Sample records for test pattern generator

  1. PLATYPUS: a PLA test pattern generation tool

    Microsoft Academic Search

    Ruey-Sing Wei; Alberto L. Sangiovanni-Vincentelli

    1985-01-01

    PLATypus (PLA Test pattern generation and logic simulation tool) is an efficient tool for large PLAs which is interfaced with other existing PLA tools such as the constrained\\/unconstrained, simple\\/multiple folding program PLEASURE and the logic minimizer ESPRESSO II-C developed at the University of California at Berkeley. PLATYPUS uses biased random test generation as a quick preprocess followed by a deterministic

  2. PLATYPUS: A PLA Test Pattern Generation Tool

    Microsoft Academic Search

    Ruey-sing Wei; Alberto L. Sangiovanni-vincentelli

    1986-01-01

    PLATypus (PLA Test pattern generation and logic simulation tool) is an efficient tool for large PLA's which is interfaced with other existing PLA tools such as the folding program PLEASURE [12] and the logic minimizer ESPRESSO II-C [11] developed at the University of California at Berkeley. A new algorithm is proposed based on complementation and the tautology check of a

  3. Generating test patterns for VLSI circuits using a genetic algorithm

    Microsoft Academic Search

    M. J. O'Dare; T. Arslan

    1994-01-01

    The authors present the development of a technique that uses genetic algorithms for the generation of test patterns that detect single stuck-at faults in combinational VLSI circuits. As the genetic algorithm evolves, an efficient set of test patterns are produced, by searching the solution space for patterns that detect the highest number of remaining faults in the fault list.

  4. Parallelization methods for circuit partitioning based parallel automatic test pattern generation

    Microsoft Academic Search

    Robert H. Klenke; Ronald D. Williams; James H. Aylor

    1993-01-01

    Generation of test vectors for the VLSI devices used in contemporary digital systems is becoming much more difficult as these devices increase in size. Automatic Test Pattern Generation (ATPG) techniques are commonly used to generate these tests. Parallel processing techniques can be applied to accelerate the process of finding test patterns. One problem with this approach is that most currently

  5. 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.

  6. DALG: A program for test pattern generation in combinational logical circuits

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A user's manual for a computer program DALG which generates test patterns for detecting faults in combinational logic circuits containing up to 200 logical gates is presented. The gates may be of logical types AND, OR, NAND, NOR, NOT, or Exclusive OR is presented. The faults may be any one gate or input struck at a fixed value (0 or 1). In addition to test pattern generation DALG will also determine whether or not the given test pattern will detect given faults in a circuit. Sample problems are given along with input data sheets and printed output to illustrate the capabilities of the program.

  7. Automatic Test Pattern Generation for Interconnect Open Defects Stefan Spinner

    E-print Network

    Polian, Ilia

    be targeted. An aggressor-victim model used in industry is employed to describe the electrical behavior. The result- ing test sets are smaller and achieve a higher defect cover- age than stuck-at n-detection test], and complex interactions with low- interlevel dielectric materials [1]. Hence, adequate coverage

  8. The KARL\\/KARATE System: Automatic Test Pattern Generation Based on RT Level Descriptions

    Microsoft Academic Search

    Gerold Affs; Reiner W. Hartenstein; Andrea Wodtko

    1988-01-01

    A system is described for automatic test-pattern generation (ATPG) using symbolic representations and heuristics to attack the test problem at RT level, where redesigns to increase the testability are relatively cheap. In contrast to other ATPG tools based on RT-level hardware descriptions, KARATE includes tests for primitive operators and allows the modification and redefinition of fault models. KARATE has been

  9. DNA computing approach for automated test pattern generation for digital circuits

    Microsoft Academic Search

    Amardeep Singh; Maninder Kaur

    2008-01-01

    Testing of digital circuits is a compute intensive problem. This article deals with the problem of automated test pattern generation for large digital circuits. A new evolutionary approach based on DNA computing is presented, which exploits the computational power of DNA molecules to solve the problem. A Boolean formula in conjunctive normal form is extracted from the circuit under test

  10. Pattern Generator

    NSDL National Science Digital Library

    2005-01-01

    This Java applet activity allows the learner to recognize patterns and extend them in a sequence of shapes, numbers, or letters. A student can choose from three levels of difficulty and then after determining the pattern, fills in the missing pieces from the right side of the board into their appropriate places in the pattern, shown on the left. There are four tabs for support: Learner, Activity, Help and Instructor and links to other related resources.

  11. Transition-fault test generation

    E-print Network

    Cobb, Bradley Douglas

    2013-02-22

    . One way to detect these timing defects is to apply test patterns to the integrated circuit that are generated using the transition-fault model. Unfortunately, industry's current transition-fault test generation schemes produce test sets that are too...

  12. Mining frequent patterns without candidate generation

    Microsoft Academic Search

    Jiawei Han; Jian Pei; Yiwen Yin

    2000-01-01

    Mining frequent patterns in transaction databases, time-series databases, and many other kinds of databases has been studied popularly in data mining research. Most of the previous studies adopt an Apriori-like candidate set generation-and-test approach. However, candidate set generation is still costly, especially when there exist prolific patterns and\\/or long patterns.In this study, we propose a novel frequent pattern tree (FP-tree)

  13. Cost analysis of Hybrid LFSR as deterministic and pseudorandom test pattern generator

    E-print Network

    Utama, Peter

    1994-01-01

    and pseudorandoin patterns. It is a finite state machine that consists of shift registers interspersed with XOR gates. Fig. 2 shows an example of an n-stage modular LFSR. hp hl h2 xp xl x2 Fig. 2. n stage modular LFSR The state or the output of the LFSR... where 13 X(t+I) = X(t) . Tc It follows that X(t + 1) = X(t) A I TcA X (t + 1) = X (t) Ts Ts =A-1 TcA The transformation creates a new finite state rnachine named the hybrid linear feedback shift register (HLFSR) with a new characteristic matrix...

  14. Test generation for sequential circuits

    Microsoft Academic Search

    Hi-keung Tony Ma; Srinivas Devadas; A. Richard Newton; Alberto L. Sangiovanni-vincentelli

    1988-01-01

    An approach to test-pattern generation for synchronous sequential circuits is presented. The deterministic sequential test-generation algorithm, based on extensions to the PODEM justification algorithm, is effective for midsized sequential circuits and can be used in conjunction with an incomplete scan design approach to generate tests for very large sequential circuits. Tests for finite-state machines with a large number of states

  15. Modeling and Automatic Test Pattern Generation for Mixed-Signal Boards in Maintenance Testing: Dealing With Simple Time Aspects

    Microsoft Academic Search

    Bertrand Gilles

    In the context of maintenance testing and diagnosis of faulty boards, a functional FSM (Finite State Machine)- based model for mixed-signal board has been introduced. The board is broken down into interconnected functional blocks. Each block has an associated functional model which describes its behavior and a test model which spec- ifies how the block can be efficiently tested. A

  16. Generating trees for permutations avoiding generalized patterns

    E-print Network

    Elizalde, Sergi

    Generating trees for permutations avoiding generalized patterns Sergi Elizalde Dartmouth College Permutation Patterns 2006, Reykjavik Permutation Patterns 2006, Reykjavik ­ p.1 #12;Generating trees patterns Generating trees Rightward generating trees Enumeration of permutations avoiding generalized

  17. 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.

  18. Test generation for large logic networks

    Microsoft Academic Search

    P. S. Bottorff; R. E. France; N. H. Garges; E. J. Orosz

    1977-01-01

    A system for automatic test pattern generation for large logic networks is described. The network to be tested is assumed to comply with a set of ground rules for testability. The system includes features for automatic subdivision of the network into easily tested sub-networks, automatic test generation programs, and a post-processor which produces a highly efficient test program. Applications to

  19. Invertebrate central pattern generator circuits

    PubMed Central

    Selverston, Allen I.

    2010-01-01

    There are now a reasonable number of invertebrate central pattern generator (CPG) circuits described in sufficient detail that a mechanistic explanation of how they work is possible. These small circuits represent the best-understood neural circuits with which to investigate how cell-to-cell synaptic connections and individual channel conductances combine to generate rhythmic and patterned output. In this review, some of the main lessons that have appeared from this analysis are discussed and concrete examples of circuits ranging from single phase to multiple phase patterns are described. While it is clear that the cellular components of any CPG are basically the same, the topology of the circuits have evolved independently to meet the particular motor requirements of each individual organism and only a few general principles of circuit operation have emerged. The principal usefulness of small systems in relation to the brain is to demonstrate in detail how cellular infrastructure can be used to generate rhythmicity and form specialized patterns in a way that may suggest how similar processes might occur in more complex systems. But some of the problems and challenges associated with applying data from invertebrate preparations to the brain are also discussed. Finally, I discuss why it is useful to have well-defined circuits with which to examine various computational models that can be validated experimentally and possibly applied to brain circuits when the details of such circuits become available. PMID:20603355

  20. Geometric pattern generation by sewing machine

    Microsoft Academic Search

    Yasumichi Hasegawa; Kihachi Takeichi; Tsuyoshi Matsuo

    1996-01-01

    The authors propose a method for geometric pattern generation by using a sewing machine. Sewing machine equipment are mainly composed of mathematical models which may be constructed by computer programs or switching and other electric circuits. These models are called commutative linear representation systems and this method is a very different graphic generation scheme. Geometric pattern generation is a trial

  1. Mining Frequent Patterns without Candidate Generation: A Frequent-Pattern Tree Approach

    Microsoft Academic Search

    Jiawei Han; Jian Pei; Yiwen Yin; Runying Mao

    2004-01-01

    Mining frequent patterns in transaction databases, time-series databases, and many other kinds of databases has been studied popularly in data mining research. Most of the previous studies adopt an Apriori-like candidate set generation-and-test approach. However, candidate set generation is still costly, especially when there exist a large number of patterns and\\/or long patterns. In this study, we propose a novel

  2. Generating image descriptions using dependency relational patterns

    E-print Network

    Ahmet Aker; Robert Gaizauskas

    This paper presents a novel approach to automatic captioning of geo-tagged images by summarizing multiple webdocuments that contain information related to an image’s location. The summarizer is biased by dependency pattern models towards sentences which contain features typically provided for different scene types such as those of churches, bridges, etc. Our results show that summaries biased by dependency pattern models lead to significantly higher ROUGE scores than both n-gram language models reported in previous work and also Wikipedia baseline summaries. Summaries generated using dependency patterns also lead to more readable summaries than those generated without dependency patterns. 1

  3. Identification of Bacteria by Patterns Generated from Odor Spectra

    E-print Network

    Hung-Chih Chang; Laszlo B. Kish; Maria D. King; Chiman Kwan

    2009-02-09

    We use the power density spectra obtained by fluctuation-enhanced sensing of bacterial odors (Escherichia coli and Anthrax-surrogate Bacillus subtilis) to generate new, highly distinguishable, types of patterns based on the average slope of the spectra in different frequency ranges. Such plots can be considered as "fingerprints" of bacterial odors. Three different ways of pattern generation are tested, including a simple binary version. The obtained patterns are simple enough to identify the situation by the naked eye without a pattern recognizer.

  4. 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.

  5. Semiformal test generation with genevieve

    Microsoft Academic Search

    Julia Dushina; Mike Benjamin; Daniel Geist

    2001-01-01

    This paper describes the first application of the Genevieve test generation methodology. The Genevieve approach uses semi-for-mal techniques derived from “model-checking” to generate test suites for specific behaviours of the design under test. An “interest-ing” behaviour is claimed to be unreachable. If a path from an ini-tial state to the state of interest does exist, a counter-example is generated. The

  6. Go patterns generated by retrograde analysis Bruno Bouzy Go patterns generated by retrograde analysis

    E-print Network

    Bouzy, Bruno

    1 Go patterns generated by retrograde analysis Bruno Bouzy Go patterns generated by retrograde 1986], retrograde analysis enabled researchers to generate all six-piece positions [Thomson1996's Morris [Gasser 1996], retrograde analysis was used to solve these games. In Go, [Zobrist 1969] [Benson

  7. FPGA Implementation of a Pattern Generator

    E-print Network

    FPGA Implementation of a Pattern Generator Jakob Toft, s012012 Technical University of Denmark is implemented on a Spartan II FPGA in two different designs: "Memory- based" and "buffer-based". Two different interfaces are used between PC and FPGA, more specific a serial and parallel port interface. The system can

  8. Organization of rhythm and pattern generation networks

    E-print Network

    Manitoba, University of

    CPG Lundberg-Brown Basic Half-centre CPG Extensor Flexor How can this basic scheme explain during) scale network will be used to test these hypothesis Koshland Smith Kriellaars et al (Jordan) Burke et al-E Ia-F R-FR-E Extensor Flexor Inpf-E Inpf-F Pattern Formation Outside the CPG Basic reciprocity module

  9. Automatically generating extraction patterns from untagged text

    SciTech Connect

    Riloff, E. [Univ. of Utah, Salt Lake City, UT (United States)

    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.

  10. 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

  11. Role of inhibition in respiratory pattern generation.

    PubMed

    Janczewski, Wiktor A; Tashima, Alexis; Hsu, Paul; Cui, Yan; Feldman, Jack L

    2013-03-27

    Postsynaptic inhibition is a key element of neural circuits underlying behavior, with 20-50% of all mammalian (nongranule) neurons considered inhibitory. For rhythmic movements in mammals, e.g., walking, swimming, suckling, chewing, and breathing, inhibition is often hypothesized to play an essential rhythmogenic role. Here we study the role of fast synaptic inhibitory neurotransmission in the generation of breathing pattern by blocking GABA(A) and glycine receptors in the preBötzinger complex (preBötC), a site essential for generation of normal breathing pattern, and in the neighboring Bötzinger complex (BötC). The breathing rhythm continued following this blockade, but the lung inflation-induced Breuer-Hering inspiratory inhibitory reflex was suppressed. The antagonists were efficacious, as this blockade abolished the profound effects of the exogenously applied GABA(A) receptor agonist muscimol or glycine, either of which under control conditions stopped breathing in vagus-intact or vagotomized, anesthetized, spontaneously breathing adult rats. In vagotomized rats, GABA(A)ergic and glycinergic antagonists had little, if any, effect on rhythm. The effect in vagus-intact rats was to slow the rhythm to a pace equivalent to that seen after suppression of the aforementioned Breuer-Hering inflation reflex. We conclude that postsynaptic inhibition within the preBötC and BötC is not essential for generation of normal respiratory rhythm in intact mammals. We suggest the primary role of inhibition is in shaping the pattern of respiratory motor output, assuring its stability, and in mediating reflex or volitional apnea, but not in the generation of rhythm per se. PMID:23536061

  12. ROLE OF INHIBITION IN RESPIRATORY PATTERN GENERATION

    PubMed Central

    Janczewski, Wiktor A.; Tashima, Alexis; Hsu, Paul; Cui, Yan; Feldman, Jack L.

    2013-01-01

    Postsynaptic inhibition is a key element of neural circuits underlying behavior, with 20-50% of all mammalian (non-granule) neurons considered inhibitory. For rhythmic movements in mammals, e.g., walking, swimming, suckling, chewing, breathing, inhibition is often hypothesized to play an essential rhythmogenic role. Here we study the role of fast synaptic inhibitory neurotransmission in the generation of breathing pattern by blocking GABAA and glycine receptors in the preBötzinger Complex (preBötC), a site essential for generation of normal breathing pattern, and in the neighboring Bötzinger Complex (BötC). The breathing rhythm continued following this blockade, but the lung inflation-induced Breuer-Hering inspiratory-inhibitory reflex was suppressed. The antagonists were efficacious, as this blockade abolished the profound effects of the exogenously applied GABAA receptor agonist muscimol or glycine, either of which under control conditions stopped breathing in vagus-intact or vagotomized, anesthetized, spontaneously breathing adult rats. In vagotomized rats, GABAAergic and glycinergic antagonists had little, if any, effect on rhythm. The effect in vagus intact rats was to slow the rhythm to a pace equivalent to that seen after suppression of the aforementioned Breuer-Hering inflation reflex. We conclude that postsynaptic inhibition within the preBötC and BötC is not essential for generation of normal respiratory rhythm in intact mammals. We suggest the primary role of inhibition is in shaping the pattern of respiratory motor output, assuring its stability, and in mediating reflex or volitional apnea, but not in the generation of rhythm per se. PMID:23536061

  13. 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.

  14. An automatic test generation system for complex digital logic

    Microsoft Academic Search

    R. A. Marlett

    1982-01-01

    This paper discusses an integrated set of software tools designed to automatically generate tests for digital logic. A testability analyzer calculates the controllability of each signal and lists those signals which are impossible to control. A unique feature is that the controllability information is also used to improve the automatic test pattern generator efficiency. An initializability analyzer provides the designer

  15. Altered gravity highlights central pattern generator mechanisms.

    PubMed

    White, Olivier; Bleyenheuft, Yannick; Ronsse, Renaud; Smith, Allan M; Thonnard, Jean-Louis; Lefèvre, Philippe

    2008-11-01

    In many nonprimate species, rhythmic patterns of activity such as locomotion or respiration are generated by neural networks at the spinal level. These neural networks are called central pattern generators (CPGs). Under normal gravitational conditions, the energy efficiency and the robustness of human rhythmic movements are due to the ability of CPGs to drive the system at a pace close to its resonant frequency. This property can be compared with oscillators running at resonant frequency, for which the energy is optimally exchanged with the environment. However, the ability of the CPG to adapt the frequency of rhythmic movements to new gravitational conditions has never been studied. We show here that the frequency of a rhythmic movement of the upper limb is systematically influenced by the different gravitational conditions created in parabolic flight. The period of the arm movement is shortened with increasing gravity levels. In weightlessness, however, the period is more dependent on instructions given to the participants, suggesting a decreased influence of resonant frequency. Our results are in agreement with a computational model of a CPG coupled to a simple pendulum under the control of gravity. We demonstrate that the innate modulation of rhythmic movements by CPGs is highly flexible across gravitational contexts. This further supports the involvement of CPG mechanisms in the achievement of efficient rhythmic arm movements. Our contribution is of major interest for the study of human rhythmic activities, both in a normal Earth environment and during microgravity conditions in space. PMID:18650309

  16. 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.

  17. Testing whether and when abstract symmetric patterns produce affective responses.

    PubMed

    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

  18. 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

  19. Contribution of motoneuron intrinsic properties to fictive motor pattern generation

    PubMed Central

    Calabrese, Ronald L.

    2011-01-01

    Previously, we reported a canonical ensemble model of the heart motoneurons that underlie heartbeat in the medicinal leech. The model motoneurons contained a minimal set of electrical intrinsic properties and received a synaptic input pattern based on measurements performed in the living system. Although the model captured the synchronous and peristaltic motor patterns observed in the living system, it did not match quantitatively the motor output observed. Because the model motoneurons had minimal intrinsic electrical properties, the mismatch between model and living system suggests a role for additional intrinsic properties in generating the motor pattern. We used the dynamic clamp to test this hypothesis. We introduced the same segmental input pattern used in the model to motoneurons isolated pharmacologically from their endogenous input in the living system. We show that, although the segmental input pattern determines the segmental phasing differences observed in motoneurons, the intrinsic properties of the motoneurons play an important role in determining their phasing, particularly when receiving the synchronous input pattern. We then used trapezoidal input waveforms to show that the intrinsic properties present in the living system promote phase advances compared with our model motoneurons. Electrical coupling between heart motoneurons also plays a role in shaping motoneuron output by synchronizing the activity of the motoneurons within a segment. These experiments provide a direct assessment of how motoneuron intrinsic properties interact with their premotor pattern of synaptic drive to produce rhythmic output. PMID:21562194

  20. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 ...892.1420 Radionuclide test pattern phantom. (a) Identification. A radionuclide test pattern phantom is a device that consists of an...

  1. Central pattern generator for swimming in Melibe.

    PubMed

    Thompson, Stuart; Watson, Winsor H

    2005-04-01

    The nudibranch mollusc Melibe leonina swims by bending from side to side. We have identified a network of neurons that appears to constitute the central pattern generator (CPG) for this locomotor behavior, one of only a few such networks to be described in cellular detail. The network consists of two pairs of interneurons, termed 'swim interneuron 1' (sint1) and 'swim interneuron 2' (sint2), arranged around a plane of bilateral symmetry. Interneurons on one side of the brain, which includes the paired cerebral, pleural and pedal ganglia, coordinate bending movements toward the same side and communicate via non-rectifying electrical synapses. Interneurons on opposite sides of the brain coordinate antagonistic movements and communicate over mutually inhibitory synaptic pathways. Several criteria were used to identify members of the swim CPG, the most important being the ability to shift the phase of swimming behavior in a quantitative fashion by briefly altering the firing pattern of an individual neuron. Strong depolarization of any of the interneurons produces an ipsilateral swimming movement during which the several components of the motor act occur in sequence. Strong hyperpolarization causes swimming to stop and leaves the animal contracted to the opposite side for the duration of the hyperpolarization. The four swim interneurons make appropriate synaptic connections with motoneurons, exciting synergists and inhibiting antagonists. Finally, these are the only neurons that were found to have this set of properties in spite of concerted efforts to sample widely in the Melibe CNS. This led us to conclude that these four cells constitute the CPG for swimming. While sint1 and sint2 work together during swimming, they play different roles in the generation of other behaviors. Sint1 is normally silent when the animal is crawling on a surface but it depolarizes and begins to fire in strong bursts once the foot is dislodged and the animal begins to swim. Sint2 also fires in bursts during swimming, but it is not silent in non-swimming animals. Instead activity in sint2 is correlated with turning movements as the animal crawls on a surface. This suggests that the Melibe motor system is organized in a hierarchy and that the alternating movements characteristic of swimming emerge when activity in sint1 and sint2 is bound together. PMID:15781895

  2. 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…

  3. Generating Circuit Tests by Exploiting Designed Behavior

    E-print Network

    Shirley, Mark Harper

    1988-12-01

    This thesis describes two programs for generating tests for digital circuits that exploit several kinds of expert knowledge not used by previous approaches. First, many test generation problems can be solved efficiently ...

  4. Automatic basic garment pattern generation using three-dimensional measurements

    Microsoft Academic Search

    Choong Hyo Kim; In Hwan Sul; Chang Kyu Park; Sungmin Kim

    2010-01-01

    Purpose – The purpose of this paper is to illustrate the generation of basic garment pattern using three-dimensional body measurement data. Design\\/methodology\\/approach – A pre-defined garment model is deformed using free-form deformation method and the model is flattened to generate flat patterns. Findings – The paper finds that individual basic garment patterns are automatically generated and verified to be well

  5. Automatic Test Program Generation for Mixed Signal ICs via Design to Test Link

    Microsoft Academic Search

    William Kao; Jean Xia; Tom Boydston

    1992-01-01

    Test development is without doubt the major bottleneck in the product delivery cycle of mixed signal ICs [ 11. One of the most time consuming tasks is to create the test programs to run a mixed signal tester. On the digital side automatic test pattern generators exist today, but for the analog and mixed signal tester rarely any tools exist

  6. 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…

  7. Computer Generated Islamic Star Patterns Craig S. Kaplan

    E-print Network

    Kaplan, Craig S.

