21 CFR 874.1120 - Electronic noise generator for audiometric testing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electronic noise generator for audiometric testing... noise generator for audiometric testing. (a) Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an...

  18. 21 CFR 874.1120 - Electronic noise generator for audiometric testing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electronic noise generator for audiometric testing... noise generator for audiometric testing. (a) Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an...

  19. 21 CFR 874.1120 - Electronic noise generator for audiometric testing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electronic noise generator for audiometric testing... noise generator for audiometric testing. (a) Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an...

  20. 21 CFR 874.1120 - Electronic noise generator for audiometric testing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electronic noise generator for audiometric testing... noise generator for audiometric testing. (a) Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an...

  1. 1.5 nm fabrication of test patterns for characterization of metrological systems

    DOE PAGESBeta

    Babin, Sergey; Calafiore, Giuseppe; Peroz, Christophe; Conley, Raymond; Bouet, Nathalie; Cabrini, Stefano; Chan, Elaine; Lacey, Ian; McKinney, Wayne R.; Yashchuk, Valeriy V.; et al

    2015-11-06

    Any metrology tool is only as good as it is calibrated. The characterization of metrology systems requires test patterns at a scale about ten times smaller than the measured features. The fabrication of patterns with linewidths down to 1.5 nm is described. The test sample was designed in such a way that the distribution of linewidths appears to be random at any location. This pseudorandom test pattern is used to characterize dimensional metrology equipment over its entire dynamic range by extracting the modulation transfer function of the system. The test pattern contains alternating lines of silicon and tungsten silicide, eachmore » according to its designed width. As a result, the fabricated test samples were imaged using a transmission electron microscope, a scanning electron microscope, and an atomic force microscope. (C) 2015 American Vacuum Society.« less

  2. 1.5 nm fabrication of test patterns for characterization of metrological systems

    SciTech Connect

    Babin, Sergey; Calafiore, Giuseppe; Peroz, Christophe; Conley, Raymond; Bouet, Nathalie; Cabrini, Stefano; Chan, Elaine; Lacey, Ian; McKinney, Wayne R.; Yashchuk, Valeriy V.; Vladar, Andras E.

    2015-11-06

    Any metrology tool is only as good as it is calibrated. The characterization of metrology systems requires test patterns at a scale about ten times smaller than the measured features. The fabrication of patterns with linewidths down to 1.5 nm is described. The test sample was designed in such a way that the distribution of linewidths appears to be random at any location. This pseudorandom test pattern is used to characterize dimensional metrology equipment over its entire dynamic range by extracting the modulation transfer function of the system. The test pattern contains alternating lines of silicon and tungsten silicide, each according to its designed width. As a result, the fabricated test samples were imaged using a transmission electron microscope, a scanning electron microscope, and an atomic force microscope. (C) 2015 American Vacuum Society.

  3. Multiloop integral system test (MIST): Test Group 34, Steam generator tube rupture

    SciTech Connect

    Gloudemans, J.R. . Nuclear Power Div.)

    1989-07-01

    The multiloop integral system test (MIST) is part of a multiphase program started in 1983 to address small-break loss-of-coolant accidents (SBLOCAs) specific to Babcock and Wilcox designed plants. MIST is sponsored by the US Nuclear Regulatory Commission, the Babcock Wilcox Owners Group, the Electric Power Research Institute, and Babcock and Wilcox. The unique features of the Babcock and Wilcox design, specifically the hot leg U-bends and steam generators, prevented the use of existing integral system data or existing integral facilities to address the thermal-hydraulic SBLOCA questions. MIST and two other supporting facilities were specifically designed and constructed for this program, and an existing facility--the Once Through Integral System (OTIS)--was also used. Data from MIST and the other facilities will be used to benchmark the adequacy of system codes, such as RELAP5 and TRAC, for predicting abnormal plant transients. The MIST program is reported in 11 volumes. The program is summarized in Volume 1; Volumes 2 through 8 describes groups of tests by test type; Volume 9 presents inter-group comparisons; Volume 10 provides comparisons between the calculations of RELAP5/MOD2 and MIST observations, and Volume 11 presents the later Phase 4 tests. This Volume 6 pertains to Test Group 34, Steam Generator Tube Rupture. The specifications, conduct, observations, and results of these tests are described. 6 refs., 189 figs., 16 tabs.

  4. Coupled chaotic oscillators and their relation to a central pattern generator for artificial quadrupeds

    NASA Astrophysics Data System (ADS)

    Castellini, Horacio; Yudiarsah, Efta; Romanelli, Lilia; Cerdeira, Hilda A.

    2005-04-01

    Animal locomotion employs different periodic patterns known as animal gaits. In 1993, Collins and Stewart recognized that gaits possessed certain symmetries and characterized the gaits of quadrupeds and bipeds using permutation symmetry groups, which impose constraints on the locomotion center called the central pattern generator (CPG) in the animal brain. They modeled the CPG by coupling four nonlinear oscillators and found that it was possible to reproduce all symmetries of the gaits by changing the coupling strength. Here we propose to extend this idea using coupled chaotic oscillators synchronized using the Pyragas method in order to characterize the CPG symmetries. We also evaluate the time series behavior when the foot is in contact with the ground: this has potential robotic applications.

  5. SSME Seal Test Program: Test results for sawtooth pattern damper seal

    NASA Technical Reports Server (NTRS)

    Childs, D. W.

    1986-01-01

    Direct and transverse force coefficients for 11, sawtooth-pattern, and damper-seal configurations were examined. The designation damper seal uses a deliberately roughened stator and smooth rotor to increase the net damping force developed by a seal. The designation sawtooth-pattern refers to a stator roughness pattern. The sawtooth pattern yields axial grooves in the stator which are interrupted by spacer elements which act as flow constrictions or dams. All seals use the same smooth rotor and have the same, constant, minimum clearance. The stators examined the consequences of changes in the following design parameters: (1) axial-groove depth; (2) number of teeth: (3) number of sawtooth sections; (4) number of spacer elements; (5) dam width; (6) axially aligned sawtooth sections versus axially-staggered sawtooth sections; and (7) groove geometry. It is found that none of the sawtooth-pattern seal performs as well as the best round-hole-pattern seal. Maximum damping configurations for the sawtooth and round-hole-pattern stators have comparable stiffness performance. Several of the sawtooth pattern stators outperformed the best round-hole pattern seal.

  6. Precise colocalization of interacting structural and pigmentary elements generates extensive color pattern variation in Phelsuma lizards

    PubMed Central

    2013-01-01

    Background Color traits in animals play crucial roles in thermoregulation, photoprotection, camouflage, and visual communication, and are amenable to objective quantification and modeling. However, the extensive variation in non-melanic pigments and structural colors in squamate reptiles has been largely disregarded. Here, we used an integrated approach to investigate the morphological basis and physical mechanisms generating variation in color traits in tropical day geckos of the genus Phelsuma. Results Combining histology, optics, mass spectrometry, and UV and Raman spectroscopy, we found that the extensive variation in color patterns within and among Phelsuma species is generated by complex interactions between, on the one hand, chromatophores containing yellow/red pteridine pigments and, on the other hand, iridophores producing structural color by constructive interference of light with guanine nanocrystals. More specifically, we show that 1) the hue of the vivid dorsolateral skin is modulated both by variation in geometry of structural, highly ordered narrowband reflectors, and by the presence of yellow pigments, and 2) that the reflectivity of the white belly and of dorsolateral pigmentary red marks, is increased by underlying structural disorganized broadband reflectors. Most importantly, these interactions require precise colocalization of yellow and red chromatophores with different types of iridophores, characterized by ordered and disordered nanocrystals, respectively. We validated these results through numerical simulations combining pigmentary components with a multilayer interferential optical model. Finally, we show that melanophores form dark lateral patterns but do not significantly contribute to variation in blue/green or red coloration, and that changes in the pH or redox state of pigments provide yet another source of color variation in squamates. Conclusions Precisely colocalized interacting pigmentary and structural elements generate extensive

  7. Coherence of light and generation of speckle patterns in photobiology and photomedicine

    NASA Astrophysics Data System (ADS)

    Zalevsky, Zeev; Belkin, Michael

    2012-03-01

    The use of diodes instead of lasers was recently suggested for phototherapeutic applications. This trend is due to economical and practical reasons and is based on the argument that lasers have no preference over diodes as light sources as the former lose their coherency upon penetrating biological tissues. This module supports this claim while providing a brief explanation to non professionals on the meaning of coherence of light as well as the physics behind the generation of speckle patterns, and the relation of these physical entities to photomedicine.

  8. Multiplexed recording with uncorrelated computer-generated reference patterns in coaxial holographic data storage.

    PubMed

    Nobukawa, Teruyoshi; Wani, Yotaro; Nomura, Takanori

    2015-05-15

    A computer-generated reference pattern (CGRP) allows improvement in light efficiency and the quality of reconstructed data in coaxial holographic data storage. In this Letter, a multiplexed recording method with uncorrelated CGRPs is proposed. With this method, crosstalk from adjacent holograms is suppressed without shifting a medium. To confirm the feasibility of the proposed method experimentally, shift selectivity is investigated, and then multiplexed recording is performed. Experimental results show that the proposed method enables high-density recording compared with conventional shift multiplexing. In addition, a theoretical analysis implies that at least 100 uncorrelated CGRPs can be designed and used for multiplexed recording. PMID:26393689

  9. Importance of the inherent and the relative surface energies in generating patterned layer in a solution process

    NASA Astrophysics Data System (ADS)

    Kim, Do-Kyung; Kwon, Hyeok Bin; Park, Hongsik; Choe, Eunji; Bae, Jin-Hyuk; Park, Jaehoon; Song, Seong-Ho

    2016-03-01

    We report the importance of the inherent and the relative surface energies in generating a patterned organic semiconductor layer through a solution process. The inherent and the relative surface energies of the substrate can be effectively controlled using polydimethylsiloxane in combination with an UV/ozone treatment. The controlled inherent surface energy in each region, as well as the high-order difference of relative surface energy, plays a significant role in generating the patterned layer. In addition, the patterned metal-semiconductor-metal (MSM) structure shows a lower lateral current than the non-patterned MSM structure because the current path is limited.

  10. Analysis of Item Response Patterns: Consistency Indices and Their Application to Criterion-Referenced Tests.

    ERIC Educational Resources Information Center

    Harnisch, Delwyn L.

    The major emphasis of this paper is in the examination of test item response patterns. Tatsuoka and Tatsuoka (1980) have developed two indices of response consistency: the norm-conformity index (NCI) and the individual consistency index (ICI). The NCI provides a measure of the degree of consistency between the response pattern of an individual and…

  11. Bio-inspired Optimal Locomotion Reconfigurability of Quadruped Rovers using Central Pattern Generators

    NASA Astrophysics Data System (ADS)

    Bohra, Murtaza

    Legged rovers are often considered as viable solutions for traversing unknown terrain. This work addresses the optimal locomotion reconfigurability of quadruped rovers, which consists of obtaining optimal locomotion modes, and transitioning between them. A 2D sagittal plane rover model is considered based on a domestic cat. Using a Genetic Algorithm, the gait, pose and control variables that minimize torque or maximize speed are found separately. The optimization approach takes into account the elimination of leg impact, while considering the entire variable spectrum. The optimal solutions are consistent with other works on gait optimization, and are similar to gaits found in quadruped animals as well. An online model-free gait planning framework is also implemented, that is based on Central Pattern Generators is implemented. It is used to generate joint and control trajectories for any arbitrarily varying speed profile, and shown to regulate locomotion transition and speed modulation, both endogenously and continuously.

  12. The internal flow pattern analysis of a tidal power turbine operating on bidirectional generation-pumping

    NASA Astrophysics Data System (ADS)

    Y Luo, Y.; Xiao, Y. X.; Wang, Z. W.

    2013-12-01

    Using tidal energy can reduce environment pollution, save conventional energy and improve energy structure, hence it presents great advantage and is developing potential. Influenced by flood tide and low tide, a fully functional tidal power station needs to experience six operating modes, including bidirectional generation, pumping and sluice; the internal unsteady flow pattern and dynamic characters are very complicated. Based on a bidirectional tidal generator unit, three-dimensional unsteady flows in the flow path were calculated for four typical operating conditions with the pressure pulsation characteristics analyzed. According to the numerical results, the internal flow characteristics in the flow path were discussed. The influence of gravity to the hydraulic performance and flow characteristics were analysed. The results provide a theoretical analysis method of the hydraulic optimization design of the same type unit as well as a direction for stable operation and optimal scheduling of existing tidal power unit.

  13. A mesh generation and machine learning framework for Drosophila gene expression pattern image analysis

    PubMed Central

    2013-01-01

    Background Multicellular organisms consist of cells of many different types that are established during development. Each type of cell is characterized by the unique combination of expressed gene products as a result of spatiotemporal gene regulation. Currently, a fundamental challenge in regulatory biology is to elucidate the gene expression controls that generate the complex body plans during development. Recent advances in high-throughput biotechnologies have generated spatiotemporal expression patterns for thousands of genes in the model organism fruit fly Drosophila melanogaster. Existing qualitative methods enhanced by a quantitative analysis based on computational tools we present in this paper would provide promising ways for addressing key scientific questions. Results We develop a set of computational methods and open source tools for identifying co-expressed embryonic domains and the associated genes simultaneously. To map the expression patterns of many genes into the same coordinate space and account for the embryonic shape variations, we develop a mesh generation method to deform a meshed generic ellipse to each individual embryo. We then develop a co-clustering formulation to cluster the genes and the mesh elements, thereby identifying co-expressed embryonic domains and the associated genes simultaneously. Experimental results indicate that the gene and mesh co-clusters can be correlated to key developmental events during the stages of embryogenesis we study. The open source software tool has been made available at http://compbio.cs.odu.edu/fly/. Conclusions Our mesh generation and machine learning methods and tools improve upon the flexibility, ease-of-use and accuracy of existing methods. PMID:24373308

  14. Entropy Generation/Availability Energy Loss Analysis Inside MIT Gas Spring and "Two Space" Test Rigs

    NASA Technical Reports Server (NTRS)

    Ebiana, Asuquo B.; Savadekar, Rupesh T.; Patel, Kaushal V.

    2006-01-01

    The results of the entropy generation and availability energy loss analysis under conditions of oscillating pressure and oscillating helium gas flow in two Massachusetts Institute of Technology (MIT) test rigs piston-cylinder and piston-cylinder-heat exchanger are presented. Two solution domains, the gas spring (single-space) in the piston-cylinder test rig and the gas spring + heat exchanger (two-space) in the piston-cylinder-heat exchanger test rig are of interest. Sage and CFD-ACE+ commercial numerical codes are used to obtain 1-D and 2-D computer models, respectively, of each of the two solution domains and to simulate the oscillating gas flow and heat transfer effects in these domains. Second law analysis is used to characterize the entropy generation and availability energy losses inside the two solution domains. Internal and external entropy generation and availability energy loss results predicted by Sage and CFD-ACE+ are compared. Thermodynamic loss analysis of simple systems such as the MIT test rigs are often useful to understand some important features of complex pattern forming processes in more complex systems like the Stirling engine. This study is aimed at improving numerical codes for the prediction of thermodynamic losses via the development of a loss post-processor. The incorporation of loss post-processors in Stirling engine numerical codes will facilitate Stirling engine performance optimization. Loss analysis using entropy-generation rates due to heat and fluid flow is a relatively new technique for assessing component performance. It offers a deep insight into the flow phenomena, allows a more exact calculation of losses than is possible with traditional means involving the application of loss correlations and provides an effective tool for improving component and overall system performance.

  15. TermGenie – a web-application for pattern-based ontology class generation

    SciTech Connect

    Dietze, Heiko; Berardini, Tanya Z.; Foulger, Rebecca E.; Hill, David P.; Lomax, Jane; Osumi-Sutherland, David; Roncaglia, Paola; Mungall, Christopher J.

    2014-01-01

    Biological ontologies are continually growing and improving from requests for new classes (terms) by biocurators. These ontology requests can frequently create bottlenecks in the biocuration process, as ontology developers struggle to keep up, while manually processing these requests and create classes. TermGenie allows biocurators to generate new classes based on formally specified design patterns or templates. The system is web-based and can be accessed by any authorized curator through a web browser. Automated rules and reasoning engines are used to ensure validity, uniqueness and relationship to pre-existing classes. In the last 4 years the Gene Ontology TermGenie generated 4715 new classes, about 51.4% of all new classes created. The immediate generation of permanent identifiers proved not to be an issue with only 70 (1.4%) obsoleted classes. Lastly, TermGenie is a web-based class-generation system that complements traditional ontology development tools. All classes added through pre-defined templates are guaranteed to have OWL equivalence axioms that are used for automatic classification and in some cases inter-ontology linkage. At the same time, the system is simple and intuitive and can be used by most biocurators without extensive training.

  16. TermGenie – a web-application for pattern-based ontology class generation

    DOE PAGESBeta

    Dietze, Heiko; Berardini, Tanya Z.; Foulger, Rebecca E.; Hill, David P.; Lomax, Jane; Osumi-Sutherland, David; Roncaglia, Paola; Mungall, Christopher J.

    2014-01-01

    Biological ontologies are continually growing and improving from requests for new classes (terms) by biocurators. These ontology requests can frequently create bottlenecks in the biocuration process, as ontology developers struggle to keep up, while manually processing these requests and create classes. TermGenie allows biocurators to generate new classes based on formally specified design patterns or templates. The system is web-based and can be accessed by any authorized curator through a web browser. Automated rules and reasoning engines are used to ensure validity, uniqueness and relationship to pre-existing classes. In the last 4 years the Gene Ontology TermGenie generated 4715 newmore » classes, about 51.4% of all new classes created. The immediate generation of permanent identifiers proved not to be an issue with only 70 (1.4%) obsoleted classes. Lastly, TermGenie is a web-based class-generation system that complements traditional ontology development tools. All classes added through pre-defined templates are guaranteed to have OWL equivalence axioms that are used for automatic classification and in some cases inter-ontology linkage. At the same time, the system is simple and intuitive and can be used by most biocurators without extensive training.« less

  17. Low frequency variability of European weather patterns and its impact on power generation in northern Europe

    NASA Astrophysics Data System (ADS)

    Masato, Giacomo; Slavov, Georgi

    2016-04-01

    It is well known that Europe is becoming increasingly reliant on the power generation from the solar and wind sources. Germany is a leader in such a trend - it is then interesting to study to what extent the low-frequency variability of the European weather patterns impacts the power production in this country. Rather than identifying such patterns starting from the weather angle, four weather regimes are identified that maximize and minimize the production of solar and wind power. The analysis of their past occurrence and trends allows us to estimate the potential amount of energy produced for any given year (assuming a constant installed capacity). It is found that the sole change in such weather regimes over the recent years is able to drive up to a 20% annual difference in power generation. This also throws an interesting challenge at the scientific community, whereby the future projection of these regimes can heavily influence both the short- and long-term Eurozone plans in terms of European renewable energy targets.

  18. Scalable and enhanced triboelectric output power generation by surface functionalized nanoimprint patterns

    NASA Astrophysics Data System (ADS)

    Hyeog Kwon, Yang; Shin, Sung-Ho; Jung, Joo-Yun; Nah, Junghyo

    2016-05-01

    We report nanoimprint lithographic submicron surface patterning for scalable output power generation and performance enhancement in triboelectric nanogenerators (TENGs). Specifically, one contact surface of a TENG is nanoimprinted with polyurethane acrylate (PUA) lines in different pitches and the counter contact surface is coated with perfluoropolyether (PFPE). The results show that a TENG with 200 nm pitch PUA lines exhibits voltage and current up to ∼430 V and ∼55 μA cm‑2, generating about a sixfold higher output power than that with a flat PUA surface at an applied force of 0.3 MPa. In addition, scalable output power was obtained by adjusting line pitches. Further enhancement in output power was also demonstrated by chemically functionalizing the PUA line patterns with poly (diallyldimethylammonium chloride) (PDDA). The PDDA functionalization boosted voltage and current up to ∼500 V and ∼100 μA cm‑2, respectively, which corresponds to ∼50% power density enhancement. The approach introduced here is a simple, effective, scalable and reproducible way to fabricate TENGs.

  19. Helical Striation Pattern Generation and Axial Field Compression in Aluminum Liner Experiments at 1 MA

    NASA Astrophysics Data System (ADS)

    Atoyan, Levon; Byvank, Tom; Greenly, John; Kusse, Bruce; Pikuz, Sergei; Potter, William; Shelkovenko, Tania; Hammer, David

    2015-11-01

    Awe et al. [Phys. Plasmas 21, 235005, 2014] found on the 20 MA Z machine that applying an externally generated axial magnetic field to an imploding liner produces a helical plasma pattern near the surface of the liner. Here we show that this phenomenon is also observed using 10 mm long cylindrical metal liners having 16 mm diameter and 3 to 6 μm wall thickness on the 1 MA, 100-200 ns COBRA pulsed power generator [T. A. Shelkovenko et al., Rev. Sci. Instrum. 77, 10F521, 2006]. The magnetic field in these experiments is created using a 150 μs rise time Helmholtz coil, and the pattern is observed using extreme ultraviolet imaging. Moreover, using B-dot probes we show that there is a 4-8% axial magnetic field compression relative to the initially applied Bz. Using a visible light framing camera, we show that this compression begins before the outside surface of the liner has become a visible light emitting plasma. This research was sponsored by the NNSA SSAP under DOE Coop Agreement DE-NA0001836 and DOE grant DE-NA0001847 as well as by NSF grant PHY-1102471.

  20. Control of traveling-wave oscillations and bifurcation behavior in central pattern generators

    NASA Astrophysics Data System (ADS)

    Landsman, Alexandra S.; Slotine, Jean-Jacques

    2012-10-01

    Understanding synchronous and traveling-wave oscillations, particularly as they relate to transitions between different types of behavior, is a central problem in modeling biological systems. Here, we address this problem in the context of central pattern generators (CPGs). We use contraction theory to establish the global stability of a traveling-wave or synchronous oscillation, determined by the type of coupling. This opens the door to better design of coupling architectures to create the desired type of stable oscillations. We then use coupling that is both amplitude and phase dependent to create either globally stable synchronous or traveling-wave solutions. Using the CPG motor neuron network of a leech as an example, we show that while both traveling and synchronous oscillations can be achieved by several types of coupling, the transition between different types of behavior is dictated by a specific coupling architecture. In particular, it is only the “repulsive” but not the commonly used phase or rotational coupling that can explain the transition to high-frequency synchronous oscillations that have been observed in the heartbeat pattern generator of a leech. This shows that the overall dynamics of a CPG can be highly sensitive to the type of coupling used, even for coupling architectures that are widely believed to produce the same qualitative behavior.

  1. Control of traveling-wave oscillations and bifurcation behavior in central pattern generators.

    PubMed

    Landsman, Alexandra S; Slotine, Jean-Jacques

    2012-10-01

    Understanding synchronous and traveling-wave oscillations, particularly as they relate to transitions between different types of behavior, is a central problem in modeling biological systems. Here, we address this problem in the context of central pattern generators (CPGs). We use contraction theory to establish the global stability of a traveling-wave or synchronous oscillation, determined by the type of coupling. This opens the door to better design of coupling architectures to create the desired type of stable oscillations. We then use coupling that is both amplitude and phase dependent to create either globally stable synchronous or traveling-wave solutions. Using the CPG motor neuron network of a leech as an example, we show that while both traveling and synchronous oscillations can be achieved by several types of coupling, the transition between different types of behavior is dictated by a specific coupling architecture. In particular, it is only the "repulsive" but not the commonly used phase or rotational coupling that can explain the transition to high-frequency synchronous oscillations that have been observed in the heartbeat pattern generator of a leech. This shows that the overall dynamics of a CPG can be highly sensitive to the type of coupling used, even for coupling architectures that are widely believed to produce the same qualitative behavior. PMID:23214622

  2. Scalable and enhanced triboelectric output power generation by surface functionalized nanoimprint patterns.

    PubMed

    Kwon, Yang Hyeog; Shin, Sung-Ho; Jung, Joo-Yun; Nah, Junghyo

    2016-05-20

    We report nanoimprint lithographic submicron surface patterning for scalable output power generation and performance enhancement in triboelectric nanogenerators (TENGs). Specifically, one contact surface of a TENG is nanoimprinted with polyurethane acrylate (PUA) lines in different pitches and the counter contact surface is coated with perfluoropolyether (PFPE). The results show that a TENG with 200 nm pitch PUA lines exhibits voltage and current up to ∼430 V and ∼55 μA cm(-2), generating about a sixfold higher output power than that with a flat PUA surface at an applied force of 0.3 MPa. In addition, scalable output power was obtained by adjusting line pitches. Further enhancement in output power was also demonstrated by chemically functionalizing the PUA line patterns with poly (diallyldimethylammonium chloride) (PDDA). The PDDA functionalization boosted voltage and current up to ∼500 V and ∼100 μA cm(-2), respectively, which corresponds to ∼50% power density enhancement. The approach introduced here is a simple, effective, scalable and reproducible way to fabricate TENGs. PMID:27053597

  3. An Experimental and Theoretical Study of Fracture Patterns Generated by Underground Explosions

    NASA Astrophysics Data System (ADS)

    Bhat, H.; Mihaly, J. M.; Rosakis, A.; Sammis, C. G.

    2012-12-01

    A dynamic micro-mechanical damage mechanics model, developed by Bhat, Rosakis and Sammis, J. Appl. Mech., 2012, is used to simulate two-dimensional explosions in a brittle material. The theoretical patterns of circumferential and radial fractures are quantitatively compared with those produced by point explosions in very brittle "candy glass" plates. In these experiments the evolution of the fracture pattern is monitored using high-speed digital photography, which also images the resultant elastic waves (P and S). Theoretical estimates of the spatial extent of circumferential and radial cracking as well as the propagation speed of the comminution front and the growth-rate of individual radial cracks all compare well with the experimental observations. The wave-forms of the P and S waves, specifically the local particle velocities, are also recorded at selected points using laser vibrometers. Asymmetric fracture patterns caused by a non isotropic pre-stress, the preferred orientation of initial flaws (a rift plane), or a lithostatic gradient lead to the generation of strong S-waves from the otherwise spherically symmetric point source.

  4. Atomic layer deposition on phase-shift lithography generated photoresist patterns for 1D nanochannel fabrication.

    PubMed

    Güder, Firat; Yang, Yang; Krüger, Michael; Stevens, Gregory B; Zacharias, Margit

    2010-12-01

    A versatile, low-cost, and flexible approach is presented for the fabrication of millimeter-long, sub-100 nm wide 1D nanochannels with tunable wall properties (wall thickness and material) over wafer-scale areas on glass, alumina, and silicon surfaces. This approach includes three fabrication steps. First, sub-100 nm photoresist line patterns were generated by near-field contact phase-shift lithography (NFC-PSL) using an inexpensive homemade borosilicate mask (NFC-PSM). Second, various metal oxides were directly coated on the resist patterns with low-temperature atomic layer deposition (ALD). Finally, the remaining photoresist was removed via an acetone dip, and then planar nanochannel arrays were formed on the substrate. In contrast to all the previous fabrication routes, the sub-100 nm photoresist line patterns produced by NFC-PSL are directly employed as a sacrificial layer for the creation of nanochannels. Because both the NFC-PSL and the ALD deposition are highly reproducible processes, the strategy proposed here can be regarded as a general route for nanochannel fabrication in a simplified and reliable manner. In addition, the fabricated nanochannels were used as templates to synthesize various organic and inorganic 1D nanostructures on the substrate surface. PMID:21047101

  5. Distinct Mammalian Precursors Are Committed to Generate Neurons with Defined Dendritic Projection Patterns

    PubMed Central

    Kelsch, Wolfgang; Mosley, Colleen P; Lin, Chia-Wei; Lois, Carlos

    2007-01-01

    The mechanisms that regulate how dendrites target different neurons to establish connections with specific cell types remain largely unknown. In particular, the formation of cell-type–specific connectivity during postnatal neurogenesis could be either determined by the local environment of the mature neuronal circuit or by cell-autonomous properties of the immature neurons, already determined by their precursors. Using retroviral fate mapping, we studied the lamina-specific dendritic targeting of one neuronal type as defined by its morphology and intrinsic somatic electrical properties in neonatal and adult neurogenesis. Fate mapping revealed the existence of two separate populations of neuronal precursors that gave rise to the same neuronal type with two distinct patterns of dendritic targeting—innervating either a deep or superficial lamina, where they connect to different types of principal neurons. Furthermore, heterochronic and heterotopic transplantation demonstrated that these precursors were largely restricted to generate neurons with a predetermined pattern of dendritic targeting that was independent of the host environment. Our results demonstrate that, at least in the neonatal and adult mammalian brain, the pattern of dendritic targeting of a given neuron is a cell-autonomous property of their precursors. PMID:18001150

  6. Central pattern generators for social vocalization: Androgen-dependent neurophysiological mechanisms

    PubMed Central

    Bass, Andrew H.; Remage-Healey, Luke

    2008-01-01

    Historically, most studies of vertebrate central pattern generators (CPGs) have focused on mechanisms for locomotion and respiration. Here, we highlight new results for ectothermic vertebrates, namely teleost fish and amphibians, showing how androgenic steroids can influence the temporal patterning of CPGs for social vocalization. Investigations of vocalizing teleosts show how androgens can rapidly (within minutes) modulate the neurophysiological output of the vocal CPG (fictive vocalizations that mimic the temporal properties of natural vocalizations) inclusive of their divergent actions between species, as well as intraspecific differences between male reproductive morphs. Studies of anuran amphibians (frogs) demonstrate that long-term steroid treatments (wks) can masculinize the fictive vocalizations of females, inclusive of its sensitivity to rapid modulation by serotonin. Given the conserved organization of vocal control systems across vertebrate groups, the vocal CPGs of fish and amphibians provide tractable models for identifying androgen-dependent events that are fundamental to the mechanisms of vocal motor patterning. These basic mechanisms can also inform our understanding of the more complex CPGs for vocalization, and social behaviors in general, that have evolved among birds and mammals. PMID:18262186

  7. GENERIC VERIFICATION PROTOCOL: DISTRIBUTED GENERATION AND COMBINED HEAT AND POWER FIELD TESTING PROTOCOL

    EPA Science Inventory

    This report is a generic verification protocol by which EPA’s Environmental Technology Verification program tests newly developed equipment for distributed generation of electric power, usually micro-turbine generators and internal combustion engine generators. The protocol will ...

  8. Resolution improvement and pattern generator development for the maskless micro-ion-beam reduction lithography system

    NASA Astrophysics Data System (ADS)

    Jiang, Ximan

    have been studied. The dependence of the throughput with the exposure field size and the speed of the mechanical stage has been investigated. In order to perform maskless lithography, different micro-fabricated pattern generators have been developed for the MMRL system. Ion beamlet switching has been successfully demonstrated on the MMRL system. A positive bias voltage around 10 volts is sufficient to switch off the ion current on the micro-fabricated pattern generators. Some unexpected problems, such as the high-energy secondary electron radiations, have been discovered during the experimental investigation. Thermal and structural analysis indicates that the aperture displacement error induced by thermal expansion can satisfy the 3delta CD requirement for lithography nodes down to 25 nm. The cross-talking effect near the surface and inside the apertures of the pattern generator has been simulated in a 3-D ray-tracing code. New pattern generator design has been proposed to reduce the cross-talking effect. In order to eliminate the surface charging effect caused by the secondary electrons, a new beam-switching scheme in which the switching electrodes are immersed in the plasma has been demonstrated on a mechanically fabricated pattern generator.

  9. Pattern generation in the lobster (Panulirus) stomatogastric ganglion. II. Pyloric network simulation.

    PubMed

    Hartline, D K

    1979-08-01

    1. Results from the companion paper were incorporated into a physiologically realistic computer model of the three principal cell types (PD/AB, LP, PY) of the pyloric network in the stomatogastric ganglion. Parameters for the model were mostly calculated (sometimes estimated) from experimental data rather than fitting the model to observed output patterns. 2. The initial run was successful in predicting several features of the pyloric pattern: the observed gap between PD and LP bursts, the appropriate sequence of the activity periods (PD, LP, PY), and a substantial PY burst not properly simulated by an earlier model. 3. The major discrepancy between model and observed patterns was the too-early occurrence of the PY burst, which resulted in a much shortened LP burst. Motivated by this discrepancy, additional investigations were made of PY properties. A hyperpolarization-enabled depolarization-activated hyperpolarizing conductance change was discovered which may make an important contribution to the late phase of PY activity in the normal burst cycle. Addition of this effect to the model brought its predictions more in line with observed patterns. 4. Other discrepancies between model and observation were instructive and are discussed. The findings force a substantial revision in previously held ideas on pattern production in the pyloric system. More weight must be given to functional properties of individual neurons and less to properties arising purely from network interactions. This shift in emphasis may be necessary in more complicated systems as well. 5. An example has been provided of the value quantitative modeling can be to network physiology. Only through rigorous quantitative testing can qualitative theories of how the nervous system operates be substantiated. PMID:227480

  10. An Efficient Functional Test Generation Method For Processors Using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Hudec, Ján; Gramatová, Elena

    2015-07-01

    The paper presents a new functional test generation method for processors testing based on genetic algorithms and evolutionary strategies. The tests are generated over an instruction set architecture and a processor description. Such functional tests belong to the software-oriented testing. Quality of the tests is evaluated by code coverage of the processor description using simulation. The presented test generation method uses VHDL models of processors and the professional simulator ModelSim. The rules, parameters and fitness functions were defined for various genetic algorithms used in automatic test generation. Functionality and effectiveness were evaluated using the RISC type processor DP32.

  11. Enhancing Students' Learning Process Through Self-Generated Tests

    NASA Astrophysics Data System (ADS)

    Sanchez-Elez, Marcos; Pardines, Inmaculada; Garcia, Pablo; Miñana, Guadalupe; Roman, Sara; Sanchez, Margarita; Risco, Jose Luis

    2013-03-01

    The use of new technologies in higher education has surprisingly emphasized students' tendency to adopt a passive behavior in class. Participation and interaction of students are essential to improve academic results. This paper describes an educational experiment aimed at the promotion of students' autonomous learning by requiring them to generate test type questions related to the contents of the course. The main idea is to make the student feel part of the evaluation process by including students' questions in the evaluation exams. A set of applications running on our university online learning environment has been developed in order to provide both students and teachers with the necessary tools for a good interaction between them. Questions uploaded by students are visible to every enrolled student as well as to each involved teacher. In this way, we enhance critical analysis skills, by solving and finding possible mistakes in the questions sent by their fellows. The experiment was applied over 769 students from 12 different courses. Results show that the students who have actively participated in the experiment have obtained better academic performance.

  12. A products generator for testing the performance of disassembly procedures

    NASA Astrophysics Data System (ADS)

    Adenso-Díaz, Belarmino; González Torre, Beatriz

    2004-12-01

    In recent decades, regulations and markets have been exerting pressure on designers and manufacturers to take more responsibility for the environmental impacts of their products throughout their life cycles. The problem of finding the disassembly sequence represents one of the major challenges when attempting to close product life cycles by carrying out reuse, recycling and remanufacturing practices. Many different techniques have been used to deal with this problem, varying from exact to heuristic solutions. So far, however, not much effort has gone into measuring and comparing the efficiency of this wide set of techniques. This is partly due to the difficulties of getting a wide population of real products, belonging to different industries and with different degree of complexity that might constitute a representative population for carrying out this kind of task. In this paper, a generator of complex products is presented that is able to build up products with hundreds of components joined by different kinds of joints in such a way that a theoretical "good" disassembly sequence is always known. The efficiency of different methods for general products can thus be easily compared. The performance of a Scatter Search algorithm is tested as an example of its application in this case.

  13. A motion artifact generation and assessment system for the rapid testing of surface biopotential electrodes.

    PubMed

    Cömert, Alper; Hyttinen, Jari

    2015-01-01

    Dry electrodes can reduce cost while increasing the usability and comfort of wearable monitoring systems. They are, however, susceptible to motion artifacts. The present electrode testing methods lack reliability and do not separate the factors that affect the motion artifact. In this paper, we introduce a first generation motion artifact generation and assessment system that generates the speed, amplitude, and pattern-wise programmable movement of the electrode. The system simultaneously measures electrode-skin impedance, the motion artifact, and one channel of an electrocardiogram that contains the motion artifact and monitors the mounting force applied to the electrode. We demonstrate the system by comparing the applied movement and the measured signals for electrode movements up to 6 mm and movement frequencies from 0.4 Hz to 4 Hz. Results show that the impedance change and surface potential are visually clearly related to the applied motion, with average correlations of 0.89 and 0.64, respectively. The applied force, electrode location, and electrode structure all affect the motion artifact. The setup enables the motion of the electrode to be accurately controlled. The system can be used as a precursor to the testing of integrated systems because it enables thorough, repeatable, and robust motion artifact studies. The system allows a deeper insight into motion artifacts and the interplay of the various factors that affect them. PMID:25500614

  14. Spike timing-dependent serotonergic neuromodulation of synaptic strength intrinsic to a central pattern generator circuit.

    PubMed

    Sakurai, Akira; Katz, Paul S

    2003-11-26

    Neuromodulation is often thought to have a static, gain-setting function in neural circuits. Here we report a counter example: the neuromodulatory effect of a serotonergic neuron is dependent on the interval between its spikes and those of the neuron being modulated. The serotonergic dorsal swim interneurons (DSIs) are members of the escape swim central pattern generator (CPG) in the mollusk Tritonia diomedea. DSI spike trains heterosynaptically enhanced synaptic potentials evoked by another CPG neuron, ventral swim interneuron B (VSI-B), when VSI-B action potentials occurred within 10 sec of a DSI spike train; however, if VSI-B was stimulated 20-120 sec after DSI, then the amplitude of VSI-B synaptic potentials decreased. Consistent with this, VSI-B-evoked synaptic currents exhibited a temporally biphasic and bidirectional change in amplitude after DSI stimulation. Both the DSI-evoked enhancement and decrement were occluded by serotonin and blocked by the serotonin receptor antagonist methysergide, suggesting that both phases are mediated by serotonin. In most preparations, however, bath-applied serotonin caused only a sustained enhancement of VSI-B synaptic strength. The heterosynaptic modulation interacted with short-term homosynaptic plasticity: DSI-evoked depression was offset by VSI-B homosynaptic facilitation. This caused a complicated temporal pattern of neuromodulation when DSI and VSI-B were stimulated to fire in alternating bursts to mimic the natural motor pattern: DSI strongly enhanced summated VSI-B synaptic potentials and suppressed single synaptic potentials after the cessation of the artificial motor pattern. Thus, spike timing-dependent serotonergic neuromodulatory actions can impart temporal information that may be relevant to the operation of the CPG. PMID:14645466

  15. Flow patterns generated by oblate medusan jellyfish: field measurements and laboratory analyses.

    PubMed

    Dabiri, John O; Colin, Sean P; Costello, John H; Gharib, Morteza

    2005-04-01

    Flow patterns generated by medusan swimmers such as jellyfish are known to differ according the morphology of the various animal species. Oblate medusae have been previously observed to generate vortex ring structures during the propulsive cycle. Owing to the inherent physical coupling between locomotor and feeding structures in these animals, the dynamics of vortex ring formation must be robustly tuned to facilitate effective functioning of both systems. To understand how this is achieved, we employed dye visualization techniques on scyphomedusae (Aurelia aurita) observed swimming in their natural marine habitat. The flow created during each propulsive cycle consists of a toroidal starting vortex formed during the power swimming stroke, followed by a stopping vortex of opposite rotational sense generated during the recovery stroke. These two vortices merge in a laterally oriented vortex superstructure that induces flow both toward the subumbrellar feeding surfaces and downstream. The lateral vortex motif discovered here appears to be critical to the dual function of the medusa bell as a flow source for feeding and propulsion. Furthermore, vortices in the animal wake have a greater volume and closer spacing than predicted by prevailing models of medusan swimming. These effects are shown to be advantageous for feeding and swimming performance, and are an important consequence of vortex interactions that have been previously neglected. PMID:15781886

  16. Next-generation Lunar Laser Retroreflectors for Precision Tests of General Relativity

    NASA Astrophysics Data System (ADS)

    Ciocci, Emanuele; dell'Agnello, Simone; Delle Monache, Giovanni; Martini, Manuele; Contessa, Stefania; Porcelli, Luca; Tibuzzi, Mattia; Salvatori, Lorenzo; Patrizi, Giordano; Maiello, Mauro; Intaglietta, Nicola; Mondaini, Chiara; Currie, Douglas; Chandler, John; Bianco, Giuseppe; Murphy, Tom

    2016-04-01

    Since 1969, Lunar Laser Ranging (LLR) to the Apollo Cube Corner Retroreflectors (CCRs) has supplied almost all significant tests of General Relativity (GR). When first installed in the 1970s, the Apollo CCRs geometry contributed only a negligible fraction of the ranging error budget. Today, because of lunar librations, this contribution dominates the error budget, limiting the precision of the experimental tests of gravitational theories. The new MoonLIGHT-2 (Moon Laser Instrumentation for General relativity High-accuracy Tests) apparatus is a new-generation LLR payload developed by the SCF_Lab (http://www.lnf.infn.it/esperimenti/etrusco/) at INFN-LNF in collaboration with the Maryland University. With the unique design of a single large CCR unaffected by librations, MoonLIGHT-2 can increase up to a factor 100 the precision of the measurement of the lunar geodetic precession and other General Relativity (GR) tests respect to Apollo CCRs. MoonLIGHT-2 is approved to be launched with the Moon Express mission MEX-1 and will be deployed on the Moon surface in 2018. MoonLIGHT-2 is also proposed for the Roscosmos mission Luna-27. To validate/optimize MoonLIGHT-2 for MEX-1, the SCF_Lab is carrying out a unique experimental test called SCF-Test: the concurrent measurement of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of the CCR under thermal conditions produced with a close-match solar simulator and simulated space environment. We perform test of GR with current LLR data and also different GR simulation of the expected improvement in GR test provided by MoonLIGHT-2, using the Planetary Ephemeris Program in collaboration with CfA. Our ultimate goal is to improve GR tests by a factor up to 100, and provide constraints on the new gravitational theories like non-miminally coupled gravity and spacetime torision.

  17. Field Testing GEOICE: A Next-Generation Polar Seismometer

    NASA Astrophysics Data System (ADS)

    Beaudoin, B. C.; Winberry, J. P.; Huerta, A. D.; Chung, P.; Parker, T.; Anderson, K. R.; Bilek, S. L.; Carpenter, P.

    2015-12-01

    We report on the development of a new NSF MRI-community supported seismic observatory designed for studies in ice-covered regions - the Geophysical Earth Observatory for Ice Covered Environs (GEOICE). This project is motivated by the need to densify and optimize the collection of high-quality seismic data relevant to key solid Earth and cryosphere science questions. The GEOICE instruments and their power and other ancillary systems are being designed to require minimal installation time and logistical load (i.e., size and weight), while maximizing ease-of-use in the field. The system is capable of advanced data handling and telemetry while being able to withstand conditions associated with icy environments, including cold/wet conditions and high-latitude solar limitations. The instrument capability will include a hybrid seismograph pool of broadband and intermediate elements for observation of both long-period signals (e.g, long-period surface waves and slow sources) and intermediate-to-short-period signals (e.g., teleseismic body waves, local seismicity, and impulsive or extended glaciogenic signals).Key features will include a design that integrates the seismometer and digitizer into a single, environmentally and mechanically robust housing; very low power requirements (~1 watt) for the intermediate-band systems; and advanced power systems that optimize battery capacity and operational limits. The envisioned ~100 element GEOICE instruments will nearly double the current polar inventory of stations and will be maintained and supported at the IRIS PASSCAL Instrument Center to ensure full and flexible peer-reviewed community use. Prototype instruments are currently deployed in Antarctica and Alaska, with a larger Antarctic deployment planned for the 2015-2016 season. The results of these field tests will help to refine instrumentation design and lead to the production of robust and capable next-generation seismic sensors.

  18. Bayesian Procedures for Identifying Aberrant Response-Time Patterns in Adaptive Testing

    ERIC Educational Resources Information Center

    van der Linden, Wim J.; Guo, Fanmin

    2008-01-01

    In order to identify aberrant response-time patterns on educational and psychological tests, it is important to be able to separate the speed at which the test taker operates from the time the items require. A lognormal model for response times with this feature was used to derive a Bayesian procedure for detecting aberrant response times.…

  19. A Psychometric Review of Norm-Referenced Tests Used to Assess Phonological Error Patterns

    ERIC Educational Resources Information Center

    Kirk, Celia; Vigeland, Laura

    2014-01-01

    Purpose: The authors provide a review of the psychometric properties of 6 norm-referenced tests designed to measure children's phonological error patterns. Three aspects of the tests' psychometric adequacy were evaluated: the normative sample, reliability, and validity. Method: The specific criteria used for determining the psychometric…

  20. A model of a flexible anguilliform swimmer driven by a central pattern generator with proprioceptive feedback

    NASA Astrophysics Data System (ADS)

    Hamlet, Christina; Tytell, Eric; Hoffman, Kathleen; Fauci, Lisa

    2015-11-01

    The swimming of a simple vertebrate, the lamprey, can shed light on how a flexible body can couple with a fluid environment to swim rapidly and efficiently. Animals use proprioceptive sensory information to sense how their bodies are bending, and then adjust the neural signals to their muscles to improve performance. We will present recent progress in the development of a computational model of a lamprey swimming in a Navier-Stokes fluid where a simple central pattern generator model, based on phase oscillators, is coupled to the evolving body dynamics of the swimmer through curvature and curvature derivative feedback. Such feedback can be positive (frequency decreasing), negative (frequency increasing), or mixed (positive to one side of the body and negative to the other, or vice versa). We will examine how the emergent swimming behavior and cost of transport depends upon these functional forms of proprioceptive feedback chosen in the model.

  1. Pattern Formation and Force Generation by Cell Ensembles in a Filamentous Matrix

    NASA Astrophysics Data System (ADS)

    Paul, R.; Schwarz, U. S.

    Adhesion-dependent soft tissue cells both create and sense tension in the extracellular matrix. Therefore cells can actively interact through the mechanics of the surrounding matrix. An intracellular positive feedback loop upregulates cellular contractility in stiff or tensed environments. Here we theoretically address the resulting pattern formation and force generation for the case of a filamentous matrix, which we model as a two-dimensional cable network. Cells are modeled as anisotropic contraction dipoles which move in favor of tensed directions in the matrix. Our Monte Carlo simulations suggest that at small densities, cells align in strings, while at high densities, they form interconnected meshworks. Cellular activation both by biochemical factors and by tension leads to a hyperbolic increase in tissue tension. We also discuss the effect of cell density on tissue tension and shape.