    Computer Generated Islamic Star Patterns Craig S. Kaplan Department of Computer Science://www.cs.washington.edu/homes/csk/tile/ Abstract Islamic star patterns are a beautiful and highly geometric art form. Many analyses have been done of the most famous and most beautiful forms of geometric art is the Islamic star pattern. Mathematically

  8. Hard-wired central pattern generators for quadrupedal locomotion

    Microsoft Academic Search

    J. J. Collins; S. A. Richmond

    1994-01-01

    Animal locomotion is generated and control- led, in part, by a central pattern generator (CPG), which is an intraspinal network of neurons capable of pro- ducing rhythmic output. In the present work, it is demon- strated that a hard-wired CPG model, made up of four coupled nonlinear oscillators, can produce multiple phase-locked oscillation patterns that correspond to three common quadrupedal

  9. Item Generation for Test Development [Book Review].

    ERIC Educational Resources Information Center

    Papanastasiou, Elena C.

    2003-01-01

    This volume, based on papers presented at a 1998 conference, collects thinking and research on item generation for test development. It includes materials on psychometric and cognitive theory, construct-oriented approaches to item generation, the item generation process, and some applications of item generative principles. (SLD)

  10. Traveling-Stripe Forcing Generates Hexagonal Patterns

    NASA Astrophysics Data System (ADS)

    Míguez, D. G.; Nicola, E. M.; Muñuzuri, A. P.; Casademunt, J.; Sagués, F.; Kramer, L.

    2004-07-01

    We study the response of Turing stripe patterns to a simple spatiotemporal forcing. This forcing has the form of a traveling wave and is spatially resonant with the characteristic Turing wavelength. Experiments conducted with the photosensitive chlorine dioxide-iodine-malonic acid reaction reveal a striking symmetry-breaking phenomenon of the intrinsic striped patterns giving rise to hexagonal lattices for intermediate values of the forcing velocity. The phenomenon is understood in the framework of the corresponding amplitude equations, which unveils a complex scenario of dynamical behaviors.

  11. Automated Test Generation from Timed Automata

    Microsoft Academic Search

    Brian Nielsen; Arne Skou

    2001-01-01

    Testing is the most dominating validation activity used by industry today, and there is an urgent need for improv- ing its effectiveness, both with respect to the time and re- sources for test generation and execution, and obtained test coverage. We present a new technique for automatic gen- eration of real-time black-box conformance tests for non- deterministic systems from a

  12. A genetic algorithm framework for test generation

    Microsoft Academic Search

    Elizabeth M. Rudnick; Janak H. Patel; Gary S. Greenstein; Thomas M. Niermann

    1997-01-01

    Test generation using deterministic fault-oriented algorithms is highly complex and time consuming. New approaches are needed to augment the existing techniques, both to reduce execution time and to improve fault coverage. Genetic algorithms (GA's) have been effective in solving many search and optimization problems. Since test generation is a search process over a large vector space, it is an ideal

  13. Computer Generated Islamic Star Patterns Craig S. Kaplan

    E-print Network

    Waterloo, University of

    Computer Generated Islamic Star Patterns Craig S. Kaplan Department of Computer Science Islamic star patterns are a beautiful and highly geometric art form whose original design techniques Introduction More than a thousand years ago, Islamic artisans began to adorn architectural surfaces

  14. Low Power CMOS Electronic Central Pattern Generator Design

    E-print Network

    Ayers, Joseph

    1 Low Power CMOS Electronic Central Pattern Generator Design for a Biomimetic Underwater Robot-based analog controller for an autonomous robot. The operation of a neuronal circuit formed of electronic programs to control the legs of autonomous robots. Index Terms-- subthreshold operation, Central Pattern

  15. Intracellular activity in cricket neurons during generation of song patterns

    Microsoft Academic Search

    David R. Bentley

    1969-01-01

    During production of song patterns by the semi-isolated CNS of Gryllus campestris, intracellullar recordings were made in fibers of the mesothoracic ganglion, including synaptic areas of identified wing opener and closer motor neurons. The normal calling song pattern and some transitional songs toward courtship and toward aggression were generated by the CNS in the absence of any phasic sensory timing

  16. 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.

  17. A method for testing association patterns of social animals.

    PubMed

    Bejder; Fletcher; BrÄger

    1998-09-01

    Association indices were originally developed to describe species co-occurrences, but have been used increasingly to measure associations between individuals. However, no statistical method has been published that allows one to test the extent to which the observed association index values differ from those of a randomly associating population. Here, we describe an adaptation of a test developed by Manly (1995, Ecology, 76, 1109-1115), which uses the observed association data as a basis for a computer-generated randomization. The observed pattern of association is tested against a randomly created one while retaining important features of the original data, for example group size and sighting frequency. We applied this new method to test four data sets of associations from two populations of Hector's dolphin, Cephalorhynchus hectori, using the Half-Weight Index (HWI) as an example of a measure of association. The test demonstrated that populations with similar median HWI values showed clear differences in association patterns, that is, some were associating nonrandomly whereas others were not. These results highlight the benefits of using this new testing method in order to validate the analysis of association indices. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9784222

  18. Generating Coherent Patterns of Activity from Chaotic Neural Networks

    E-print Network

    Columbia University

    Neuron Article Generating Coherent Patterns of Activity from Chaotic Neural Networks David Sussillo be used to alter the chaotic activity of a recurrently connected neural network and generate complex but controlled outputs. Training a neural network is a process through which network parameters (typically

  19. Thrombin generation test in microfluidic systems

    NASA Astrophysics Data System (ADS)

    Koch, Kaspar; van Berkel, Sander S.; van de Wal, Marloes M. E. B.; Nieuwland, Pieter J.; van Hest, Jan C. M.; Rutjes, Floris P. J. T.

    2009-05-01

    The thrombin generation test is one of the diagnostic tests currently in use as a universal method for measuring hemostatic disorders. We envisioned that conventional monitoring of thrombin generation could be miniaturized resulting in a time-saving, accurate, easy-to-operate, and cost-efficient test. For the translation of the conventional thrombin generation test to microfluidic devices, our focus was directed to parameters such as the detection limit, temperature, protein-surface interactions (i.e., hydrophilicity of microchannels), and mixing behavior. Scaling down to microchannels (e.g., capillaries) resulted in volume reduction and allowed us to study the effect of a microchannel surface (either hydrophilic or hydrophobic) on the thrombin activity. Finally, the use of a micromixer enabled us to perform efficient on-chip mixing, resulting in the successful measurement of a thrombin generation in a microfluidic device.

  20. High Quality Compact Delay Test Generation

    E-print Network

    Wang, Zheng

    2011-08-08

    HIGH QUALITY COMPACT DELAY TEST GENERATION A Dissertation by ZHENG WANG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY... May 2010 Major Subject: Computer Engineering HIGH QUALITY COMPACT DELAY TEST GENERATION A Dissertation by ZHENG WANG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. Searching and generating test inputs for mutation testing.

    PubMed

    Papadakis, Mike; Malevris, Nicos

    2013-12-01

    Mutation testing is usually regarded as an important method towards fault revealing. Despite this advantage, it has proved to be impractical for industrial use because of its expenses. To this extend, automated techniques are needed in order to apply and reduce the method's demands. Whilst there is much evidence that automated test data generation techniques can effectively automate the testing process, there has been little work on applying them in the context of mutation testing. In this paper, search-based testing is used in order to effectively generate test inputs capable of revealing mutants. To this end, a dynamic execution scheme capable of introducing and guiding the search towards the sought mutants is proposed. Experimentation with the proposed approach reveals its superiority from the previously proposed methods. Additionally, the framework's feasibility and practicality of producing mutation based test cases are also demonstrated. PMID:23607084

  6. Tolerance analysis of linear antenna arrays generating shaped beam patterns

    Microsoft Academic Search

    M. Alvarez-Folgueiras; J. A. Rodriguez-Gonzalez; F. Ares-Pena

    2011-01-01

    The problem of synthesizing a linear array generating a shaped beam pattern with M filled nulls has 2 M alternative solutions. The sensitivity of the performance to errors in element position, excitation phase or amplitude of the solutions provided by the synthesis of a flat-topped beam pattern using an array of 16 isotropic elements spaced ?\\/2 was analysed. 0.0000 -1.9358

  7. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Electroencephalograph test signal generator. 882.1430 Section 882.1430... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a device used to test or...

  8. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Electroencephalograph test signal generator. 882.1430 Section 882.1430... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a device used to test or...

  9. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Electroencephalograph test signal generator. 882.1430 Section 882.1430... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a device used to test or...

  10. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Electroencephalograph test signal generator. 882.1430 Section 882.1430... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a device used to test or...

  11. 21 CFR 882.1430 - Electroencephalograph test signal generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Electroencephalograph test signal generator. 882.1430 Section 882.1430... Electroencephalograph test signal generator. (a) Identification. An electroencephalograph test signal generator is a device used to test or...

  12. Digital holographic moiré pattern for optical numerical code generation

    NASA Astrophysics Data System (ADS)

    de Oliveira, G. N.; de Oliveira, M. E.; da Rocha Freire, R. B., Jr.; dos Santos, P. A. M.

    2014-07-01

    In the present paper low frequency moiré fringe patterns are used as secure numerical code generator. These moiré patterns are experimentally obtained by the superposition of two sinusoidal gratings with slightly different pitches. The Bi12TiO20 photorefractive crystal sample is used as holographic medium An optical numerical base was defined with patterns representing 0,1 and -1 digits like bits. Then, the complete set of these optical bits are combined to form bytes, where a numerical sequence is represented. The results show that the proposed numerical code could be used as standard numerical identification in robotic vision or in transmition of security numerical keys.

  13. Biped Walking Pattern Generator allowing Auxiliary ZMP Control

    E-print Network

    Treuille, Adrien

    that ZMP based walking controls lack the adaptivity which is observed in the passive dynamic walk [3], [4], the compliance based walking control [5], the central pattern generator (CPG) [6] or the hybrid zero dynamics [7 parameters like walking cycle or step width are modified to hold consistency of the system dynamics. By using

  14. Modelling a Respiratory Central Pattern Generator Neuron in Lymnaea stagnalis

    E-print Network

    Campbell, Sue Ann

    Modelling a Respiratory Central Pattern Generator Neuron in Lymnaea stagnalis Sharene D. Bungay). The central nervous system of the Lymnaea is composed of a relatively small number of large, identifiable neurons. In 1990, Syed et al. [1] established that respiratory rhythmogenesis in the Lymnaea is controlled

  15. Structural characterization of a hypothalamic visceromotor pattern generator network

    Microsoft Academic Search

    Richard H Thompson; Larry W Swanson

    2003-01-01

    A high resolution PHAL analysis of axonal connections suggests the existence of a visceromotor pattern generator network in the periventricular region of the rat hypothalamus (HVPG), and a preliminary account of its structure is provided here. Six nodes identified thus far include the dorsomedial nucleus and five small nuclei in the preoptic region (anteroventral and anterodorsal preoptic, parastrial, median preoptic,

  16. A transitive closure algorithm for test generation

    Microsoft Academic Search

    Srimat T. Chakradhar; Vishwani D. Agrawal; Steven G. Rothweiler

    1993-01-01

    A transitive-closure-based test generation algorithm is presented. A test is obtained by determining signal values that satisfy a Boolean equation derived from the neural network model of the circuit incorporating necessary conditions for fault activation and path sensitization. The algorithm is a sequence of two main steps that are repeatedly executed: transitive closure computation and decision-making. A key feature of

  17. Logic design verification via test generation

    Microsoft Academic Search

    Magdy S. Abadir; Jack Ferguson; Tom E. Kirkland

    1988-01-01

    A method for logic design verification is introduced in which a gate-level implementation of a circuit is compared with a functional-level specification. In this method, test patterns that were developed to detect single stuck-line faults in the gate-level implementation are used instead to compare the gate-level implementation with the functional-level specification. In the presence of certain hypothesized design errors, such

  18. Calibrating Droplet Generator for Pressurized Testing Vessel

    NASA Technical Reports Server (NTRS)

    Defever, G. J.; Exposito, T.

    1985-01-01

    Device helps to aline laser for droplet-sizing interferometer. Monodispersing Droplet Generator creates uniformly sized droplets. Laser source and receiver of interferometer alined and focused on droplets. MDG mounted in high-pressure flange on tank. Line extensions pass through flange to outside. Flange allows MDG to operate at high injector back pressures used for tests.

  19. Nine test tubes generate any RE language

    Microsoft Academic Search

    Claudio Ferretti; Giancarlo Mauri; Claudio Zandron

    2000-01-01

    In this paper we discuss how any recursively enumerable language can be generated using a distributed splicing system with a fixed number of nine test tubes. This number has been recently reduced by other authors, and in this work we try to give an insightful algorithmic description of this kind of systems.

  20. 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...

  1. Wisconsin Test Facility Transmitting Antenna Pattern and Steering Measurements

    Microsoft Academic Search

    PETER R. BANNISTER; FREDERICK J. WILLIAMS; ALAN L. DAHLVIG; WILLIAM A. KRAIMER

    1974-01-01

    During August and September 1971, the New London Laboratory, Naval Underwater Systems Center, performed pattern and steering measurements on the Wisconsin Test Facility (WTF) antennas. The pattern measurements were made at 13 locations in Minnesota and Wisconsin (covering approximately 120° of arc), while the far-field steering tests were taken in Maine and North Carolina. To be certain that the receiving

  2. 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.

  3. Test factoring with amock: generating readable unit tests from system tests

    E-print Network

    Glasser, David Samuel

    2007-01-01

    Automated unit tests are essential for the construction of reliable software, but writing them can be tedious. If the goal of test generation is to create a lasting unit test suite (and not just to optimize execution of ...

  4. 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, wafer map, and across wafer sampling, generate recipe. Utilizing this new technology, we can expect improved CD-SEM utilization and overall productivity defined by measurements acquired per unit time and by number of recipes that can be created. In addition, the control of recipe generation is improved as this automated data flow reduces the opportunities for errors. Finally, recipe creation automation can improve the time for production and development by enabling preparation before wafers get to the critical metrology steps. This is especially true in a development or foundry environment where the metrology recipe locations are updated frequently. A system is demonstrated where CDs and images can be acquired based on automated recipe generation, pattern recognition using the design polygons, and the measured CDís compared to the target CDís derived from the design. In addition, the presence of the design enables advanced information extraction such as edge placement error (EPE) in addition to traditional CD measurement. Example images and CD control analysis are presented for a critical resist inspection steps (poly, metal, and contact) and an etched poly pattern where an underlying layer is visible in SEM and used as part of the pattern matching template.

  5. A test pattern identification algorithm and its application to CINRAD/SA(B) data

    NASA Astrophysics Data System (ADS)

    Jiang, Yuan; Liu, Liping

    2014-03-01

    A variety of faulty radar echoes may cause serious problems with radar data applications, especially radar data assimilation and quantitative precipitation estimates. In this study, "test pattern" caused by test signal or radar hardware failures in CINRAD (China New Generation Weather Radar) SA and SB radar operational observations are investigated. In order to distinguish the test pattern from other types of radar echoes, such as precipitation, clear air and other non-meteorological echoes, five feature parameters including the effective reflectivity data percentage ( R Z), velocity RF (range folding) data percentage ( R RF), missing velocity data percentage ( R M), averaged along-azimuth reflectivity fluctuation and averaged along-beam reflectivity fluctuation are proposed. Based on the fuzzy logic method, a test pattern identification algorithm is developed, and the statistical results from all the different kinds of radar echoes indicate the performance of the algorithm. Analysis of two typical cases with heavy precipitation echoes located inside the test pattern are performed. The statistical results show that the test pattern identification algorithm performs well, since the test pattern is recognized in most cases. Besides, the algorithm can effectively remove the test pattern signal and retain strong precipitation echoes in heavy rainfall events.

  6. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Steam generator inspections and tests. 229.114 Section...SAFETY STANDARDS Safety Requirements Steam Generators § 229.114 Steam generator inspections and tests. (a) Periodic...

  7. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Steam generator inspections and tests. 229.114 Section...SAFETY STANDARDS Safety Requirements Steam Generators § 229.114 Steam generator inspections and tests. (a) Periodic...

  8. 49 CFR 229.114 - Steam generator inspections and tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Steam generator inspections and tests. 229.114 Section...SAFETY STANDARDS Safety Requirements Steam Generators § 229.114 Steam generator inspections and tests. (a) Periodic...

  9. Hierarchical Testing Designs for Pattern Recognition

    E-print Network

    Blanchard, Gilles

    intense, processing. To this end, we consider a family of hypothesis tests for Y # A versus the non Introduction 4 2 Organization of the Paper 8 3 Overview of Results 9 4 Previous Work 11 4.1 Decision trees

  10. Modeling Fault Coverage of Random Test Patterns

    Microsoft Academic Search

    Hailong Cui; Sharad C. Seth; Shashank K. Mehta

    2003-01-01

    We present a new probabilistic fault coverage model that is accurate, simple, predictive, and easily integrated with the normal design o w of built-in self-test circuits. The parameters of the model are determined by tting the fault simulation data obtained on an initial segment of the random test. A cost-based analysis nds the point at which to stop fault simulation,

  11. Research on Test Case of Generating Scenario Based on UML

    Microsoft Academic Search

    ZHENG Guang-cheng

    2009-01-01

    (Abstract)Test case of generating scenario based on UML is very helpful for the design of test case. The method of a DHCP generating scenario test case is illustrated by using UML sequence diagram, integrate class graph and state graph. The test method based on UML sequence diagram are discussed, from finding scenario to generating test. And the environment condition of

  12. 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.

  13. The principle that generates dissimilar patterns inside aggregates of organisms

    NASA Astrophysics Data System (ADS)

    Miguel, Antonio F.; Bejan, Adrian

    2009-03-01

    Pattern formation and self-organization are phenomena that occur across the board, in animate and inanimate systems. In this paper, we rely on the constructal law to explain the generation of patterns (shapes, structures) in aggregates of organisms-pedestrian crowds and stony corals. In pedestrian crowds a variety of patterns are often observed, from ‘chaotic’ appearances to spontaneous organization in lanes of uniform walking direction. Stony corals and other organisms also present intraspecific variability in shape. We show that flow systems develop in time patterns which provide easier access to the nutrients and space, within a set of constraints imposed by each situation. Flow systems have the freedom to morph their shape in search for architectures that allows them to have greater access to the space that they inhabit. We identify the mechanisms allowing pedestrians to evolve in space and time. We also show that stony corals may develop branched or spherical shapes, depending on which shape performs best in response to the environmental conditions. The constructal law allows systems with complex internal flows to be described and understood for a unified view.

  14. 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

  15. Temperature-Dependent Regulation of Vocal Pattern Generator

    PubMed Central

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

    2008-01-01

    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

  16. Torque-stiffness-controlled dynamic walking with central pattern generators.

    PubMed

    Huang, Yan; Vanderborght, Bram; Van Ham, Ronald; Wang, Qining

    2014-12-01

    Walking behavior is modulated by controlling joint torques in most existing passivity-based bipeds. Controlled Passive Walking with adaptable stiffness exhibits controllable natural motions and energy efficient gaits. In this paper, we propose torque-stiffness-controlled dynamic bipedal walking, which extends the concept of Controlled Passive Walking by introducing structured control parameters and a bio-inspired control method with central pattern generators. The proposed walking paradigm is beneficial in clarifying the respective effects of the external actuation and the internal natural dynamics. We present a seven-link biped model to validate the presented walking. Effects of joint torque and joint stiffness on gait selection, walking performance and walking pattern transitions are studied in simulations. The work in this paper develops a new solution of motion control of bipedal robots with adaptable stiffness and provides insights of efficient and sophisticated walking gaits of humans. PMID:25128320

  17. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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 phantom. (a) Identification. A...

  18. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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 phantom. (a) Identification. A...

  19. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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 phantom. (a) Identification. A...

  20. Area-based tests for association between spatial patterns

    Microsoft Academic Search

    Susan L. Maruca; Geoffrey M. Jacquez

    2002-01-01

    .  ?Edge effects pervade natural systems, and the processes that determine spatial heterogeneity (e.g. physical, geochemical,\\u000a biological, ecological factors) occur on diverse spatial scales. Hence, tests for association between spatial patterns should\\u000a be unbiased by edge effects and be based on null spatial models that incorporate the spatial heterogeneity characteristic\\u000a of real-world systems. This paper develops probabilistic pattern association tests that

  1. Test Generation and Animation Based on Object-Oriented Specifications

    E-print Network

    Paris-Sud XI, Université de

    Test Generation and Animation Based on Object-Oriented Specifications Th`ese pr´esent´ee et;Abstract The goal of this thesis is the development of support for test generation and animation based generation and animation based on OCL specifications. For test generation, we have implemented several

  2. 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.

  3. A random walk based algorithm for structural test case generation

    Microsoft Academic Search

    Jifeng Xuan; He Jiang; Zhilei Ren; Yan Hu; Zhongxuan Luo

    2010-01-01

    Structural testing is a significant and expensive process in software development. By converting test data generation into an optimization problem, search-based software testing is one of the key technologies of automated test case generation. Motivated by the success of random walk in solving the satisfiability problem (SAT), we proposed a random walk based algorithm (WalkTest) to solve structural test case

  4. Precision measurement and nondestructive testing by means of digital phase shifting speckle pattern and speckle pattern shearing interferometry

    Microsoft Academic Search

    L. X. Yang; W. Steinchen; M. Schuth; G. Kupfer

    1995-01-01

    Speckle pattern and speckle pattern shearing interferometry, which were developed in the last two decades, are becoming more and more important in the areas of precision measurement and nondestructive testing. The fringe pattern of speckle pattern interferometry depicts loci of displacements, whereas the fringe pattern of speckle pattern shearing interferometry depicts loci of displacement gradients. By applying phase shifting technique

  5. 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

  6. 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.

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

    SciTech Connect

    Urban, Alexander; Ermentrout, Bard [Department of Physics, University of Pittsburgh, 100 Allen Hall, 3941 O'Hara Street, Pittsburgh, Pennsylvania 15260 (United States); Department of Mathematics, University of Pittsburgh, 139 University Place, Pittsburgh, Pennsylvania 15260 (United States)

    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.

  8. 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

  9. Automated optimum test case generation using web navigation graphs

    Microsoft Academic Search

    Ahmad Shahzad; Sajjad Raza; Muhammad N. Azam; Khurram Bilal; S. Shamail

    2009-01-01

    Increased diversity and complexity of software systems derived the need for test automation. Test Automation is the use of software for automatic execution of tests, comparison of results with expected outcome, setting up preconditions for test and test reporting functions. Model based testing is a test automation approach that generates and maintains more useful and flexible tests from explicit descriptions

  10. 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…

  11. Validation Testing of Hydrogen Generation Technology

    SciTech Connect

    Smith, Barton [ORNL; Toops, Todd J [ORNL

    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.

  12. Experimental tests of hypotheses for microsaccade generation.

    PubMed

    Ghasia, Fatema F; Shaikh, Aasef G

    2015-04-01

    Fixational eye movements such as microsaccades are important to prevent fading. These miniature eye movements are also necessary to redirect gaze to the target after a drift. Generation of saccades and microsaccades utilizes common neural substrates. We, therefore, hypothesized that physiological modulators of saccades should also affect microsaccades. Test of this hypothesis will also provide support for the models of a microsaccade generation. We performed two experiments. In the first experiment, complete darkness led to a decrease in the frequency and velocity, but increased the amplitude of microsaccades. In the second experiment, active eyelid closure further reduced the velocity and frequency of microsaccades, but increased their amplitude. Darkness reduces the superior colliculus activity leading to a reduction in the velocity and frequency of microsaccades. Eye closure might cause sustained inhibition of the omnipause neurons. Subsequent disinhibition of the burst neurons might cause a reduction in the post-inhibitory rebound firing resulting in a decreased velocity of microsaccades. Sustained inhibition of the omnipause neurons could also reduce the inhibitory drive that would otherwise abort microsaccades. Hence, by inhibiting the activity of omnipause neurons, the eye closure could increase the amplitude of microsaccades. PMID:25563497

  13. Distributed Central Pattern Generator Control for a Serpentine Robot

    E-print Network

    Jörg Conradt; Paulina Varshavskaya

    2003-01-01

    We have built a biologically and neurally inspired autonomous mobile robotic worm. The main aim of the project is to demonstrate elegant motion on a robot with a large number of degrees of freedom (DOFs) under the control of a simple distributed neural system as found in many animals' spinal cord. Our robot consists of individually controlled segments that exhibit Central-Pattern-Generator (CPG)-driven biomorphic motion. An important aspect of the project is to achieve a level of modularity while closely mimicking the neural control of e.g., the lamprey. This paper presents our robotic platform and the distributed CPG control algorithms. We will mainly focus on the architecture of the initial system and on future developments, and also report some preliminary experimental results.