  2. A new Pulse-Pattern Generator based on LabVIEW FPGA

    NASA Astrophysics Data System (ADS)

    Ziegler, F.; Beck, D.; Brand, H.; Hahn, H.; Marx, G.; Schweikhard, L.

    2012-07-01

    For the control of experimental sequences composed of triggers, gates and delays a Pulse-Pattern Generator (PPG) has been developed based on a Field Programmable Gate Array (FPGA) addressed in a LabVIEW environment. It allows a highly reproducible timing of measurement procedures by up to 64 individual channels with pulse and delay periods from the nanoseconds to the minutes range. The PPG has been implemented in the context of the development of a new control system for the ClusterTrap setup, an ion storage device for atomic-cluster research, in close contact with the SHIPTRAP and ISOLTRAP collaborations at GSI and CERN, respectively. As the new PPG is not ion-trap specific it can be employed in any experiment based on sequences of triggers, pulses and delays.

  3. Development of a morphing structure with the incorporation of central pattern generators

    NASA Astrophysics Data System (ADS)

    Bliss, Thomas K.; Bart-Smith, Hilary; Iwasaki, Tetsuya

    2006-03-01

    The Manta Ray, Manta birostris, is an amazing creature, propelling itself through the water with the elegant and complex flapping of its wings. Achieving outstanding efficiencies, engineers are looking for ways to mimic its flight through the water and harness its propulsive techniques. This study combines two biologically inspired aspects to achieve this goal: morphing structures actuated with a biomimetic neural network control system. It is believed that this combination will prove capable of producing the oscillatory motions necessary for locomotion. In this paper, a four-truss structure with three actuators is chosen and its performance capabilities are analyzed. A synthetic central pattern generator, which provides the fundamental control mechanisms for rhythmic motion in animals, is designed to realize an oscillatory control of the three actuators. The control system is simulated using Matlab, then combined with LabVIEW to control the four-truss structure. The system's performance is analyzed, with specific attention to both transient and steady-state behavior.

  4. Emergent Central Pattern Generator Behavior in Gap-Junction-Coupled Hodgkin-Huxley Style Neuron Model

    PubMed Central

    Memelli, Heraldo; Solomon, Irene C.

    2012-01-01

    Most models of central pattern generators (CPGs) involve two distinct nuclei mutually inhibiting one another via synapses. Here, we present a single-nucleus model of biologically realistic Hodgkin-Huxley neurons with random gap junction coupling. Despite no explicit division of neurons into two groups, we observe a spontaneous division of neurons into two distinct firing groups. In addition, we also demonstrate this phenomenon in a simplified version of the model, highlighting the importance of afterhyperpolarization currents (IAHP) to CPGs utilizing gap junction coupling. The properties of these CPGs also appear sensitive to gap junction conductance, probability of gap junction coupling between cells, topology of gap junction coupling, and, to a lesser extent, input current into our simulated nucleus. PMID:23365558

  5. Retrieval Mode Distinguishes the Testing Effect from the Generation Effect

    ERIC Educational Resources Information Center

    Karpicke, Jeffrey D.; Zaromb, Franklin M.

    2010-01-01

    A series of four experiments examined the effects of generation vs. retrieval practice on subsequent retention. Subjects were first exposed to a list of target words. Then the subjects were shown the targets again intact for Read trials or they were shown fragments of the targets. Subjects in Generate conditions were told to complete the fragments…

  6. A muscarinic cholinergic mechanism underlies activation of the central pattern generator for locust flight.

    PubMed

    Buhl, Edgar; Schildberger, Klaus; Stevenson, Paul A

    2008-07-01

    A central question in behavioural control is how central pattern generators (CPGs) for locomotion are activated. This paper disputes the key role generally accredited to octopamine in activating the CPG for insect flight. In deafferented locusts, fictive flight was initiated by bath application of the muscarinic agonist pilocarpine, the acetylcholine analogue carbachol, and the acetylcholinesterase blocker eserine, but not by nicotine. Furthermore, in addition to octopamine, various other amines including dopamine, tyramine and histamine all induced fictive flight, but not serotonin or the amine-precursor amino acid tyrosine. However, flight initiation was not reversibly blocked by aminergic antagonists, and was still readily elicited by both natural stimulation (wind) and pilocarpine in reserpinized, amine-depleted locusts. By contrast, the muscarinic antagonists atropine and scopolamine reversibly blocked flight initiated by wind, cholinergic agonists, octopamine, and by selective stimulation of a flight-initiating interneurone (TCG). The short delay from TCG stimulation to flight onset suggests that TCG acts directly on the flight CPG, and accordingly that TCG, or its follower cell within the flight generating circuit, is cholinergic. We conclude that acetylcholine acting via muscarinic receptors is the key neurotransmitter in the mechanism underlying the natural activation of the locust flight CPG. Amines are not essential for this, but must be considered as potential neuromodulators for facilitating flight release and tuning the motor pattern. We speculate that muscarinic activation coupled to aminergic facilitation may be a general feature of behavioural control in insects for ensuring conditional recruitment of individual motor programs in accordance with momentary adaptive requirements. PMID:18587129

  7. Generation of rhythmic patterns of activity by ventral interneurones in rat organotypic spinal slice culture

    PubMed Central

    Ballerini, Laura; Galante, Micaela; Grandolfo, Micaela; Nistri, Andrea

    1999-01-01

    In the presence of certain excitatory substances the rat isolated spinal cord generates rhythmic oscillations believed to be an in-built locomotor programme (fictive locomotion). However, it is unknown whether a long-term culture of the same tissue can express rhythmic activity. Such a simplified model system would provide useful data on the minimal circuitry involved and the cellular mechanisms mediating this phenomenon. For this purpose we performed patch clamp recording (under whole-cell voltage or current clamp conditions) from visually identified ventral horn interneurones of an organotypic slice culture of the rat spinal cord. Ventral horn interneurones expressed rhythmic bursting when the extracellular [K+] was raised from 4 to 6-7 mM. Under voltage clamp this activity consisted of composite synaptic currents grouped into bursts lasting 0.9 ± 0.5 s (2.8 ± 1.5 s period) and was generated at network level as it was blocked by tetrodotoxin or low-Ca2+-high-Mg2+ solution and its periodicity was unchanged at different potential levels. In current clamp mode bursting was usually observed as episodes comprising early depolarizing potentials followed by hyperpolarizing events with tight temporal patterning. Bursting was fully suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and reduced in amplitude and duration by N-methyl-D-aspartate (NMDA) receptor antagonism without change in periodicity. Extracellular field recording showed bursting activity over a wide area of the ventral horn. Regular, rhythmic activity similar to that induced by K+ also appeared spontaneously in Mg2+-free solution. The much slower rhythmic pattern induced by strychnine and bicuculline was also accelerated by high-K+ solution. The fast and regular rhythmic activity of interneurones in the spinal organotypic culture is a novel observation which suggests that the oversimplified circuit present in this culture is a useful model for investigating spinal rhythmic activity. PMID:10332095

  8. A Modeling Approach on Why Simple Central Pattern Generators Are Built of Irregular Neurons

    PubMed Central

    Reyes, Marcelo Bussotti; Carelli, Pedro Valadão; Sartorelli, José Carlos; Pinto, Reynaldo Daniel

    2015-01-01

    The crustacean pyloric Central Pattern Generator (CPG) is a nervous circuit that endogenously provides periodic motor patterns. Even after about 40 years of intensive studies, the rhythm genesis is still not rigorously understood in this CPG, mainly because it is made of neurons with irregular intrinsic activity. Using mathematical models we addressed the question of using a network of irregularly behaving elements to generate periodic oscillations, and we show some advantages of using non-periodic neurons with intrinsic behavior in the transition from bursting to tonic spiking (as found in biological pyloric CPGs) as building components. We studied two- and three-neuron model CPGs built either with Hindmarsh-Rose or with conductance-based Hodgkin-Huxley-like model neurons. By changing a model’s parameter we could span the neuron’s intrinsic dynamical behavior from slow periodic bursting to fast tonic spiking, passing through a transition where irregular bursting was observed. Two-neuron CPG, half center oscillator (HCO), was obtained for each intrinsic behavior of the neurons by coupling them with mutual symmetric synaptic inhibition. Most of these HCOs presented regular antiphasic bursting activity and the changes of the bursting frequencies was studied as a function of the inhibitory synaptic strength. Among all HCOs, those made of intrinsic irregular neurons presented a wider burst frequency range while keeping a reliable regular oscillatory (bursting) behavior. HCOs of periodic neurons tended to be either hard to change their behavior with synaptic strength variations (slow periodic burster neurons) or unable to perform a physiologically meaningful rhythm (fast tonic spiking neurons). Moreover, 3-neuron CPGs with connectivity and output similar to those of the pyloric CPG presented the same results. PMID:25799556

  9. Correlation of hierarchal Upper Silurian stacking patterns generated by Milankovitch orbital forcing

    SciTech Connect

    Mauriello, D.J.; Ketterer, M.W. . Dept. of Geology)

    1993-03-01

    The Upper Silurian Wills Creek Formation in Pennsylvania and Maryland is entirely divisible into meter-scale allocycles. Stacking patterns of these allocycles reveal a hierarchy consistent with predictions based on the Milankovitch model of orbital forcing. Asymmetrical Sixth-Order cycles (PACs), bounded by surfaces produced by precessional sea-level rises, are divisible into a lower highstand portion and an upper lowstand portion separated by a sharp sea-level fall surface produced by a rapid sea-level drop within the precessional cycle. Sixth-Order cycles may be genetically grouped into Fifth-Order (100 ky.) and subsequently, Fourth-Order (400 ky.) cycles, each of which exhibits a distinct internal symmetry. Fifth-Order cycles, on average three to four meters in thickness, are composed of a basal transgressive portion consisting of two PACs followed by two or three successively regressive PACs. Four Fifth-Order cycles constitute a complete Fourth-Order cycle, in which the second Fifth-Order cycle contains facies representing the deepest or least restricted paleoenvironments. In each case, the fundamental Sixth-Order cycles were generated by the precessional signal modulated by orbital eccentricity variations. Over distances in excess of 100 km, Wills Creek facies change laterally from nearshore marine to fluvial coastal plain. Stacking patterns in these distinct facies are identical, and thus correlative, indicating the basin-wide extent of the stratigraphic events which produced these patterns. These correlations demonstrate that Milankovitch-driven eustatic sea-level fluctuations were occurring during the Late Silurian.

  10. Diversity of wing patterns and abdomen-generated substrate sounds in 3 European scorpionfly species

    PubMed Central

    Hartbauer, Manfred; Gepp, Johannes; Hinteregger, Karin; Koblmüller, Stephan

    2016-01-01

    In the genus Panorpa (Insecta: Mecoptera), also known as scorpionflies, premating behavior includes repeated sequences of slow wing movements (waving, fanning, flagging) which are accompanied by rapid abdomen vibrations that generate substantial substrate-borne sound. It is still unknown whether wing patterns or vibratory signals contain information about species identity, sex and/or the quality of potential mating partners. Besides species-specific pheromones, these multimodal signals may be of particular importance for the maintenance of reproductive isolation in sympatrically occurring scorpionfly species. Here, we analyzed phyologenetic relationships among, and the pattern of forewings as well as substrate-borne sound in 3 different sympatric Central-European scorpionfly species (P. communis, P. germanica, and P. alpina). Divergence time estimates, based on 879 bp of the mitochondrial COI gene, indicate longstanding separate evolutionary histories for the studied Panorpa species. Morphological analysis revealed that wing length as an indicator of body size increased in the following order: P. alpina < P. germanica < P. communis. Individuals can be assigned to the correct species and sex with high accuracy just by evaluation of the number of dark spots and the proportion of wing pigmentation. Despite high variability of interpulse period at an individual level, across species analysis revealed a positive correlation of average interpulse period as well as mean signal amplitude with forewing length. These results suggest wing patterns, but less likely vibratory signals, to contain information about species identity. Furthermore, receivers may be able to estimate the body size of a signaler solely on the basis of substrate-borne sound. PMID:24818592

  11. Diversity of wing patterns and abdomen-generated substrate sounds in 3 European scorpionfly species.

    PubMed

    Hartbauer, Manfred; Gepp, Johannes; Hinteregger, Karin; Koblmüller, Stephan

    2015-08-01

    In the genus Panorpa (Insecta: Mecoptera), also known as scorpionflies, premating behavior includes repeated sequences of slow wing movements (waving, fanning, flagging) which are accompanied by rapid abdomen vibrations that generate substantial substrate-borne sound. It is still unknown whether wing patterns or vibratory signals contain information about species identity, sex and/or the quality of potential mating partners. Besides species-specific pheromones, these multimodal signals may be of particular importance for the maintenance of reproductive isolation in sympatrically occurring scorpionfly species. Here, we analyzed phyologenetic relationships among, and the pattern of forewings as well as substrate-borne sound in 3 different sympatric Central-European scorpionfly species (P. communis, P. germanica, and P. alpina). Divergence time estimates, based on 879 bp of the mitochondrial COI gene, indicate longstanding separate evolutionary histories for the studied Panorpa species. Morphological analysis revealed that wing length as an indicator of body size increased in the following order: P. alpina < P. germanica < P. communis. Individuals can be assigned to the correct species and sex with high accuracy just by evaluation of the number of dark spots and the proportion of wing pigmentation. Despite high variability of interpulse period at an individual level, across species analysis revealed a positive correlation of average interpulse period as well as mean signal amplitude with forewing length. These results suggest wing patterns, but less likely vibratory signals, to contain information about species identity. Furthermore, receivers may be able to estimate the body size of a signaler solely on the basis of substrate-borne sound. PMID:24818592

  12. Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy.

    PubMed

    Eldridge, Tilly; Łangowski, Łukasz; Stacey, Nicola; Jantzen, Friederike; Moubayidin, Laila; Sicard, Adrien; Southam, Paul; Kennaway, Richard; Lenhard, Michael; Coen, Enrico S; Østergaard, Lars

    2016-09-15

    Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue-level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity. PMID:27624834

  13. Wave patterns generated by an axisymmetric obstacle in a two-layer flow

    NASA Astrophysics Data System (ADS)

    Lacaze, L.; Paci, A.; Cid, E.; Cazin, S.; Eiff, O.; Esler, J. G.; Johnson, E. R.

    2013-12-01

    Gravity waves generated by a moving obstacle in a two-layer stratified fluid are investigated. The experimental configuration is three-dimensional with an axisymmetric obstacle which is towed in one of the two layers. The experimental method used in the present study is based on a stereoscopic technique allowing the 3D reconstruction of the interface between the two layers. Investigation into the wave pattern as a function of the Froude number, Fr, based on the relative density of the fluid layers and the velocity of the towed obstacle is presented. Specific attention is paid to the transcritical regime for which Fr is close to one. Potential energy trapped in the wave field patterns is also extracted from the experimental results and is analyzed as a function of both the Froude number, Fr, and the transcritical similarity parameter . In particular, a remarkable increase in the potential energy around Fr = 1 is observed and a scaling allowing to assemble data resulting from different experimental parameters is proposed.

  14. Homologues of serotonergic central pattern generator neurons in related nudibranch molluscs with divergent behaviors.

    PubMed

    Newcomb, James M; Katz, Paul S

    2007-04-01

    Homologues of a neuron that contributes to a species-specific behavior were identified and characterized in species lacking that behavior. The nudibranch Tritonia diomedea swims by flexing its body dorsally and ventrally. The dorsal swim interneurons (DSIs) are components of the central pattern generator (CPG) underlying this rhythmic motor pattern and also activate crawling. Homologues of the DSIs were identified in six nudibranchs that do not exhibit dorsal-ventral swimming: Tochuina tetraquetra, Melibe leonina, Dendronotus iris, D. frondosus, Armina californica, and Triopha catalinae. Homology was based upon shared features that distinguish the DSIs from all other neurons: (1) serotonin immunoreactivity, (2) location in the Cerebral serotonergic posterior (CeSP) cluster, and (3) axon projection to the contralateral pedal ganglion. The DSI homologues, named CeSP-A neurons, share additional features with the DSIs: irregular basal firing, synchronous inputs, electrical coupling, and reciprocal inhibition. Unlike the DSIs, the CeSP-A neurons were not rhythmically active in response to nerve stimulation. The CeSP-A neurons in Tochuina and Triopha also excited homologues of the Tritonia Pd5 neuron, a crawling efferent. Thus, the CeSP-A neurons and the DSIs may be part of a conserved network related to crawling that may have been co-opted into a rhythmic swim CPG in Tritonia. PMID:17180703

  15. Successive Pattern Learning based on Test Feature Classifier and its application to Defect Image Classification

    NASA Astrophysics Data System (ADS)

    Sakata, Yukinobu; Kaneko, Shun'Ichi; Takagi, Yuji; Okuda, Hirohito

    A novel sequential learning algorithm of Test Feature Classifier (TFC) which is non-parametric and effective even for small data is proposed for efficiently handling consecutively provided training data. Fundamental characteristics of the sequential learning are examined. In the learning, after recognition of a set of unknown objects, they are fed into the classifier in order to obtain a modified classifier. We propose an efficient algorithm for reconstruction of prime tests, which are irreducible combinations of features which are capable to discriminate training patterns into correct classes, is formalized in cases of addition and removal of training patterns. Some strategies for the modification of training patterns are investigated with respect to their precision and performance by use of real pattern data. A real world problem of classification of defects on wafer images has been tackled by the proposed classifier, obtaining excellent performance even through efficient modification strategies.

  16. Comparision of Limit Load Solutions with Results of a Collapse Tests of Perforated Plates with a Triangular Penetration Pattern

    SciTech Connect

    D.P. Jones; J.L. Gordon

    2001-12-13

    Limit load solutions obtained by elastic-perfectly plastic finite element analysis (EPP-FEA) are compared to results of tests of low-alloy steel perforated plate geometries loaded to full plastic collapse. Results are given for two plastic-collapse tests of flat circular disks with circular penetrations arranged in a triangular pattern and drilled normal to the surface of the plate. The ligament efficiency (minimum distance between holes divided by the distance between the centers of the holes) of the pattern is 0.32 and the plate thickness is 2.39 inches (60.7 mm). The tests were designed so that a transverse load generated plastic collapse in the outer row of penetrations due to a combination of transverse shear and in-plane bending. Limit-load solutions were obtained using EPP-FEA with small-strain, small-defection linear geometry assumptions. Two FEA models are used: one where the perforated region is modeled using an equivent solid plate (EQS) representation and another where each hole is explicitly modeled by FEA. The results presented in this paper demonstrate that the deformation patterns produced by the EPP-FEA solutions match exactly with the deformation patterns produced by the test. The EQS-EPP FEA solution is about 15% lower than the explicit-hole EPP-FEA solution. Using one-third the actual ultimate strength of the material as the strength parameter in the limit load calculation produces a calculated limit load that is greater than a factor of three less than the mean measured plastic-collapse load obtained in the tests. This paper adds to the qualification of the use of limit-load solutions obtained using small-strain, small deflection EPP-FEA programs for the calculation of the limit load for perforated plates.

  17. Field test of two high-pressure direct-contact downhole steam generators. Volume II. Oxygen/diesel system

    SciTech Connect

    Moreno, J.B.

    1983-07-01

    A field test of an oxygen/diesel fuel, direct contact steam generator has been completed. The field test, which was a part of Project DEEP STEAM and was sponsored by the US Department of Energy, involved the thermal stimulation of a well pattern in the Tar Zone of the Wilmington Oil Field. The activity was carried out in cooperation with the City of Long Beach and the Long Beach Oil Development Company. The steam generator was operated at ground level, with the steam and combustion products delivered to the reservoir through 2022 feet of calcium-silicate insulated tubing. The objectives of the test included demonstrations of safety, operational ease, reliability and lifetime; investigations of reservoir response, environmental impact, and economics; and comparison of those points with a second generator that used air rather than oxygen. The test was extensively instrumented to provide the required data. Excluding interruptions not attributable to the oxygen/diesel system, steam was injected 78% of the time. System lifetime was limited by the combustor, which required some parts replacement every 2 to 3 weeks. For the conditions of this particular test, the use of trucked-in LOX resulted in liess expense than did the production of the equivalent amount of high pressure air using on site compressors. No statistically significant production change in the eight-acre oxygen system well pattern occurred during the test, nor were any adverse effects on the reservoir character detected. Gas analyses during the field test showed very low levels of SOX (less than or equal to 1 ppM) in the generator gaseous effluent. The SOX and NOX data did not permit any conclusion to be drawn regarding reservoir scrubbing. Appreciable levels of CO (less than or equal to 5%) were measured at the generator, and in this case produced-gas analyses showed evidence of significant gas scrubbing. 64 figures, 10 tables.

  18. A Method for Generating Natural and User-Defined Sniffing Patterns in Anesthetized or Reduced Preparations

    PubMed Central

    Carey, Ryan M.; Wachowiak, Matt

    2009-01-01

    Sniffing has long been thought to play a critical role in shaping neural responses to odorants at multiple levels of the nervous system. However, it has been difficult to systematically examine how particular parameters of sniffing behavior shape odorant-evoked activity, in large part because of the complexity of sniffing behavior and the difficulty in reproducing this behavior in an anesthetized or reduced preparation. Here we present a method for generating naturalistic sniffing patterns in such preparations. The method involves a nasal ventilator whose movement is controlled by an analog command voltage. The command signal may consist of intranasal pressure transients recorded from awake rats and mice or user-defined waveforms. This “sniff playback” device generates intranasal pressure and airflow transients in anesthetized animals that approximate those recorded from the awake animal and are reproducible across trials and across preparations. The device accurately reproduces command waveforms over an amplitude range of approximately 1 log unit and up to frequencies of approximately 12 Hz. Further, odorant-evoked neural activity imaged during sniff playback appears similar to that seen in awake animals. This method should prove useful in investigating how the parameters of odorant sampling shape neural responses in a variety of experimental settings. PMID:18791186

  19. HIV Testing Patterns among Black Men Who Have Sex with Men: A Qualitative Typology

    PubMed Central

    Hussen, Sophia A.; Stephenson, Robert; del Rio, Carlos; Wilton, Leo; Wallace, Jermel; Wheeler, Darrell

    2013-01-01

    Background Black men who have sex with men (MSM) in the Southeastern United States are disproportionately affected by HIV. Black MSM are more likely to have unrecognized HIV infection, suggesting that testing may occur later and/or infrequently relative to current recommendations. The objective of this qualitative study was to explore the HIV testing behaviors of Black MSM in Atlanta, Georgia, who were participants in the HIV Prevention Trials Network Brothers Study (HPTN 061). Methods and Findings We conducted 29 in-depth interviews and four focus groups with a community-recruited sample. Modified grounded theory methodologies were used to guide our inductive analysis, which yielded a typology comprised of four distinct HIV testing patterns. Participants could be categorized as: (1) Maintenance Testers, who tested regularly as part of routine self-care; (2) Risk-Based Testers, whose testing depended on relationship status or sexual behavior; (3) Convenience Testers, who tested irregularly depending on what testing opportunities arose; or (4) Test Avoiders, who tested infrequently and/or failed to follow up on results. We further characterized these groups with respect to age, socioeconomic factors, identity, stigma and healthcare access. Conclusions Our findings highlight the heterogeneity of HIV testing patterns among Black MSM, and offer a framework for conceptualizing HIV testing in this group. Public health messaging must account for the diversity of Black MSM's experiences, and multiple testing approaches should be developed and utilized to maximize outreach to different types of testers. PMID:24069408

  20. Different patterns of language activation in post-stroke aphasia are detected by overt and covert versions of the verb generation fMRI task

    PubMed Central

    Allendorfer, Jane B.; Kissela, Brett M.; Holland, Scott K.; Szaflarski, Jerzy P.