  14. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Generation of test atmospheres. 53.22 Section 53.22 Protection...NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B...preferred methods for generating test atmospheres and suggested methods of...

  15. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Generation of test atmospheres. 53.22 Section 53.22 Protection...NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B...preferred methods for generating test atmospheres and suggested methods of...

  16. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Generation of test atmospheres. 53.22 Section 53.22 Protection...NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B...preferred methods for generating test atmospheres and suggested methods of...

  17. Refinement and Test Case Generation in UTP

    Microsoft Academic Search

    Bernhard K. Aichernig; Jifeng He

    2007-01-01

    This paper presents a theory of testing that integrates into Hoare and He's Unifying Theory of Programming (UTP). We give test cases a denotational semantics by viewing them as specification predicates. This reformulation of test cases allows for relating test cases via refinement to specifications and programs. Having such a refinement order that integrates test cases, we develop a testing

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

    PubMed

    Schöneich, Stefan; Hedwig, Berthold

    2012-11-01

    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

  19. 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.

  20. Disparate SPF testing methodologies generate similar SPFs.

    PubMed

    Garzarella, Katherine; Caswell, Michael

    2013-01-01

    Regulatory agencies throughout the world have developed exclusive methodologies for assessing and classifying sunscreen product efficacy in their respective markets. Three prevalent methods, the Food and Drug Administration-Final Monograph (FDA-FM) method, the Australia/New Zealand (Aus/NZ) method, and the COLIPA International (International) method, contain procedural and statistical dissimilarities with undefined significance. The objective of our clinical trials was to evaluate the influence of these disparities on sun protection factor (SPF) values. Our clinical trials evaluated the SPF of 59 test materials, using two or all three of the aforementioned methods in simultaneous trials, providing two or three SPF values for each formulation. A total of 135 trials were conducted. The consequent mean SPF values generated per trial were used to compare methods in a correlation and variance analysis. The correlation coefficients for each method pair, International vs. FDA-FM, Aus/NZ vs. FDA-FM, and International vs. Aus/NZ, were each ?0.94. The difference in least square mean SPF for each method pair was 0.12, 0.62, and 0.81, respectively. Our juxtaposition of the mean SPFs produced by these methods clearly illustrate that any disparities between average SPF values produced by these methods are not clinically or statistically significant and that using one method should be sufficient for SPF labeling in all three respective markets. PMID:23931092

  1. The chaining approach for software test data generation

    Microsoft Academic Search

    Roger Ferguson; Bogdan Korel

    1996-01-01

    Software testing is very labor intensive and expensive and accounts for a significant portion of software system development cost. If the testing process could be automated, the cost of developing software could be significantly reduced. Test data generation in program testing is the process of identifying a set of test data that satisfies a selected testing criterion, such as statement

  2. Observation-based test set generation

    E-print Network

    Cobb, Jeffrey Lee

    2013-02-22

    achieved with test vectors created usmg only observation BDDs. After creating the tests, I ran them through a bridging fault simulator called "Atalanta" This program uses a given set of tests to determme what percentage of all bridgmg faults...

  3. The Generation of Antiphase Oscillations and Synchrony by a Rebound-Based Vertebrate Central Pattern Generator

    PubMed Central

    Merrison-Hort, Robert; Zhang, Hong-Yan; Borisyuk, Roman

    2014-01-01

    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

  4. Advanced test equipment for third generation FLIRs

    Microsoft Academic Search

    Thomas H. Kelly Jr

    2001-01-01

    Traditional test equipment for FLIR testing is typically comprised of a blackbody source back irradiating an assortment of stationary discrete etched targets to produce a differential image at the focal plane of a collimator. Even though this basic tester is a time proven tool for testing the performance of scanning systems, it does not adequately address tomorrow's staring array test

  5. "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…

  6. 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.

  7. Systemic pattern of free radical generation during coronary bypass surgery.

    PubMed Central

    Davies, S W; Underwood, S M; Wickens, D G; Feneck, R O; Dormandy, T L; Walesby, R K

    1990-01-01

    Diffuse impairment of ventricular function after cardiac surgery may be related to the generation during reperfusion of the myocardium of free radicals derived from oxygen. Fifteen patients undergoing elective coronary bypass surgery were studied by previously described assays for peroxidised lipids and for isomerised lipids which were used as indices of free radical activity. Serial blood samples were obtained from systemic arterial, mixed venous, and coronary sinus catheters before, during, and after the ischaemic period. The patients underwent coronary artery surgery on cardiopulmonary bypass with a membrane oxygenator, relative hypothermia 30-34 degrees C, and intermittent cross-clamping of the aorta. During the ischaemic periods there were no significant changes in the indices of free radical activity. During the reperfusion phase there was a significant increase in free radical indices in arterial and mixed venous blood. A small rise in free radical indices in coronary venous blood was not statistically significant. These data indicate that free radical activity is increased in patients shortly after the cessation of cardiopulmonary bypass. The pattern of distribution between the different sampling sites suggests that much of the observed increase in isomerised and peroxidised lipids originates from tissues other than the myocardium. PMID:2223301

  8. Coverage-Directed Test Generation Using Symbolic Techniques

    Microsoft Academic Search

    Daniel Geist; Monica Farkas; Avner Landver; Yossi Lichtenstein; Ur Shmuel; Yaron Wolfsthal

    1996-01-01

    In this paper, we present a verification methodology that integrates formal verification techniques with verification by simulation, thereby providing means for generating simulation test suites that ensure coverage. We derive the test suites by means of BDD-based symbolic techniques for describing and traversing the implementation state space. In our approach, we provide a high-level of control over the generated test

  9. Search-based software test data generation: a survey

    Microsoft Academic Search

    Phil Mcminn

    2004-01-01

    The use of metaheuristic search techniques for the automatic genera- tion of test data has been a burgeoning interest for many researchers in recent years. Previous attempts to automate the test generation process have been limited, having been constrained by the size and complexity of software, and the basic fact that in general, test data generation is an un- decidable

  10. Using UML Collaboration Diagrams for Static Checking and Test Generation

    E-print Network

    Offutt, Jeff

    diagrams. The most novel aspect of this is that tests can be generated automatically from the softwareUsing UML Collaboration Diagrams for Static Checking and Test Generation Aynur Abdurazik and Jeff Modeling Language (UML '00), pages 383--395, York, UK, October 2000. Abstract. Software testing can only

  11. Symbolic Test Case Generation for Time-Discrete Hybrid Systems

    Microsoft Academic Search

    Jan Peleska; Martin Franzle; Tino Teige

    In this article we present a model-based test case specification and associated test data generation meth- ods for embedded systems processing Boolean, integral and real-valued variables. Testing experts are relieved from the task of constructing input data to the system under test in an explicit way and manually calculating the expected reactions. Instead, test cases are specified by means of

  12. On the Automated Generation of Program Test Data

    Microsoft Academic Search

    C. V. Ramamoorthy; Siu-bun F. Ho; Wen-Tsuen Chen

    1976-01-01

    Software validation through testing will continue to be a very important tool for ensuring correctness of large scale software systems. Automation of testing tools can greatly enhance their power and reduce testing cost. In this paper, techniques for automated test data generation are discussed. Given a program graph, a set of paths are identified to satisfy some given testing criteria.

  13. Automatic test generation using genetically-engineered distinguishing sequences

    Microsoft Academic Search

    Michael S. Hsiao; Elizabeth M. Rudnick; Janak H. Patel

    1996-01-01

    A fault-oriented sequential circuit test generator isdescribed in which various types of distinguishing sequencesare derived, both statically and dynamically,to aid the test generation process. A two-phase algorithmis used during test generation. The first phaseactivates the target fault, and the second phase propagatesthe fault effects (FE's) from the flip-flops withassistance from the distinguishing sequences. Thisstrategy improves the propagation of FE's to

  14. A test case generation approach for conformance testing of SDL systems1

    E-print Network

    Aboulhamid, El Mostapha

    1 A test case generation approach for conformance testing of SDL systems1 C. Bourhfir2 , E This paper presents an approach for automatic executable test case and test sequence generation for a protocol modeled by an SDL system. Our methodology uses a uni- fied method which tests an Extended Finite

  15. The Full Function Test Explosive Generator

    SciTech Connect

    Reisman, D B; Javedani, J B; Griffith, L V; Ellsworth, G F; Kuklo, R M; Goerz, D A; White, A D; Tallerico, L J; Gidding, D A; Murphy, M J; Chase, J B

    2009-12-13

    We have conducted three tests of a new pulsed power device called the Full Function Test (FFT). These tests represented the culmination of an effort to establish a high energy pulsed power capability based on high explosive pulsed power (HEPP) technology. This involved an extensive computational modeling, engineering, fabrication, and fielding effort. The experiments were highly successful and a new US record for magnetic energy was obtained.

  16. 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.

  17. F-1 Engine Gas Generator Testing - Duration: 1:50.

    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...

  18. Heuristic Search with Reachability Tests for Automated Generation of Test Programs

    E-print Network

    Leow, Wee Kheng

    the outputs, which are evaluated by a test evaluation tool. Our research complements the current research, which are checked by a test evaluation tool. Test execution and test result evaluation are easy to au separate tools for test execution and test evaluation. The core of the test program generator is a partial

  19. Patterns of rock fragment cover generated by tillage erosion

    Microsoft Academic Search

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

    1997-01-01

    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 km2 was digitised, and for each pixel total topographic

  20. Function generator for synthesizing complex vibration mode patterns

    NASA Technical Reports Server (NTRS)

    Naumann, E. C.; Hagood, G. J., Jr. (inventors)

    1973-01-01

    A simple highly flexible device for synthesizing complex vibration mode patterns is described. These mode patterns can be used to identify vibration mode data. This device sums selected sine and cosine functions and then plots the sum against a linear function.

  1. COTTAGE: Test Data Generation based on Consistency Techniques

    E-print Network

    Deville, Yves

    Introduction 1.1 Test Data Generation Software testing is an expensive and diOEcult task, accounting for up coverage algorithm. The COTTAGE system, a 13,000 Java lines software, imple­ ments our approach for C variables; arrays, procedures, path coverage, statement cov­ erage). Keywords software testing, test data

  2. COTTAGE: Test Data Generation based on Consistency Techniques

    E-print Network

    Deville, Yves

    Introduction 1.1 Test Data Generation Software testing is an expensive and di cult task, accounting for up coverage algorithm. The COTTAGE system, a 13,000 Java lines software, imple- ments our approach for C variables arrays, procedures, path coverage, statement cov- erage). Keywords software testing, test data

  3. Automatic GUI test generation for smartphone applications - an evaluation

    Microsoft Academic Search

    Antti Jääskeläinen; Mika Katara; Antti Kervinen; Mika Maunumaa; Tuula Pääkkönen; Tommi Takala; Heikki Virtanen

    2009-01-01

    We present the results of an evaluation where we studied the effectiveness of automatic test generation for graphical user interface (GUI) testing of smartphone applications. To describe the context of our evaluation, the tools and the test model library we have developed for the evaluation are also presented. The library contains test models for basic S60 applications, such as camera,

  4. 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…

  5. Test-Architecture Optimization and Test Scheduling for SOCs with Core-Level Expansion of Compressed Test Patterns

    E-print Network

    Chakrabarty, Krishnendu

    (TDC) has recently emerged as a popular technique to reduce test data volume and test time. TDC has common in industry [7, 8, 9]. In TDC, on-chip decompressors are used to expand compressed test patterns before they are loaded into a core's scan chains. The benefits of TDC can be further enhanced

  6. Bio-inspired design strategies for central pattern generator control in modular robotics.

    PubMed

    Herrero-Carrón, F; Rodríguez, F B; Varona, P

    2011-03-01

    New findings in the nervous system of invertebrates have shown how a number of features of central pattern generator (CPG) circuits contribute to the generation of robust flexible rhythms. In this paper we consider recently revealed strategies that living CPGs follow to design CPG control paradigms for modular robots. To illustrate them, we divide the task of designing an example CPG for a modular robot into independent problems. We formulate each problem in a general way and provide a bio-inspired solution for each of them: locomotion information coding, individual module control and inter-module coordination. We analyse the stability of the CPG numerically, and then test it on a real robot. We analyse steady state locomotion and recovery after perturbations. In both cases, the robot is able to autonomously find a stable effective locomotion state. Finally, we discuss how these strategies can result in a more general design approach for CPG-based locomotion. PMID:21335644

  7. AVPGEN-A test generator for architecture verification

    Microsoft Academic Search

    Ashok K. Chandra; Vijay S. Iyengar; D. Jameson; R. V. Jawalekar; Indira Nair; Barry K. Rosen; Michael P. Mullen; J. Yoon; R. Armoni; Daniel Geist; Yaron Wolfsthal

    1995-01-01

    This paper describes a system (AVPGEN) for generating tests (called architecture verification programs or AVP's) to check the conformance of processor designs to the specified architecture. To generate effective tests, AVPGEN uses novel concepts like symbolic execution and constraint solving, along with various biasing techniques. Unlike many earlier systems that make biased random choices, AVPGEN often chooses intermediate or final

  8. Validation of Gas Flow Measurement During Ozone Generator Performance Testing

    Microsoft Academic Search

    Kerwin L. Rakness; David Henry; Bruno Langlais

    2000-01-01

    Key measurements for ozone generator efficiency testing include generator power, ozone concentration, and gas flow rate. Accurate gas flow measurement must address numerous issues such as: meter precision, meter calibration, gas density changes due to variations in molecular composition, and gas compression and expansion changes due to variation in temperature and pressure. Preferably, the gas flowmeter for performance testing is

  9. Towards a New Extension Relation for Compositional Test Case Generation

    E-print Network

    Chan, Wing-Kwong Ricky

    in September 2003 Software concurrent systems such as electronic financial services are very popular todayTowards a New Extension Relation for Compositional Test Case Generation for CSP Concurrent Towards a New Extension Relation for Compositional Test Case Generation for CSP Concurrent Processes

  10. 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.

  11. Systematic Testing of Model-Based Code Generators

    Microsoft Academic Search

    Ingo Stuermer; Mirko Conrad; Heiko Doerr; Peter Pepper

    2007-01-01

    Unlike for conventional compilers for imperative programming languages such as C or ADA, no establishedmethods for safeguarding artifacts generated by model-based code generators exist despite progress in the field of formalverification. Several test approaches dominate the engineering practice. This paper describes a general and toolindependenttest architecture for code generators used in model-based development. We evaluate the effectiveness of ourtest approach

  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. 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.

  14. On Low-Capture-Power Test Generation for Scan Testing

    Microsoft Academic Search

    Xiaoqing Wen; Yoshiyuki Yamashita; Seiji Kajihara; Laung-terng Wang; Kewal K. Saluja; Kozo Kinoshita

    2005-01-01

    Research on low-power scan testing has been focused on the shift mode, with little or no consideration given to the capture mode power. However, high switching activity when capturing a test response can cause excessive IR drop, resulting in significant yield loss. This paper addresses this problem with a novel low-capture-power X-filling method by assigning 0's and 1's to unspecified

  15. 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.

  16. HPGAST: High Performance GA-based Sequential circuits Test generation on Beowulf PC-Cluster

    Microsoft Academic Search

    This paper deals with a High Performance Automated Test Pattern Generation for sequential circuits on single stuck-at fault model. HPGAST Parallel Genetic Algorithm on Beowulf PC-Cluster is presented. In this work, we describe a parallel version of an existing GA-based ATPG and tools: (PGAPack parallel genetic algorithm library to evolve candidate test vectors, HOPE fault simulator to compute the fitness

  17. Generating Test Cases for Web Services Using Data Perturbation

    E-print Network

    Offutt, Jeff

    Generating Test Cases for Web Services Using Data Perturbation Jeff Offutt & Wuzhi Xu Department presents a new approach to testing Web services based on data perturbation. Exist- ing XML messages two methods to test Web services: data value perturbation and interaction perturbation. Data value per

  18. 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.

  19. Personalized Power Saving Profiles Generation Analyzing Smart Device Usage Patterns

    E-print Network

    Gesbert, David

    ; Privacy; Usage pattern. I. INTRODUCTION The Android smartphones and tablets are being adopted and playback, navigation, sharing of digital content through social media apps and more. These devices also change. For instance, users socialize using mobile applications of Google+, Facebook & Twitter, use

  20. Generation of Polynomial Discriminant Functions for Pattern Recognition

    Microsoft Academic Search

    Donald F. Specht

    1967-01-01

    A practical method of determining weights for crossproduct and power terms in the variable inputs to an adaptive threshold element used for statistical pattern classification is derived. The objective is to make it possible to realize general nonlinear decision surfaces, in contrast with the linear (hyperplanar) decision surfaces that can be realized by a threshold element using only first-order terms

  1. 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)

  2. 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.

  3. 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.

  4. Improving Generation of Object-Oriented Test Suites by Avoiding Redundant Tests

    Microsoft Academic Search

    Tao Xie; Darko Marinov; David Notkin

    2004-01-01

    Object-oriented tests consist of sequences of method invocations. Behavior of an invocation depends on the state of the receiver ob- ject and method arguments at the beginning of the invocation. Ex- isting tools for automatic generation of object-oriented test suites, such as Jtest and JCrasher for Java, typically ignore object states. These tools generate redundant tests that exercise the same

  5. A Materials Science Driven Pattern Generation Solution to Fracturing Computer Generated Glass for Films and Games

    E-print Network

    Monroe, David Charles

    2014-08-11

    fracture patterns used for breaking objects apart based on input values, materials science literature, and fracture mechanics. After determining all of the fracture pattern variables such as the number of radial and concentric cracks, the artist is able...

  6. Heuristic Search with Reachability Tests for Automated Generation of Test Programs

    E-print Network

    Leow, Wee Kheng

    the outputs, which are checked by a test evaluation tool. Test execution and test result evaluation are easy which plans the sequence of instructions required in the test program. A first-cut implementation evaluation. The first stage generates test cases from a software system's specification. Before the system

  7. Performance testing of a Transit generator at JPL.

    NASA Technical Reports Server (NTRS)

    Rouklove, P.

    1973-01-01

    A Transit type thermoelectric generator, serial number QM-III, assembled with lightweight Isotec type thermoelectric panels, has been placed on test at the Jet Propulsion Laboratory. In its exterior appearance and main constructive features, generator QM-III is similar to the generator which was flown on the Transit satellite, launched into circular polar orbit on Sept. 2, 1972. The main difference between the flight generator and QM-III is that the flight hardware is heated by radioisotope decay, while QM-III is an ETG and is assembled with three different types of thermoelectric panels. The paper describes the generator and test equipment used and presents the results of the tests performed to date.

  8. Feedback-Based Coverage Directed Test Generation: An Industrial Evaluation

    NASA Astrophysics Data System (ADS)

    Ioannides, Charalambos; Barrett, Geoff; Eder, Kerstin

    Although there are quite a few approaches to Coverage Directed test Generation aided by Machine Learning which have been applied successfully to small and medium size digital designs, it is not clear how they would scale on more elaborate industrial-level designs. This paper evaluates one of these techniques, called MicroGP, on a fully fledged industrial design. The results indicate relative success evidenced by a good level of code coverage achieved with reasonably compact tests when compared to traditional test generation approaches. However, there is scope for improvement especially with respect to the diversity of the tests evolved.

  9. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7900 Thromboplastin generation test. (a) Identification....

  10. 21 CFR 864.7900 - Thromboplastin generation test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7900 Thromboplastin generation test. (a) Identification....

  11. Using ordered partial decision diagrams for manufacture test generation

    E-print Network

    Cobb, Bradley Douglas

    2004-09-30

    Improvements to sByDDer..................................................................30 Test Generation ........................................................................................................30 RESULTS.......................................................................16 Figure 9. Boolean-difference observation function calculation.......................................18 Figure 10. Boolean-difference unguided..........................................................................20 Figure 11. Boolean...

  12. Approaches to test set generation using binary decision diagrams

    E-print Network

    Wingfield, James

    2004-09-30

    This research pursues the use of powerful BDD-based functional circuit analysis to evaluate some approaches to test set generation. Functional representations of the circuit allow the measurement of information about faults that is not directly...

  13. Generation of Spatial Patterns in Boreal Forest Landscapes

    Microsoft Academic Search

    John Pastor; Yosef Cohen; Ron Moen

    1999-01-01

    Boreal forests are composed of a few plant species with contrasting traits with respect to ecosystem functioning and spatial\\u000a patterning. Early successional deciduous species, such as birch and aspen, disperse seeds widely, do not tolerate low light\\u000a and nitrogen availabilities, have rapidly decaying litter, and are highly preferred by herbivores. These later succeed to\\u000a conifers, such as spruce and fir,

  14. Gentest: An Automatic Test-Generation System for Sequential Circuits

    Microsoft Academic Search

    Wu-tung Cheng; Tapan J. Chakraborty

    1989-01-01

    A description is given of Gentest, with emphasis on STG2, a sequential test generator that uses the Back test-generation algorithm and the Split value model. The performance of STG2 on a Convex C-1 computer is compared with that of its predecessor, STG1 and STG1.5. Results are also presented for another set of experiments for Gentest on a Sun 3\\/60 workstation.

  15. Design, Fabrication and testing of quantum well thermoelectric generator

    Microsoft Academic Search

    Velimir Jovanovic; Saeid Ghamaty; Norbert B. Elsner

    2006-01-01

    A prototype energy-harvesting thermoelectric generator (TEG) is being designed, fabricated and tested to provide power for wireless sensors used in health monitoring of Navy ship machinery. TEGs utilize the heat transfer between shipboard waste heat sources and the ambient air to generate electricity directly and without any moving parts. In order to satisfy the required small design volume of 16.4

  16. Analysis of radiation patterns of interaction tones generated by inlet rods in the JT15D engine

    NASA Technical Reports Server (NTRS)

    Heidmann, M. F.; Saule, A. V.

    1979-01-01

    Interaction tones were intentionally generated by circumferential arrays of equally spaced rods that protrude radially from the inlet wall near the face of the 28-blade fan. Arrays of 28 and 41 rods, selected to give specific far field radiation properties, were tested. The expected properties were readily apparent in the measured radiation patterns. A more detailed analysis of the test data showed both the precision and limitations of the applied acoustic theory. Rods protruding 23 percent of the radius predominantly generated only lowest radial order modes, as expected. Measured and predicted radiation patterns were generally in good agreement. The agreement, however, depended on a significant degree of implied refraction due to inlet velocity gradients. Refraction, if present, would impact static-flight noise comparisons.

  17. VanetMobiSim: generating realistic mobility patterns for VANETs

    Microsoft Academic Search

    Jérôme Härri; Fethi Filali; Christian Bonnet; Marco Fiore

    2006-01-01

    In this paper, we present and describe VanetMobiSim, a generator of realistic vehicular movement traces for telecommunication networks simulators. VanetMobiSim mobility description is validated by illustrating how the interaction between featured macro- and micro-mobility is able to reproduce typical phenomena of vehicular traffic.

  18. Converging Laser Generated Ultrasonic Waves using Annular Patterns Irradiation

    NASA Astrophysics Data System (ADS)

    Zamiri, S.; Reitinger, B.; Bauer, S.; Burgholzer, P.

    2014-06-01

    We report on a contactless method to focus laser generated bulk and surface ultrasound waves in the thermo-elastic coupling mode by annular shaped illumination. By using a spatial light modulator (SLM) the beam profile of a pulsed picoseconds laser was shaped to annular forms flexibly and further rings with a thickness of 50 ?m and a generation energy as low as 2 mJ were generated on the surface of aluminum plates. The annular shapes have been used to focus acoustic waves toward the center. In this work, a photorefractive adaptive interferometer set up based on Two-Wave Mixing in a fast BSO crystal was used to probe and detect the converging acoustic pulses at the center of the laser generated rings. By moving the detection point about 1 mm out of the ring epicenter, the amplitude of bulk and surface waves drop quickly which shows the converging evidence of the acoustic waves in the ring center. For a 3 mm thick aluminum plate, the ring size from 1 mm to 10 mm was scanned. The optimum ring diameter and the focal length of the acoustic waves along the central axis were found. Applications of this technique in subsurface defects detection as well as sample thickness measurement are investigated.

  19. Testing random number generators for Monte Carlo applications.

    PubMed

    Sim, L H; Nitschke, K N

    1993-03-01

    Central to any system for modelling radiation transport phenomena using Monte Carlo techniques is the method by which pseudo random numbers are generated. This method is commonly referred to as the Random Number Generator (RNG). It is usually a computer implemented mathematical algorithm which produces a series of numbers uniformly distributed on the interval [0,1). If this series satisfies certain statistical tests for randomness, then for practical purposes the pseudo random numbers in the series can be considered to be random. Tests of this nature are important not only for new RNGs but also to test the implementation of known RNG algorithms in different computer environments. Six RNGs have been tested using six statistical tests and one visual test. The statistical tests are the moments, frequency (digit and number), serial, gap, and poker tests. The visual test is a simple two dimensional ordered pair display. In addition the RNGs have been tested in a specific Monte Carlo application. This type of test is often overlooked, however it is important that in addition to satisfactory performance in statistical tests, the RNG be able to perform effectively in the applications of interest. The RNGs tested here are based on a variety of algorithms, including multiplicative and linear congruential, lagged Fibonacci, and combination arithmetic and lagged Fibonacci. The effect of the Bays-Durham shuffling algorithm on the output of a known "bad" RNG has also been investigated. PMID:8470994

  20. The test suite generation problem: Optimal instances and their implications

    Microsoft Academic Search

    Christine T. Cheng

    2007-01-01

    In the test suite generation problem (TSG) for software systems, I is a set of n input parameters where each I 2 I has (I) data values, and O is a collection of subsets ofI where the interactions of the parameters in each O 2O are thought to aect the outcome of the system. A test case for (I;O; )

  1. An Enhanced Framework for Microprocessor Test-Program Generation

    E-print Network

    Fernandez, Thomas

    An Enhanced Framework for Microprocessor Test-Program Generation F. Corno, G. Squillero Politecnico microprocessor, engineers may exploit test programs to uncover errors and blunders. Such a process is sometimes microprocessors or microcontrollers by exposing internal defects to accessible outputs trough suitable sequences

  2. A Universal Statistical Test for Random Bit Generators

    Microsoft Academic Search

    Ueli M. Maurer

    1992-01-01

    A new statistical test for random bit generators is presented which, in contrast to presently used statistical tests, is universal in the sense that it can detect any significant deviation of a device's output statistics from the statistics of a truly random bit source when the device can be modeled as an ergodic stationary source with finite memory but arbitrary

  3. Diagnoses of AC Generator Insulation Condition by Nondestructive Tests

    Microsoft Academic Search

    A. W. W. Cameron

    1952-01-01

    Data are presented from comparison of nondestructive and destructive tests on several synchronous generator stators ranging from 800 to 33,000 kva. It is shown that the breakdown voltage of the weakest point in a winding can be forecast nondestructively by insulation resistance tests at increasing voltages. A new method of stating dielectric-absorption effect is suggested and its value as a

  4. A simple approach for stochastic generation of spatial rainfall patterns

    NASA Astrophysics Data System (ADS)

    Tarpanelli, A.; Franchini, M.; Brocca, L.; Camici, S.; Melone, F.; Moramarco, T.

    2012-11-01

    SummaryRainfall scenarios are of considerable interest for design flood and flood risk analysis. To this end, the stochastic generation of continuous rainfall sequences is often coupled with the continuous hydrological modelling. In this context, the spatial and the temporal rainfall variability represents a significant issue, especially for basins in which the rainfall field cannot be approximated through the use of a single station. Therefore, methodologies for the spatially and temporally correlated rainfall generation are welcome. An example of such a methodology is the well-established Spatial-Temporal Neyman-Scott Rectangular Pulse (STNSRP), a modification of the single-site Neyman-Scott Rectangular Pulse (NSRP) approach, designed to incorporate specific features to reproduce the rainfall spatial cross-correlation. In order to provide a simple alternative to the STNSRP, a new method of generating synthetic rainfall time series with pre-set spatial-temporal correlation is proposed herein. This approach relies on the single-site NSRP model, which is used to generate synthetic hourly independent rainfall time series at each rain gauge station with the required temporal autocorrelation (and several other appropriately selected statistics). The rank correlation method of Iman and Conover (IC) is then applied to these synthetic rainfall time series in order to introduce the same spatial cross-correlation that exists between the observed time series. This combination of the NSRP model with the IC method consents the reproduction of the observed spatial-temporal variability of a rainfall field. In order to verify the proposed procedure, four sub-basins of the Upper Tiber River basin are investigated whose basin areas range from 165 km2 to 2040 km2. Results show that the procedure is able to preserve both the rainfall temporal autocorrelation at single site and the rainfall spatial cross-correlation at basin scale, and its performance is comparable with that of the STNSRP model for rainfall field generation. Given its simple formal structure (based on well established methods: i.e. NSRP and IC), we believe that the proposed approach can be conveniently utilized to generate spatially and temporally correlated rainfall scenarios.

  5. Experimental observations of shear patterns in direct shear tests

    NASA Astrophysics Data System (ADS)

    Scarpelli, G.; Wood, D. M.

    A series of simple experiments were performed using direct shear apparatus in order to study the rupture patterns in sands. Measurements of internal displacements were made by observing with X-rays the positions of lead shot placed in a regular array within the sample. Shear displacement was applied manually and radiographs were taken after each increment of horizontal movement in order to observe the incremental strain field. The sand used was 30/52 Leighton Buzzard sand with a grain size between 0.3mm and 0.5mm. It was concluded that, while caution should be exercised in extrapolating the results of these low stress tests, the results matched some theoretical estimates for the orientation of shear bands. It was suggested that characteristic lengths and thicknessess of shear bands might be related to the average particle size of the sand.

  6. 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…

  7. Dynamic control of a central pattern generator circuit: a computational model of the snail feeding network

    E-print Network

    Feng, Jianfeng

    ­Huxley models, Lymnaea stagnalis Abstract Central pattern generators (CPGs) are networks underlying rhythmic to the rhythmogenic circuit. In the feeding system of the pond snail, Lymnaea stagnalis, the extrinsic slow oscillator the CPG-driven motor pattern underlying feeding in the pond snail, Lymnaea (Fig. 1). One type of cell

  8. Symmetric patterns in the cellular automaton that generates Pascal's triangle modulo 2

    Microsoft Academic Search

    André Barbé

    2000-01-01

    A binary difference pattern (BDP) is a pattern obtained by covering an equilateral triangular grid by black and white circles in a dense hexagonal packing under a simple symmetric local matching rule. It is a subpattern in a specific graphical representation of the orbit of a cellular automaton that generates Pascal's triangle modulo 2. Analytic conditions for certain types of

  9. 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…

  10. 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.

  11. 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.

  12. 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.

  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 developing downstream a straight single channel reach; and c) branches in sinuous-second order lateral channels. Velocity maps and an analysis of secondary currents provide information on the three-dimensional flows of water within the channel indicating that bed and channel morphology affect hydraulic characteristics. Several cross sections present unusually deep pools up to ~80m depth in the outer bank and significant increases in the local water slope. These are related to geological constraints, which manifest in the over deepening from the preferentially downwards secondary flow, exacerbating erosion. The anabranching patterns in large rivers such as the Madeira are not just controlled by intrinsic morphodynamics and hydraulic geometry variables but though a variety of interactions with the architecture of the floodplain and the control exerted by older fluvial geomorphological units.

  14. 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.

  15. The RANLUX Generator:. Resonances in a Random Walk Test

    NASA Astrophysics Data System (ADS)

    Shchur, Lev N.; Butera, Paolo

    Using a recently proposed directed random walk test, we systematically investigate the popular random number generator RANLUX developed by Lüscher and implemented by James. We confirm the good quality of this generator with the recommended luxury level. At a smaller luxury level (for instance equal to 1) resonances are observed in the random walk test. We also find that the lagged Fibonacci and Subtract-with-Carry recipes exhibit similar failures in the random walk test. A revised analysis of the corresponding dynamical systems leads to the observation of resonances in the eigenvalues of Jacobi matrix.

  16. TestU01: A C library for empirical testing of random number generators

    Microsoft Academic Search

    Pierre L'ecuyer; Richard J. Simard

    2007-01-01

    a collection of utilities for the empirical statistical testing of uniform random number generators (RNGs). It provides general implementations of the classical statistical tests for RNGs, as well as several others tests proposed in the literature, and some original ones. Predefined tests suites for sequences of uniform random numbers over the interval (0,1) and for bit sequences are available. Tools

  17. Generation of Electrically Induced Stimuli for MEMS Self-Test

    Microsoft Academic Search

    Benoît Charlot; Salvador Mir; Fabien Parrain; Bernard Courtois

    2001-01-01

    A major task for the implementation of Built-In-Self-Test (BIST) strategies for MEMS is the generation of the test stimuli. These devices can work in different energy domains and are thus designed to sense signals which are generally not electrical. In this work, we describe, for different types of MEMS, how the required non-electrical test stimuli can be induced on-chip by

  18. Automated Test Generation for AspectJ Programs

    Microsoft Academic Search

    Tao Xie; Jianjun Zhao; Darko Marinov; David Notkin

    Aspect-oriented software development (AOSD) is a new paradigm that improves separation of concerns in software development. AOSD has gained popularity with the adoption of languages such as As- pectJ. Automated test generation for AspectJ programs is important for reducing the manual effort in testing AspectJ programs. This position paper proposes Wrasp, a framework for automatic gener- ation of tests for

  19. CityMob: A Mobility Model Pattern Generator for VANETs

    Microsoft Academic Search

    Francisco J. Martinez; Juan-Carlos Cano; Carlos T. Calafate; Pietro Manzoni

    2008-01-01

    Ad hoc networking is regarded as an adequate solution to cooperative driving between communicating cars on the road. Deploying and testing these networks, usually known as Vehicular Ad-hoc Networks (VANETs), involves a high cost in the real world, and so simulation is an useful alternative in research. One of the most critical issues in a simulation study of VANETs is

  20. Comparison between LCOS projector and DLP projector in generating digital sinusoidal fringe patterns

    NASA Astrophysics Data System (ADS)

    Li, Beiwen; Gibson, John; Middendorf, Jill; Wang, Yajun; Zhang, Song

    2013-09-01

    Digital-light-processing (DLP) and liquid-crystal-on-silicon (LCOS) are two digital projection technologies which enjoy great popularity. This paper will demonstrate the performance of the two technologies in generating digital sinusoidal fringe patterns in the two following ways: focused-sinusoidal-patterns (FSP) method and defocused-binary-patterns (DBP) method. Experiment shows that for the FSP method, LCOS projector is a better choice since nonlinear gamma effect is less significant and there is no need for precise synchronization; While for the DBP method, DLP projector has the advantage over LCOS projector since the generated images have higher contrast ratio.

  1. 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 based on a range of metrics. Although the specific means of scoring depends highly on the application, the use of formal scoring - metrics has high value in identifying and prioritizing anomalies, and in presenting an overall picture of the state of the test program. In this paper we present a case study based on automatic generation and assessment of faulted test runs for the Dawn mission, and discuss its role in optimizing the allocation of resources for completing the test program.

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

    Microsoft Academic Search

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

    2005-01-01

    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

  3. RESTORATION OF PITCH PATTERN OF SPEECH BASED ON A PITCH GENERATION MODEL

    E-print Network

    Edinburgh, University of

    RESTORATION OF PITCH PATTERN OF SPEECH BASED ON A PITCH GENERATION MODEL Hiroshi Shimodaira extractor is investigated. In contrast to the conventional pitch trackers based on numerical curve-fitting, the proposed method em- ploys a quantitative pitch generation model, which is often used for synthesizing F0

  4. Using triangle-based cubic interpolation in generation of object-adaptive fringe pattern

    NASA Astrophysics Data System (ADS)

    Peng, Junzheng; Yu, Yingjie; Zhou, Wenjing; Chen, Mingyi

    2014-01-01

    The object-adaptive fringe projection technique employs user-defined uneven spaced fringe patterns, instead of the evenly spaced fringe patterns, to measure the deformation of the object surface. With this technique, the quality of the object-adaptive fringe patterns is very important for guaranteeing the measurement accuracy. In this paper, a simple and effective method to generate such fringe patterns based on the cubic Beziér interpolation is presented. It can realize the cubic Beziér interpolation through three nearest points and thereby the time required for generating the adaptive fringe patterns is significantly reduced without loss of accuracy. Numerical simulations and experiments have demonstrated the accuracy and effectiveness of the proposed method.

  5. Automatic Generation of English-Japanese Translation Pattern Utilizing Genetic Programming Technique

    NASA Astrophysics Data System (ADS)

    Matsumura, Koki; Tamekuni, Yuji; Kimura, Shuhei

    There are a lot of constructional differences in an English-Japanese phrase template, and that often makes the act of translation difficult. Moreover, there exist various and tremendous phrase templates and sentence to be refered to. It is not easy to prepare the corpus that covers the all. Therefore, it is very significant to generate the translation pattern of the sentence pattern automatically from a viewpoint of the translation success rate and the capacity of the pattern dictionary. Then, for the purpose of realizing the automatic generation of the translation pattern, this paper proposed the new method for the generation of the translation pattern by using the genetic programming technique (GP). The technique tries to generate the translation pattern of various sentences which are not registered in the phrase template dictionary automatically by giving the genetic operation to the parsing tree of a basic pattern. The tree consists of the pair of the English-Japanese sentence generated as the first stage population. The analysis tree data base with 50,100,150,200 pairs was prepared as the first stage population. And this system was applied and executed for an English input of 1,555 sentences. As a result, the analysis tree increases from 200 to 517, and the accuracy rate of the translation pattern has improved from 42.57% to 70.10%. And, 86.71% of the generated translations was successfully done, whose meanings are enough acceptable and understandable. It seemed that this proposal technique became a clue to raise the translation success rate, and to find the possibility of the reduction of the analysis tree data base.

  6. 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.

  7. 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.

  8. Patterns of mating, generation of diversity, and fitness of offspring in a Geum hybrid swarm.

    PubMed

    Ruhsam, Markus; Hollingsworth, Peter M; Ennos, Richard A

    2013-09-01

    To understand the evolutionary consequences of hybridization between the outcrossing plant Geum rivale (Rosaceae) and the selfer Geum urbanum, we tested the predictions of two simple models that assume either (A) low or (B) high pollen fitness in hybrids. Model A predicts only four genotypic classes (G. rivale, G. rivale backcross [BC(R)], F1, and Geum urbanum) and asymmetric introgression from inbreeding to outbreeding species. Model B predicts additional genotypic classes and potential generation of novel inbreeding lines in the hybrid swarm. Amplified fragment length polymorphism (AFLP) analysis of adults revealed only the four genotypes predicted by model A. However, microsatellite analysis of parent-progeny arrays demonstrated production of selfed offspring by F1 and BC(R) maternal parents and contribution of these genotypes to outcross pollen pools, as predicted by model B. Moreover, AFLP and morphological analysis showed that the offspring generation comprised genotypes and phenotypes covering the entire spectrum of variation between the two parental species, in line with model B. A common garden experiment indicated no systematic reduction in fitness of offspring derived from hybrid parents. The genetic structure of the adults in the Geum hybrid swarm cannot be explained by restricted mating patterns but may result from ecological selection acting on a diverse offspring population. PMID:24033179

  9. Hemispatial PCA dissociates temporal from parietal ERP generator patterns

    PubMed Central

    Tenke, Craig E.; Kayser, Jürgen; Shankman, Stewart A.; Griggs, Carlye B.; Leite, Paul; Stewart, Jonathan W.; Bruder, Gerard E.

    2008-01-01

    Event-related potentials (31-channel ERPs) were recorded from 38 depressed, unmedicated outpatients and 26 healthy adults (all right-handed) in tonal and phonetic oddball tasks developed to exploit the perceptual challenge of a dichotic stimulation. Tonal nontargets were pairs of complex tones (corresponding to musical notes G and B above middle C) presented simultaneously to each ear (L/R) in an alternating series (G/B or B/G; 2-s fixed SOA). A target tone (note A) replaced one of the pair on 20% of the trials (A/B, G/A, B/A, A/G). Phonetic nontargets were L/R pairs of syllables (/ba/, /da/) with a short voice onset time (VOT), and targets contained a syllable (/ta/) with a long VOT. Subjects responded with a left or right button press to targets (counterbalanced across blocks). Target detection was poorer in patients than controls and for tones than syllables. Reference-free current source densities (CSDs; spherical spline Laplacian) derived from ERP waveforms were simplified and measured using temporal, covariance-based PCA followed by unrestricted Varimax rotation. Target-related N2 sinks and mid-parietal P3 sources were represented by CSD factors peaking at 245 and 440 ms. The P3 source topography included a secondary, left-lateralized temporal lobe maximum for both targets and nontargets. However, a subsequent hemispheric spatiotemporal PCA disentangled temporal lobe N1 and P3 sources as distinct factors. P3 sources were reduced in patients compared with controls, even after using performance as a covariate. Results are consistent with prior reports of P3 reduction in depression and implicate distinct parietal and temporal generators of P3 when using a dichotic oddball paradigm. PMID:17963912

  10. 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.

  11. 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.

  12. Generator of predictive verification pattern using vision system based on higher-order local autocorrelation

    NASA Astrophysics Data System (ADS)

    Matsunawa, Tetsuaki; Maeda, Shimon; Ichikawa, Hirotaka; Nojima, Shigeki; Tanaka, Satoshi; Mimotogi, Shoji; Nosato, Hirokazu; Sakanashi, Hidenori; Murakawa, Masahiro; Takahashi, Eiichi

    2012-03-01

    Although lithography conditions, such as NA, illumination condition, resolution enhancement technique (RET), and material stack on wafer, have been determined to obtain hotspot-free wafer images, hotspots are still often found on wafers. This is because the lithography conditions are optimized with a limited variety of patterns. For 40 nm technology node and beyond, it becomes a critical issue causing not only the delay of process development but also the opportunity loss of the business. One of the easiest ways to avoid unpredictable hotspots is to verify an enormous variety of patterns in advance. This, however, is time consuming and cost inefficient. This paper proposes a new method to create a group of patterns to cover pattern variations in a chip layout based on Higher-Order Local Autocorrelation (HLAC), which consists of two phases. The first one is the "analyzing phase" and the second is the "generating phase". In the analyzing phase, geometrical features are extracted from actual layouts using the HLAC technique. Those extracted features are statistically analyzed and define the "feature space". In the generating phase, a group of patterns representing actual layout features are generated by correlating the feature space and the process margin. By verifying the proposed generated patterns, the lithography conditions can be optimized efficiently and the number of hotspots dramatically reduced.

  13. Fault-Based Test Case Generation for Component Connectors

    Microsoft Academic Search

    Bernhard K. Aichernig; Farhad Arbab; Lacramioara Astefanoaei; Frank S. De Boer; Sun Meng; Jan J. M. M. Rutten

    2009-01-01

    Abstract The complex,interactions appearing,in service-oriented computing,make,coordination,a key concern,in service- oriented systems. In this paper, we present a fault-based method,to generate test cases for component,connectors from specifications. For connectors, faults are caused by possible errors during the development process, such as wrongly used channels, missing or redundant subcircuits, or circuits with wrongly constructed topology. We give test cases and connectors a

  14. 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).

  15. Computational fluid dynamics (CFD) simulation of test chamber and smoke-generating device

    NASA Astrophysics Data System (ADS)

    Nusca, Michael J.

    1995-01-01

    The U.S. Army Research Laboratory (ARL) has completed an initial investigation of the flow field within a typical U.S. Army Edgewood Research, Development, and Engineering Center (ERDEC) test chamber via numerical simulation. The ERDEC test chamber is designed to mix compressor-driven airflow with gas/solid effluent from a test article placed inside the chamber. An example of such a test article is a smoke generator, or smoke pot. Simulation of this flow utilized ARL computational fluid dynamics (CFD) codes that include multispecies chemical kinetics. Numerical solutions of the gas flow and effluent concentration distributions in the test chamber were generated for operating times up to 4.5 min. Numerical simulations reveal that certain values of chamber through-flow induce flow patterns within the chamber that are dominated by rotating vortices. This flow pattern increases the effluent residence time in the chamber as well as the mixing of gas/particulate from the test article with air. As a result, pockets of high effluent concentration can form in the chamber. Graphical results with discussion are presented.

  16. 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.

  17. 46 CFR 111.12-5 - Construction and testing of generators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Construction and testing of generators. 111.12-5 Section 111...SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111...12-5 Construction and testing of generators. Each generator...

  18. 46 CFR 111.12-5 - Construction and testing of generators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Construction and testing of generators. 111.12-5 Section 111...SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111...12-5 Construction and testing of generators. Each generator...

  19. 46 CFR 111.12-5 - Construction and testing of generators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Construction and testing of generators. 111.12-5 Section 111...SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits § 111...12-5 Construction and testing of generators. Each generator...

  20. Usability of pattern customising technology in the achievement and testing of fit for mass customisation

    Microsoft Academic Search

    Phoebe R. Apeagyei; Rose Otieno

    2007-01-01

    Purpose – The paper seeks to evaluate and present the usability of one pattern customising technology in the achievement and testing of garment fit. Design\\/methodology\\/approach – This study focuses on the use of 3D technology in the testing of garment fit. It examines the usability of one pattern customising technology in the achievement and testing of fit and presents primary

  1. Model Based Test Generation for Microprocessor Architecture Validation

    E-print Network

    Minnesota, University of

    Model Based Test Generation for Microprocessor Architecture Validation Sreekumar V. Kodakara.dingankar@intel.com Abstract Functional validation of microprocessors is growing in complexity in current and future microprocessors. Tra- ditionally, the different components (or validation collaterals) used in simulation based

  2. Fault-based Test Case Generation for Component Connectors

    Microsoft Academic Search

    Bernhard K. Aichernig; Farhad Arbab

    The complex interactions appearing in service-oriented computing make coordination a key concern in service- oriented systems. In this paper, we present a fault-based method to generate test cases for component connectors from specifications. For connectors, faults are caused by possible errors during the development process, such as wrongly used channels, missing or redundant subcircuits, or circuits with wrongly constructed topology.