    2012-01-01

    Summary Background Post-stroke language functions depend on the relative contributions of the dominant and non-dominant hemispheres. Thus, we aimed to identify the neural correlates of overt and covert verb generation in adult post-stroke aphasia. Material/Methods Sixteen aphasic LMCA stroke patients (SPs) and 32 healthy controls (HCs) underwent language testing followed by fMRI while performing an overt event-related verb generation task (ER-VGT) isolating activations related to noun-verb semantic processing or to articulation and auditory processing, and a covert block design verb generation task (BD-VGT). Results BD-VGT activation patterns were consistent with previous studies, while ER-VGT showed different patterns in SPs relative to HCs including less left-hemispheric involvement during semantic processing and predominantly right-sided activation related to articulation and auditory processing. ER-VGT intra-scanner performance was positively associated with activation during semantic associations in the left middle temporal gyrus for HCs (p=0.031) and left middle frontal gyrus for SPs (p=0.042). Increased activation in superior frontal/cingulate gyri was associated with better intra-scanner performance (p=0.020). Lesion size negatively impacted verbal fluency tested with Controlled Oral Word Association Test (p=0.0092) and the Semantic Fluency Test (p=0.033) and trended towards a negative association with verb generation performance on the event-related verb generation task (p=0.081). Conclusions Greater retention of pre-stroke language skills is associated with greater involvement of the left hemisphere with different cortical recruitment patterns observed in SPs versus HCs. Post-stroke verbal fluency may depend more upon the structural and functional integrity of the dominant left hemisphere language network rather than the shift to contralateral homologues. PMID:22367124

  1. The Hyper-X Antenna Radiation Pattern Tests and Radio Frequency System Redesign

    NASA Technical Reports Server (NTRS)

    Hodge, Mark W.; Kelley, John W.

    2006-01-01

    Testing was performed to determine the antenna radiation pattern measurements of the Hyper-X, X-43 ship 2 aircraft. One test was conducted at the Air Force Flight Test Center (AFFTC) Benefield Anechoic Facility (BAF) on January 24-January 27, 2000. A second test was done at MicroCraft in Tullahoma Tennessee by the Naval Air Weapons Center (NAWC) China Lake, California on September 8, 2001. The overall test objective was to gather qualitative antenna radiation pattern data from installed antennas on the HXRV. This objective was accomplished by collecting antenna radiation patterns at selected elevations of the HXRV. The test data was used to identify areas of RF coverage and assist in positioning the P-3 aircraft for best RF reception. The antenna pattern data presented nulls and possible low RF reception areas around the aircraft. This led to a redesign of the RF system. The redesigned system provided redundancy in case a telemetry transmitter should fail. The redesign provided more complete RF coverage within the antenna's capabilities. A second look at the flight path and necessary data collection led to a change in the beacon transponder system.

  2. Nanophotonic reservoir computing with photonic crystal cavities to generate periodic patterns.

    PubMed

    Fiers, Martin Andre Agnes; Van Vaerenbergh, Thomas; Wyffels, Francis; Verstraeten, David; Schrauwen, Benjamin; Dambre, Joni; Bienstman, Peter

    2014-02-01

    Reservoir computing (RC) is a technique in machine learning inspired by neural systems. RC has been used successfully to solve complex problems such as signal classification and signal generation. These systems are mainly implemented in software, and thereby they are limited in speed and power efficiency. Several optical and optoelectronic implementations have been demonstrated, in which the system has signals with an amplitude and phase. It is proven that these enrich the dynamics of the system, which is beneficial for the performance. In this paper, we introduce a novel optical architecture based on nanophotonic crystal cavities. This allows us to integrate many neurons on one chip, which, compared with other photonic solutions, closest resembles a classical neural network. Furthermore, the components are passive, which simplifies the design and reduces the power consumption. To assess the performance of this network, we train a photonic network to generate periodic patterns, using an alternative online learning rule called first-order reduced and corrected error. For this, we first train a classical hyperbolic tangent reservoir, but then we vary some of the properties to incorporate typical aspects of a photonics reservoir, such as the use of continuous-time versus discrete-time signals and the use of complex-valued versus real-valued signals. Then, the nanophotonic reservoir is simulated and we explore the role of relevant parameters such as the topology, the phases between the resonators, the number of nodes that are biased and the delay between the resonators. It is important that these parameters are chosen such that no strong self-oscillations occur. Finally, our results show that for a signal generation task a complex-valued, continuous-time nanophotonic reservoir outperforms a classical (i.e., discrete-time, real-valued) leaky hyperbolic tangent reservoir (normalized root-mean-square errors=0.030 versus NRMSE=0.127). PMID:24807033

  3. Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder

    NASA Technical Reports Server (NTRS)

    Staats, Matt

    2009-01-01

    We present work on a prototype tool based on the JavaPathfinder (JPF) model checker for automatically generating tests satisfying the MC/DC code coverage criterion. Using the Eclipse IDE, developers and testers can quickly instrument Java source code with JPF annotations covering all MC/DC coverage obligations, and JPF can then be used to automatically generate tests that satisfy these obligations. The prototype extension to JPF enables various tasks useful in automatic test generation to be performed, such as test suite reduction and execution of generated tests.

  4. Classifying performance impairment in response to sleep loss using pattern recognition algorithms on single session testing

    PubMed Central

    St. Hilaire, Melissa A.; Sullivan, Jason P.; Anderson, Clare; Cohen, Daniel A.; Barger, Laura K.; Lockley, Steven W.; Klerman, Elizabeth B.

    2012-01-01

    There is currently no “gold standard” marker of cognitive performance impairment resulting from sleep loss. We utilized pattern recognition algorithms to determine which features of data collected under controlled laboratory conditions could most reliably identify cognitive performance impairment in response to sleep loss using data from only one testing session, such as would occur in the “real world” or field conditions. A training set for testing the pattern recognition algorithms was developed using objective Psychomotor Vigilance Task (PVT) and subjective Karolinska Sleepiness Scale (KSS) data collected from laboratory studies during which subjects were sleep deprived for 26 – 52 hours. The algorithm was then tested in data from both laboratory and field experiments. The pattern recognition algorithm was able to identify performance impairment with a single testing session in individuals studied under laboratory conditions using PVT, KSS, length of time awake and time of day information with sensitivity and specificity as high as 82%. When this algorithm was tested on data collected under real-world conditions from individuals whose data were not in the training set, accuracy of predictions for individuals categorized with low performance impairment were as high as 98%. Predictions for medium and severe performance impairment were less accurate. We conclude that pattern recognition algorithms may be a promising method for identifying performance impairment in individuals using only current information about the individual’s behavior. Single testing features (e.g., number of PVT lapses) with high correlation with performance impairment in the laboratory setting may not be the best indicators of performance impairment under real-world conditions. Pattern recognition algorithms should be further tested for their ability to be used in conjunction with other assessments of sleepiness in real-world conditions to quantify performance impairment in

  5. 40 CFR 86.1333-2010 - Transient test cycle generation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... less than four seconds. (See 40 CFR 1065.514 for allowances in the cycle validation criteria.) (d... engines: ER13JY05.001 Where: MaxTestSpeed = the maximum test speed as calculated in 40 CFR part 1065. (ii... CFR part 1065. (2) Torque is normalized to the maximum torque at the rpm listed with it. Therefore,...

  6. Improving Large Enrollment Undergraduate Instruction With Computer Generated, Repeatable Tests.

    ERIC Educational Resources Information Center

    Hammer, Mark; Henderson, C. Obert

    In addition to the usual drawbacks of large enrollment college classes such as impersonal atmosphere, discouragement of questions, and insensitivity to individual differences, the testing methods that tend to be associated with large classes can be detrimental to the learning process. Objective tests decrease the level of intellectual mastery…

  7. The next generation of microbiological testing of poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbiological testing of food products is a common practice of food processors to ensure compliance with food safety criteria. Sampling on its own is of limited value, but when applied regularly at different stages of the food chain, microbiology testing can be an integral part of a quality contr...

  8. A central pattern generator producing alternative outputs: phase relations of leech heart motor neurons with respect to premotor synaptic input.

    PubMed

    Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

    2007-11-01

    The central pattern generator (CPG) for heartbeat in leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts: synchronous and peristaltic. Using extracellular techniques, we recorded, in 61 isolated nerve cords, the activity of motor neurons in conjunction with the phase reference premotor heart interneuron, HN(4), and another premotor interneuron that allowed us to assess the coordination mode. These data were then coupled with a previous description of the temporal pattern of premotor interneuron activity in the two coordination modes to synthesize a global phase diagram for the known elements of the CPG and the entire motor neuron ensemble. These average data reveal the stereotypical side-to-side asymmetric patterns of intersegmental coordination among the motor neurons and show how this pattern meshes with the activity pattern of premotor interneurons. Analysis of animal-to-animal variability in this coordination indicates that the intersegmental phase progression of motor neuron activity in the midbody in the peristaltic coordination mode is the most stereotypical feature of the fictive motor pattern. Bilateral recordings from motor neurons corroborate the main features of the asymmetric motor pattern. PMID:17728387

  9. PLAP efficiently generates mature antigenic peptides in vitro but in patterns distinct from ERAP11

    PubMed Central

    Georgiadou, Dimitra; Hearn, Arron; Evnouchidou, Irini; Chroni, Angeliki; Leondiadis, Leondios; York, Ian A.; Rock, Kenneth L.; Stratikos, Efstratios

    2010-01-01

    All three members of the oxytocinase sub-family of M1 aminopeptidases, ERAP1 (ERAAP), ERAP2 and PLAP (IRAP), have been implicated in the generation of MHC class I-presented peptides. ERAP1 and 2 trim peptides in the endoplasmic reticulum for direct presentation whereas PLAP has been recently implicated in cross presentation. The best characterized member of the family, ERAP1, has unique enzymatic properties that fit well with its role in antigen processing. ERAP1 can trim a large variety of long peptide sequences and efficiently accumulate mature antigenic epitopes of 8–9 amino acids long. In this study we evaluate the ability of PLAP to process antigenic peptide precursors in vitro and compare it to ERAP1. We find that, similarly to ERAP1, PLAP can trim a variety of long peptide sequences efficiently and, in most cases, accumulates appreciable amounts of correct length mature antigenic epitope. Again, similarly to ERAP1, PLAP continued trimming some of the epitopes tested and accumulated smaller products effectively destroying the epitope. However, the intermediate accumulation properties of ERAP1 and PLAP are distinct and epitope dependent, suggesting that these two enzymes may impose different selective pressures on epitope generation. Overall, although PLAP has the necessary enzymatic properties to participate in generating or destroying MHC class I presented peptides, its trimming behavior is distinct from that of ERAP1, something that supports a separate role for these two enzymes in antigen processing. PMID:20592285

  10. K+ homeostasis and central pattern generation in the metathoracic ganglion of the locust.

    PubMed

    Rodgers, Corinne I; Labrie, John D; Robertson, R Meldrum

    2009-07-01

    Stress-induced arrest of ventilatory motor pattern generation is tightly correlated with an abrupt increase in extracellular potassium concentration ([K+]o) within the metathoracic neuropil of the locust, Locusta migratoria. Na+/K+-ATPase inhibition with ouabain elicits repetitive surges of [K+]o that coincide with arrest and recovery of motor activity. Here we show that ouabain induces repetitive [K+]o events in a concentration-dependent manner. 10(-5)M, 10(-4)M, and 10(-3)M ouabain was bath-applied in semi-intact locust preparations. 10(-4)M and 10(-3)M ouabain reliably induced repetitive [K+]o events whereas 10(-5)M ouabain had no significant effect. In comparison to 10(-4)M ouabain, 10(-3)M ouabain increased the number and hastened the time to onset of repetitive [K+]o waves, prolonged [K+]o event duration, increased resting [K+]o, and diminished the absolute value of [K+]o waves. Recovery of motor patterning following [K+]o events was less likely in 10(-3)M ouabain. In addition, we show that K+ channel inhibition using TEA suppressed the onset and decreased the amplitude of ouabain-induced repetitive [K+]o waves. Our results demonstrate that ventilatory circuit function in the locust CNS is dependent on the balance between mechanisms of [K+] accumulation and [K+] clearance. We suggest that with an imbalance in favour of accumulation the system tends towards a bistable state with transitions mediated by positive feedback involving voltage-dependent K+ channels. PMID:19482133

  11. Neuromodulator-evoked synaptic metaplasticity within a central pattern generator network.

    PubMed

    Kvarta, Mark D; Harris-Warrick, Ronald M; Johnson, Bruce R

    2012-11-01

    Synapses show short-term activity-dependent dynamics that alter the strength of neuronal interactions. This synaptic plasticity can be tuned by neuromodulation as a form of metaplasticity. We examined neuromodulator-induced metaplasticity at a graded chemical synapse in a model central pattern generator (CPG), the pyloric network of the spiny lobster stomatogastric ganglion. Dopamine, serotonin, and octopamine each produce a unique motor pattern from the pyloric network, partially through their modulation of synaptic strength in the network. We characterized synaptic depression and its amine modulation at the graded synapse from the pyloric dilator neuron to the lateral pyloric neuron (PD→LP synapse), driving the PD neuron with both long square pulses and trains of realistic waveforms over a range of presynaptic voltages. We found that the three amines can differentially affect the amplitude of graded synaptic transmission independently of the synaptic dynamics. Low concentrations of dopamine had weak and variable effects on the strength of the graded inhibitory postsynaptic potentials (gIPSPs) but reliably accelerated the onset of synaptic depression and recovery from depression independently of gIPSP amplitude. Octopamine enhanced gIPSP amplitude but decreased the amount of synaptic depression; it slowed the onset of depression and accelerated its recovery during square pulse stimulation. Serotonin reduced gIPSP amplitude but increased the amount of synaptic depression and accelerated the onset of depression. These results suggest that amine-induced metaplasticity at graded chemical synapses can alter the parameters of synaptic dynamics in multiple and independent ways. PMID:22933725

  12. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Unknown

    2002-03-31

    The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002.

  13. Characterization of photochromic computer-generated holograms for optical testing

    NASA Astrophysics Data System (ADS)

    Pariani, Giorgio; Bertarelli, Chiara; Bianco, Andrea; Schaal, Frederik; Pruss, Christof

    2012-09-01

    We investigate the possibility to produce photochromic CGHs with maskless lithography methods. For this purpose, optical properties and requirements of photochromic materials will be shown. A diarylethene-based polyurethane is developed and characterized. The resolution limit and the in uence of the writing parameters on the produced patterns, namely speed rate and light power, have been determined. After the optimization of the writing process, gratings and Fresnel Zone Plates are produced on the photochromic layer and diraction eciencies are measured. Improvements and perspectives will be discussed.

  14. Improved zonal wavefront reconstruction algorithm for Hartmann type test with arbitrary grid patterns

    NASA Astrophysics Data System (ADS)

    Li, Mengyang; Li, Dahai; Zhang, Chen; E, Kewei; Hong, Zhihan; Li, Chengxu

    2015-08-01

    Zonal wavefront reconstruction by use of the well known Southwell algorithm with rectangular grid patterns has been considered in the literature. However, when the grid patterns are nonrectangular, modal wavefront reconstruction has been extensively used. We propose an improved zonal wavefront reconstruction algorithm for Hartmann type test with arbitrary grid patterns. We develop the mathematical expressions to show that the wavefront over arbitrary grid patterns, such as misaligned, partly obscured, and non-square mesh grids, can be estimated well. Both iterative solution and least-square solution for the proposed algorithm are described and compared. Numerical calculation shows that the zonal wavefront reconstruction over nonrectangular profile with the proposed algorithm results in a significant improvement in comparison with the Southwell algorithm.

  15. Automatically generated acceptance test: A software reliability experiment

    NASA Technical Reports Server (NTRS)

    Protzel, Peter W.

    1988-01-01

    This study presents results of a software reliability experiment investigating the feasibility of a new error detection method. The method can be used as an acceptance test and is solely based on empirical data about the behavior of internal states of a program. The experimental design uses the existing environment of a multi-version experiment previously conducted at the NASA Langley Research Center, in which the launch interceptor problem is used as a model. This allows the controlled experimental investigation of versions with well-known single and multiple faults, and the availability of an oracle permits the determination of the error detection performance of the test. Fault interaction phenomena are observed that have an amplifying effect on the number of error occurrences. Preliminary results indicate that all faults examined so far are detected by the acceptance test. This shows promise for further investigations, and for the employment of this test method on other applications.

  16. R. F. testing of the third generation defense communication satellite

    NASA Technical Reports Server (NTRS)

    Sargent, J.; Massaro, M.

    1980-01-01

    The approach taken to test a completed DSCS communications satellite on a system level is described. Areas to be described are measuring RF isolation of separate communications subsystems and a test method which insures that one RF subsystem does not interfere with another. In addition, the method of complying with MIL-STD-1541 in the area of demonstrating safety of electroexplosive devices in an RF field is discussed.

  17. Concept and analytical basis for revistas - A fast, flexible computer/graphic system for generating periodic satellite coverage patterns

    NASA Technical Reports Server (NTRS)

    King, J. C.

    1976-01-01

    The generation of satellite coverage patterns is facilitated by three basic strategies: use of a simplified physical model, permitting rapid closed-form calculation; separation of earth rotation and nodal precession from initial geometric analyses; and use of symmetries to construct traces of indefinite length by repetitive transposition of basic one-quadrant elements. The complete coverage patterns generated consist of a basic nadir trace plus a number of associated off-nadir traces, one for each sensor swath edge to be delineated. Each trace is generated by transposing one or two of the basic quadrant elements into a circle on a nonrotating earth model sphere, after which the circle is expanded into the actual 'helical' pattern by adding rotational displacements to the longitude coordinates. The procedure adapts to the important periodic coverage cases by direct insertion of the characteristic integers N and R (days and orbital revolutions, respectively, per coverage period).

  18. Idler-efficiency-enhanced long-wave infrared beam generation using aperiodic orientation-patterned GaAs gratings.

    PubMed

    Gürkan Figen, Ziya; Aytür, Orhan; Arıkan, Orhan

    2016-03-20

    In this paper, we design aperiodic gratings based on orientation-patterned gallium arsenide (OP-GaAs) for converting 2.1 μm pump laser radiation into long-wave infrared (8-12 μm) in an idler-efficiency-enhanced scheme. These single OP-GaAs gratings placed in an optical parametric oscillator (OPO) or an optical parametric generator (OPG) can simultaneously phase match two optical parametric amplification (OPA) processes, OPA 1 and OPA 2. We use two design methods that allow simultaneous phase matching of two arbitrary χ(2) processes and also free adjustment of their relative strength. The first aperiodic grating design method (Method 1) relies on generating a grating structure that has domain walls located at the zeros of the summation of two cosine functions, each of which has a spatial frequency that equals one of the phase-mismatch terms of the two processes. Some of the domain walls are discarded considering the minimum domain length that is achievable in the production process. In this paper, we propose a second design method (Method 2) that relies on discretizing the crystal length with sample lengths that are much smaller than the minimum domain length and testing each sample's contribution in such a way that the sign of the nonlinearity maximizes the magnitude sum of the real and imaginary parts of the Fourier transform of the grating function at the relevant phase mismatches. Method 2 produces a similar performance as Method 1 in terms of the maximization of the height of either Fourier peak located at the relevant phase mismatch while allowing an adjustable relative height for the two peaks. To our knowledge, this is the first time that aperiodic OP-GaAs gratings have been proposed for efficient long-wave infrared beam generation based on simultaneous phase matching. PMID:27140581

  19. GENETIC ACTIVITY PROFILES AND PATTERN RECOGNITION IN TEST BATTERY SELECTION (JOURNAL VERSION)

    EPA Science Inventory

    Computer-generated genetic activity profiles and pairwise matching procedures may aid in the selection of the most appropriate short-term bioassays to be used in test batteries for the evaluation of the genotoxicity of a given chemical or group of chemicals. Selection of test bat...

  20. Brief Report: Eye-Movement Patterns during an Embedded Figures Test in Children with ASD

    ERIC Educational Resources Information Center

    Keehn, Brandon; Brenner, Laurie A.; Ramos, Aurora I.; Lincoln, Alan J.; Marshall, Sandra P.; Muller, Ralph-Axel

    2009-01-01

    The present study examined fixation frequency and duration during an Embedded Figures Test (EFT) in an effort to better understand the attentional and perceptual processes by which individuals with autism spectrum disorder (ASD) achieve accelerated EFT performance. In particular, we aimed to elucidate differences in the patterns of eye-movement in…

  1. Multislit interference patterns in high-order harmonic generation in C60

    NASA Astrophysics Data System (ADS)

    Ciappina, M. F.; Becker, A.; Jaroń-Becker, A.

    2007-12-01

    We study high-order harmonic generation in C60 molecules interacting with a linearly polarized intense short laser pulse at near- and mid-infrared wavelengths, using an extension of the so-called three-step or Lewenstein model to the molecular case. The results exhibit modulations in the plateaus of the spectra at the longer wavelengths, which are present for ensembles of aligned as well as randomly oriented fullerenes. The analysis of the results show that the minima can be explained by a multislit interference effect arising from the contributions of the 60 atomic centers to the dipole moment. Good agreement between the positions of the minima in the spectra obtained in the length gauge are found with those of the recombination matrix element, but not for those in the velocity gauge calculations. We further use a simple spherical model to analyze how geometrical information, such as the radius of the fullerene cage, can be obtained from the interference pattern in the harmonic spectra.