  3. 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.

  4. Testing of sliding electrical contacts for homopolar generators

    Microsoft Academic Search

    M. Brennan; Z. Eliezer; W. F. Weldon; H. G. Rylander; H. H. Woodson

    1977-01-01

    Due to the recent interest in homopolar generators as pulsed power supplies, the need has arisen for pulsed brush data on slip rings at high current levels and high surface velocities. Tests were conducted to examine the effect that varying the apparent area of contact has on the coefficient of friction, voltage drop and wear rate. Brush areas from 0.806

  5. Tests with Solid Brushes on the Canberra Homopolar Generator

    Microsoft Academic Search

    R. A. Marshall

    1964-01-01

    EARLY in 1963 a programme was begun with the view of establishing whether or not solid brushes could be used instead of liquid metal jets to collect the required current (1.6 million amp) from the rotors of the Canberra homopolar generator. Within the first few weeks of investigation it became clear that there were no insuperable problems. Many pilot tests

  6. Efficient Path Delay Test Generation with Boolean Satisfiability

    E-print Network

    Bian, Kun

    2013-12-10

    delay test generator CodGen. A mixed structural-functional approach was implemented in CodGen where longest paths were detected using the K Longest Path Per Gate (KLPG) algorithm and path justification and dynamic compaction were handled with the SAT...

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

    Microsoft Academic Search

    Praitoon Chaiwongsa; Nithiroth Pornsuwancharoen; Preecha P. Yupapin

    2009-01-01

    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

  8. 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…

  9. The Asymmetric Traveling Salesman Problem: Algorithms, Instance Generators, and Tests

    E-print Network

    Zhang, Weixiong

    The Asymmetric Traveling Salesman Problem: Algorithms, Instance Generators, and Tests Jill heuristics for the asymmetric traveling salesmen problem ATSP. There are cur- rently three general classes concentrated on the symmetric case the STSP, where dc;c0 = dc0;c for all pairs of cities c;c0. Surveys

  10. Real time motion generation and control for biped robot -2nd report: Running gait pattern generation

    Microsoft Academic Search

    Toru Takenaka; Takashi Matsumoto; Takahide Yoshiike; Shinya Shirokura

    2009-01-01

    Bipedal running can easily result in a fall due to poor availability of the ground reaction force at the boundary of the flight and support phases. We propose methods to decompose and synthesize a running gait pattern into vertical, horizontal and rotational components so that time-dependent ground friction limits are satisfied. We also extend previously proposed boundary condition, the divergent

  11. Generation of mesoscopic patterns of viable Escherichia coli by ambient laser transfer

    Microsoft Academic Search

    B. R. Ringeisen; D. B. Chrisey; A. Piqué; H. D. Young; R. Modi; M. Bucaro; J. Jones-Meehan; B. J. Spargo

    2002-01-01

    We have generated mesoscopic patterns of viable Escherichia coli on Si(111), glass, and nutrient agar plates by using a novel laser-based transfer process termed matrix assisted pulsed laser evaporation direct write (MAPLE DW). We observe no alterations to the E. coli induced by the laser–material interaction or the shear forces during the transfer. Transferred E. coli patterns were observed by

  12. 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.

  13. Tests of an explosive-driven coaxial generator

    SciTech Connect

    Caird, R.S.; Erickson, D.J.; Fowler, C.M.; Benjamin, R.F.; Williams, A.H.; Goforth, J.H.; Freeman, B.L.; Veeser, L.R.; Felber, F.S.

    1985-01-01

    The results of four tests on an explosive-driven sweeping-wave coaxial generator are reported. The first shot of the series used a capacitor bank to supply the initial current. The remaining three shots used an explosive-driven sweeping-wave helical generator to boost the initial current. On the final shot, a peak current of 50 MA was reached in a 12 nH load, corresponding to a peak energy of 15 MJ. The peak power was 1.5 TW and the final current-doubling time was 12.5 ..mu..s. In addition to conventional Rogowsky loops, Faraday rotation sensors were employed to measure the current. Arrays of microballoon optical-fiber pins were used to measure the shape of the armature under the action of the magnetic forces in the generator. The coaxial generator should be capable of achieving still higher output energies if higher input energies are provided.

  14. 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

  15. 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

  16. Thermal Analysis and Testing of Fastrac Gas Generator Design

    NASA Technical Reports Server (NTRS)

    Nguyen, H.

    1998-01-01

    The Fastrac Engine is being developed by the Marshall Space Flight Center (MSFC) to help meet the goal of substantially reducing the cost of access to space. This engine relies on a simple gas-generator cycle, which burns a small amount of RP-1 and oxygen to provide gas to drive the turbine and then exhausts the spent fuel. The Fastrac program envisions a combination of analysis, design and hot-fire evaluation testing. This paper provides the supporting thermal analysis of the gas generator design. In order to ensure that the design objectives were met, the evaluation tests have started on a component level and a total of 15 tests of different durations were completed to date at MSFC. The correlated thermal model results will also be compared against hot-fire thermocouple data gathered.

  17. Two-stage Turing model for generating pigment patterns on the leopard and the jaguar R. T. Liu,1

    E-print Network

    Maini, Philip K.

    Two-stage Turing model for generating pigment patterns on the leopard and the jaguar R. T. Liu,1 S from this spotted pattern, we successfully generate patterns of adult leopards and jaguars by tuning coats has certainly raised questions in every curious mind. In his story "How the leopard got his spots

  18. Focal High Cell Density Generates a Gradient of Patterns in Self-Organizing Vascular Mesenchymal Cells

    PubMed Central

    Cheng, Henry; Reddy, Aneela; Sage, Andrew; Lu, Jinxiu; Garfinkel, Alan; Tintut, Yin; Demer, Linda

    2012-01-01

    In embryogenesis, structural patterns, such as vascular branching, may form via a reaction-diffusion mechanism in which activator and inhibitor morphogens guide cells into periodic aggregates. We previously found that vascular mesenchymal cells (VMC) spontaneously aggregate into nodular structures and that morphogen pairs regulate the aggregation into patterns of spots and stripes. To test the effect of a focal change in activator morphogen on VMC pattern formation, we created a focal zone of high cell density by plating a second layer VMC within a cloning ring over a confluent monolayer. After 24 hours, the ring was removed, and pattern formation monitored by phase-contrast microscopy. At days 2–8, the patterns progressed from uniform distributions to swirl, labyrinthine, and spot patterns. Within the focal high-density zone and a narrow halo zone, cells aggregated into spot patterns; in the outermost zone of the plate, cells formed a labyrinthine pattern. Area occupied by aggregates was significantly greater in the outermost zone than in the HDZ or halo. The rate of pattern progression within the HDZ increased as a function of its plating density. Thus, focal differences in cell density may drive pattern formation gradients in tissue architecture, such as vascular branching. PMID:22797747

  19. 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.

  20. 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.

  1. 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.

  2. Testing of ground conductors with artificially generated lightning current

    SciTech Connect

    Tobias, J.M. [USA CECOM, Fort Monmouth, NJ (United States)] [USA CECOM, Fort Monmouth, NJ (United States)

    1996-05-01

    Alternative conductors for lightning protection applications favorable for use in mobile systems have been tested to demonstrate high levels of protection against maximal lightning events. The method of determining the survivability of the down conductors was to expose each type of conductor to maximal lightning events generated by a large Marx capacitor bank. Each type of conductor was tested until mechanical failure occurred or until it survived four exposures to the lightning event. A test to determine the effect of physical damage on conductor performance was also conducted. A theory attributing interstrand or intraconductor magnetic forces, rather than ohmic heating, as the primary cause of conductor failure is proposed. Results indicate that two types of tested conductor exist which can provide protection against maximal lightning events, yet have properties that lend themselves to mobile application.

  3. Testing and evaluation of Second-Generation Heliostat mirror modules

    SciTech Connect

    Burolla, V.P.; Delameter, W.R.

    1982-01-01

    The testing and evaluation of the Second Generation Heliostat mirror modules are reported here. It was found that all of the previous design problems of mirror modules, such as silver corrosion, thermal defocus, and high glass stress, were eliminated by one or more of these designs. The single most important conclusion to be drawn from this program is that laminated glass mirror module designs are the most technically conservative; it is Sandia's recommendation that this concept be used for near-term applications. Two other Second Generation designs were found to have potential for reduced weight and improved performance, but one design required some significant design changes, and both require further outdoor testing to better estimate their lifetime potential.

  4. MDA-based automated generation method of test cases and supporting framework

    Microsoft Academic Search

    Bin Wang; Chunhua Zhu; Jinfang Sheng

    2010-01-01

    Automated test framework and automated generation method of test cases can alleviate the time conflict between software development and testing. In this paper, an improved automated unit test framework-i-NUnit is proposed, which can solve the redundancy problem in test codes by separating test codes and test data. And then a method based on MDA to generate unit test cases for

  5. 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.

  6. 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.

  7. The Testing of Sliding Electrical Contacts for Homopolar Generators

    Microsoft Academic Search

    MIRE BRENNAN; ZWY ELIEZER; WILLIAM F. WELDON; H. GRADY RYLANDER; HERBERT H. WOODSON

    1979-01-01

    Due to the recent interest in homopolar generators as pulsed power supplies, the need has arisen for pulsed brush data on slip rings at high current levels and high surface velocities. Tests were conducted to examine the effect of varying the apparent area of contact on the coefficient of friction, voltage drop, and wear rate. Brush areas from 0.806-3.23 cm2were

  8. Using Model Checking for Reducing the Cost of Test Generation

    Microsoft Academic Search

    Hyoung Seok Hong; Hasan Ural

    2004-01-01

    \\u000a This paper presents a method for reducing the cost of test generation. A spanning set for a coverage criterion is a set of\\u000a entities such that exercising every entity in the spanning set guarantees exercising every entity defined by the coverage\\u000a criterion. The central notion used in constructing a minimum spanning set is subsumption relation. An entity subsumes another\\u000a entity

  9. 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.

  10. Electrically switchable finite energy Airy beams generated by a liquid crystal cell with patterned electrode

    E-print Network

    Demir, Hilmi Volkan

    Electrically switchable finite energy Airy beams generated by a liquid crystal cell with patterned electrode D. Luo, H.T. Dai, X.W. Sun , H.V. Demir School of Electrical and Electronic Engineering, Nanyang Keywords: Diffraction Liquid crystal devices Propagation A pair of electrically switchable finite energy

  11. Generation of static and dynamic patterned co-cultures using microfabricated parylene-C stencils

    E-print Network

    Dokmeci, Mehmet

    Generation of static and dynamic patterned co-cultures using microfabricated parylene-C stencils static or dynamic conditions. In the static case, embryonic stem (ES) cells were co, wound healing and development, involve dynamic interactions between cells and their microenvironment

  12. This symposium covered learning about the spinal cord (e.g. interneuronal systems, central pattern generators)

    E-print Network

    Valero-Cuevas, Francisco

    This symposium covered learning about the spinal cord (e.g. interneuronal systems, central pattern generators) and learning in the spinal cord (e.g. training, plasticity, regeneration). Attempts to reanimate cord, so there is a tendency to think that it is largely irrelevant. In fact, the spinal cord

  13. Colocalized Neuropeptides Activate a Central Pattern Generator by Acting on Different Circuit Targets

    E-print Network

    Thirumalai, Vatsala

    Colocalized Neuropeptides Activate a Central Pattern Generator by Acting on Different Circuit, whereas the anterior burster (AB) and pyloric dilator (PD) neurons were rhythmically active at a low frequency. Exogenous application of 10 6 M RPCH activated the LP neuron but not the PY neurons; 10 6 M Cab

  14. Oscillatory command input to the motor pattern generators of the crustacean stomatogastric ganglion

    Microsoft Academic Search

    Robert M. Robertson; Maurice Moulins

    1984-01-01

    1.In the rock lobsterHomarus gammarus, the gastric rhythm controls the chewing movements of three cuticular teeth in the stomach (gastric mill). The rhythmic motor output (Fig. 3) arises from a network of neurones, the gastric pattern generator (GPG), located within the stomatogastric ganglion. In addition our in vitro recordings indicate that in each of the two commissural ganglia there is

  15. Evidence for a Hypothalamic Oxytocin-Sensitive Pattern-Generating Network Governing Oxytocin Neurons In Vitro

    E-print Network

    Alford, Simon

    Evidence for a Hypothalamic Oxytocin-Sensitive Pattern- Generating Network Governing Oxytocin During lactation and parturition, magnocellular oxytocin (OT) neurons display a characteristic bursting%. The peptide also triggered bursting in 27% of nonbursting neurons. These effects were mimicked by the oxytocin

  16. Polarization pattern of vector vortex beams generated by q-plates with different topological charges

    E-print Network

    Marrucci, Lorenzo

    Polarization pattern of vector vortex beams generated by q-plates with different topological angular momentum (OAM) [5]. Among vector vortex beams, radially or azimuthally polarized vec- tor beams; posted 3 January 2012 (Doc. ID 159438); published 5 March 2012 We describe the polarization topology

  17. 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%.

  18. Testing of the Mark 101 magnetic flux compression generator

    SciTech Connect

    Freeman, B.L.; Fowler, C.M.; King, J.C.; Martinez, A.R.

    1986-01-01

    The Mark 101 explosive flux compression generator is a line-initiated, vacuum/magnetically insulated, helical generator. This device offered some unique challenges in transforming the theoretical design into a testable experiment. The two main reasons for this are that in theory an eight-turn, four-wire Mark 101 possesses a terminal dL/dt of approx.0.5 ..cap omega.. and operates with electric fields which are greater than the threshold for electron field emission. With this in mind, we designed an integral vacuum-jacket-generator configuration with a passive load inductance of less than or equal to0.5 ..mu..H. The generator contained approx.8 ..mu..H of initial inductance. The field emission required the stator to be entirely sealed within the vacuum jacket. The open, helical stator resulted in the presence of non-trivial leakage fields and voltages. To accommodate these fields, the vacuum chamber for the generator was segmented and axially insulated with rings of acrylic, similar to stacked-ring diodes. We made no attempt to break the azimuthal metal surfaces due to the physical difficulty this would incur. Diagnostics included an input current Rogowski loop, a load Rogowski loop, two dB/dt probes in the load, a Faraday fiber-optic current sensor, and two dB/dt probes in the region between the stator winding and the vacuum jacket to measure the leakage azimuthal and axial magnetic fields. The results of explosive tests are presented.

  19. Use of the SMPTE test pattern in picture archiving and communication systems.

    PubMed

    Gray, J E

    1992-02-01

    In 1985 the Society of Motion Picture and Television Engineers (SMPTE) published a Recommended Practice (RP-133) entitled Specifications for Medical Diagnostic Imaging Test Pattern for Television Monitors and Hard-copy Cameras. Since that time the SMPTE monochrome test pattern has been applied to the acceptance testing and quality control of video and image display systems, and hard-copy (film) recorders. The major features of the test pattern will be discussed along with applications and the problems demonstrated with the pattern. Furthermore, the test pattern will be used to demonstrate that color displays may exhibit only one-half of the resolution of a monochrome monitor whereas the display contrast (due to limited dynamic range) may be only 10 to 20% of that obtained with a monochrome display. PMID:1554759

  20. 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

  1. 46 CFR 111.12-5 - Construction and testing of generators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Construction and testing of generators. 111.12-5 Section...ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Generator Construction and Circuits...Construction and testing of generators. Each...

  2. Motor unit firing rate patterns during voluntary muscle force generation: a simulation study

    NASA Astrophysics Data System (ADS)

    Hu, Xiaogang; Rymer, William Z.; Suresh, Nina L.

    2014-04-01

    Objective. Muscle force is generated by a combination of motor unit (MU) recruitment and changes in the discharge rate of active MUs. There have been two basic MU recruitment and firing rate paradigms reported in the literature, which describe the control of the MUs during force generation. The first (termed the reverse ‘onion skin’ profile), exhibits lower firing rates for lower threshold units, with higher firing rates occurring in higher threshold units. The second (termed the ‘onion skin’ profile), exhibits an inverse arrangement, with lower threshold units reaching higher firing rates. Approach. Using a simulation of the MU activity in a hand muscle, this study examined the force generation capacity and the variability of the muscle force magnitude at different excitation levels of the MU pool under these two different MU control paradigms. We sought to determine which rate/recruitment scheme was more efficient for force generation, and which scheme gave rise to the lowest force variability. Main results. We found that the force output of both firing patterns leads to graded force output at low excitation levels, and that the force generation capacity of the two different paradigms diverged around 50% excitation. In the reverse ‘onion skin’ pattern, at 100% excitation, the force output reached up to 88% of maximum force, whereas for the ‘onion skin’ pattern, the force output only reached up to 54% of maximum force at 100% excitation. The force variability was lower at the low to moderate force levels under the ‘onion skin’ paradigm than with the reverse ‘onion skin’ firing patterns, but this effect was reversed at high force levels. Significance. This study captures the influence of MU recruitment and firing rate organization on muscle force properties, and our results suggest that the different firing organizations can be beneficial at different levels of voluntary muscle force generation and perhaps for different tasks.

  3. Jewish Culture and the WISC and WAIS Test Patterns

    ERIC Educational Resources Information Center

    Dershowitz, Zecharia; Frankel, Yaakov

    1975-01-01

    WISC performance of Jewish children has revealed a highly consistent and stable pattern, characterized by relatively low scores on Picture Completion, Picture Arrangement, Block Design, and Object Assembly. Some of these findings might be understood by reference to relative weakness of Jewish subjects on tasks related to psychological…

  4. Flexibility of the axial central pattern generator network for locomotion in the salamander.

    PubMed

    Ryczko, D; Knüsel, J; Crespi, A; Lamarque, S; Mathou, A; Ijspeert, A J; Cabelguen, J M

    2015-03-15

    In tetrapods, limb and axial movements are coordinated during locomotion. It is well established that inter- and intralimb coordination show considerable variations during ongoing locomotion. Much less is known about the flexibility of the axial musculoskeletal system during locomotion and the neural mechanisms involved. Here we examined this issue in the salamander Pleurodeles waltlii, which is capable of locomotion in both aquatic and terrestrial environments. Kinematics of the trunk and electromyograms from the mid-trunk epaxial myotomes were recorded during four locomotor behaviors in freely moving animals. A similar approach was used during rhythmic struggling movements since this would give some insight into the flexibility of the axial motor system. Our results show that each of the forms of locomotion and the struggling behavior is characterized by a distinct combination of mid-trunk motor patterns and cycle durations. Using in vitro electrophysiological recordings in isolated spinal cords, we observed that the spinal networks activated with bath-applied N-methyl-d-aspartate could generate these axial motor patterns. In these isolated spinal cord preparations, the limb motor nerve activities were coordinated with each mid-trunk motor pattern. Furthermore, isolated mid-trunk spinal cords and hemicords could generate the mid-trunk motor patterns. This indicates that each side of the cord comprises a network able to generate coordinated axial motor activity. The roles of descending and sensory inputs in the behavior-related changes in axial motor coordination are discussed. PMID:25540227

  5. Performance evaluations of MHD generator tests at CDIF

    NASA Astrophysics Data System (ADS)

    Daniel, V. W.; Lineberry, J. T.; Wu, Y. C. L.

    1992-01-01

    Experimental data from CDIF coal-fired MHD generator test 90-DIAG-3 are analyzed. The results of two independent studies are presented and compared. Both studies impose experimental data upon modeling to derive information on plasma properties and electrical loss mechanisms. The first technique applies routine electrical data to special solutions of the MHD electrical equations to determine gross electrophysical properties and nonuniformity parameters of the generator medium (plasma plus slag) over one pitch control volumes along the length of the MHD channel. The second technique pits a predictive 1D MHD generator model against input experimental Hall voltage data. The generator model solves for the MHD plasmadynamic and electrical processes required to fit the experimental voltage distribution to determine plasma properties with wall and electrical losses. Among the parameters that are estimated by these methods are conductivity, Hall parameter, interelectrode resistances, and the plasma nonuniformity factors (e.g., G). The magnitude of leakage current (slag or otherwise) can also inferred from these analyses.

  6. 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.

  7. In-Situ Pressure Testing of Steam Generator Tubes

    SciTech Connect

    Chandler, Cordelia K. [Framatome ANP (United States)

    2002-07-01

    The anatomist John Hunter said, 'But why think? Why not try the experiment?' His words are applicable to in-situ pressure testing as a means of performing condition monitoring of steam generator tubes. Other methods of performing condition monitoring include the application of theoretical burst and leakage equations (deterministic methods), probabilistic analyses, and tube pull. The deterministic and probabilistic methods must address uncertainties in the material properties and flow measurements. Destructive examination of a pulled tube provides the verification of the damage mechanism and possible causes of the degradation; however, the axial loads required to pull the tube may affect the degradation. The results of a tube pull are generally not available until after the plant has returned to service. In-situ pressure testing provides structural and leakage integrity of SG tubing conditions. Candidates are selected for in-situ testing based on te EPRI Guidelines and include an evaluation of crack depth, length and/or voltage response from the eddy-current inspection results. Appropriate selection of tubes for in-situ testing provides confidence that the results adequately address the structural and leakage integrity of the SG tube population. In-situ pressure testing, combined with conservative operational assessments for the next cycle, assures that the integrity of the SG tubing is maintained. (authors)

  8. Multiple Rhythmic States in a Model of the Respiratory Central Pattern Generator

    PubMed Central

    Rubin, Jonathan E.; Shevtsova, Natalia A.; Ermentrout, G. Bard; Smith, Jeffrey C.; Rybak, Ilya A.

    2009-01-01

    The three-phase respiratory pattern observed during normal breathing changes with alterations in metabolic or physiological conditions. A recent study using in situ perfused rat brain preparations demonstrated a reorganization of the respiratory pattern with sequential reduction of the brain stem respiratory network. Specifically, with removal of the pons, the normal three-phase pattern transformed to a two-phase inspiratory–expiratory pattern and, with more caudal transections, to one-phase, intrinsically generated inspiratory oscillations. A minimal neural network proposed to reproduce these transformations includes 1) a ringlike mutually inhibitory network composed of the postinspiratory, augmenting expiratory, and early-inspiratory neurons and 2) an excitatory preinspiratory neuron, with persistent sodium current (INaP)-dependent intrinsic bursting properties, that dynamically participates in the expiratory–inspiratory phase transition and inspiratory phase generation. We used activity-based single-neuron models and applied numerical simulations, bifurcation methods, and fast–slow decomposition to describe the behavior of this network in the functional states corresponding to the three-, two-, and one-phase oscillatory regimes, as well as to analyze the transitions between states and between respiratory phases within each state. We demonstrate that, although INaP is not necessary for the generation of three- and two-phase oscillations, it contributes to control of the oscillation period in each state. We also show that the transitions between states can be produced by progressive changes of drives to particular neurons and proceed through intermediate regimes, featuring high-amplitude late-expiratory and biphasic-expiratory activities or ectopic burst generation. Our results provide important insights for understanding the state-dependent mechanisms for respiratory rhythm generation and control. PMID:19193773

  9. Generation and characterization of test atmospheres with nanomaterials.

    PubMed

    Ma-Hock, L; Gamer, A O; Landsiedel, R; Leibold, E; Frechen, T; Sens, B; Linsenbuehler, M; van Ravenzwaay, B

    2007-08-01

    To ensure the product safety of nanomaterials, BASF has initiated an extensive program to study the potential inhalation toxicity of nanosize particles. As preparation work for upcoming inhalation studies, the following manufactured nanomaterials have been evaluated for their behavior in an exposure system designed for inhalation toxicity studies: titanium dioxide, carbon black, Aerosil R104, Aerosil R106, aluminum oxide, copper(II) oxide, amorphous silicon dioxide, zinc oxide, and zirconium(IV) oxide. As the physicochemical properties and the complex nature of ultrafine aerosols may substantially influence the toxic potential, the particle size, specific surface area, zeta potential, and morphology of each of the materials were determined. Aerosols of each material were generated using a dry powder aerosol generator and by nebulization of particle suspensions. The mass concentration of the particles in the inhalation atmosphere was determined gravimetrically and the particle size was determined using a cascade impactor, an optical particle counter, and a scanning mobility particle sizer. The dispersion techniques used generated fine aerosols with particle size distributions in the respiratory range. However, as a result of the significant agglomeration of nanoparticles in the test materials evaluated, no more than a few mass percent of the materials were present as single nanoparticles (i.e., < 100 nm). Considering the number, a greater percentage of nanoparticles was present. Based on the obtained results and experience with the equipment, a technical setup for inhalation studies with nanomaterials is proposed. Furthermore, a stepwise testing approach is recommended that also could reduce the number of animals used in testing. PMID:17687715

  10. A method for testing association patterns of social animals

    Microsoft Academic Search

    LARS BEJDER; DAVID FLETCHER; STEFAN BRÄGER

    1998-01-01

    Association indices were originally developed to describe species co-occurrences, but have been used increasingly to measure associations between individuals. However, no statistical method has been published that allows one to test the extent to which the observed association index values differ from those of a randomly associating population. Here, we describe an adaptation of a test developed by Manly (1995,Ecology,76,

  11. 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.

  12. 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.

  13. Stable and flexible multiple spot pattern generation using LCOS spatial light modulator.

    PubMed

    Matsumoto, Naoya; Itoh, Haruyasu; Inoue, Takashi; Otsu, Tomoko; Toyoda, Haruyoshi

    2014-10-01

    The LCOS spatial light modulator (LCOS-SLM) can generate desired multiple spot patterns (MSPs) via the application of suitable computer-generated-holograms (CGHs), but the MSP intensity distribution varies because ambient temperature affects the phase modulation characteristic and causes wavefront distortion. To generate high-optical-quality MSPs we use our hardware-compensated (with a Peltier system to even out phase modulation) and software-corrected (via multiplication of the CGH by temperature correction coefficients) LCOS-SLMs. Experimental results with a 14 × 14 MSP generation show that the hardware-compensated LCOS-SLM provides stable MSPs between 9 to 32 °C. The software-corrected LCOS-SLM provides uniform spots over twice the temperature range obtained with conventional SLM method. We confirm that our methods are highly efficient for use in two-photon excitation microscopy application such as multifocal mulitphoton microscopy. PMID:25322047

  14. Evolving cellular automata for diversity generation and pattern recognition: deterministic versus random strategy

    NASA Astrophysics Data System (ADS)

    Argollo de Menezes, Marcio; Brigatti, Edgardo; Schwämmle, Veit

    2013-08-01

    Microbiological systems evolve to fulfil their tasks with maximal efficiency. The immune system is a remarkable example, where the distinction between self and non-self is made by means of molecular interaction between self-proteins and antigens, triggering affinity-dependent systemic actions. Specificity of this binding and the infinitude of potential antigenic patterns call for novel mechanisms to generate antibody diversity. Inspired by this problem, we develop a genetic algorithm where agents evolve their strings in the presence of random antigenic strings and reproduce with affinity-dependent rates. We ask what is the best strategy to generate diversity if agents can rearrange their strings a finite number of times. We find that endowing each agent with an inheritable cellular automaton rule for performing rearrangements makes the system more efficient in pattern-matching than if transformations are totally random. In the former implementation, the population evolves to a stationary state where agents with different automata rules coexist.

  15. Artistic Pattern Generation by a Model of Territory Competing Kokichi Sugihara

    E-print Network

    Yamamoto, Hirosuke

    �º � � ��� � � Ý ��� � ���� � � ��� � ��Ð � � �� �� �� � � ��Ý� � �Ð �º #12;Artistic Pattern This paper presents a method for generating artistic pat- terns using the Voronoi diagram. In this method, we amount of beautiful and artistic pictures, which could have never been generated without computers [1

  16. An Analysis of Fault Partitioned Parallel Test Generation1 Joseph M. Wolf

    E-print Network

    Klenke, Robert H.

    to circuit size, the application of parallel processing techniques to accelerate the process of generatingAn Analysis of Fault Partitioned Parallel Test Generation1 Joseph M. Wolf Lori M. Kaufman Robert H and ASC-9201822. #12;An Analysis of Fault Partitioned Parallel Test Generation Abstract Generation of test

  17. Energy efficient walking with central pattern generators: from passive dynamic walking to biologically inspired control

    Microsoft Academic Search

    B. W. Verdaasdonk; H. F. J. M. Koopman; Frans C. T. Van Der Helm

    2009-01-01

    Like human walking, passive dynamic walking—i.e.walkingdownaslopewithnoactuationexcept gravity—is energy efficient by exploiting the natural dynam- ics. In the animal world, neural oscillators termed central pattern generators (CPGs) provide the basic rhythm for mus- cularactivityinlocomotion.WepresentaCPGmodel,which automatically tunes into the resonance frequency of the pas- sive dynamics of a bipedal walker, i.e. the CPG model exhib- its resonance tuning behavior. Each leg is

  18. Five types of nonspiking interneurons in local pattern-generating circuits of the crayfish swimmeret system

    PubMed Central

    Smarandache-Wellmann, Carmen; Weller, Cynthia; Wright, Terrence M.

    2013-01-01

    We conducted a quantitative analysis of the different nonspiking interneurons in the local pattern-generating circuits of the crayfish swimmeret system. Within each local circuit, these interneurons control the firing of the power-stroke and return-stroke motor neurons that drive swimmeret movements. Fifty-four of these interneurons were identified during physiological experiments with sharp microelectrodes and filled with dextran Texas red, Neurobiotin, or both. Five types of neurons were identified on the basis of combinations of physiological and anatomical characteristics. Anatomical categories were based on 16 anatomical parameters measured from stacks of confocal images obtained from each neuron. The results support the recognition of two functional classes: inhibitors of power stroke (IPS) and inhibitors of return stroke (IRS). The IPS class of interneuron has three morphological types with similar physiological properties. The IRS class has two morphological types with physiological properties and anatomical features different from the IPS neurons but similar within the class. Three of these five types have not been previously identified. Reviewing the evidence for dye coupling within each type, we conclude that each type of IPS neuron and one type of IRS neuron occur as a single copy in each local pattern-generating circuit. The last IRS type includes neurons that might occur as a dye-coupled pair in each local circuit. Recognition of these different interneurons in the swimmeret pattern-generating circuits leads to a refined model of the local pattern-generating circuit that includes synaptic connections that encode and decode information required for intersegmental coordination of swimmeret movements. PMID:23615552

  19. Self-Adjusting Ring Modules (SARMs) for Flexible Gait Pattern Generation

    Microsoft Academic Search

    Manfred Hild; Frank Pasemann

    2007-01-01

    Using the principle of homeostasis, we derive a learning rule for a specific recurrent neural network structure, the so-called Self-Adjusting Ring Mod- ule (SARM). Several of these Ring Modules can be plugged together to drive segmented artificial or- ganisms, for example centipede-like robots. Con- trolling robots of variable morphologies by SARMs has major advantages over using Central Pattern Generators (CPGs).

  20. Estradiol interacts with an opioidergic network to achieve rapid modulation of a vocal pattern generator

    Microsoft Academic Search

    Luke Remage-Healey; Andrew H. Bass

    2010-01-01

    Estrogens rapidly regulate neuronal activity within seconds-to-minutes, yet it is unclear how estrogens interact with neural\\u000a circuits to rapidly coordinate behavior. This study examines whether 17-beta-estradiol interacts with an opioidergic network\\u000a to achieve rapid modulation of a vocal control circuit. Adult plainfin midshipman fish emit vocalizations that mainly differ\\u000a in duration, and rhythmic activity of a hindbrain–spinal vocal pattern generator

  1. Development of Multimode Biomimetic Robotic Fish Based on Central Pattern Generator

    Microsoft Academic Search

    Wei Zhao; Junzhi Yu; Yimin Fang; Long Wang

    2006-01-01

    This paper presents the construction and motion control of a biologically inspired, multi-mode biomimetic robotic fish capable of three-dimensional locomotion. The mechanical configuration and the control system are described. The rhythmic movements of swimming are driven by the biological neural networks, called the central pattern generators (CPGs). The CPGs are modeled as nonlinear oscillators for joints and inter-joint coordination is

  2. Low power CMOS electronic central pattern generator design for a biomimetic underwater robot

    Microsoft Academic Search

    Young-jun Lee; Jihyun Lee; Kyung Ki Kim; Yong-bin Kim; Joseph Ayers

    2007-01-01

    This paper, presents a feasability study of a central pattern generator-based analog controller for an autonomous robot. The operation of a neuronal circuit formed of electronic neurons based on Hindmarsh-Rose neuron dynamics and first order chemical synapses ls modeled. The controller is based on a standard CMOS process with 2V supply voltage. In order to achieve low power consumption, CMOS

  3. Convolution-sum-based generation of walking patterns for uneven terrains

    Microsoft Academic Search

    H. Andy Park; Muhammad A. Ali; C. S. George Lee

    2010-01-01

    In generating walking patterns for humanoid robots, a Center-of-Mass trajectory is usually derived from the desired Zero-Moment-Point (ZMP) trajectory. One way to accomplish this is the use of the preview-control method, which tracks the desired ZMP trajectory while minimizing the jerk. Another method, which is more computationally efficient, is based on the convolution-sum method. Although this method is simple to

  4. The 3D linear inverted pendulum mode: a simple modeling for a biped walking pattern generation

    Microsoft Academic Search

    Shuuji Kajita; Fumio Kanehiro; Kenji Kaneko; Kazuhito Yokoi; Hirohisa Hirukawa

    2001-01-01

    For 3D walking control of a biped robot we analyze the dynamics of a 3D inverted pendulum in which motion is constrained to move along an arbitrarily defined plane. This analysis yields a simple linear dynamics, the 3D linear inverted pendulum mode (3D-LIPM). Geometric nature of trajectories under the 3D-LIPM and a method for walking pattern generation are discussed. A

  5. 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

  6. Design, fabrication, and testing of energy-harvesting thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Jovanovic, Velimir; Ghamaty, Saeid

    2006-03-01

    An energy-harvesting thermoelectric generator (TEG) is being developed to provide power for wireless sensors used in health monitoring of Navy machinery. TEGs are solid-state devices that convert heat directly into electricity without any moving parts. In this application, the TEGs utilize the heat transfer between shipboard waste heat sources and the ambient air to generate electricity. In order to satisfy the required small design volume of less than one cubic inch, Hi-Z is using its innovative thin-film Quantum Well (QW) thermoelectric technology that will provide a factor of four increase in efficiency and a large reduction in the device volume over the currently used bulk Bi IITe 3 based thermoelectics. QWs are nanostructured multi-layer films. These wireless sensors can be used to detect cracks, corrosion, impact damage, and temperature and vibration excursions as part of the Condition Based Maintenance (CBM) of the Navy ship machinery. The CBM of the ship machinery can be significantly improved by automating the process with the use of self-powered wireless sensors. These power-harvesting TEGs can be used to replace batteries as electrical power sources and to eliminate power cables and data lines. The first QW TEG module was fabricated and initial tests were successful. It is planned to conduct performance tests the entire prototype QW TEG device (consisting of the TEG module, housing, thermal insulation and the heat sink) in a simulated thermal environment of a Navy ship.

  7. 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.

  8. Generating tactile afferent stimulation patterns for slip and touch feedback in neural prosthetics.

    PubMed

    Rager, Danielle M; Alvares, Darren; Birznieks, Ingvars; Redmond, Stephen J; Morley, John W; Lovell, Nigel H; Vickery, Richard M

    2013-01-01

    Current prosthetic limbs are limited by a lack of tactile feedback. Slip feedback is particularly important to inform grip. Object slip is marked by both a change in the normal grip force applied and a change in force tangential to the fingertips. In this study, we demonstrate that a new multi-axial tactile sensor composed of gold nanoparticle strain gauges is able to record slip and reconstruct the X, Y, and Z forces incident on the sensor's surface due to a slipping object. We entered the X, Y, and Z force components generated by the slip event into a noisy leaky integrate and fire model to simulate the firing responses of SA1 and FA1 afferents. We also recorded a uniaxial normal force input representative of tactile contact. A single set of SA1 model and FA1 model parameters generated realistic firing patterns for both the slip and normal force recordings. These results suggest that canonical SA1 and FA1 afferent models could be used to generate biomimetic electrical stimulation patterns for both slip and touch stimuli. When used to activate the tactile afferents of an amputee, these electrical stimulation patterns could create natural and distinguishable slip and touch percepts for closed loop control of an upper limb neural prosthesis. PMID:24111087

  9. From Spinal Central Pattern Generators to Cortical Network: Integrated BCI for Walking Rehabilitation

    PubMed Central

    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

  10. Mutation Sampling Technique for the Generation of Structural Test Data M. Scholiv1

    E-print Network

    Paris-Sud XI, Université de

    Mutation Sampling Technique for the Generation of Structural Test Data M. Scholivé1 , V. Beroulle1 detail an original test-oriented mutation sampling technique used for generating such data and we present testing method for generating validation data. It is based on the well-known mutation testing principle

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

    PubMed

    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

  12. 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

  13. 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%.

  14. 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…

  15. Migration Patterns after Natural Disasters: A Test of the Resilience Hypothesis?

    E-print Network

    Botea, Adi

    1 Migration Patterns after Natural Disasters: A Test of the Resilience Hypothesis? Siew-Ean Khoo Consequences of Asian Disasters: Family Dynamics, Social Capital and Migration Patterns', April 2012 at ANU after a natural disaster (Hugo 2008). It has been suggested that people move away from areas affected

  16. Automatic Test Case Generation Using Multi-protocol Test Method Soo-in Lee, Yongbum Park, and Myungchul Kim

    E-print Network

    Lee, Ben

    Automatic Test Case Generation Using Multi-protocol Test Method Soo-in Lee, Yongbum Park, mckim}@icu.ac.kr Abstract - A method for testing multi-protocol implementation under test (IUT) with a single test suite has been proposed in the literature. It tests a multi-protocol IUT in an integrated way

  17. Capacitive charge generation apparatus and method for testing circuits

    DOEpatents

    Cole, Jr., Edward I. (Albuquerque, NM); Peterson, Kenneth A. (Albuquerque, NM); Barton, Daniel L. (Albuquerque, NM)

    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.

  18. 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.

  19. SMPTE Test Pattern For Certification Of Medical Diagnostic Display Devices

    NASA Astrophysics Data System (ADS)

    Lisk, Kenneth G.

    1984-08-01

    Since the invention of x-rays by Wilhelm Conrad Roentgen, rapid advances have been made in the radiological detection of body abnormalities. This was very evident in the 1960's and 70's when the marriage of computers to radiology gave birth to a new generation of imaging modalities such as computerized tomography, ultrasound, digital radiographic imaging, nuclear medicine, and nuclear magnetic resonance. Many of these devices employ digital computer techniques for signal manipulation, and the resultant analog diagnostic images are displayed on television monitors for viewing and on imaging cathode-ray tubes for a photographic hard copy.

  20. Experience With The SMPTE Test Pattern In Quality Control Of Magnetic Resonance Images

    NASA Astrophysics Data System (ADS)

    Bronskill, Michael J.

    1984-08-01

    The SMPTE test pattern has proven to be an effective tool for calibrating and monitoring the image display devices of a magnetic resonance (MR) imaging system. Linearity and size adjustments of video displays are particulary important because of the proximity of magnetic fields. The 5% and 95% intensity levels of the test pattern are extremely useful for adjusting the grayscale of both video displays and multiformat hardcopy devices. An appropriate sequence of operations for adjusting and monitoring image display devices is recommended.

  1. Wind flow patterns around a test cell in a sheltered location: Wind tunnel visualisation

    Microsoft Academic Search

    M. M. Eftekhari; D. J. Pinnock; I. Lau

    1998-01-01

    The aim of this research was to investigate the flow pattern around a test room which is used for natural ventilation studies. The test cell effectively represents an in-fill development of a low-rise building located adjacent to high-rise buildings. When considering natural ventilation in a building in such a location it is beneficial to understand the local wind flow patterns

  2. Implementation of a data packet generator using pattern matching for wearable ECG monitoring systems.

    PubMed

    Noh, Yun Hong; Jeong, Do Un

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  3. Statistical spatial properties of speckle patterns generated by multiple laser beams

    SciTech Connect

    Le Cain, A.; Sajer, J. M. [CEA, DAM, CESTA, BP 2, F-33114 Le Barp (France); Riazuelo, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2011-08-15

    This paper investigates hot spot characteristics generated by the superposition of multiple laser beams. First, properties of speckle statistics are studied in the context of only one laser beam by computing the autocorrelation function. The case of multiple laser beams is then considered. In certain conditions, it is shown that speckles have an ellipsoidal shape. Analytical expressions of hot spot radii generated by multiple laser beams are derived and compared to numerical estimates made from the autocorrelation function. They are also compared to numerical simulations performed within the paraxial approximation. Excellent agreement is found for the speckle width as well as for the speckle length. Application to the speckle patterns generated in the Laser MegaJoule configuration in the zone where all the beams overlap is presented. Influence of polarization on the size of the speckles as well as on their abundance is studied.

  4. 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.

  5. 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 up of filter cake on the disks and therefore the performance of the filter. The filter performed well with the simulant. Very little drop in production was noticed between the 5 and 10 wt% insoluble solids feed. Increasing to 15 wt% had a more pronounced impact due to the rheology of the feed. Acid cleaning was used to clean the filter disks in-situ and restore filtration rate to almost 90% of the initial clean disk rate. Eighty liters of 0.2 M nitric acid in conjunction with water rinses were used to clean the filter in less than 2 hours. Filter testing was completed after 1000 hours of operation were performed on the final filter assembly configuration. The total run time for the testing was over 1500 hours. At the end of the test, the sludge washing was performed successfully from approximately 5.6 M to less than 1 M sodium.

  6. 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.

  7. Automatic generation of software test cases based on improved genetic algorithm

    Microsoft Academic Search

    Yuehua Dong; Jidong Peng

    2011-01-01

    Software testing is the key of guaranteeing software quality, but the generation of testing data is one of the key steps which has a great effect on the automation of software testing, therefore the generation of testing data is relating the quality of software production indirectly. This article has analysed the basic principle of genetic algorithm on software testing detailedly,

  8. 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.

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

    PubMed

    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. PMID:24387584

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

    E-print Network

    Sajiya Jalil; Dane Allen; Joe Youker; Andrey Shilnikov

    2013-10-03

    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, that govern vital motor behaviors in invertebrates such as chewing, swimming, etc. 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 {\\it 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.

  11. Micropunching lithography for generating micro- and submicron-patterns on polymer substrates.

    PubMed

    Chakraborty, Anirban; Liu, Xinchuan; Luo, Cheng

    2012-01-01

    Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 1977(1). They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications(2,3). Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials(4). For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form(5,6). One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes. A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers(4), polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures(7). The fabricated microstructures of conducting polymers have been used as humidity(8), chemical(8), and glucose sensors(9). Combined microstructures of Al and conducting polymers have been employed to fabricate capacitors and various heterojunctions(9,10,11). The "cutting" operation was also applied to generate submicron-patterns, such as 100- and 500-nm-wide PPy lines as well as 100-nm-wide Au wires. The "drawing" operation was employed for two applications: (i) produce Au sidewall patterns on high density polyethylene (HDPE) channels which could be used for building 3D microsystems(12,13,14), and (ii) fabricate polydimethylsiloxane (PDMS) micropillars on HDPE substrates to increase the contact angle of the channel(15). PMID:22805740

  12. Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

    PubMed Central

    Chakraborty, Anirban; Liu, Xinchuan; Luo, Cheng

    2012-01-01

    Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications2,3. Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials4. For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form5,6. One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes. A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers4, polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures7. The fabricated microstructures of conducting polymers have been used as humidity8, chemical8, and glucose sensors9. Combined microstructures of Al and conducting polymers have been employed to fabricate capacitors and various heterojunctions9,10,11. The "cutting" operation was also applied to generate submicron-patterns, such as 100- and 500-nm-wide PPy lines as well as 100-nm-wide Au wires. The "drawing" operation was employed for two applications: (i) produce Au sidewall patterns on high density polyethylene (HDPE) channels which could be used for building 3D microsystems12,13,14, and (ii) fabricate polydimethylsiloxane (PDMS) micropillars on HDPE substrates to increase the contact angle of the channel15. PMID:22805740

  13. Direct generation of abruptly focusing vortex beams using a 3/2 radial phase-only pattern.

    PubMed

    Davis, Jeffrey A; Cottrell, Don M; Zinn, Jonathan M

    2013-03-20

    Abruptly focusing Airy beams have previously been generated using a radial cubic phase pattern that represents the Fourier transform of the Airy beam. The Fourier transform of this pattern is formed using a system length of 2f, where f is the focal length of the Fourier transform lens. In this work, we directly generate these abruptly focusing Airy beams using a 3/2 radial phase pattern encoded onto a liquid crystal display. The resulting optical system is much shorter. In addition, we can easily produce vortex patterns at the focal point of these beams. Experimental results match theoretical predictions. PMID:23518733

  14. 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 ...