  2. The contribution of a central pattern generator in a reflex-based neuromuscular model

    PubMed Central

    Dzeladini, Florin; van den Kieboom, Jesse; Ijspeert, Auke

    2014-01-01

    Although the concept of central pattern generators (CPGs) controlling locomotion in vertebrates is widely accepted, the presence of specialized CPGs in human locomotion is still a matter of debate. An interesting numerical model developed in the 90s’ demonstrated the important role CPGs could play in human locomotion, both in terms of stability against perturbations, and in terms of speed control. Recently, a reflex-based neuro-musculo-skeletal model has been proposed, showing a level of stability to perturbations similar to the previous model, without any CPG components. Although exhibiting striking similarities with human gaits, the lack of CPG makes the control of speed/step length in the model difficult. In this paper, we hypothesize that a CPG component will offer a meaningful way of controlling the locomotion speed. After introducing the CPG component in the reflex model, and taking advantage of the resulting properties, a simple model for gait modulation is presented. The results highlight the advantages of a CPG as feedforward component in terms of gait modulation. PMID:25018712

  3. GMOtrack: generator of cost-effective GMO testing strategies.

    PubMed

    Novak, Petra Krau; Gruden, Kristina; Morisset, Dany; Lavrac, Nada; Stebih, Dejan; Rotter, Ana; Zel, Jana

    2009-01-01

    Commercialization of numerous genetically modified organisms (GMOs) has already been approved worldwide, and several additional GMOs are in the approval process. Many countries have adopted legislation to deal with GMO-related issues such as food safety, environmental concerns, and consumers' right of choice, making GMO traceability a necessity. The growing extent of GMO testing makes it important to study optimal GMO detection and identification strategies. This paper formally defines the problem of routine laboratory-level GMO tracking as a cost optimization problem, thus proposing a shift from "the same strategy for all samples" to "sample-centered GMO testing strategies." An algorithm (GMOtrack) for finding optimal two-phase (screening-identification) testing strategies is proposed. The advantages of cost optimization with increasing GMO presence on the market are demonstrated, showing that optimization approaches to analytic GMO traceability can result in major cost reductions. The optimal testing strategies are laboratory-dependent, as the costs depend on prior probabilities of local GMO presence, which are exemplified on food and feed samples. The proposed GMOtrack approach, publicly available under the terms of the General Public License, can be extended to other domains where complex testing is involved, such as safety and quality assurance in the food supply chain. PMID:20166592

  4. Versatile pattern generation of periodic, high aspect ratio Si nanostructure arrays with sub-50-nm resolution on a wafer scale

    PubMed Central

    2013-01-01

    We report on a method of fabricating variable patterns of periodic, high aspect ratio silicon nanostructures with sub-50-nm resolution on a wafer scale. The approach marries step-and-repeat nanoimprint lithography (NIL) and metal-catalyzed electroless etching (MCEE), enabling near perfectly ordered Si nanostructure arrays of user-defined patterns to be controllably and rapidly generated on a wafer scale. Periodic features possessing circular, hexagonal, and rectangular cross-sections with lateral dimensions down to sub-50 nm, in hexagonal or square array configurations and high array packing densities up to 5.13 × 107 structures/mm2 not achievable by conventional UV photolithography are fabricated using this top-down approach. By suitably tuning the duration of catalytic etching, variable aspect ratio Si nanostructures can be formed. As the etched Si pattern depends largely on the NIL mould which is patterned by electron beam lithography (EBL), the technique can be used to form patterns not possible with self-assembly methods, nanosphere, and interference lithography for replication on a wafer scale. Good chemical resistance of the nanoimprinted mask and adhesion to the Si substrate facilitate good pattern transfer and preserve the smooth top surface morphology of the Si nanostructures as shown in TEM. This approach is suitable for generating Si nanostructures of controlled dimensions and patterns, with high aspect ratio on a wafer level suitable for semiconductor device production. PMID:24289275

  5. Versatile pattern generation of periodic, high aspect ratio Si nanostructure arrays with sub-50-nm resolution on a wafer scale

    NASA Astrophysics Data System (ADS)

    Ho, Jian-Wei; Wee, Qixun; Dumond, Jarrett; Tay, Andrew; Chua, Soo-Jin

    2013-12-01

    We report on a method of fabricating variable patterns of periodic, high aspect ratio silicon nanostructures with sub-50-nm resolution on a wafer scale. The approach marries step-and-repeat nanoimprint lithography (NIL) and metal-catalyzed electroless etching (MCEE), enabling near perfectly ordered Si nanostructure arrays of user-defined patterns to be controllably and rapidly generated on a wafer scale. Periodic features possessing circular, hexagonal, and rectangular cross-sections with lateral dimensions down to sub-50 nm, in hexagonal or square array configurations and high array packing densities up to 5.13 × 107 structures/mm2 not achievable by conventional UV photolithography are fabricated using this top-down approach. By suitably tuning the duration of catalytic etching, variable aspect ratio Si nanostructures can be formed. As the etched Si pattern depends largely on the NIL mould which is patterned by electron beam lithography (EBL), the technique can be used to form patterns not possible with self-assembly methods, nanosphere, and interference lithography for replication on a wafer scale. Good chemical resistance of the nanoimprinted mask and adhesion to the Si substrate facilitate good pattern transfer and preserve the smooth top surface morphology of the Si nanostructures as shown in TEM. This approach is suitable for generating Si nanostructures of controlled dimensions and patterns, with high aspect ratio on a wafer level suitable for semiconductor device production.

  6. Testing aspherics without rotational symmetry using a Fizeau interferometer with computer-generated holograms

    NASA Astrophysics Data System (ADS)

    Pfeifer, Tilo; Evertz, Jens; Tutsch, Rainer; Rothe, Hendrik

    1993-01-01

    Non-rotational aspherics offer new perspectives for the development of new concepts for high power laser resonators (e.g., CO2-laser with unstable resonator). Furthermore, the intensity profile of the laser beam can be adapted to the needs of special working processes (e.g., cutting, welding, surface treatments). At the IPT a variety of mirrors with complex shapes are manufactured with a proprietary fast-tool-servo on a diamond turning lathe. For these mirrors an aspheric testing interferometer with computer generated holograms has been developed. Research work was done on the design of the optical system, the development of algorithms and software for the computation of the holograms, the techniques for manufacturing the computer generated holograms (CGH) and an appropriate strategy for adjustment of the measurement system. The hologram pattern is plotted using a CAD-plotter and photographically reduced in scale. To overcome this time-consuming technique and to improve the precision of the holograms a laser-based direct writing hologram-plotter is under development. We describe the concept of the measurement system, and discuss several systematic error sources. Some recent results are presented.

  7. NEXT GENERATION SEDIMENT TOXICITY TESTING VIA DNA MICROARRAYS - PHASE I

    EPA Science Inventory

    The current SBIR solicitation states that the EPA is seeking “better sampling, analysis, and monitoring technologies” to improve hazardous waste management.  Development of new methods for testing contaminated sediments is an area of particular concern because many industri...

  8. Acceptance Test Report for Fourth Generation Hanford Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-10-23

    This Acceptance Test Report (ATR) will document the satisfactory operation of the corrosion probe cabinets destined for installation on tanks 241-AN-102 and 241-AN-107. This ATR will be performed by the manufacturer on each cabinet prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion monitoring cabinets to be installed on tanks 241-AN-102 and 241-AN-107. One cabinet will be installed on each tank. Each cabinet will contain corrosion monitoring hardware to be connected to existing corrosion probes already installed in each tank. The test will consist of a continuity test of the cabinet wiring from the end of cable to be connected to corrosion probe, through the appropriate intrinsic safety barriers and out to the 15 pin D-shell connectors to be connected to the corrosion monitoring instrument. Additional testing will be performed using a constant current and voltage source provided by the corrosion monitoring hardware manufacturer to verify proper operation of corrosion monitoring instrumentation (input a known signal and see if the instrumentation records the proper value).

  9. Acceptance test plan for fourth generation Hanford corrosion monitoring system

    SciTech Connect

    NORMAN, E.C.

    2000-07-27

    This Acceptance Test Plan (ATP) will document the satisfactory operation of the corrosion probe cabinets destined for installation on tanks 241-AN-102 and 241-AN-107. This ATP will be performed by the manufacturer on each cabinet prior to delivery to the site. The objective of this procedure is to demonstrate and document the acceptance of the corrosion monitoring cabinets to be installed on tanks 241-AN-102 and 241-AN-107. One cabinet will be installed on each tank. Each cabinet will contain corrosion monitoring hardware to be connected to existing corrosion probes already installed in each tank. The test will consist of a continuity test of the cabinet wiring from the end of cable to be connected to corrosion probe, through the appropriate intrinsic safety barriers and out to the 15 pin D-shell connectors to be connected to the corrosion monitoring instrument. Additional testing will be performed using a constant current and voltage source provided by the corrosion monitoring hardware manufacturer to verify proper operation of corrosion monitoring instrumentation (input a known signal and see if the instrumentation records the proper value).

  10. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... test. The torque and rpm feedback signals may be filtered. (d) Idle Speed Enhancement Devices (e.g... feedback torque equal to zero (using, for example, clutch disengagement, speed to torque control switching... longer, the average feedback torque must be within ±10 ft-lbs of zero. To allow for transition, up to...

  11. Evolution of Courtship Songs in Xenopus : Vocal Pattern Generation and Sound Production.

    PubMed

    Leininger, Elizabeth C; Kelley, Darcy B

    2015-01-01

    The extant species of African clawed frogs (Xenopus and Silurana) provide an opportunity to link the evolution of vocal characters to changes in the responsible cellular and molecular mechanisms. In this review, we integrate several robust lines of research: evolutionary trajectories of Xenopus vocalizations, cellular and circuit-level mechanisms of vocalization in selected Xenopus model species, and Xenopus evolutionary history and speciation mechanisms. Integrating recent findings allows us to generate and test specific hypotheses about the evolution of Xenopus vocal circuits. We propose that reduced vocal sex differences in some Xenopus species result from species-specific losses of sexually differentiated neural and neuromuscular features. Modification of sex-hormone-regulated developmental mechanisms is a strong candidate mechanism for reduced vocal sex differences. PMID:26138673

  12. TID Test Results for 4th Generation iPad(TradeMark)

    NASA Technical Reports Server (NTRS)

    Guertin, S. M.; Allen, G. R.; McClure, S. S.; LaBel, K. A.

    2013-01-01

    TID testing of 4th generation iPads is reported. Of iPad subsystems, results indicate that the charging circuitry and display drivers fail at lowest TID levels. Details of construction are investigated for additional testing of components.

  13. BRH test pattern for the evaluation of gamma-camera performance

    SciTech Connect

    Paras, P.; Hine, G.J.; Adams, R.

    1981-05-01

    A transmission test pattern has been developed for the simultaneous evaluation of intrinsic resolution, field uniformity, and spatial distortion of gamma cameras of any model and age. Holes 2.5 mm in diameter are drilled with high precision through a 3.2-mm thick lead-alloy plate, forming an orthogonal array of holes. The performance of gamma cameras has been investigated with the gamma rays of Tc-99m and the low-energy photons from Xe-133 and Tl-201. Images of the test pattern provide a simple, rapid, and sensitive method for gamma camera quality control, acceptance testing of new instruments, and checking of a camera's operating and maintenance procedures.

  14. Computerized In Vitro Test for Chemical Toxicity Based on Tetrahymena Swimming Patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

    1994-01-01

    An apparatus and a method for rapidly determining chemical toxicity have been evaluated as an alternative to the rabbit eye initancy test (Draize). The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The method, called the motility assay (MA), is tested for 30 s to determine the chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy.

  15. [Testing Research of Transient Temperature Distribution for the Barrel Surface by Speckle Pattern Interferometry].

    PubMed

    Lang, Wen-jie; Chen, Guo-guang; Tian, Xiao-li; Xin, Chang-fan

    2016-02-01

    There are some problems in the traditional transient temperature test equipment. The thermal inertia is great, and can only be a single point of detection. To be able to achieve real-time monitoring for transient temperature distribution change of the gun body surface, the test system for transient temperature distribution was designed based on Speckle Pattern Interferometry (SPI) and spectroscopy. In the system, transient temperature change of the barrel led to slight deformation, and it was converted into speckle interference fringes by SPI technology. Spectral distribution function was obtained by the interference fringes by the Fourier transform, so the information of interference fringe deformation was incorporated into the frequency domain. The data of temperature distribution can be inverted on any sampling time by spectral distribution function. In experiments, the ZX-FB1 fiber optic thermometer was used to test transient temperature on a single point as the standard value. The center wavelength of the laser was 555 nm, and the speckle pattern interference fringes were collected by area array CCD. Image Recognition-Speckle Pattern Interferometry (IR-SPI) and Fourier Transform-Speckle Pattern Interferometry (FT-SPI) were used in experiments, the calculation of transient temperature was completed through two methods. Experimental results are that both methods can achieve transient temperature detection. But the FT-SPI is higher in terms of accuracy, and it can effectively overcome the gross error caused by the surface defects, paint wear and other similar problems. PMID:27209730

  16. Diagnostic testing patterns of Renibacterium salmoninarum in spawning salmonid stocks in Michigan.

    PubMed

    Faisal, M; Eissa, A E

    2009-04-01

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a slowly progressing disease that threatens salmon conservation and restoration programs in North America. The purpose of this study was to track naturally occurring R. salmoninarum infection in representative, Michigan, USA, salmonid stocks using nested polymerase chain reaction (nPCR), quantitative enzyme-linked immunosorbent assay (Q-ELISA), and culture. The Q-ELISA test detected 67.6% infection prevalence, which is lower than culture (77.2%) or nPCR (94.2%), yet it provided semiquantitative data on infection intensity. The disagreement in results among the three assays may reflect the different phases of R. salmoninarum infection at the time of sampling. The testing results demonstrated the presence of six patterns, with each of the patterns representing a probable stage along the course of natural R. salmoninarum infection. Findings also suggest that fish stocks tested in this study were not uniform in the distribution of the diagnostic patterns and that, from studying such patterns, one can determine the course of BKD infection in a particular population. PMID:19395754

  17. Decomposing risk: landscape structure and wolf behavior generate different predation patterns in two sympatric ungulates.

    PubMed

    Gervasi, Vincenzo; Sand, Hakan; Zimmermann, Barbara; Mattisson, Jenny; Wabakken, Petter; Linnell, John D C

    2013-10-01

    Recolonizing carnivores can have a large impact on the status of wild ungulates, which have often modified their behavior in the absence of predation. Therefore, understanding the dynamics of reestablished predator-prey systems is crucial to predict their potential ecosystem effects. We decomposed the spatial structure of predation by recolonizing wolves (Canis lupus) on two sympatric ungulates, moose (Alces alces) and roe deer (Capreolus capreolus), in Scandinavia during a 10-year study. We monitored 18 wolves with GPS collars, distributed over 12 territories, and collected records from predation events. By using conditional logistic regression, we assessed the contributions of three main factors, the utilization patterns of each wolf territory, the spatial distribution of both prey species, and fine-scale landscape structure, in determining the spatial structure of moose and roe deer predation risk. The reestablished predator-prey system showed a remarkable spatial variation in kill occurrence at the intra-territorial level, with kill probabilities varying by several orders of magnitude inside the same territory. Variation in predation risk was evident also when a spatially homogeneous probability for a wolf to encounter a prey was simulated. Even inside the same territory, with the same landscape structure, and when exposed to predation by the same wolves, the two prey species experienced an opposite spatial distribution of predation risk. In particular, increased predation risk for moose was associated with open areas, especially clearcuts and young forest stands, whereas risk was lowered for roe deer in the same habitat types. Thus, fine-scale landscape structure can generate contrasting predation risk patterns in sympatric ungulates, so that they can experience large differences in the spatial distribution of risk and refuge areas when exposed to predation by a recolonizing predator. Territories with an earlier recolonization were not associated with a lower

  18. Using aberration test patterns to optimize the performance of EUV aerial imaging microscopes

    SciTech Connect

    Mochi, Iacopo; Goldberg, Kenneth A.; Miyakawa, Ryan; Naulleau, Patrick; Han, Hak-Seung; Huh, Sungmin

    2009-06-16

    The SEMATECH Berkeley Actinic Inspection Tool (AIT) is a prototype EUV-wavelength zoneplate microscope that provides high quality aerial image measurements of EUV reticles. To simplify and improve the alignment procedure we have created and tested arrays of aberration-sensitive patterns on EUV reticles and we have compared their images collected with the AIT to the expected shapes obtained by simulating the theoretical wavefront of the system. We obtained a consistent measure of coma and astigmatism in the center of the field of view using two different patterns, revealing a misalignment condition in the optics.

  19. Chronic Malaria Revealed by a New Fluorescence Pattern on the Antinuclear Autoantibodies Test

    PubMed Central

    Hommel, Benjamin; Charuel, Jean-Luc; Jaureguiberry, Stéphane; Arnaud, Laurent; Courtin, Regis; Kassab, Petra; Prendki, Virginie; Paris, Luc; Ghillani-Dalbin, Pascale; Thellier, Marc; Caumes, Eric; Amoura, Zahir; Mazier, Dominique; Musset, Lucile; Buffet, Pierre; Miyara, Makoto

    2014-01-01

    Background Several clinical forms of malaria such as chronic carriage, gestational malaria or hyper-reactive malarial splenomegaly may follow a cryptic evolution with afebrile chronic fatigue sometimes accompanied by anemia and/or splenomegaly. Conventional parasitological tests are often negative or not performed, and severe complications may occur. Extensive explorations of these conditions often include the search for antinuclear autoantibodies (ANA). Methods We analysed fluorescence patterns in the ANA test in patients with either chronic cryptic or acute symptomatic malaria, then conducted a one-year prospective study at a single hospital on all available sera drawn for ANA detections. We then identified autoantibodies differentially expressed in malaria patients and in controls using human protein microarray. Results We uncovered and defined a new, malaria-related, nucleo-cytoplasmic ANA pattern displaying the specific association of a nuclear speckled pattern with diffuse cytoplasmic perinuclearly-enhanced fluorescence. In the one-year prospective analysis, 79% of sera displaying this new nucleo-cytoplasmic fluorescence were from patients with malaria. This specific pattern, not seen in other parasitic diseases, allowed a timely reorientation of the diagnosis toward malaria. To assess if the autoantibody immune response was due to autoreactivity or molecular mimicry we isolated 42 autoantigens, targets of malarial autoantibodies. BLAST analysis indicated that 23 of recognized autoantigens were homologous to plasmodial proteins suggesting autoimmune responses directly driven by the plasmodial infection. Conclusion In patients with malaria in whom parasitological tests have not been performed recognition of this new, malaria-related fluorescence pattern on the ANA test is highly suggestive of the diagnosis and triggers immediate, easy confirmation and adapted therapy. PMID:24551116

  20. Parametric Analysis of a Hover Test Vehicle using Advanced Test Generation and Data Analysis

    NASA Technical Reports Server (NTRS)

    Gundy-Burlet, Karen; Schumann, Johann; Menzies, Tim; Barrett, Tony

    2009-01-01

    Large complex aerospace systems are generally validated in regions local to anticipated operating points rather than through characterization of the entire feasible operational envelope of the system. This is due to the large parameter space, and complex, highly coupled nonlinear nature of the different systems that contribute to the performance of the aerospace system. We have addressed the factors deterring such an analysis by applying a combination of technologies to the area of flight envelop assessment. We utilize n-factor (2,3) combinatorial parameter variations to limit the number of cases, but still explore important interactions in the parameter space in a systematic fashion. The data generated is automatically analyzed through a combination of unsupervised learning using a Bayesian multivariate clustering technique (AutoBayes) and supervised learning of critical parameter ranges using the machine-learning tool TAR3, a treatment learner. Covariance analysis with scatter plots and likelihood contours are used to visualize correlations between simulation parameters and simulation results, a task that requires tool support, especially for large and complex models. We present results of simulation experiments for a cold-gas-powered hover test vehicle.

  1. Control Theoretic Modeling and Generated Flow Patterns of a Fish-Tail Robot

    NASA Astrophysics Data System (ADS)

    Massey, Brian; Morgansen, Kristi; Dabiri, Dana

    2003-11-01

    Many real-world engineering problems involve understanding and manipulating fluid flows. One of the challenges to further progress in the area of active flow control is the lack of appropriate models that are amenable to control-theoretic studies and algorithm design and also incorporate reasonably realistic fluid dynamic effects. We focus here on modeling and model-verification of bio-inspired actuators (fish-fin type structures) used to control fluid dynamic artifacts that will affect speed, agility, and stealth of Underwater Autonomous Vehicles (UAVs). Vehicles using fish-tail type systems are more maneuverable, can turn in much shorter and more constrained spaces, have lower drag, are quieter and potentially more efficient than those using propellers. We will present control-theoretic models for a simple prototype coupled fluid and mechanical actuator where fluid effects are crudely modeled by assuming only lift, drag, and added mass, while neglecting boundary effects. These models will be tested with different control input parameters on an experimental fish-tail robot with the resulting flow captured with DPIV. Relations between the model, the control function choices, the obtained thrust and drag, and the corresponding flow patterns will be presented and discussed.

  2. Stereotypic Laryngeal and Respiratory Motor Patterns Generate Different Call Types in Rat Ultrasound Vocalization

    PubMed Central

    RIEDE, TOBIAS

    2014-01-01

    Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The role of larynx muscles in controlling sound features across different call types in ultrasound vocalization (USV) was investigated using laryngeal muscle electromyographic (EMG) activity, subglottal pressure measurements and vocal sound output in awake and spontaneously behaving Sprague–Dawley rats. Results support the hypothesis that glottal shape determines fundamental frequency. EMG activities of thyroarytenoid and cricothyroid muscles were aligned with call duration. EMG intensity increased with fundamental frequency. Phasic activities of both muscles were aligned with fast changing fundamental frequency contours, for example in trills. Activities of the sternothyroid and sternohyoid muscles, two muscles involved in vocal production in other mammals, are not critical for the production of rat USV. To test how stereotypic laryngeal and respiratory activity are across call types and individuals, sets of ten EMG and subglottal pressure parameters were measured in six different call types from six rats. Using discriminant function analysis, on average 80% of parameter sets were correctly assigned to their respective call type. This was significantly higher than the chance level. Since fundamental frequency features of USV are tightly associated with stereotypic activity of intrinsic laryngeal muscles and muscles contributing to build-up of subglottal pressure, USV provide insight into the neurophysiological control of peripheral vocal motor patterns. PMID:23423862

  3. Massive alterations of the methylation patterns around DNA transposons in the first four generations of a newly formed wheat allohexaploid.

    PubMed

    Yaakov, Beery; Kashkush, Khalil

    2011-01-01

    Rapid and reproducible genomic changes can be induced during the early stages of the life of nascent allopolyploid species. In a previous study, it was shown that following allopolyploidization, cytosine methylation changes can affect up to 11% of the wheat genome. However, the methylation patterns around transposable elements (TEs) were never studied in detail. We used transposon methylation display (TMD) to assess the methylation patterns of CCGG sites flanking three TE families (Balduin, Apollo, and Thalos) in the first four generations of a newly formed wheat allohexaploid. In addition, transposon display (TD), using a methylation-insensitive restriction enzyme, was applied to search for genomic rearrangements at the TE insertion sites. We observed that up to 54% of CCGG sites flanking the three TE families showed changes in methylation patterns in the first four generations of a newly formed wheat allohexaploid, where hypermethylation was predominant. Over 70% of the changes in TMD patterns occurred in the first two generations of the newly formed allohexaploid. Furthermore, analysis of 555 TE insertion sites by TD and 18 cases by site-specific PCR revealed a full additive pattern in the allohexaploid, an indication for lack of massive rearrangements. These data indicate that following allopolyplodization, DNA-TE insertion sites can undergo a significantly high level of methylation changes compared with methylation changes of other genomic sequences. PMID:21217805

  4. Generating Random Parallel Test Forms Using CTT in a Computer-Based Environment.

    ERIC Educational Resources Information Center

    Weiner, John A.; Gibson, Wade M.