  15. Engineering systems for the generation of patterned co-cultures for controlling cell-cell interactions

    PubMed Central

    Kaji, Hirokazu; Camci-Unal, Gulden; Langer, Robert; Khademhosseini, Ali

    2010-01-01

    Background Inside the body, cells lie in direct contact or in close proximity to other cell types in a tightly controlled architecture that often regulates the resulting tissue function. Therefore, tissue engineering constructs that aim to reproduce the architecture and the geometry of tissues will benefit from methods of controlling cell–cell interactions with microscale resolution. Scope of the review We discuss the use of microfabrication technologies for generating patterned co-cultures. In addition, we categorize patterned co-culture systems by cell type and discuss the implications of regulating cell-cell interactions in the resulting biological function of the tissues. Major conclusions Patterned co-cultures are a useful tool for fabricating tissue engineered constructs and for studying cell–cell interactions in vitro, because they can be used to control the degree of homotypic and heterotypic cell–cell contact. In addition, this approach can be manipulated to elucidate important factors involved in cell-matrix interactions. General significance Patterned co-culture strategies hold significant potential to develop biomimetic structures for tissue engineering. It is expected that they would create opportunities to develop artificial tissues in the future. PMID:20655984

  16. Design Fault Directed Test Generation for Microprocessor Validation Deepak A. Mathaikutty,

    E-print Network

    Minnesota, University of

    Design Fault Directed Test Generation for Microprocessor Validation Deepak A. Mathaikutty, Sandeep validation of modern microprocessors is an impor- tant and complex problem. One of the problems in functional a microprocessor modeling and test generation framework that generates test suites to satisfy Modi- fied Condition

  17. 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 variation in lizard color patterns. Our results indicate the need to identify the developmental mechanisms responsible for the control of the size, shape, and orientation of nanocrystals, and the superposition of specific chromatophore types. This study opens up new perspectives on Phelsuma lizards as models in evolutionary developmental biology. PMID:24099066

  18. Distinct inspiratory rhythm and pattern generating mechanisms in the preBötzinger complex.

    PubMed

    Kam, Kaiwen; Worrell, Jason W; Janczewski, Wiktor A; Cui, Yan; Feldman, Jack L

    2013-05-29

    In the mammalian respiratory central pattern generator, the preBötzinger complex (preBötC) produces rhythmic bursts that drive inspiratory motor output. Cellular mechanisms initiated by each burst are hypothesized to be necessary to determine the timing of the subsequent burst, playing a critical role in rhythmogenesis. To explore mechanisms relating inspiratory burst generation to rhythmogenesis, we compared preBötC and hypoglossal (XII) nerve motor activity in medullary slices from neonatal mice in conditions where periods between successive inspiratory XII bursts were highly variable and distributed multimodally. This pattern resulted from rhythmic preBötC neural population activity that consisted of bursts, concurrent with XII bursts, intermingled with significantly smaller "burstlets". Burstlets occurred at regular intervals during significantly longer XII interburst intervals, at times when a XII burst was expected. When a preBötC burst occurred, its high amplitude inspiratory component (I-burst) was preceded by a preinspiratory component that closely resembled the rising phase of burstlets. Cadmium (8 ?M) eliminated preBötC and XII bursts, but rhythmic preBötC burstlets persisted. Burstlets and preinspiratory activity were observed in ~90% of preBötC neurons that were active during I-bursts. When preBötC excitability was raised significantly, burstlets could leak through to motor output in medullary slices and in vivo in adult anesthetized rats. Thus, rhythmic bursting, a fundamental mode of nervous system activity and an essential element of breathing, can be deconstructed into a rhythmogenic process producing low amplitude burstlets and preinspiratory activity that determine timing, and a pattern-generating process producing suprathreshold I-bursts essential for motor output. PMID:23719793

  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. The attention network test: a characteristic pattern of deficits in children with ADHD

    Microsoft Academic Search

    Steinunn Adólfsdóttir; Lin Sørensen; Astri J Lundervold

    2008-01-01

    BACKGROUND: The Attention Network test (ANT) gives measures of different aspects of the complex process of attention. We ask if children with Attention Deficit Hyperactivity Disorder (ADHD) will show a characteristic pattern of deficits on this test. METHODS: The sample included 157 children (M = 10 years) who performed the child version of ANT as participants of the Bergen Child

  1. 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.…

  2. Polarization pattern of vector vortex beams generated by $q$-plates with different topological charges

    E-print Network

    Cardano, Filippo; Slussarenko, Sergei; Marrucci, Lorenzo; de Lisio, Corrado; Santamato, Enrico

    2012-01-01

    We describe the polarization topology of the vector beams emerging from a patterned birefringent liquid crystal plate with a topological charge $q$ at its center ($q$-plate). The polarization topological structures for different $q$-plates and different input polarization states have been studied experimentally by measuring the Stokes parameters point-by-point in the beam transverse plane. Furthermore, we used a tuned $q=1/2$-plate to generate cylindrical vector beams with radial or azimuthal polarizations, with the possibility of switching dynamically between these two cases by simply changing the linear polarization of the input beam.

  3. Digital pattern generator: an electron-optical MEMS for massively parallel reflective electron beam lithography

    NASA Astrophysics Data System (ADS)

    Grella, Luca; Carroll, Allen; Murray, Kirk; McCord, Mark A.; Tong, William M.; Brodie, Alan D.; Gubiotti, Thomas; Sun, Fuge; Kidwingira, Françoise; Kojima, Shinichi; Petric, Paul; Bevis, Christopher F.; Vereecke, Bart; Haspeslagh, Luc; Mane, Anil U.; Elam, Jeffrey W.

    2013-07-01

    The digital pattern generator (DPG) is a complex electron-optical MEMS that pixelates the electron beam in the reflective electron beam lithography (REBL) e-beam column. It potentially enables massively parallel printing, which could make REBL competitive with optical lithography. The development of the REBL DPG, from the CMOS architecture, through the lenslet modeling and design, to the fabrication of the MEMS device, is described in detail. The imaging and printing results are also shown, which validate the pentode lenslet concept and the fabrication process.

  4. Refinement and test case generation in Unifying Theory of Programming

    Microsoft Academic Search

    Ji-Feng He

    2008-01-01

    This talk presents a theory of testing that integrates into Hoare and Hepsilas Unifying Theory of Programming (UTP). We give test cases a denotational semantics by viewing them as specification predicates. This reformulation of test cases allows for relating test cases via refinement to specifications and programs. Having such a refinement order that integrates test cases, we develop a testing

  5. 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.

  6. Effects of Glycinergic Inhibition Failure on Respiratory Rhythm and Pattern Generation

    PubMed Central

    Shevtsova, Natalia A.; Büsselberg, Dietrich; Molkov, Yaroslav I.; Bischoff, Anne M.; Smith, Jeffrey C.; Richter, Diethelm W.; Rybak, Ilya A.

    2014-01-01

    Inhibitory interactions between neurons of the respiratory network are involved in rhythm generation and pattern formation. Using a computational model of brainstem respiratory networks, we investigated the possible effects of suppressing glycinergic inhibition on the activity of different respiratory neuron types. Our study revealed that progressive suppression of glycinergic inhibition affected all neurons of the network and disturbed neural circuits involved in termination of inspiration. Causal was a dysfunction of postinspiratory inhibition targeting inspiratory neurons, which often led to irregular preterm reactivation of these neurons, producing double or multiple short-duration inspiratory bursts. An increasing blockade of glycinergic inhibition led to apneustic inspiratory activity. Similar disturbances of glycinergic inhibition also occur during hypoxia. A clear difference in prolonged hypoxia, however, is that the rhythm terminates in expiratory apnea. The critical function of glycinergic inhibition for normal respiratory rhythm generation and the consequences of its reduction, including in pathological conditions, are discussed. PMID:24746041

  7. 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.

  8. Population genetics of Mediterranean and Saharan olives: geographic patterns of differentiation and evidence for early generations of admixture

    PubMed Central

    Besnard, G.; El Bakkali, A.; Haouane, H.; Baali-Cherif, D.; Moukhli, A.; Khadari, B.

    2013-01-01

    Background and Aims The olive (Olea europaea subsp. europaea) was domesticated in the Mediterranean area but its wild relatives are distributed over three continents, from the Mediterranean basin to South Africa and south-western Asia. Recent studies suggested that this crop originated in the Levant while a secondary diversification occurred in most westward areas. A possible contribution of the Saharan subspecies (subsp. laperrinei) has been highlighted, but the data available were too limited to draw definite conclusions. Here, patterns of genetic differentiation in the Mediterranean and Saharan olives are analysed to test for recent admixture between these taxa. Methods Nuclear microsatellite and plastid DNA (ptDNA) data were compiled from previous studies and completed for a sample of 470 cultivars, 390 wild Mediterranean trees and 270 Saharan olives. A network was reconstructed for the ptDNA haplotypes, while a Bayesian clustering method was applied to identify the main gene pools in the data set and then simulate and test for early generations of admixture between Mediterranean and Saharan olives. Key Results Four lineages of ptDNA haplotypes are recognized: three from the Mediterranean basin and one from the Sahara. Only one haplotype, primarily distributed in the Sahara, is shared between laperrinei and europaea. This haplotype is detected once in ‘Dhokar’, a cultivar from the Maghreb. Nuclear microsatellites show geographic patterns of genetic differentiation in the Mediterranean olive that reflect the primary origins of cultivars in the Levant, and indicate a high genetic differentiation between europaea and laperrinei. No first-generation hybrid between europaea and laperrinei is detected, but recent, reciprocal admixture between Mediterranean and Saharan subspecies is found in a few accessions, including ‘Dhokar’. Conclusions This study reports for the first time admixture between Mediterranean and Saharan olives. Although its contribution remains limited, Laperrine's olive has been involved in the diversification of cultivated olives. PMID:24013386

  9. 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.

  10. Surveys on specific patterns of facility intallation of photovoltaic power generating technologies for international cooperation

    NASA Astrophysics Data System (ADS)

    1993-03-01

    The objective is to contribute to the international introduction of photovoltaic power generation. To do this, its load patterns, device constitution, land areas, and prices were rearranged and standardized so that design standardization and efficiency improvement may be achieved, and appropriate introduction patterns may be selected from climatic conditions at various sites. Areas dealt with are Africa, Asia, Oceania, and South and Central America. The basic design consists of combination of solar cells with storage batteries for DC load, whereas inverters were added for AC load. Facility capacities were designed so that they can be calculated by assuming general load menus comprising lighting, pumps, and electric appliances, as well as load patterns. Because of non-electrified areas requiring insolation to take care of all of the annual load, minimum monthly average insolation on slopes was used to calculate solar cell capacities. While storage battery capacities will be established upon investigating climatic conditions at proposed sites, arrangements were made on selecting charge controllers that can avoid overcharging and overdischarging due to variation in insolation. A design procedure document was prepared so that the basic design could be carried out efficiently.

  11. 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

  12. 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

  13. Differential proliferation rates generate patterns of mechanical tension that orient tissue growth

    PubMed Central

    Mao, Yanlan; Tournier, Alexander L; Hoppe, Andreas; Kester, Lennart; Thompson, Barry J; Tapon, Nicolas

    2013-01-01

    Orientation of cell divisions is a key mechanism of tissue morphogenesis. In the growing Drosophila wing imaginal disc epithelium, most of the cell divisions in the central wing pouch are oriented along the proximal–distal (P–D) axis by the Dachsous-Fat-Dachs planar polarity pathway. However, cells at the periphery of the wing pouch instead tend to orient their divisions perpendicular to the P–D axis despite strong Dachs polarization. Here, we show that these circumferential divisions are oriented by circumferential mechanical forces that influence cell shapes and thus orient the mitotic spindle. We propose that this circumferential pattern of force is not generated locally by polarized constriction of individual epithelial cells. Instead, these forces emerge as a global tension pattern that appears to originate from differential rates of cell proliferation within the wing pouch. Accordingly, we show that localized overgrowth is sufficient to induce neighbouring cell stretching and reorientation of cell division. Our results suggest that patterned rates of cell proliferation can influence tissue mechanics and thus determine the orientation of cell divisions and tissue shape. PMID:24022370

  14. Tests of Micro-Pattern Gaseous Detectors for active target time projection chambers in nuclear physics

    NASA Astrophysics Data System (ADS)

    Pancin, J.; Damoy, S.; Perez Loureiro, D.; Chambert, V.; Dorangeville, F.; Druillole, F.; Grinyer, G. F.; Lermitage, A.; Maroni, A.; Noël, G.; Porte, C.; Roger, T.; Rosier, P.; Suen, L.

    2014-01-01

    Active target detection systems, where the gas used as the detection medium is also a target for nuclear reactions, have been used for a wide variety of nuclear physics applications since the eighties. Improvements in Micro-Pattern Gaseous Detectors (MPGDs) and in micro-electronics achieved in the last decade permit the development of a new generation of active targets with higher granularity pad planes that allow spatial and time information to be determined with unprecedented accuracy. A novel active target and time projection chamber (ACTAR TPC), that will be used to study reactions and decays of exotic nuclei at facilities such as SPIRAL2, is presently under development and will be based on MPGD technology. Several MPGDs (Micromegas and Thick GEM) coupled to a 2×2 mm2 pixelated pad plane have been tested and their performances have been determined with different gases over a wide range of pressures. Of particular interest for nuclear physics experiments are the angular and energy resolutions. The angular resolution has been determined to be better than 1° FWHM for short traces of about 4 cm in length and the energy resolution deduced from the particle range was found to be better than 5% for 5.5 MeV ? particles. These performances have been compared to Geant4 simulations. These experimental results validate the use of these detectors for several applications in nuclear physics.

  15. 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.

  16. Transition of pattern generation: The phenomenon of post-scratching locomotion.

    PubMed

    Trejo, A; Tapia, J A; De la Torre Valdovinos, B; Huidobro, N; Flores, G; Flores-Hernandez, J; Flores, A; Manjarrez, E

    2015-03-12

    A fundamental problem in neurophysiology is the understanding of neuronal mechanisms by which the central nervous system produces a sequence of voluntary or involuntary motor acts from a diverse repertory of movements. These kinds of transitions between motor acts are extremely complex; however, they could be analyzed in a more simple form in decerebrate animals in the context of spinal central pattern generation. Here, we present for the first time a physiological phenomenon of post-scratching locomotion in which decerebrate cats exhibit a compulsory locomotor activity after an episode of scratching. We found flexor, extensor and intermediate single interneurons rhythmically firing in the same phase during both scratching and the subsequent post-scratching locomotion. Because no changes in phase of these neurons from scratching to post-scratching locomotion were found, we suggest that in the lumbar spinal cord there are neurons associated with both motor tasks. Moreover, because of its high reproducibility we suggest that the study of post-scratching fictive locomotion, together with the unitary recording of neurons, could become a useful tool to study neuronal mechanisms underlying transitions from one rhythmic motor task to another, and to study in more detail the central pattern generator circuitry in the spinal cord. PMID:25556832

  17. Theory and application of Marsaglia's monkey test for pseudorandom number generators

    Microsoft Academic Search

    Ora E. Percus; Paula A. Whitlock

    1995-01-01

    A theoretical analysis is given for a new test, the “Monkey” test, for pseudorandom number sequences, which was proposed by Marsaglia. Selected results, using the test on several pseudorandom number generators in the literature, are also presented.

  18. Pattern generation in caudal-lumbar and sacrococcygeal segments of the neonatal rat spinal cord.

    PubMed

    Gabbay, H; Delvolvé, I; Lev-Tov, A

    2002-08-01

    The rhythmogenic capacity of the tail-innervating segments (L4-Co3) of the spinal cord was studied in isolated spinal cord and tail-spinal cord preparations of neonatal rats. Bath-applied serotonin/N-methyl-D-aspartate (NMDA) failed to produce a robust sacrococcygeal rhythmicity following midlumbar transection of the spinal cord. By contrast, a regular alternating left-right rhythm could be induced in the sacrococcygeal segments by application of noradrenaline (NA) or NA and NMDA before and after midlumbar transection of the cord. This rhythm was accelerated with the concentration of NMDA and was blocked by alpha1 or alpha2 adrenoceptor antagonists. The efferent bursts induced by NA/NMDA were accompanied by rhythmic tail movements produced by alternating activation of the left and right tail muscles and by coactivation of flexors, extensors, and abductors on a given side of the tail. This coactivation implies that reciprocal inhibitory pathways were not activated during the rhythm. Lesion experiments revealed that the rhythmogenic circuitry is distributed along all or most of the sacrococcygeal segments. The NA/NMDA-induced rhythm persisted in the isolated sacrococcygeal (S1-Co3), sacral (S1-S4), coccygeal (Co1-Co3), and smaller isolated regions of the sacrococcygeal cord. The rhythm also could be maintained in longitudinally split sacrococcygeal hemicords in which flexor, extensor, and abductor motoneurons are coactivated. This finding indicates that neither left/right nor flexor/extensor inhibitory interactions are required for rhythmogenesis in the sacrococcygeal cord. A slow rhythm lacking the alternating left-right pattern was induced by NA/NMDA in tail-innervating caudal lumbar segments of isolated L4-Co3 preparations. This rhythm was independent of the concurrent sacrococcygeal rhythm and the activity pattern of the tail musculature and it does not seem to contribute to rhythmic tail movements under these conditions. Comparative studies of the rhythm produced in the isolated caudal lumbar, sacrococcygeal cord, and caudal thoracic-rostral lumbar segments revealed that the S1-Co3 rhythm was faster than the L4-L6 pattern and slower than the T6-L3 rhythm. It is suggested that the caudal lumbar and sacrococcygeal segments of the cord are normally driven by the faster rostral lumbar central pattern generators. The relevance of the findings described above to pattern generation in the mammalian spinal cord is discussed. PMID:12163525

  19. Abnormal typical pattern of platelet function and thromboxane generation in unstable angina.

    PubMed

    Zahavi, M; Zahavi, J; Schafer, R; Firsteter, E; Laniado, S

    1989-11-24

    Platelet aggregation (PA), platelet thromboxane B2 (TXB2) generation and 14C 5-hydroxytryptamine (5HT) release were studied in 13 patients with unstable angina, and compared to 14 patients with stable angina and 16 healthy controls. A typical pattern, distinct in 4 aspects from stable angina patients or controls, was observed in the unstable angina patients. ADP or collagen induced shape change was 3-4 times greater, the extent of epinephrine induced PA was nil or very low, the extent of collagen induced 14C 5HT release was also reduced while collagen induced platelet TXB2 generation was increased in spite of a reduced extent of PA. The extent of ADP or collagen induced PA was also significantly reduced. These results indicate a platelet membrane abnormality occurring presumably during contact of the circulating platelets with a non-occlusive thrombus observed at sites of ruptured plaques in unstable angina patients. Since also the pattern (20-30% overlap with control values) was distinct from that of stable angina patients, it might indicate an active thrombotic process. Plasma beta-thromboglobulin (beta TG) and TXB2 levels and serum TXB2 generation were also studied in the cardiac patients and controls and in another 10 patients with advanced peripheral occlusive arterial disease (POAD). Plasma beta TG and TXB2 levels were slightly elevated in the unstable angina patients and markedly elevated in the POAD patients. Serum TXB2 generation was, however, elevated in the stable angina patients (p less than 0.002) and more so in the unstable angina patients (p less than 0.001) compared to controls or to POAD patients. This was presumably mediated through enhanced thrombin generation. These results suggest that the measured plasma beta TG variable in the unstable angina patients is not useful in the assessment of in vivo platelet activation. It is presumably reflecting the sum of local enhanced platelet activation (at sites of ruptured plaques) and of reduced function of the "defective" circulating platelets. The ability of the platelets of unstable angina patients to generate large amounts of TXB2 if occurring in vivo might induce an intense coronary vasospasm. PMID:2531938

  20. 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

  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. XUnit test patterns and smells: improving the ROI of test code

    Microsoft Academic Search

    Gerard G. Meszaros

    2010-01-01

    High quality automated unit tests are one of the key development practices that enable incremental development and delivery of software by reducing the number of bugs introduced into code as it is evolved. But writing lots of tests is not enough as the tests need to be maintained over the life of the software. This maintenance cost can quickly outweigh

  3. Generating Parallel Test Forms for Minimum Competency Exams.

    ERIC Educational Resources Information Center

    Nassif, Paula M.; And Others

    A procedure which employs a method of item substitution based on item difficulty is recommended for developing parallel criterion referenced test forms. This procedure is currently being used in the Florida functional literacy testing program and the Georgia teacher certification testing program. Reasons for developing parallel test forms involve…

  4. Testing Scenarios of Lorentz Symmetry Violation Generated at the Planck Scale

    NASA Astrophysics Data System (ADS)

    Gonzalez-Mestres, Luis

    2003-07-01

    Using new theoretical to ols, which allow to better understand ultra-high energy (UHE) dynamics, several patterns of Lorentz symmetry violation (LSV) are studied and compared with experiment. It is claimed that quadratically deformed relativistic kinematics (QDRK), where the parameter driving LSV varies like the square of the energy scale, remains the best suited pattern to describe LSV generated at the Planck scale. Implications of existing data are discussed and prosp ects are presented having in mind next-generation experiments.

  5. The Journal of Neuroscience, May 1994, 14(5): 30193035 Muscarinic Modulation of a Pattern-Generating Network: Control of

    E-print Network

    Bal, Thierry

    that under certain conditions of muscarinic modulation a new composite pacemaker could be created, composed, in a rhythmic "pattern-generating network," the pacemaker role may not be definitely attributed to a given, muscarinic modulation, oscillations, pacemaker] The generation of simple motor behaviors in both vertebrates

  6. Analysis of a Random Cut Test Instance Generator for the TSP

    E-print Network

    Tovey, Craig A.

    Analysis of a Random Cut Test Instance Generator for the TSP Ronald L. Rardin School of Industrial, University of Washington, Seattle, WA 98105 USA Abstract Test Instance Generators (TIG's) are important to Pilcher and Rardin, is based on a random cut method. We show that it generates a class of instances

  7. Module generation for self-testing integrated systems

    NASA Astrophysics Data System (ADS)

    Vanriessen, Ronald Pieter

    Hardware used for self test in VLSI (Very Large Scale Integrated) systems is reviewed, and an architecture to control the test hardware in an integrated system is presented. Because of the increase of test times, the use of self test techniques has become practically and economically viable for VLSI systems. Beside the reduction in test times and costs, self test also provides testing at operational speeds. Therefore, a suitable combination of scan path and macrospecific (self) tests is required to reduce test times and costs. An expert system that can be used in a silicon compilation environment is presented. The approach requires a minimum of testability knowledge from a system designer. A user friendly interface was described for specifying and modifying testability requirements by a testability expert. A reason directed backtracking mechanism is used to solve selection failures. Both the hierarchical testable architecture and the design for testability expert system are used in a self test compiler. The definition of a self test compiler was given. A self test compiler is a software tool that selects an appropriate test method for every macro in a design. The hardware to control a macro test will be included in the design automatically. As an example, the integration of the self-test compiler in a silicon compilation system PIRAMID was described. The design of a demonstrator circuit by self test compiler is described. This circuit consists of two self testable macros. Control of the self test hardware is carried out via the test access port of the boundary scan standard.

  8. Strong Higher Order Mutation-Based Test Data Generation Mark Harman

    E-print Network

    Harman, Mark

    Strong Higher Order Mutation-Based Test Data Generation Mark Harman CREST Centre University College introduces SHOM, a mutation-based test data generation approach that combines Dynamic Symbolic Ex- ecution and Search Based Software Testing. SHOM targets strong mutation adequacy and is capable of killing both first

  9. An Incomplete Scan Design Approach to Test Generation for Sequential Machines

    Microsoft Academic Search

    Hi-keung Tony Ma; A. Richard Newton; Srinivas Devadas; Alberto L. Sangiovanni-vincentelli

    1988-01-01

    An incomplete scan design approach to sequential test generation is presented. This approach represents a significant departure from previous methods. First, using an efficient sequential testing algorithm, test sequences are generated for a large number of possible faults in the given sequential circuit. A minimal subset of memory elements is then found, which if made observable and controllable will result

  10. Eclat : automatic generation and classification of test inputs

    E-print Network

    Pacheco, Carlos, S.M. Massachusetts Institute of Technology

    2005-01-01

    This thesis describes a technique that selects, from a large set of test inputs, a small subset likely to reveal faults in the software under test. The technique takes a program or software component, plus a set of correct ...