    1998-01-01

    Describes a procedure for automated-test-forms assembly based on Classical Test Theory (CTT). The procedure uses stratified random-content sampling and test-form preequating to ensure both content and psychometric equivalence in generating virtually unlimited parallel forms. Extends the usefulness of CTT in automated test construction. (Author/SLD)

  5. Designing responsive pattern generators: stable heteroclinic channel cycles for modeling and control.

    PubMed

    Horchler, Andrew D; Daltorio, Kathryn A; Chiel, Hillel J; Quinn, Roger D

    2015-04-01

    A striking feature of biological pattern generators is their ability to respond immediately to multisensory perturbations by modulating the dwell time at a particular phase of oscillation, which can vary force output, range of motion, or other characteristics of a physical system. Stable heteroclinic channels (SHCs) are a dynamical architecture that can provide such responsiveness to artificial devices such as robots. SHCs are composed of sequences of saddle equilibrium points, which yields exquisite sensitivity. The strength of the vector fields in the neighborhood of these equilibria determines the responsiveness to perturbations and how long trajectories dwell in the vicinity of a saddle. For SHC cycles, the addition of stochastic noise results in oscillation with a regular mean period. In this paper, we parameterize noise-driven Lotka-Volterra SHC cycles such that each saddle can be independently designed to have a desired mean sub-period. The first step in the design process is an analytic approximation, which results in mean sub-periods that are within 2% of the specified sub-period for a typical parameter set. Further, after measuring the resultant sub-periods over sufficient numbers of cycles, the magnitude of the noise can be adjusted to control the mean period with accuracy close to that of the integration step size. With these relationships, SHCs can be more easily employed in engineering and modeling applications. For applications that require smooth state transitions, this parameterization permits each state's distribution of periods to be independently specified. Moreover, for modeling context-dependent behaviors, continuously varying inputs in each state dimension can rapidly precipitate transitions to alter frequency and phase. PMID:25712192

  6. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments

    PubMed Central

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin–Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development. PMID:24319408

  7. Error compensation in computer generated hologram-based form testing of aspheres.

    PubMed

    Stuerwald, Stephan

    2014-12-10

    Computer-generated holograms (CGHs) are used relatively often to test aspheric surfaces in the case of medium and high lot sizes. Until now differently modified measurement setups for optical form testing interferometry have been presented, like subaperture stitching interferometry and scanning interferometry. In contrast, for testing low to medium lot sizes in research and development, a variety of other tactile and nontactile measurement methods have been developed. In the case of CGH-based interferometric form testing, measurement deviations in the region of several tens of nanometers typically occur. Deviations arise especially due to a nonperfect alignment of the asphere relative to the testing wavefront. Therefore, the null test is user- and adjustment-dependent, which results in insufficient repeatability and reproducibility of the form errors. When adjusting a CGH, an operator usually performs a minimization of the spatial frequency of the fringe pattern. An adjustment to the ideal position, however, often cannot be performed with sufficient precision by the operator as the position of minimum spatial fringe density is often not unique, which also depends on the asphere. Thus, the scientific and technical objectives of this paper comprise the development of a simulation-based approach to explain and quantify typical experimental errors due to misalignment of the specimen toward a CGH in an optical form testing measurement system. A further step is the programming of an iterative method to realize a virtual optimized realignment of the system on the basis of Zernike polynomial decomposition, which should allow for the calculation of the measured form for an ideal alignment and thus a careful subtraction of a typical alignment-based form error. To validate the simulation-based findings, a series of systematic experiments is performed with a recently developed hexapod positioning system in order to allow an exact and reproducible positioning of the optical CGH

  8. A novel approach to locomotion learning: Actor-Critic architecture using central pattern generators and dynamic motor primitives

    PubMed Central

    Li, Cai; Lowe, Robert; Ziemke, Tom

    2014-01-01

    In this article, we propose an architecture of a bio-inspired controller that addresses the problem of learning different locomotion gaits for different robot morphologies. The modeling objective is split into two: baseline motion modeling and dynamics adaptation. Baseline motion modeling aims to achieve fundamental functions of a certain type of locomotion and dynamics adaptation provides a “reshaping” function for adapting the baseline motion to desired motion. Based on this assumption, a three-layer architecture is developed using central pattern generators (CPGs, a bio-inspired locomotor center for the baseline motion) and dynamic motor primitives (DMPs, a model with universal “reshaping” functions). In this article, we use this architecture with the actor-critic algorithms for finding a good “reshaping” function. In order to demonstrate the learning power of the actor-critic based architecture, we tested it on two experiments: (1) learning to crawl on a humanoid and, (2) learning to gallop on a puppy robot. Two types of actor-critic algorithms (policy search and policy gradient) are compared in order to evaluate the advantages and disadvantages of different actor-critic based learning algorithms for different morphologies. Finally, based on the analysis of the experimental results, a generic view/architecture for locomotion learning is discussed in the conclusion. PMID:25324773

  9. A novel approach to locomotion learning: Actor-Critic architecture using central pattern generators and dynamic motor primitives.

    PubMed

    Li, Cai; Lowe, Robert; Ziemke, Tom

    2014-01-01

    In this article, we propose an architecture of a bio-inspired controller that addresses the problem of learning different locomotion gaits for different robot morphologies. The modeling objective is split into two: baseline motion modeling and dynamics adaptation. Baseline motion modeling aims to achieve fundamental functions of a certain type of locomotion and dynamics adaptation provides a "reshaping" function for adapting the baseline motion to desired motion. Based on this assumption, a three-layer architecture is developed using central pattern generators (CPGs, a bio-inspired locomotor center for the baseline motion) and dynamic motor primitives (DMPs, a model with universal "reshaping" functions). In this article, we use this architecture with the actor-critic algorithms for finding a good "reshaping" function. In order to demonstrate the learning power of the actor-critic based architecture, we tested it on two experiments: (1) learning to crawl on a humanoid and, (2) learning to gallop on a puppy robot. Two types of actor-critic algorithms (policy search and policy gradient) are compared in order to evaluate the advantages and disadvantages of different actor-critic based learning algorithms for different morphologies. Finally, based on the analysis of the experimental results, a generic view/architecture for locomotion learning is discussed in the conclusion. PMID:25324773

  10. Integration of Scale Invariant Generator Technique and S-A Technique for Characterizing 2-D Patterns for Information Retrieve

    NASA Astrophysics Data System (ADS)

    Cao, L.; Cheng, Q.

    2004-12-01

    The scale invariant generator technique (SIG) and spectrum-area analysis technique (S-A) were developed independently relevant to the concept of the generalized scale invariance (GSI). The former was developed for characterizing the parameters involved in the GSI for characterizing and simulating multifractal measures whereas the latter was for identifying scaling breaks for decomposition of superimposed multifractal measures caused by multiple geophysical processes. A natural integration of these two techniques may yield a new technique to serve two purposes, on the one hand, that can enrich the power of S-A by increasing the interpretability of decomposed patterns in some applications of S-A and, on the other hand, that can provide a mean to test the uniqueness of multifractality of measures which is essential for application of SIG technique in more complicated environment. The implementation of the proposed technique has been done as a Dynamic Link Library (DLL) in Visual C++. The program can be friendly used for method validation and application in different fields.

  11. Multiple hypotheses testing of fish incidence patterns in an urbanized ecosystem

    USGS Publications Warehouse

    Chizinski, C.J.; Higgins, C.L.; Shavlik, C.E.; Pope, K.L.

    2006-01-01

    Ecological and evolutionary theories have focused traditionally on natural processes with little attempt to incorporate anthropogenic influences despite the fact that humans are such an integral part of virtually all ecosystems. A series of alternate models that incorporated anthropogenic factors and traditional ecological mechanisms of invasion to account for fish incidence patterns in urban lakes was tested. The models were based on fish biology, human intervention, and habitat characteristics. However, the only models to account for empirical patterns were those that included fish invasiveness, which incorporated species-specific information about overall tolerance and fecundity. This suggests that species-specific characteristics are more important in general distributional patterns than human-mediated dispersal. Better information of illegal stocking activities is needed to improve human-mediated models, and more insight into basic life history of ubiquitous species is needed to truly understand underlying mechanisms of biotic homogenization. ?? Springer 2005.

  12. Generation and Testing of Autonomous Mineral Detectors for Mars Rovers

    NASA Astrophysics Data System (ADS)

    Merrill, M. D.; Gilmore, M. S.; Castaño, R.; Bornstein, B.; Greenwood, J.

    2004-05-01

    Currently Mars missions can collect more data than can be returned. Autonomous systems for data collection, processing and return will aid future Mars rovers in prioritizing and returning geologically important information. We have created a neural net detector that is able to successfully recognize carbonates from Visible/NIR (350-2500 nm) spectra of rocks collected from Mars analog environments (Gilmore et al. JGR 105, 29,223). In order to characterize and improve the detector's sensitivity, we are evaluating the performance of the detector under more realistic Martian environments: 1) carbonate minerals covered with palagonitic dust, and 2) carbonate minerals intimately mixed with basalt and palagonite. Lessons learned will be applied to the generation of additional detectors for minerals of interest (e.g., hydrothermal minerals). Aliquots of Martian Soil Simulant JSC Mars-1 palagonite were sieved to <45 microns and air fall deposited onto a calcite crystal and an adjacent glass slide. Spectra in the Vis/NIR were taken of the calcite after every layer up to a thickness of 270 microns (35 layers) with an Analytical Spectral Devices Field Spec Pro spectrometer operating from 350-2500 nm. The carbonate detector, operating over the range 2000-2400 nm, has an empirically established detection threshold based on training with thousands of synthetic linear combinations of laboratory mineral spectra designed to simulate expected Martian rocks. The detection threshold was reached in this experiment when the dust layer thickness reached 102 -116 microns (78-85% aerial coverage). This corresponds to a real change in the depth of the 2300 nm carbonate band (continuum depth, D= 1- [reflectance at trough center/reflectance at continuum] = ~0.1), and is similar to the detection threshold of the human experimenter. Very thin (~10-20 microns) coatings of palagonite dust had a large effect on the spectral response of the substrate, exemplifying the nonlinear mixing of the two

  13. Instructional Topics in Educational Measurement (ITEMS) Module: Using Automated Processes to Generate Test Items

    ERIC Educational Resources Information Center

    Gierl, Mark J.; Lai, Hollis

    2013-01-01

    Changes to the design and development of our educational assessments are resulting in the unprecedented demand for a large and continuous supply of content-specific test items. One way to address this growing demand is with automatic item generation (AIG). AIG is the process of using item models to generate test items with the aid of computer…

  14. CD-ROM Based Multimedia Homework Solutions and Self Test Generator.

    ERIC Educational Resources Information Center

    Rhodes, Jeffrey M.; Bell, Christopher C.

    1998-01-01

    Discusses a prototype multimedia application that was designed to help college students solve problems and generate practice tests for an economics textbook. Highlights include step-by-step problem solving; a friendly interface; student tracking; inexpensive development costs; examples of screen displays; and generating random, scored tests on…

  15. The case for endurance testing of sodium-heated steam generators

    SciTech Connect

    Onesto, A.T.; Zweig, H.R.; Gibbs, D.C. . Rocketdyne Division.); Carlson, R.D. ); Rodwell, E. ); Kakarala, C.R. )

    1993-08-01

    After operating pressurized water reactor (PWR) steam generators in U.S. nuclear plants during the past 33 years and plugging thousands of tubes and replacing numerous steam generators at immense costs, utility and steam generator designers are now confident that they can design, build, and operate PWR steam generators successfully. Deployment of liquid-metal fast breeder reactors (LMFBRs) will likely follow the same scenario if long-term testing is not performed and development completed prior to commercial deployment. A case is made for endurance testing of steam generators to be used in future LMFBRs.

  16. Coincident steam generator tube rupture and stuck-open safety relief valve carryover tests: MB-2 steam generator transient response test program

    SciTech Connect

    Garbett, K; Mendler, O J; Gardner, G C; Garnsey, R; Young, M Y

    1987-03-01

    In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. In addition to the release of fission products from the bulk steam generator water by moisture carryover, there exists the possibility that some primary coolant may be released without having first mixed with the bulk water - a process called primary coolant bypassing. The MB-2 Phase II test program was designed specifically to identify the processes for droplet carryover during SGTR faults and to provide data of sufficient accuracy for use in developing physical models and computer codes to describe activity release. The test program consisted of sixteen separate tests designed to cover a range of steady-state and transient fault conditions. These included a full SGTR/SORV transient simulation, two SGTR overfill tests, ten steady-state SGTR tests at water levels ranging from very low levels in the bundle up to those when the dryer was flooded, and three moisture carryover tests without SGTR. In these tests the influence of break location and the effect of bypassing the dryer were also studied. In a final test the behavior with respect to aerosol particles in a dry steam generator, appropriate to a severe accident fault, was investigated.

  17. Next-generation PIR security sensors: concept testing and evaluation

    NASA Astrophysics Data System (ADS)

    Liddiard, Kevin C.

    2009-05-01

    In previous presentations to this SPIE forum a new technology was outlined aimed at replacing pyroelectric sensors with resistance microbolometer MOEMS-based sensors capable of vastly superior performance. The technology can be implemented as either a PCB replacement to current sensors, giving extended detection range and ability to sense slow temperature change, or a 'smart' sensor with further performance enhancements and imaging capability. This paper reports the results of new laboratory and field tests of a laboratory prototype sensor and extrapolates these results to performance of production sensors. In particular, results are presented for NETD, detection range for human targets and detection of simulated electrical faults and developing fires. Previous results were reported for FPA operated without evacuation and using a low cost plastic Fresnel lens. However with wafer level packaging now becoming widely available in MEMS and CMOS foundries, much high performance can be achieved, opening up many additional applications. Performance of new FPAs designed for vacuum packaging is highlighted.

  18. Development and Demonstration of an Ada Test Generation System

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In this project we have built a prototype system that performs Feasible Path Analysis on Ada programs: given a description of a set of control flow paths through a procedure, and a predicate at a program point feasible path analysis determines if there is input data which causes execution to flow down some path in the collection reaching the point so that tile predicate is true. Feasible path analysis can be applied to program testing, program slicing, array bounds checking, and other forms of anomaly checking. FPA is central to most applications of program analysis. But, because this problem is formally unsolvable, syntactic-based approximations are used in its place. For example, in dead-code analysis the problem is to determine if there are any input values which cause execution to reach a specified program point. Instead an approximation to this problem is computed: determine whether there is a control flow path from the start of the program to the point. This syntactic approximation is efficiently computable and conservative: if there is no such path the program point is clearly unreachable, but if there is such a path, the analysis is inconclusive, and the code is assumed to be live. Such conservative analysis too often yields unsatisfactory results because the approximation is too weak. As another example, consider data flow analysis. A du-pair is a pair of program points such that the first point is a definition of a variable and the second point a use and for which there exists a definition-free path from the definition to the use. The sharper, semantic definition of a du-pair requires that there be a feasible definition-free path from the definition to the use. A compiler using du-pairs for detecting dead variables may miss optimizations by not considering feasibility. Similarly, a program analyzer computing program slices to merge parallel versions may report conflicts where none exist. In the context of software testing, feasibility analysis plays an

  19. Gas Generation Testing of Neptunium Oxide Generated Using the HB-Line Phase IIFlowsheet

    SciTech Connect

    Duffey, J

    2003-08-29

    The hydrogen (H{sub 2}) gas generation rate for neptunium dioxide (NpO{sub 2}) samples produced on a laboratory scale using the HB-Line Phase II flowsheet has been measured following exposure to 75% relative humidity (RH). As expected, the observed H{sub 2} generation rates for these samples increase with increasing moisture content. A maximum H{sub 2} generation rate of 1.8 x 10{sup -6} moles per day per kilogram (mol {center_dot} day{sup -1} kg{sup -1}) was observed for NpO{sub 2} samples with approximately one and one-half times (1 1/2 X) the expected specific surface area (SSA) for the HB-Line Phase II product. The SSA of NpO{sub 2} samples calcined at 650 C is similar to plutonium dioxide (PuO{sub 2}) calcined at 950 C according to the Department of Energy (DOE) standard for packaging and storage of PuO{sub 2}. This low SSA of the HB-Line Phase II product limits moisture uptake to less than 0.2 weight percent (wt %) even with extended exposure to 75% RH.

  20. Understanding Referral Patterns for Bone Mineral Density Testing among Family Physicians: A Qualitative Descriptive Study

    PubMed Central

    Munce, Sarah E. P.; Allin, Sonya; Carlin, Leslie; Sale, Joanna; Hawker, Gillian; Kim, Sandra; Butt, Debra A.; Polidoulis, Irene; Tu, Karen; Jaglal, Susan B.

    2016-01-01

    Introduction. Evidence of inappropriate bone mineral density (BMD) testing has been identified in terms of overtesting in low risk women and undertesting among patients at high risk. In light of these phenomena, the objective of this study was to understand the referral patterns for BMD testing among Ontario's family physicians (FPs). Methods. A qualitative descriptive approach was adopted. Twenty-two FPs took part in a semi-structured interview lasting approximately 30 minutes. An inductive thematic analysis was performed on the transcribed data in order to understand the referral patterns for BMD testing. Results. We identified a lack of clarity about screening for osteoporosis with a tendency for baseline BMD testing in healthy, postmenopausal women and a lack of clarity on the appropriate age for screening for men in particular. A lack of clarity on appropriate intervals for follow-up testing was also described. Conclusions. These findings lend support to what has been documented at the population level suggesting a tendency among FPs to refer menopausal women (at low risk). Emphasis on referral of high-risk groups as well as men and further clarification and education on the appropriate intervals for follow-up testing is warranted. PMID:26904357

  1. Test case set generation method on MC/DC based on binary tree

    NASA Astrophysics Data System (ADS)

    Wang, Jun-jie; Zhang, Bo; Chen, Yuan

    2013-03-01

    Exploring efficient, reliable test case design methods has been tester pursuit of the goal. Along with the aerospace software logic complexity of improving and software scale enlarging, this requirement also gets more compelling. Test case design techniques suited for MC/DC improved test case design efficiency, increase the test coverage. It is suitable to test the software that logical relationship is complicated comparatively. Some software test tools provide the function to calculate the test coverage. And it can assess the test cases whether on the MC/DC or not. But the software tester needs the reverse thinking. The paper puts forward that design the test case by Unique-cause and Masking approach. And it proposes automatic generation method of test case on MC/DC. It improved the efficiency and correctness of generation the test case set on DC/DC.

  2. Functional test generation for digital circuits described with a declarative language: LUSTRE

    NASA Astrophysics Data System (ADS)

    Almahrous, Mazen

    1990-08-01

    A functional approach to the test generation problem starting from a high level description is proposed. The circuit tested is modeled, using the LUSTRE high level data flow description language. The different LUSTRE primitives are translated to a SATAN format graph in order to evaluate the testability of the circuit and to generate test sequences. Another method of testing the complex circuits comprising an operative part and a control part is defined. It consists of checking experiments for the control part observed through the operative part. It was applied to the automata generated from a LUSTRE description of the circuit.

  3. Summary of DEEP STEAM downhole steam generator development activities. [Kern River and Long Beach field tests

    SciTech Connect

    Donaldson, A.B.; Fox, R.L.; Mulac, A.J.

    1981-01-01

    In this paper the concept and goals of the DOE program, DEEP STEAM, as related to the development of a downhole steam generator for deep heavy oil recovery will be discussed. Additionally, the past, present and future activities of the development program being carried out at Sandia National Laboratories will be discussed. These include evaluation studies, surface testing at Bakersfield, CA, a run-in test at Hobbs, NM, and status of field testing at Long Beach, CA. The Long Beach test includes both a downhole diesel-air generator and a surface diesel-oxygen generator. 7 figures.

  4. Comparison of acuity tests and pattern evoked potential criteria: two mechanisms underly acuity maturation in man.

    PubMed

    Spekreijse, H

    1983-10-01

    A comparative study of acuity tests and pattern evoked potential (EP) criteria was performed on a total of 307 subjects, 214 of them at an age between 2 months post-term and 12 years. All were examined ophthalmologically prior to testing. It was shown that both psychophysical and EP estimated acuity improve in the same way until puberty. From birth to about 6 months a rapid improvement is found. This fast phase can probably be attributed to retinal morphological maturation. During this period a fair estimate of acuity can be obtained by determining the checksize that yields the largest EP; a conclusion of practical importance for screening. The subsequent slow improvement phase, which ends around puberty, is reflected in the development of the waveform of the pattern onset EP. Since it correlates with the growth of a spatial contrast specific component of extrastriate origin in the EP, the slow improvement phase most likely reflects maturation of central processes. PMID:6639719

  5. Electronic speckle pattern shearing interferometry for nondestructive testing of thermal sprayed alloy coatings

    NASA Astrophysics Data System (ADS)

    Xue, Yueqiang; Kennedy, David; Mihaylova, Emilia

    2005-06-01

    Thermal sprayed coatings have wide engineering applications. There now exists a wide range of destructive and nondestructive testing (NDT) methods for surface coating inspections. This paper describes an application of Electronic Speckle Pattern Shearing Interferometry (ESPSI) for NDT of thermal sprayed surface coatings. In contrast to other conventional methods such as eddy current, ultrasonic or X-ray, ESPSI allows fast and large survey area inspection. Experimental results of shearographic measurements are presented. Thermal sprayed coatings were tested using ESPSI. Delaminations of the coatings were detected and the fringe patterns were captured using this method. It is shown that the shearography technique can be applied successfully to surface coating quality inspection and it is very effective for delamination detection.

  6. Extreme ultraviolet lithography patterned mask defect detection performance evaluation toward 16- to 11-nm half-pitch generation

    NASA Astrophysics Data System (ADS)

    Hirano, Ryoichi; Iida, Susumu; Amano, Tsuyoshi; Watanabe, Hidehiro; Hatakeyama, Masahiro; Murakami, Takeshi; Yoshikawa, Shoji; Terao, Kenji

    2015-07-01

    High-sensitivity and low-noise extreme ultraviolet (EUV) mask pattern defect detection is one of the major issues remaining to be addressed in device fabrication using extreme ultraviolet lithography (EUVL). We have designed a projection electron microscopy (PEM) system, which has proven to be quite promising for half-pitch (hp) 16-nm node to hp 11-nm node mask inspection. The PEM system was integrated into a pattern inspection system for defect detection sensitivity evaluation. To improve the performance of hp 16-nm patterned mask defect detection toward hp 11-nm EUVL patterned mask, defect detection signal characteristics, which depend on hp 64-nm pattern image intensity deviation on EUVL mask, were studied. Image adjustment effect of the captured images for die-to-die defect detection was evaluated before the start of the defect detection image-processing sequence. Image correction of intrafield intensity unevenness and L/S pattern image contrast deviation suppresses the generation of false defects. Captured images of extrusion and intrusion defects in hp 64-nm L/S patterns were used for detection. Applying the image correction for defect detection, 12-nm sized intrusion defect, which was smaller than our target size for hp 16-nm defect detection requirements, was identified without false defects.

  7. Aging and Generational Patterns of Alcohol Consumption among Mexican Americans, Cuban Americans and Mainland Puerto Ricans.

    ERIC Educational Resources Information Center

    Black, Sandra A.; Markides, Kyriakos S.

    1994-01-01

    Used data from Hispanic Health and Nutrition Examination Survey to describe life-course patterns of alcohol consumption among Mexican Americans, Cuban Americans, and Puerto Ricans residing in mainland United States. Found age differences in patterns of consumption among Mexican American and Puerto Rican males that reflect aging effects. Found…

  8. Automatic Generation of Rasch-Calibrated Items: Figural Matrices Test GEOM and Endless-Loops Test EC

    ERIC Educational Resources Information Center

    Arendasy, Martin

    2005-01-01

    The future of test construction for certain psychological ability domains that can be analyzed well in a structured manner may lie--at the very least for reasons of test security--in the field of automatic item generation. In this context, a question that has not been explicitly addressed is whether it is possible to embed an item response theory…

  9. Genetic Algorithm-Based Test Data Generation for Multiple Paths via Individual Sharing

    PubMed Central

    Gong, Dunwei

    2014-01-01

    The application of genetic algorithms in automatically generating test data has aroused broad concerns and obtained delightful achievements in recent years. However, the efficiency of genetic algorithm-based test data generation for path testing needs to be further improved. In this paper, we establish a mathematical model of generating test data for multiple paths coverage. Then, a multipopulation genetic algorithm with individual sharing is presented to solve the established model. We not only analyzed the performance of the proposed method theoretically, but also applied it to various programs under test. The experimental results show that the proposed method can improve the efficiency of generating test data for many paths' coverage significantly. PMID:25691894

  10. Pattern recognition techniques for failure trend detection in SSME ground tests

    NASA Technical Reports Server (NTRS)

    Choudry, A.

    1987-01-01

    The Space Shuttle Main Engine (SSME) is a complex power plant. To evaluate its performance 1200 hot-wire ground tests have been conducted, varying in duration from 0 to 500 secs. During the test some 500 sensors are sampled every 20 ms. The sensors are generally bounded by red lines so that an excursion beyond could lead to premature shutdown. In 27 tests it was not possible to effect an orderly premature shutdown, resulting in major incidents with serious damage to the SSME and test stand. The application of pattern recognition are investigated to detect SSME performance trends that may lead to major incidents. Based on the sensor data a set of (n) features is defined. At any time during the test, the state of the SSME is given by a point in the n-dimensional feature space. The history of a test can now be represented as a trajectory in the n-dimensional feature space. Portions of the normal trajectories and failed test trajectories would lie in different regions of the n-dimensional feature space. The latter can now be partitioned into regions of normal and failed tests. Thus, it is possible to examine the trajectory of a test in progress and predict if it is going into the normal or failure region.

  11. Convective thermal fluxes in unsteady non-homogeneous flows generating complex three dimensional vorticity patterns

    NASA Astrophysics Data System (ADS)

    Tellez Alvarez, Jackson David; Redondo, Jose Manuel; Sanchez, Jesu Mary

    2016-04-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form convective driven mixing. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2, 3]. We parametrize the role of unstable stratification by means of the Rayleigh and Atwood numbers and compare the scaling and the multifractal structure functions of the different markers used to visualize the non-homogeneous. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overall turbulent process is evaluated [4 - 6]. Diffusion is measured in the transition from a homogeneous linearly stratified fluid to a cellular or layered structure by means of Thermoelectric generated heating and cooling [2, 4]. Patterns arise by setting up a convective flow generated by a buoyant heat flux either in the base or in a side wall of the convective enclosure [1, 6]. The experiments described here investigate high Prandtl number mixing using brine or sugar solutions and fresh water in order to form a density interface and low Prandtl number mixing with only temperature gradients [7]. The set of dimensionless parameters define conditions of numeric and small scale laboratory modeling of environmental flows. Fields of velocity, density and their gradients were computed and visualized [8, 9]. When convective heating and cooling takes place the combination of internal waves and buoyant turbulence is much more complicated if the Rayleigh and Reynolds numbers are high in order to study entrainment and mixing. The experiments described here investigate high Prandtl number mixing using salt or sugar solutions and

  12. Computerized in vitro test for chemical toxicity based on tetrahymena swimming patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

    1994-01-01

    An apparatus and method for rapidly determining chemical toxicity was evaluated. The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The device, called the Motility Assay Apparatus (MAA) is tested for 30 second determination of chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy, in addition to agreeing for all chemicals with previous manual evaluations of single cell motility.

  13. Modular organization of the multipartite central pattern generator for turtle rostral scratch: knee-related interneurons during deletions.

    PubMed

    Stein, Paul S G; Daniels-McQueen, Susan; Lai, Jessica; Liu, Z; Corman, Tanya S

    2016-06-01

    Central pattern generators (CPGs) are neuronal networks in the spinal cord that generate rhythmic patterns of motor activity in the absence of movement-related sensory feedback. For many vertebrate rhythmic behaviors, CPGs generate normal patterns of motor neuron activities as well as variations of the normal patterns, termed deletions, in which bursts in one or more motor nerves are absent from one or more cycles of the rhythm. Prior work with hip-extensor deletions during turtle rostral scratch supports hypotheses of hip-extensor interneurons in a hip-extensor module and of hip-flexor interneurons in a hip-flexor module. We present here single-unit interneuronal recording data that support hypotheses of knee-extensor interneurons in a knee-extensor module and of knee-flexor interneurons in a knee-flexor module. Members of knee-related modules are not members of hip-related modules and vice versa. These results in turtle provide experimental support at the single-unit interneuronal level for the organizational concept that the rostral-scratch CPG for the turtle hindlimb is multipartite, that is, composed of more than two modules. This work, when combined with experimental and computational work in other vertebrates, does not support the classical view that the vertebrate limb CPG is bipartite with only two modules, one controlling all the flexors of the limb and the other controlling all the extensors of the limb. Instead, these results support the general principle that spinal CPGs are multipartite. PMID:27030737

  14. A test sheet generating algorithm based on intelligent genetic algorithm and hierarchical planning

    NASA Astrophysics Data System (ADS)

    Gu, Peipei; Niu, Zhendong; Chen, Xuting; Chen, Wei

    2013-03-01

    In recent years, computer-based testing has become an effective method to evaluate students' overall learning progress so that appropriate guiding strategies can be recommended. Research has been done to develop intelligent test assembling systems which can automatically generate test sheets based on given parameters of test items. A good multisubject test sheet depends on not only the quality of the test items but also the construction of the sheet. Effective and efficient construction of test sheets according to multiple subjects and criteria is a challenging problem. In this paper, a multi-subject test sheet generation problem is formulated and a test sheet generating approach based on intelligent genetic algorithm and hierarchical planning (GAHP) is proposed to tackle this problem. The proposed approach utilizes hierarchical planning to simplify the multi-subject testing problem and adopts genetic algorithm to process the layered criteria, enabling the construction of good test sheets according to multiple test item requirements. Experiments are conducted and the results show that the proposed approach is capable of effectively generating multi-subject test sheets that meet specified requirements and achieve good performance.

  15. A test sheet generating algorithm based on intelligent genetic algorithm and hierarchical planning

    NASA Astrophysics Data System (ADS)

    Gu, Peipei; Niu, Zhendong; Chen, Xuting; Chen, Wei

    2012-04-01

    In recent years, computer-based testing has become an effective method to evaluate students' overall learning progress so that appropriate guiding strategies can be recommended. Research has been done to develop intelligent test assembling systems which can automatically generate test sheets based on given parameters of test items. A good multisubject test sheet depends on not only the quality of the test items but also the construction of the sheet. Effective and efficient construction of test sheets according to multiple subjects and criteria is a challenging problem. In this paper, a multi-subject test sheet generation problem is formulated and a test sheet generating approach based on intelligent genetic algorithm and hierarchical planning (GAHP) is proposed to tackle this problem. The proposed approach utilizes hierarchical planning to simplify the multi-subject testing problem and adopts genetic algorithm to process the layered criteria, enabling the construction of good test sheets according to multiple test item requirements. Experiments are conducted and the results show that the proposed approach is capable of effectively generating multi-subject test sheets that meet specified requirements and achieve good performance.

  16. Direct imaging of periodic subwavelength patterns generated by optical phase masks

    SciTech Connect

    Tonyushkin, Alexei; Sleator, Tycho

    2006-11-15

    We have demonstrated direct imaging of interference fringes of total atomic density with periods {lambda}/4 and {lambda}/2 for optical wavelength {lambda} that have been produced in a de Broglie wave atom interferometer. The imaging was done by means of an 'optical mask' technique, which allowed us to observe subwavelength periodic patterns with a resolution of up to {lambda}/16. In addition, the dependence of the fringe pattern on the recoil phase and pulse area reveals quantum dynamics in the atomic center-of-mass motion. The behavior of the fringe patterns near the interference times distinguishes the effects of phase gratings from those of amplitude gratings.

  17. Testing amniote models of prey transport kinematics: a quantitative analysis of mouth opening patterns in lizards.

    PubMed

    McBrayer, Lance D; Reilly, Stephen M

    2002-01-01

    Two models have been proposed to describe the prey transport kinematics of terrestrial vertebrates (Bramble and Wake, 1985; Reilly and Lauder, 1990). The critical difference between the models is the presence or absence of a slow open-II phase (SO-II) in the gape profile during mouth opening. Each of these models has been applied to lizards, however to date, lizard feeding kinematics have not been adequately quantified to assess the utility of these models for this clade. Neither model has been sufficiently tested due to the lack of a methodology to assess the specific differences between the models. We describe a method that uses explicit mathematical criteria to define the kinematic phases in tetrapod feeding. This "slope analysis& is used to precisely quantify and compare the transport kinematics of seven lizard species. Lizard transport kinematics were highly variable both within and across taxa. However, several common gape cycle patterns were identified. The predominant patterns were slow-fast opening (37.3%), fast opening only (22.9%) and slow opening only (21.2%). The most common pattern explicitly fits the prediction of the Reilly and Lauder model while the other two are similar to patterns observed in salamanders. Thus, lizards possess both the slow opening-fast opening pattern predicted for amniotes and the more primitive, simple opening pattern characteristic of more basal tetrapods. Plateau phases were found in only 12.8% of the profiles and only a fourth of these (3.4% of the total) explicitly fit the Bramble and Wake model (slow opening, plateau, fast opening) and two species never exhibited plateaus in their gape cycles. Thus, it is clear that the Bramble and Wake model is not supported as a generalized model for lizards or generalized tetrapods. PMID:16351858

  18. Physician Care Patterns and Adherence to Postpartum Glucose Testing after Gestational Diabetes Mellitus in Oregon

    PubMed Central

    Hunsberger, Monica L.; Donatelle, Rebecca J.; Lindsay, Karen; Rosenberg, Kenneth D.

    2012-01-01

    Objective This study examines obstetrician/gynecologists and family medicine physicians' reported care patterns, attitudes and beliefs and predictors of adherence to postpartum testing in women with a history of gestational diabetes mellitus. Research Design and Methods In November–December 2005, a mailed survey went to a random, cross-sectional sample of 683 Oregon licensed physicians in obstetrician/gynecologists and family medicine from a population of 2171. Results Routine postpartum glucose tolerance testing by both family physicians (19.3%) and obstetrician/gynecologists physicians (35.3%) was reportedly low among the 285 respondents (42% response rate). Factors associated with high adherence to postpartum testing included physician stated priority (OR 4.39, 95% CI: 1.69–7.94) and physician beliefs about norms or typical testing practices (OR 3.66, 95% CI: 1.65–11.69). Specialty, sex of physician, years of practice, location, type of practice, other attitudes and beliefs were not associated with postpartum glucose tolerance testing. Conclusions Postpartum glucose tolerance testing following a gestational diabetes mellitus pregnancy was not routinely practiced by responders to this survey. Our findings indicate that physician knowledge, attitudes and beliefs may in part explain suboptimal postpartum testing. Although guidelines for postpartum care are established, some physicians do not prioritize these guidelines in practice and do not believe postpartum testing is the norm among their peers. PMID:23071709

  19. Patterned mask inspection technology with Projection Electron Microscope (PEM) technique for 11 nm half-pitch (hp) generation EUV masks

    NASA Astrophysics Data System (ADS)

    Hirano, Ryoichi; Iida, Susumu; Amano, Tsuyoshi; Watanabe, Hidehiro; Hatakeyama, Masahiro; Murakami, Takeshi; Yoshikawa, Shoji; Suematsu, Kenichi; Terao, Kenji

    2015-07-01

    High-sensitivity EUV mask pattern defect detection is one of the major issues in order to realize the device fabrication by using the EUV lithography. We have already designed a novel Projection Electron Microscope (PEM) optics that has been integrated into a new inspection system named EBEYE-V30 ("Model EBEYE" is an EBARA's model code), and which seems to be quite promising for 16 nm hp generation EUVL Patterned mask Inspection (PI). Defect inspection sensitivity was evaluated by capturing an electron image generated at the mask by focusing onto an image sensor. The progress of the novel PEM optics performance is not only about making an image sensor with higher resolution but also about doing a better image processing to enhance the defect signal. In this paper, we describe the experimental results of EUV patterned mask inspection using the above-mentioned system. The performance of the system is measured in terms of defect detectability for 11 nm hp generation EUV mask. To improve the inspection throughput for 11 nm hp generation defect detection, it would require a data processing rate of greater than 1.5 Giga- Pixel-Per-Second (GPPS) that would realize less than eight hours of inspection time including the step-and-scan motion associated with the process. The aims of the development program are to attain a higher throughput, and enhance the defect detection sensitivity by using an adequate pixel size with sophisticated image processing resulting in a higher processing rate.

  20. Relating HIV testing patterns in Poland to risky and protective behaviour.

    PubMed

    Rosińska, Magdalena; Simmons, Ruth; Marzec-Bogusławska, Anna; Janiec, Janusz; Porter, Kholoud

    2016-04-01

    The aim of the study was to understand HIV testing patterns needed to improve access to early HIV diagnosis, and to investigate the spread of the virus in different populations. We examined prior testing history of individuals presenting for an HIV test across all 30 voluntary testing and counselling sites in Poland, 2008-2010 to determine factors associated with the testing rate using zero-truncated Poisson regression. Of 2397 persons presenting for an HIV test, 25 (1%) were HIV positive and 470 (19.6%) were repeat testers. The proportion of repeat testers was higher among men who have sex with men (MSM) at 37% (90/246), and people who inject drugs (PWID) at 32% (21/65). Higher testing rate was independently associated with exposure category (testing rate ratio, RR for MSM = 2.0, 95% CI 1.6-2.6, and 1.6, 0.9-2.6 for PWID), >5 sex partners (1.9, 1.4-2.7), high-risk partner (1.3, 1.1-1.6), urban residence (2.1, 1.3-3.5) and higher education attainment (1.1, 1.0-1.5). Inconsistent condom use with casual partners and sex under the influence of alcohol were associated with lower testing rates. There is a need to increase HIV testing uptake in Poland, especially among the rural population. Despite testing rates being higher among populations with higher risk of exposure to HIV (MSM and PWID), they still remain low, indicating the existence of barriers to testing. PMID:26559856

  1. Control strategies of 3-cell Central Pattern Generator via global stimuli

    PubMed Central

    Lozano, Álvaro; Rodríguez, Marcos; Barrio, Roberto

    2016-01-01

    The study of the synchronization patterns of small neuron networks that control several biological processes has become an interesting growing discipline. Some of these synchronization patterns of individual neurons are related to some undesirable neurological diseases, and they are believed to play a crucial role in the emergence of pathological rhythmic brain activity in different diseases, like Parkinson’s disease. We show how, with a suitable combination of short and weak global inhibitory and excitatory stimuli over the whole network, we can switch between different stable bursting patterns in small neuron networks (in our case a 3-neuron network). We develop a systematic study showing and explaining the effects of applying the pulses at different moments. Moreover, we compare the technique on a completely symmetric network and on a slightly perturbed one (a much more realistic situation). The present approach of using global stimuli may allow to avoid undesirable synchronization patterns with nonaggressive stimuli. PMID:27021970

  2. Control strategies of 3-cell Central Pattern Generator via global stimuli

    NASA Astrophysics Data System (ADS)

    Lozano, Álvaro; Rodríguez, Marcos; Barrio, Roberto

    2016-03-01

    The study of the synchronization patterns of small neuron networks that control several biological processes has become an interesting growing discipline. Some of these synchronization patterns of individual neurons are related to some undesirable neurological diseases, and they are believed to play a crucial role in the emergence of pathological rhythmic brain activity in different diseases, like Parkinson’s disease. We show how, with a suitable combination of short and weak global inhibitory and excitatory stimuli over the whole network, we can switch between different stable bursting patterns in small neuron networks (in our case a 3-neuron network). We develop a systematic study showing and explaining the effects of applying the pulses at different moments. Moreover, we compare the technique on a completely symmetric network and on a slightly perturbed one (a much more realistic situation). The present approach of using global stimuli may allow to avoid undesirable synchronization patterns with nonaggressive stimuli.

  3. The Negative Testing and Negative Generation Effects Are Eliminated by Delay

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Peterson, Daniel J.

    2015-01-01

    Although retrieval often enhances subsequent memory (the testing effect), a negative testing effect has recently been documented in which prior retrieval harms later recall compared with restudying. The negative testing effect was predicated on the negative generation effect and the item-specific-relational framework. The present experiments…

  4. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. An engineering unit, the ASRG engineering unit (EU), was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently under extended operation test at the NASA Glenn Research Center (GRC) to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for the ASRG EU. This paper summarizes details of the test facility design, including the mechanical mounting, heat-rejection system, argon system, control systems, and maintenance. The effort proceeded from requirements definition through design, analysis, build, and test. Initial testing and facility performance results are discussed.

  5. Performance testing of thermoelectric generators including Voyager and LES 8/9 flight results

    NASA Technical Reports Server (NTRS)

    Garvey, L.; Stapfer, G.

    1979-01-01

    Several thermoelectric generators ranging in output power from 0.5 to 155 W have been completed or are undergoing testing at JPL. These generators represent a wide range of technologies, using Bi2Te3, PbTe and SiGe thermoelectric materials. Several of these generators are of a developmental type, such as HPG S/N2, and others are representative of Transit and Multi-Hundred Watt (MHW) Technology. Representative flight performance data of LES 8/9 and Voyager RTG's are presented and compared with the DEGRA computer program based on the data observed from tests of SiGe couples, modules and MHW generators.

  6. An unsupervised pattern recognition approach for AE data originating from fatigue tests on polymer-composite materials

    NASA Astrophysics Data System (ADS)

    Doan, D. D.; Ramasso, E.; Placet, V.; Zhang, S.; Boubakar, L.; Zerhouni, N.

    2015-12-01

    This work investigates acoustic emission generated during tension fatigue tests carried out on a carbon fiber reinforced polymer (CFRP) composite specimen. Since massive fatigue data processing, especially noise reduction, remains an important challenge in AE data analysis, a Mahalanobis distance-based noise modeling has been proposed in the present work to tackle this problem. A sequential feature selection based on Davies-Bouldin index has been implemented for fast dimensionality reduction. An unsupervised classifier offline-learned from quasi-static data is then used to classify the data to different AE sources with the possibility to dynamically accommodate with unseen ones. With an efficient proposed noise removal and automatic separation of AE events, this pattern discovery procedure provides an insight into fatigue damage development in composites in the presence of millions of AE events.

  7. Convective thermal fluxes in unsteady non-homogeneous flows generating complex three dimensional vorticity patterns

    NASA Astrophysics Data System (ADS)

    Tellez Alvarez, Jackson David; Redondo, Jose Manuel; Sanchez, Jesu Mary

    2016-04-01

    The improvements in experimental methods and high resolution image analysis are nowadays able to detect subtle changes in the structure of the turbulence over a wide range of temporal and spatial scales [1], we compare the scaling shown by different mixing fronts driven by buoyancy that form convective driven mixing. We use PIV and density front tracking in several experimental configurations akin to geophysical overturning [2, 3]. We parametrize the role of unstable stratification by means of the Rayleigh and Atwood numbers and compare the scaling and the multifractal structure functions of the different markers used to visualize the non-homogeneous. Both reactive and passive scalar tracers are used to investigate the mixing structure and the intermittency of the flow. Different initial conditions are compared and the mixing efficiency of the overall turbulent process is evaluated [4 - 6]. Diffusion is measured in the transition from a homogeneous linearly stratified fluid to a cellular or layered structure by means of Thermoelectric generated heating and cooling [2, 4]. Patterns arise by setting up a convective flow generated by a buoyant heat flux either in the base or in a side wall of the convective enclosure [1, 6]. The experiments described here investigate high Prandtl number mixing using brine or sugar solutions and fresh water in order to form a density interface and low Prandtl number mixing with only temperature gradients [7]. The set of dimensionless parameters define conditions of numeric and small scale laboratory modeling of environmental flows. Fields of velocity, density and their gradients were computed and visualized [8, 9]. When convective heating and cooling takes place the combination of internal waves and buoyant turbulence is much more complicated if the Rayleigh and Reynolds numbers are high in order to study entrainment and mixing. The experiments described here investigate high Prandtl number mixing using salt or sugar solutions and

  8. Field Test Protocol: Standard Internal Load Generation in Unoccupied Test Homes

    SciTech Connect

    Fang, X.; Christensen, D.; Barker, G.; Hancock, E.

    2011-06-01

    This document describes a simple and general way to generate House Simulation Protocol (HSP)-consistent internal sensible and latent loads in unoccupied homes. It is newly updated based on recent experience, and provides instructions on how to calculate and set up the operational profiles in unoccupied homes. The document is split into two sections: how to calculate the internal load magnitude and schedule, and then what tools and methods should be used to generate those internal loads to achieve research goals.

  9. Field Test Protocol. Standard Internal Load Generation for Unoccupied Test Homes

    SciTech Connect

    Fang, X.; Christensen, D.; Barker, G.; Hancock, E.

    2011-06-01

    This document describes a simple and general way to generate House Simulation Protocol (HSP)-consistent internal sensible and latent loads in unoccupied homes. It is newly updated based on recent experience, and provides instructions on how to calculate and set up the operational profiles in unoccupied homes. The document is split into two sections: how to calculate the internal load magnitude and schedule, and then what tools and methods should be used to generate those internal loads to achieve research goals.

  10. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Unknown

    2002-01-31

    The objective of this report period was to continue the development of the Gas Generator design, fabrication and test of the non-polluting unique power turbine drive Gas Generator. Focus during this past report period has been to continue completion the Gas Generator design, completing the brazing and bonding experiments to determine the best method and materials necessary to fabricate the Gas Generator hardware, continuing to making preparations for fabricating and testing this Gas Generator and commencing with the fabrication of the Gas Generator hardware and ancillary hardware. Designs have been completed sufficiently such that Long Lead Items [LLI] have been ordered and upon arrival will be readied for the fabrication process. The keys to this design are the platelet construction of the injectors that precisely measures/meters the flow of the propellants and water all throughout the steam generating process and the CES patented gas generating cycle. The Igniter Assembly injector platelets fabrication process has been completed and bonded to the Igniter Assembly and final machined. The Igniter Assembly is in final assembly and is being readied for testing in the October 2001 time frame. Test Plan dated August 2001, was revised and finalized, replacing Test Plan dated May 2001.

  11. Rapid Generation of Multiplexed Cell Cocultures Using Acoustic Droplet Ejection Followed by Aqueous Two-Phase Exclusion Patterning

    PubMed Central

    Fang, Yu; Frampton, John P.; Raghavan, Shreya; Sabahi-Kaviani, Rahman; Luker, Gary

    2012-01-01

    The development of tools for patterning cocultures of cells is a fundamental interest among cell biologists and tissue engineers. Although a variety of systems exist for micropatterning cells, the methods used to generate cell micropatterns are often cumbersome and difficult to adapt for tissue engineering purposes. This study combines acoustic droplet ejection and aqueous two-phase system exclusion patterning to introduce a method for patterning cocultures of cells in multiplexed arrays. This new method uses focused acoustic radiation pressure to eject discrete droplets of uniform size from the surface of a dextran solution containing cells. The size of droplets is controlled by adjusting ultrasound parameters, such as pulse, duration, and amplitude. The ejected dextran droplets are captured on a cell culture substrate that is manipulated by a computer-controlled 3D positioning system according to predesigned patterns. Polyethylene glycol solution containing an additional cell type is then added to the culture dish to produce a two-phase system capable of depositing different types of cells around the initial pattern of cells. We demonstrate that our method can produce patterns of islands or lines with two or more cell types. Further, we demonstrate that patterns can be multiplexed for studies involving combinations of multiple cell types. This method offers a tool to transfer cell-containing samples in a contact-free, nozzle-less manner, avoiding sample cross-contamination. It can be used to pattern cell cocultures without complicated fabrication of culture substrates. These capabilities were used to examine the response of cancer cells to the presence of a ligand (CXCL12) secreted from surrounding cocultured cells. PMID:22356298

  12. Direct magnetic patterning due to the generation of ferromagnetism by selective ion irradiation of paramagnetic FeAl alloys.

    PubMed

    Menéndez, Enric; Liedke, Maciej Oskar; Fassbender, Jürgen; Gemming, Thomas; Weber, Anja; Heyderman, Laura J; Rao, K V; Deevi, Seetharama C; Suriñach, Santiago; Baró, Maria Dolors; Sort, Jordi; Nogués, Josep

    2009-02-01

    Sub-100-nm magnetic dots embedded in a non-magnetic matrix are controllably generated by selective ion irradiation of paramagnetic Fe(60)Al(40) (atomic %) alloys, taking advantage of the disorder-induced magnetism in this material. The process is demonstrated by sequential focused ion beam irradiation and by in-parallel broad-beam ion irradiation through lithographed masks. Due to the low fluences used, this method results in practically no alteration of the surface roughness. The dots exhibit a range of magnetic properties depending on the size and shape of the structures, with the smallest dots (<100 nm) having square hysteresis loops with coercivities in excess of micro(0)H(C) = 50 mT. Importantly, the patterning can be fully removed by annealing. The combination of properties induced by the direct magnetic patterning is appealing for a wide range of applications, such as patterned media, magnetic separators, or sensors. PMID:19089839

  13. Clinical audit of genetic testing and referral patterns for fragile X and associated conditions.

    PubMed

    Cotter, Megan; Archibald, Alison D; McClaren, Belinda J; Burgess, Trent; Francis, David; Hills, Louise; Martyn, Melissa; Oertel, Ralph; Slater, Howard; Cohen, Jonathan; Metcalfe, Sylvia A

    2016-06-01

    An audit was conducted of laboratory/clinical databases of genetic tests performed between January 2003 and December 2009, and for 2014, as well as referrals to the clinical service and a specialist multidisciplinary clinic, to determine genetic testing request patterns for fragile X syndrome and associated conditions and referrals for genetic counseling/multidisciplinary management in Victoria, Australia. An expanded allele (full mutation, premutation or intermediate) was found in 3.7% of tests. Pediatricians requested ∼70% of test samples, although fewer general practitioners and more obstetricians/gynecologists ordered tests in 2014. Median age at testing for individuals with a full mutation seeking a diagnosis without a fragile X family history was 4.3 years (males) and 9.4 years (females); these ages were lower when pediatricians ordered the tests (2.1 years and 6.1 years, respectively). Individuals with a premutation were generally tested at a later age (median age: males, 33.2 years; females, 36.4 years). Logistic regression showed that a family history of ID (OR 3.28 P = 0.005, CI 1.77-5.98) was the only indication to independently increase the likelihood of a test-positive (FM or PM) result. Following testing, ∼25% of full mutation or premutation individuals may not have attended clinical services providing genetic counseling or multidisciplinary management for these families. The apparent delay in fragile X syndrome diagnosis and lack of appropriate referrals for some may result in less than optimal management for these families. These findings suggest continued need for awareness and education of health professionals around diagnosis and familial implications of fragile X syndrome and associated conditions. © 2016 Wiley Periodicals, Inc. PMID:26892444

  14. Generating custom test plans for CASE{sup *}Dictionary 5.0

    SciTech Connect

    Atkins, K.D.

    1994-04-01

    Most database development organizations use a formal software development methodology that requires a certain amount of formal testing. The amount of formal testing that will be performed will vary from methodology to methodology and from site to site. If a very detailed formal test plan is required for each module in a system, the work involved to produce the test plan can be tedious and costly. After a system has been designed and developed using Oracle*CASE, there is much useful information in the CASE*Dictionary repository. If this information could be tied to specific test requirements, a test plan could be generated automatically, saving much time and resources. This paper shows how CASE*Dictionary can be used to store test plan information that can then be used to generate a specific test plan for each module based on it`s detailed data usage.

  15. Belly dancer's myoclonus and chronic abdominal pain: pain-related dysinhibition of a spinal cord central pattern generator?

    PubMed

    Tamburin, Stefano; Idone, Domenico; Zanette, Giampietro

    2007-07-01

    We report on a patient with segmental rhythmic myoclonus resembling belly dance. This patient developed the myoclonus in temporal and anatomical association with chronic abdominal pain. No structural or metabolic abnormalities were found. EMG recordings suggested the presence of a spinal cord central pattern generator (CPG). We hypothesize that pain-related spinal plasticity might have contributed to the hyperactivity of a spinal CPG, thus leading to the myoclonic jerks in our patient. PMID:17049297

  16. The Identification of Discriminating Patterns from 16S rRNA Gene to Generate Signature for Bacillus Genus.

    PubMed

    More, Ravi P; Purohit, Hemant J

    2016-08-01

    The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification. PMID:27104769

  17. High-harmonic generation from a coherent superposition of electronic states: Controlling interference patterns via short and long quantum orbits

    NASA Astrophysics Data System (ADS)

    Chelkowski, Szczepan; Bredtmann, Timm; Bandrauk, André D.

    2013-09-01

    Laser pump-probe schemes are explored numerically from a molecular time-dependent Schrödinger equation for monitoring attosecond electron motion by high-order-harmonic generation (HHG) from a coherent superposition of electronic states. Varying the time delay between the probe and pump pulse on an attosecond time scale alters the HHG signal, leading to universal interference patterns. By using an extended three-step recollision model, we show that various regular interference patterns in the HHG spectra, including continuous harmonic frequency redshifts as a function of pump-probe delay, are related to interference between specific pairs of short or long quantum orbits. For small excited-state population (regime A), interferences are controlled by electron-tunneling times, whereas for equal populations (regime B), recollision time control dominates thus allowing for control of the HHG process by the pump-probe delay time and by electron-state populations. We show that each specific pattern is closely related to the interference between pairs of specific (short or long) quantum orbits originating from a specific electron bound state. One can generate a specific pattern by varying the populations in the coherent superposition, the laser intensity, wavelength, and ionization potential of the electronic states.

  18. Mixed Methods Case Study of Generational Patterns in Responses to Shame and Guilt

    ERIC Educational Resources Information Center

    Ng, Tony

    2013-01-01

    Moral socialization and moral learning are antecedents of moral motivation. As many as 4 generations interact in workplace and education settings; hence, a deeper understanding of the moral motivation of members of those generations is needed. The purpose of this convergent mixed methods case study was to understand the moral motivation of 5…

  19. Vibration Testing of the Pluto/New Horizons Radioisotope Thermoelectric Generator

    SciTech Connect

    Charles D. Griffin

    2006-06-01

    The Radioisotopic Thermal Generator (RTG) for the Pluto/New Horizons spacecraft was subjected to a flight dynamic acceptance test to demonstrate that it would perform successfully following launch. Seven RTGs of this type had been assembled and tested at Mound, Ohio from 1984 to 1997. This paper chronicles major events in establishing a new vibration test laboratory at the Idaho National Laboratory and the nineteen days of dynamic testing.

  20. Use of chaotic and random vibrations to generate high frequency test inputs

    SciTech Connect

    Gregory, D. L.; Paez, T. L.

    1990-01-01

    This paper and a companion paper show the traditional limits on amplitude and frequency that can be generated in a laboratory test on a vibration exciter can be substantially extended. This is accomplished by attaching a device to the shaker that permits controlled metal to metal impacts that generate high frequency, high acceleration environment on a test surface. A companion paper (Reference 1) shows that a sinusoidal or random shaker input can be used to generate a random vibration environment on the test surface. This paper derives the three response components that occur on the test surface due to an impact on the bottom surface and the base driven response from the shaker input. These response components are used to generate impulse response functions and frequency response functions which are used in the companion paper to derive power spectral density functions for the overall response. 9 refs., 8 figs.

  1. Testing of the Advanced Stirling Radioisotope Generator Engineering Unit at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.

    2013-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a high-efficiency generator being developed for potential use on a Discovery 12 space mission. Lockheed Martin designed and fabricated the ASRG Engineering Unit (EU) under contract to the Department of Energy. This unit was delivered to NASA Glenn Research Center in 2008 and has been undergoing extended operation testing to generate long-term performance data for an integrated system. It has also been used for tests to characterize generator operation while varying control parameters and system inputs, both when controlled with an alternating current (AC) bus and with a digital controller. The ASRG EU currently has over 27,000 hours of operation. This paper summarizes all of the tests that have been conducted on the ASRG EU over the past 3 years and provides an overview of the test results and what was learned.

  2. Hydrogel thin film with swelling-induced wrinkling patterns for high-throughput generation of multicellular spheroids.

    PubMed

    Zhao, Ziqi; Gu, Jianjun; Zhao, Yening; Guan, Ying; Zhu, X X; Zhang, Yongjun

    2014-09-01

    Three-dimensional (3D) multicellular spheroids (MCSs) mimic the structure and function of real tissue much better than the conventional 2D cell monolayers, however, their application was severely hindered by difficulties in their generation. An ideal method for MCS fabrication should produce spheroids with narrow size distribution and allow for control over their size. The method should also be simple, cheap, and scalable. Here, we use patterned nonadhesive poly(2-hydroxyethyl methacrylate) hydrogel films to guide the self-assembly of cells. The films were fabricated directly in the wells of cell culture plates. They were patterned spontaneously by swelling in water, without the use of any template or specialized facilities. When cell suspension is added, the cells settle down by gravity to the bottom. Because of the presence of the wrinkling pattern composed of uniformed microcaves, the cells accumulate to the center of the microcaves and gradually self-assemble into MCSs. Using this method, monodisperse MCSs were generated. The size of the spheroids can be facilely controlled by the number of cells seeded. The method is compatible with the conventional monolayer cell culture method. Thousands of spheroids can be generated in a single well. We expect this method will pave the way for the application of MCSs in various biomedical areas. PMID:25072634

  3. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution.

    PubMed

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

  4. Design of Spiking Central Pattern Generators for Multiple Locomotion Gaits in Hexapod Robots by Christiansen Grammar Evolution

    PubMed Central

    Espinal, Andres; Rostro-Gonzalez, Horacio; Carpio, Martin; Guerra-Hernandez, Erick I.; Ornelas-Rodriguez, Manuel; Sotelo-Figueroa, Marco

    2016-01-01

    This paper presents a method to design Spiking Central Pattern Generators (SCPGs) to achieve locomotion at different frequencies on legged robots. It is validated through embedding its designs into a Field-Programmable Gate Array (FPGA) and implemented on a real hexapod robot. The SCPGs are automatically designed by means of a Christiansen Grammar Evolution (CGE)-based methodology. The CGE performs a solution for the configuration (synaptic weights and connections) for each neuron in the SCPG. This is carried out through the indirect representation of candidate solutions that evolve to replicate a specific spike train according to a locomotion pattern (gait) by measuring the similarity between the spike trains and the SPIKE distance to lead the search to a correct configuration. By using this evolutionary approach, several SCPG design specifications can be explicitly added into the SPIKE distance-based fitness function, such as looking for Spiking Neural Networks (SNNs) with minimal connectivity or a Central Pattern Generator (CPG) able to generate different locomotion gaits only by changing the initial input stimuli. The SCPG designs have been successfully implemented on a Spartan 6 FPGA board and a real time validation on a 12 Degrees Of Freedom (DOFs) hexapod robot is presented. PMID:27516737

  5. Large-Scale Multiobjective Static Test Generation for Web-Based Testing with Integer Programming

    ERIC Educational Resources Information Center

    Nguyen, M. L.; Hui, Siu Cheung; Fong, A. C. M.

    2013-01-01

    Web-based testing has become a ubiquitous self-assessment method for online learning. One useful feature that is missing from today's web-based testing systems is the reliable capability to fulfill different assessment requirements of students based on a large-scale question data set. A promising approach for supporting large-scale web-based…

  6. Generation of a reference radiation pattern of string instruments using automatic excitation and acoustic centering.

    PubMed

    Shabtai, Noam R; Behler, Gottfried; Vorländer, Michael

    2015-11-01

    Radiation patterns of musical instruments are important for the understanding of music perception in concert halls, and may be used to improve the plausibility of virtual acoustic systems. Many attempts have been performed to measure the spatial response of musical instruments using surrounding spherical microphone arrays with a limited number of microphones. This work presents a high-resolution spatial sampling of the radiation pattern of an electrically excited violin, and addresses technical problems that arise due to mechanical reasons of the excitation apparatus using acoustic centering. PMID:26627818

  7. A simple model for polar cap convection patterns and generation of theta auroras

    NASA Technical Reports Server (NTRS)

    Lyons, L. R.

    1985-01-01

    An addition of the uniform interplanetary magnetic field and the earth's dipole magnetic field is used to evaluate electric field convection patterns over the polar caps that result from solar wind flow across open geomagnetic field lines. The model also accounts for field-aligned patterns within, and auroral arcs across, the polar cap. The qualitative predictions derived from the model express the electric field magnitudes, aurora intensity, sunward and antisunward flow, and the dusk-side reversal of the convection field in terms of the x and y components of the interplanetary magnetic field.

  8. Effect of two microshear test devices on bond strength and fracture pattern in primary teeth.

    PubMed

    Tedesco, Tamara Kerber; Garcia, Eugenio Jose; Soares, Fabio Zovico Maxnuck; Rocha, Rachel de Oliveira; Grande, Rosa Helena Miranda

    2013-01-01

    This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate. PMID:24474357

  9. 78 FR 53484 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... COMMISSION Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4... acceptance criteria (ITAAC) completion. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) staff has... acceptance criteria are met for ITAAC E.2.5.04.05.05.02, for the Vogtle Electric Generating Plant, Unit...

  10. 78 FR 53483 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... COMMISSION Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3... acceptance criteria (ITAAC) completion. SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) staff has... acceptance criteria are met for ITAAC E.2.5.04.05.05.02, for the Vogtle Electric Generating Plant, Unit...

  11. Optimization of Gas Generation Testing of Contact-Handled Transuranic Solidified

    SciTech Connect

    Tamara Shokes; Kevin J. Liekhus; Vivian Bowman; Eric Schweinsberg

    2006-05-18

    The Contact-Handled Transuranic Waste Authorized methods for Payload Control (CH-TRAMPAC) requires that drums containing Waste Type IV (solidified organic waste) must be evaluated by gas generation testing (GGT) because a G-value, a measure of gas generation potential, has not been determined for Waste Type IV.

  12. Non-contact acoustic tests based on nanosecond laser ablation: Generation of a pulse sound source with a small amplitude

    NASA Astrophysics Data System (ADS)

    Hosoya, Naoki; Kajiwara, Itsuro; Inoue, Tatsuo; Umenai, Koh

    2014-09-01

    A method to generate a pulse sound source for acoustic tests based on nanosecond laser ablation with a plasma plume is discussed. Irradiating a solid surface with a laser beam expands a high-temperature plasma plume composed of free electrons, ionized atoms, etc. at a high velocity throughout ambient air. The shockwave generated by the plasma plume becomes the pulse sound source. A laser ablation sound source has two features. Because laser ablation is induced when the laser fluence reaches 1012-1014 W/m2, which is less than that for laser-induced breakdown (1015 W/m2), laser ablation can generate a lower sound pressure, and the sound source has a hemispherical radiation pattern on the surface where laser ablation is generated. Additionally, another feature is that laser-induced breakdown sound sources can fluctuate, whereas laser ablation sound sources do not because laser ablation is produced at a laser beam-irradiation point. We validate this laser ablation method for acoustic tests by comparing the measured and theoretical resonant frequencies of an impedance tube.

  13. Generation and use of observational data patterns in the evaluation of data quality for AmeriFlux and FLUXNET

    NASA Astrophysics Data System (ADS)

    Pastorello, G.; Agarwal, D.; Poindexter, C.; Papale, D.; Trotta, C.; Ribeca, A.; Canfora, E.; Faybishenko, B.; Gunter, D.; Chu, H.

    2015-12-01

    The fluxes-measuring sites that are part of AmeriFlux are operated and maintained in a fairly independent fashion, both in terms of scientific goals and operational practices. This is also the case for most sites from other networks in FLUXNET. This independence leads to a degree of heterogeneity in the data sets collected at the sites, which is also reflected in data quality levels. The generation of derived data products and data synthesis efforts, two of the main goals of these networks, are directly affected by the heterogeneity in data quality. In a collaborative effort between AmeriFlux and ICOS, a series of quality checks are being conducted for the data sets before any network-level data processing and product generation take place. From these checks, a set of common data issues were identified, and are being cataloged and classified into data quality patterns. These patterns are now being used as a basis for implementing automation for certain data quality checks, speeding up the process of applying the checks and evaluating the data. Currently, most data checks are performed individually in each data set, requiring visual inspection and inputs from a data curator. This manual process makes it difficult to scale the quality checks, creating a bottleneck for the data processing. One goal of the automated checks is to free up time of data curators so they can focus on new or less common issues. As new issues are identified, they can also be cataloged and classified, extending the coverage of existing patterns or potentially generating new patterns, helping both improve existing automated checks and create new ones. This approach is helping make data quality evaluation faster, more systematic, and reproducible. Furthermore, these patterns are also helping with documenting common causes and solutions for data problems. This can help tower teams with diagnosing problems in data collection and processing, and also in correcting historical data sets. In this

  14. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2009-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

  15. Automating test case generation for coverages required by FAA standard DO-178B

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey M.; Payne, Jeffery E.; Miller, Keith W.

    1993-01-01

    Coverage testing techniques are required by the FAA for various levels of subsystem criticality at the unit testing level. Higher levels of criticality require coverage schemes that frequently require more and more test cases, particularly when the number of conditions in a decision grows. For example, if we have a decision with n conditions of the form: if (/ci/ or /c2/ or .... or /cn/) then there are 2(n) possible combinations of condition outcomes. Given the enormous number of inputs that may be required to satisfy different coverages, and given that there are no automated tools for determining these inputs (to our knowledge), we will show how one alternative testing technique, mutation testing, can be coerced into generating inputs that satisfy a code coverage scheme X, i.e., if we modify the rules for mutant generation during mutation testing, this technique will provide test cases that satisfy X.

  16. Patterns of Stress Testing and Diagnostic Catheterization after Coronary Stenting in 250,350 Medicare Beneficiaries

    PubMed Central

    Mudrick, Daniel; Shah, Bimal R.; McCoy, Lisa A.; Lytl, Barbara L.; Masoudi, Frederick A.; Federspiel, Jerome J.; Cowper, Patricia A.; Green, Cynthia; Douglas, Pamela S.

    2013-01-01

    Background Patterns of non-invasive stress test (ST) and invasive coronary angiography (CA) utilization after percutaneous coronary intervention (PCI) are not well described in older populations. Methods and Results We linked National Cardiovascular Data Registry® CathPCI Registry® data with longitudinal Medicare claims data for 250,350 patients undergoing PCI from 2005 to 2007 and described subsequent testing and outcomes. Between 60 days post-PCI and end of follow-up (median 24 months), 49% (n=122,894) received stress testing first, 10% (n=25,512) underwent invasive CA first, and 41% (n=101,944) had no testing (NT). A number of clinical risk factors at time of index PCI were associated with decreased likelihood of downstream testing (ST or CA, p<0.05 for all), including older age (HR 0.784 per 10 year increase), male sex (HR 0.946), heart failure (HR 0.925), diabetes (HR 0.954), smoking (HR 0.804), and renal failure (HR 0.880). Fifteen percent of patients with ST first proceeded to subsequent CA within 90 days of testing (n=18,472/101,884); of these, 48% (n=8831) underwent revascularization within 90 days, compared to 53% (n=13,316) of CA first patients (p<0.0001). Conclusions In this descriptive analysis, stress testing and invasive CA were common in older patients after PCI. Paradoxically, patients with higher-risk features at baseline were less likely to undergo post-PCI testing. The revascularization yield was low on patients referred for ST after PCI, with only 9% undergoing revascularization within 90 days. PMID:23074343

  17. A computer test bench for checking and adjusting the automatic regulators of generator excitation systems

    SciTech Connect

    Dovganyuk, I. Ya.; Labunets, I. A.; Plotnikova, T. V.; Sokur, P. V.

    2008-05-15

    A computer test bench for testing and debugging natural samples of the automatic excitation regulation systems of generators, the protection units and the power part of the excitation system is described. The bench includes a personal computer with specialized input-output circuit boards for analog and digital signals, and enables the time and cost involved in developing and checking control systems to be reduced considerably. The program employed operates in real time and enables the automatic excitation regulators of synchronous generators and generators with longitudinal-transverse excitation in a specific power system to be adjusted.

  18. Failures related to surveillance testing of standby equipment. Volume 2. Diesel generators. Final report

    SciTech Connect

    Mollerus, F.J.; Allen, R.D.

    1985-09-01

    A study is made of failures of emergency diesel generators at nuclear power plants. The objective is to identify failures in which surveillance testing (in particular, fast starts, fast loading and the large number of starts) has been a contributing factor. The failures are described, corrective actions identified, and information is presented on diesel vendors' recommendations for testing and maintenance. An example of a successful effort to improve diesel generator reliability is detailed. A description of reference documents on nuclear plant stand-by diesel generators is also included. 8 refs., 2 figs., 7 tabs.

  19. Changes in muscle activation and force generation patterns during cycling movements because of low-intensity squat training with slow movement and tonic force generation.

    PubMed

    Tanimoto, Michiya; Arakawa, Hiroshi; Sanada, Kiyoshi; Miyachi, Motohiko; Ishii, Naokata

    2009-11-01

    Our previous studies showed that relatively low-load (approximately 50-60% 1 repetition maximum [1RM]) resistance training with slow movement and tonic force generation (LST) significantly increased muscle size and strength. However, LST is a very specific movement that differs from natural movements associated with sport activities and activities of daily life, and therefore, it might have some unfavorable effects on dynamic sport movement. We investigated the effects of LST on muscle activity and force generation patterns during cycling movement as a representative dynamic sports movement. Twenty-four healthy young men who were not in the habit of bicycle riding and did not have a history of regular resistance training were randomly assigned to the LST (approximately 60% 1RM load, 3-second lifting, and 3-second lowering movement without a relaxing phase: n = 8), a high-intensity exercise at normal speed (HM) group (85% 1RM load, 1-second lifting, 1-second lowering, and 1-second relaxed movement: n = 8), or sedentary control (CON, n = 8) group. Subjects in the training groups performed vertical squats by the assigned method. Exercise sessions consisted of 3 sets and were performed twice a week for 13 weeks. Pre- and posttraining muscle activation and force generation patterns during the cycling movements were evaluated by the coefficient of variation (CV) of the rectified electromyographic (EMG) wave from the vastus lateralis and CV of pedaling force. Both the CV of the rectified EMG and of pedaling force decreased significantly in the LST group (-21 and -18%, p < 0.05, respectively), whereas there were no significant changes in either the HN or the CON group. This decrease in CV in the LST group could mean that muscle activity and force generation during cycling movement have become more tonic. This result following LST may have an unfavorable effect on cycling movement and other dynamic sports movements. PMID:19826286

  20. Design, fabrication, test qualification and price analysis of a third generation solar cell module

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The design, fabrication, test, and qualification of a third generation intermediate load solar cell module are presented. A technical discussion of the detailed module design, preliminary design review, design modifications, and environmental testing are included. A standardized pricing system is utilized to establish the cost competitiveness of this module design.