  11. Reticular activating system of a central pattern generator: premovement electrical potentials

    PubMed Central

    Tapia, Jesus A; Trejo, Argelia; Linares, Pablo; Alva, J Manuel; Kristeva, Rumyana; Manjarrez, Elias

    2013-01-01

    For the first time, here we characterize a bulbar reticular activating system (RAS) of neurons in decerebrate, deafferented and decerebellated cats producing a premovement electrical potential that we named obex slow potential (OSP). The OSP occurs about 0.8 ± 0.4 sec prior to the onset of a fictive-scratching-episode. Here, we describe two classes of bulbar neurons, off-on, which are silent but exhibit a 80 ± 56 Hz firing discharge at the beginning of (and during) the OSP, and on-off interneurons, with a 27 ± 14 Hz firing activity that stops at the beginning of (and during) the OSP. We suggest that these OSP-associated neurons belong to a descending RAS, which contributes to the activation of the spinal central pattern generators. PMID:24303193

  12. 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

  13. A Customer Test Generator for Web-Based Systems

    Microsoft Academic Search

    Rick Mugridge; Bruce Macdonald; Partha S. Roop

    2003-01-01

    Customer (or acceptance) tests enable the customer to drive the overall design of a required system. We introduce an approach\\u000a to developing customer tests for web-based applications. The customer specifies such tests through sample web pages. A test\\u000a may consist of a traversal through a sequence of HTML pages in the required system. This is specified as a trace, defined

  14. Automating the Generation and Sequencing of Test Cases from Model-Based Specifications

    Microsoft Academic Search

    Jeremy Dick; Alain Faivre

    1993-01-01

    Formal specifications contain a great deal of information that can be exploited in the testing of an implementation, either for the generation of test-cases, for sequencing the tests, or as an oracle in verifying the tests. This papers presents automatic techniques for partition analysis in state-based specifications, specifically VDM. Test domains for individual operations are calculated by reduction of their

  15. A study in coverage-driven test generation

    Microsoft Academic Search

    Mike Benjamin; Daniel Geist; Alan Hartman; Gerard Mas; Ralph Smeets; Yaron Wolfsthal

    1999-01-01

    1. ABSTRACT One possible solution to the verification crisis is to bridge the gap between formal verification and simulation by using hybrid techniques. This paper presents a study of such a functional verification methodology that uses coverage of formal models to specify tests. This was applied to a modern superscalar microprocessor and the resulting tests were compared to tests gen-

  16. Test input generation for java containers using state matching

    Microsoft Academic Search

    Willem Visser; Corina S. Pasareanu; Radek Pelánek

    2006-01-01

    The popularity of object-oriented programming has led to the wide use of container libraries. It is important for the re- liability of these containers that they are tested adequately. We describe techniques for automated test input genera- tion of Java container classes. Test inputs are sequences of method calls from the container interface. The tech- niques rely on state matching

  17. A thermal cycling type test for generator stator winding insulation

    Microsoft Academic Search

    G. C. Stone; J. F. Lyles; J. M. Braun; C. L. Kaul

    1991-01-01

    A test has been designed and implemented which cycles the temperature between 40°C and 150°C in about 80 min by the use of circulating currents and cooling air. The test has been successfully used to evaluate the relative performance of similar stator bars made by three different manufacturers. The thermal cycling test was able to duplicate the insulation delamination process

  18. Photolithographic patterning of organosilane monolayer for generating large area two-dimensional B lymphocyte arrays†

    PubMed Central

    Li, Nan

    2009-01-01

    High-density live cell array serves as a valuable tool for the development of high-throughput immunophenotyping systems and cell-based biosensors. In this paper, we have, for the first time, demonstrated a simple fabrication process to form the hexamethyldisilazane (HMDS) and poly(ethylene glycol) (PEG) binary molecular surface which can be used to effectively form high fidelity cell arrays. The HMDS self-assembled monolayer (SAM) on glass substrates was photolithographically patterned and its ability to physically adsorb proteins was characterized by contact angle measurement and fluorescence microscopy respectively. Passivation of the non-HMDS coated background by PEG was verified to have no impact on the pre-patterned HMDS and greatly inhibited the non-specific protein binding. Using the biotin–streptavidin complexation as an intermediate, uniform orientation and high bioactivity were achieved for the immobilized B lymphocyte specific anti-CD19 antibodies and therefore ensured the formation of high resolution B lymphocyte arrays. The cell–ligand interaction specificity was investigated and the anti-CD19 decorated micropatterns presented a much higher cell-capturing rate (88%) than those modified by non-specific ligands (15% for anti-CD5 and 7% for streptavidin). The approach was verified to be biocompatible and the properties of the antibody-modified surface were maintained after 12 h cell culture. The HMDS monolayer formation and patterning processes, and the universal HMDS/biotin-BSA/streptavidin template, provide a very simple and convenient process to generate high resolution micropatterns of cell-adhesive ligands and are extendable to form arrays of other types of cells as well. PMID:19023473

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

    PubMed

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

    2014-05-12

    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

  20. 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

  1. 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

  2. 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...

  3. Expression patterns and transcript concentrations of the autosomal DAZL gene in testes of azoospermic men

    Microsoft Academic Search

    Yung Ming Lin; Chaio Wei Chen; H. Sunny Sun; Shaw Jeng Tsai; Chao Chin Hsu; Yen Ni Teng; Johnny Shinn; Nan Lin; Pao Lin Kuo

    2001-01-01

    The DAZ (Deleted in AZoospermia) gene cluster on the Y chromosome is a strong candidate for the azoospermia factor. The DAZ gene was derived from an autosomal homologue, DAZL (DAZ-Like). This study was designed to assess the functional role of DAZL in human spermatogenesis. The expression patterns and mRNA transcript levels of DAZL in the testes of 17 azoospermic men

  4. 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…

  5. Changing patterns in climate-driven landslide hazard: an alpine test site Audrey Baills(1)

    E-print Network

    Paris-Sud XI, Université de

    Changing patterns in climate-driven landslide hazard: an alpine test site Audrey Baills(1 will be different depending on both the location of the site and the type of landslide considered. Indeed, mass valley (France) using present and past climate conditions. Keywords: hazard, landslide, climate change

  6. Generating different genetic expression patterns in the early embryo: insights from the mouse model.

    PubMed

    Bruce, Alexander W

    2013-12-01

    The divergence of two differentiating extraembryonic cell types (trophectoderm and primitive endoderm) from the pluripotent epiblast population (the source of fetal progenitor cells) by the blastocyst stage of mouse development relies upon the activation and execution of lineage-specific gene expression programmes. While our understanding of the central transcription factor 'effectors' directing these cell-fate choices has accumulated rapidly, what is less clear is how the differential expression of such genes within the diverging lineages is initially generated. This review summarizes and consolidates current understanding. I introduce the traditional concept and importance of a cell's spatial location within the embryo, referencing recent mechanistic and molecular insights relating to cell fate. Additionally, I address the growing body of evidence that suggests that heterogeneities among blastomeres precede, and possibly inform, their spatial segregation in the embryo. I also discuss whether the origins of such early heterogeneity are stochastic and/or indicative of intrinsic properties of the embryo. Lastly, I argue that the robustness and regulative capacity of preimplantation embryonic development may reflect the existence of multiple converging, if not wholly redundant, mechanisms that act together to generate the necessary diversity of inter-cell-lineage gene expression patterns. PMID:23768616

  7. Alternative splicing generates metabotropic glutamate receptors inducing different patterns of calcium release in Xenopus oocytes.

    PubMed Central

    Pin, J P; Waeber, C; Prezeau, L; Bockaert, J; Heinemann, S F

    1992-01-01

    A splice variant of the metabotropic glutamate receptor (mGluR) 1a, named mGluR1c, was isolated. Compared to mGluR1a, the predicted mGluR1c protein is 302 amino acids shorter at its C-terminal end. Despite this difference, mGluR1c activates phospholipase C in Xenopus oocytes with a pharmacological profile identical to that of mGluR1a. However, in contrast to the large fast transient responses induced by mGluR1a, mGluR1c receptors elicit a small more slowly generated long-lasting oscillatory current, suggesting that these two receptors do not generate the same pattern of Ca2+ release in Xenopus oocytes. In situ hybridization data show that mGluR1c mRNA is expressed at a lower level than the other splice variants of mGluR1. Some differences in the regional distribution of these transcripts were observed in the cerebellum, the olfactory bulb, and the striatum. Images PMID:1438218

  8. The motor pattern that a central pattern generator (CPG) produces is determined by the synaptic interactions among, and

    E-print Network

    DiCaprio, Ralph

    interactions among, and intrinsic membrane properties of, the neurons that make up the CPG network. In early their response to driving inputs. One such intrinsic property results in the generation of plateau potentials the neuron to a depolarized voltage that may be superthreshold for the generation of action potentials

  9. Analytical methods for establishing least cost search patterns for fault isolation in testing procedures

    E-print Network

    Howie, Thomas Fisher

    1970-01-01

    basic con! c?!' of testing procedures a?d to prr scant methods to identify the various state. , Lhrough which the system passes as Lh, . Lest proce!. ds. Assume 1 hypothetical system of fourteen element funcLionally confi g?red as shown in Figure 1... the highest fipure of merit, therefore, Lhis !~ill be the first test. 0 6 If Lhe test passes *he ncw state wi:Ll be 0011, if the te -t fails it wi j 1 be 1100. The fol3 owing t abl e Lists the results from a ne-evaluation using the new Lest patterns...

  10. 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.

  11. 78 FR 65007 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-30

    ...Generating Plant, Unit 3 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and acceptance...SUMMARY: The U.S. Nuclear Regulatory Commission (NRC...determined that the inspections, tests, and analyses have been...

  12. Model Validation using Automatically Generated Requirements-Based Tests

    Microsoft Academic Search

    Ajitha Rajan; Michael W. Whalen; Mats P. E. Heimdahl

    2007-01-01

    In current model-based development practice, validation that we are building a correct model is achieved by manually deriving requirements-based test cases for model testing. Model validation performed this way is time consuming and expensive, particularly in the safety critical systems domain where high confidence in the model correctness is required. In an effort to reduce the validation effort, we propose

  13. Model Validation using Automatically Generated Requirements-Based Tests

    Microsoft Academic Search

    Ajitha Rajan; Michael W. Whalen; Mats Per Erik Heimdahl

    2007-01-01

    In current model-baseddevelopmentpractice, validation that we are building a correct model is achieved by manu- ally deriving requirements-based test cases for model test- ing. Model validation performed this way is time consum- ing and expensive, particularly in the safety critical systems domain where high confidence in the model correctness is required. In an effort to reducethe validationeffort, we proposean approach

  14. A Comparative Evaluation of Tests Generated from Different UML Diagrams

    E-print Network

    Offutt, Jeff

    such as UML diagrams. When deriving tests from model-based descriptions of the software, the test engineer, Thailand supaporn.k@psu.ac.th Jeff Offutt, Aynur Abdurazik, Andrea Baldini Software Engineering George software. Sequence diagrams capture time dependent (temporal) sequences of interactions between objects

  15. Generating Feedback Reports for Adults Taking Basic Skills Tests

    E-print Network

    Williams, Sandra

    leaflets based on a smoker's responses to a questionnaire about her smoking habits, beliefs, and so forth There are a growing number of short assessment tests available on the Web, which people can use to assess their health) technology, in the belief that better feedback will make such tests more useful and effective. #12;This paper

  16. Investigation of properties of surface acoustic waves generated by periodically patterned ZnO on silicon substrate.

    PubMed

    Sai Krishna Santosh, G; Nemade, Harshal B

    2015-05-01

    The paper presents the characteristics of vertically polarized surface waves generated in silicon substrate by acoustic coupling of bulk waves excited in a periodically patterned ZnO film on silicon. The finite element simulations are performed on the proposed patterned-ZnO/Si structure and vertically polarized modes in silicon are found to be dominant in the frequency dependent analysis. The generated modes in silicon are concentrated near the surface within a wavelength depth and exhibit surface wave properties. Dispersion curves of phase velocity and coupling coefficient for the surface modes are reported. The results indicate high electromechanical coupling coefficient of 6.4% as well as high phase velocity of 5332m/s for the surface mode generated in silicon owing to the acoustic coupling of the first order bulk mode in ZnO pattern observed at ZnO height to wavelength ratio of 0.19. PMID:25677540

  17. AETGSM Web: A Web Based Service for Automatic Efficient Test Generation from Functional Requirements

    Microsoft Academic Search

    Siddhartha R. Dalal; Ashish Jain; Gardner C. Patton; Manish Rathi; Paul D. Seymour

    1998-01-01

    AETG Web is a web based service developed by Bell- core researchers for enabling model based testing. In model based testing, the functional test requirements of the system are first modeled and then testcases based on this model are created or generated. AETG Web employs a web based user interface to model the functional requirements of the System Under Test,

  18. Interactions of pattern-generating interneurons controlling feeding in Lymnaea stagnalis.

    PubMed

    Elliott, C J; Benjamin, P R

    1985-12-01

    Intracellular recordings were made from rhythm-generating interneurons in the Lymnaea feeding system. The feeding pattern is a three-phase rhythm of interneuronal activity (N1, N2, N3) corresponding to protraction, rasp, and swallow. We describe the firing pattern and anatomy of the premotor interneurons, each of which fires a predominant burst in only one phase of the feeding rhythm. The rhythm can be driven by steady depolarization of N1 cells. The phase of the rhythm is reset by brief stimulation of N2 or N3 interneurons. N1 neurons excite the N2 interneurons, and these in turn inhibit the N1 cells. This recurrent inhibitory pathway can account for the switch from the N1 phase of the feeding cycles to the N2 phase. The endogenous properties of the N2 interneurons are apparently responsible for the termination of N2 bursts. N3 interneurons display postinhibitory rebound (PIR), and this probably contributes to their burst after the end of the N2 inhibitory input. N2 and N3 interneurons inhibit the N1 cells. When the N3 burst dies away, activity in N1 cells resumes under the stimulus of depolarizing current. Interactions between interneurons are mainly by discrete, monophasic postsynaptic potentials, that follow 1:1. They have relatively short latency (2-12 ms) and duration (up to 100 ms). The synaptic connections between the three types of premotor interneurons are sufficient to account for the sequence of activity seen during feeding. PMID:4087040

  19. Decade Quad design and testing status [pulsed power generator

    Microsoft Academic Search

    P. Sincerny; K. Childers; D. Kortbawi; I. Roth; C. Stallings; J. Riordan; B. Hoffman; L. Schlitt; C. Myers

    1997-01-01

    The Decade Quad (DQ) is a high power generator that will be built at Arnold Engineering Development Center (AEDC) in Tullahoma, Tennessee by the Defense Special Weapons Agency (DSWA). The DQ will consist of four independent command triggered pulsed power modules. The building at AEDC has been completed and has the capacity to accommodate up to four DQ machines for

  20. 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.

  1. Fault simulation and test generation for small delay faults

    E-print Network

    Qiu, Wangqi

    2007-04-25

    Delay faults are an increasingly important test challenge. Traditional delay fault models are incomplete in that they model only a subset of delay defect behaviors. To solve this problem, a more realistic delay fault model has been developed which...

  2. 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...

  3. 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

  4. 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-based setup. Additionally a CGH phase function using an exact geometric model is compared to the other approaches. The phase function is utilized to enhance the overall reliability of the sensitivity functions with regard to alignment errors in interferometric testing. PMID:25608066

  5. 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.

  6. Residual pattern based test for interactions in two-way ANOVA.

    PubMed

    Ning, Wei; Kim, Hyune-Ju

    2008-06-01

    This article proposes a new test to detect interactions in replicated two-way ANOVA models, more powerful than the classical F -test and more general than the test of Terbeck and Davies (1998, Annals of Statistics 26, 1279-1305) developed for the case with unconditionally identifiable interaction pattern. We use the parameterization without the conventional restrictions on the interaction terms and base our test on the maximum of the standardized disturbance estimates. We show that our test is unbiased and consistent, and discuss how to estimate the p -value of the test. In a 3 x 3 case, which is our main focus in this article, the exact p -value can be computed by using four-dimensional integrations. For a general I x J case which requires an (I - 1) x (J - 1) dimensional integration for a numerical evaluation of the exact p -value, we propose to use an improved Bonferroni inequality to estimate an upperbound of the p -value and simulations indicate a reasonable accuracy of the upperbound. Via simulations, we show that our test is more powerful than the classical F -test and also that it can deal with both situations: unconditionally identifiable and non-unconditionally identifiable cases. An application to genetic data is presented in which the new test is significant, while the classical F -test failed to detect interactions. PMID:18481362

  7. SemiFormal Test Generation for a Block of Industrial DSP

    Microsoft Academic Search

    Julia Dushina; Mike Benjamin; Daniel Geist

    2001-01-01

    This article describes an industrial application of the Genevieve test generation methodology. The Genevieve ap- proach (1) uses formal techniques to generate test suites for specific design behaviour. The example, which is a part of the ST100 DSP, was chosen in order to highlight real life problems such as big data structures, complex control log- ic, and complex environments where

  8. Delay fault models and test generation for random logic sequential circuits

    Microsoft Academic Search

    Tapan J. Chakraborty; Vishwani D. Agrawal; Michael L. Bushnell

    1992-01-01

    In this paper, we study delay fault modeta and the corresponding test generation methodology for gen- eral sequential circuits. Our test generation method Is based on transzlion and hazard states of signals and is applicable to any sequential circuit irrespective of its structure, including the circuits where the flipflops can form a scan register. No hold requirement need be bnpased

  9. 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

  10. 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.

  11. Comparison of force and power generation patterns and their predictions under different external dynamic environments.

    PubMed

    Chhatbar, Pratik Y; Francis, Joseph T

    2010-01-01

    Use of neural activity to predict kinematic variables such as position, velocity and direction etc of movements has been implemented in real-time control of robotic systems and computer cursors. In everyday life, however, we generate variable amounts of force to manipulate objects of different inertial properties or to follow the same trajectory under different external dynamic environments like air or water. The resultant work during such movements, and its time derivative power, should depend on the dynamics of the movement. In order to give the users of a brain-machine interface (BMI) comprehensive control of a prosthetic limb under different dynamic conditions, it is imperative to consider the dynamics-related parameters like end-effector forces, joint torques or power. In this paper, we show distribution patterns of two such dynamics parameters - force and power - and their predictive efficiency under different dynamic environmental conditions. We intend to find the force-related parameter, which has optimal predictive efficiency across different dynamic environments that is generalization. Our ultimate goal is to materialize a force-based brain-machine interface (fBMI). PMID:21096397

  12. Energy efficient walking with central pattern generators: from passive dynamic walking to biologically inspired control.

    PubMed

    Verdaasdonk, B W; Koopman, H F J M; van der Helm, F C T

    2009-07-01

    Like human walking, passive dynamic walking-i.e. walking down a slope with no actuation except gravity-is energy efficient by exploiting the natural dynamics. In the animal world, neural oscillators termed central pattern generators (CPGs) provide the basic rhythm for muscular activity in locomotion. We present a CPG model, which automatically tunes into the resonance frequency of the passive dynamics of a bipedal walker, i.e. the CPG model exhibits resonance tuning behavior. Each leg is coupled to its own CPG, controlling the hip moment of force. Resonance tuning above the endogenous frequency of the CPG-i.e. the CPG's eigenfrequency-is achieved by feedback of both limb angles to their corresponding CPG, while integration of the limb angles provides resonance tuning at and below the endogenous frequency of the CPG. Feedback of the angular velocity of both limbs to their corresponding CPG compensates for the time delay in the loop coupling each limb to its CPG. The resonance tuning behavior of the CPG model allows the gait velocity to be controlled by a single parameter, while retaining the energy efficiency of passive dynamic walking. PMID:19504121

  13. 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

  14. 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.

  15. Test Case Generation from UML State Machines Dirk Seifert

    E-print Network

    Paris-Sud XI, Université de

    to model embedded systems. We intend to use state machine models not only for development but also describe a comprehensive approach for confor- mance testing of embedded reactive systems. Based on a formal The impact of embedded systems in our everyday life is steadily growing. They are present not only in very

  16. Math Test Generator. Volume 2: Special Skills [CD-ROM].

    ERIC Educational Resources Information Center

    Aud, Joel; Gintz, Chris

    This computer software program helps to make classroom worksheets, take home assignments, and school mathematics tests easy to design and manufacture. The accompanying printed teaching guide provides technical information for setting up and using the program, along with sample worksheets and instructions on how to create them using the software.…

  17. 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.

  18. Automated Generation of Test Programs From Closed Specifications of Classes and Test Cases

    E-print Network

    Leow, Wee Kheng

    scripts to obtain the outputs, which are evaluated by a test evaluation tool. This paper complements scripts to obtain the outputs, which are evaluated by a test evaluation tool. Test execution and test result evaluation are easy to au- tomate, and tools for these stages in software testing are already

  19. Use of the Society of Motion Picture and Television Engineers test pattern in picture archiving and communication systems (PACS)

    NASA Astrophysics Data System (ADS)

    Gray, Joel E.

    1991-05-01

    In 1985 the Society of Motion Picture and Television Engineers (SMPTE) published a Recommended Practice (RP-133) entitled Specifications for Medical Diagnostic Imaging Test Pattern for Television Monitors and Hard-copy Cameras. Since that time the SMPTE monochrome test pattern has been applied to the acceptance testing and quality control of video and image display systems, and hard-copy (film) recorders. The major features of the test pattern will be discussed along with applications and the problems demonstrated with the pattern. Furthermore, the test pattern will be used to demonstrate that color displays may exhibit only one-half of the resolution of a monochrome monitor while the display contrast (due to limited dynamic range) may be only 10 to 20 of that obtained with a monochrome display.

  20. 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.

  1. A sequential nonparametric pattern classification algorithm based on the Wald SPRT. [Sequential Probability Ratio Test

    NASA Technical Reports Server (NTRS)

    Poage, J. L.

    1975-01-01

    A sequential nonparametric pattern classification procedure is presented. The method presented is an estimated version of the Wald sequential probability ratio test (SPRT). This method utilizes density function estimates, and the density estimate used is discussed, including a proof of convergence in probability of the estimate to the true density function. The classification procedure proposed makes use of the theory of order statistics, and estimates of the probabilities of misclassification are given. The procedure was tested on discriminating between two classes of Gaussian samples and on discriminating between two kinds of electroencephalogram (EEG) responses.

  2. 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…

  3. 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

  4. 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

  5. Stationary wave patterns generated by an impurity moving with supersonic velocity through a Bose-Einstein condensate

    E-print Network

    . For a supersonic motion of an impurity, the Cherenkov radiation of sound waves is the main mechanism] in which the waves were generated by the flow of a condensate expanding through an obstacle created situation it was noticed that the interference of sound (Bogoliubov) waves yields the wave pattern located

  6. The Test Suite Generation Problem: Optimal Instances and Their Implications

    E-print Network

    Cheng, Christine

    .6}, {North, South, East, West}, and {TDC, BDM}. Thus, there are a total of 2 Ã? 4 Ã? 2 = 16 test cases TDC BDM BDM TDC TDC BDM BDM TDC On the other hand, Schroeder and Korel noted that this program has two are enough as shown below. A 1.5 3.6 1.5 3.6 B North South East West C TDC BDM BDM TDC Solving TSG is likely

  7. Test generation for ultra-high-speed asynchronous pipelines

    Microsoft Academic Search

    Feng Shi; Yiorgos Makris; Steven M. Nowick; Montek Singh

    2005-01-01

    We propose a methodology for testing ultra-high-speed asynchronous pipelines, the latest and most promising asynchronous circuit design style. Unlike traditional delay-insensitive asynchronous micro-pipelines, which use slow capture-pass latches, these circuits employ aggressive handshaking protocols and transparent latches between fine-grain pipeline stages, in order to achieve high performance. Their functional robustness, however, relies on certain timing constraints that need to be

  8. 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 hunting success for wolves. Such constant efficiency in wolf predation during the recolonization process is in line with previous findings about the naive nature of Scandinavian moose to wolf predation. This, together with the human-dominated nature of the Scandinavian ecosystem, seems to limit the possibility for wolves to have large ecosystem effects and to establish a behaviorally mediated trophic cascade in Scandinavia. PMID:24261051

  9. Is Next Generation Sequencing the future of blood group testing?

    PubMed

    Tilley, Louise; Grimsley, Shane

    2014-04-01

    Blood group genotyping has many advantages over conventional phenotyping for both blood donors and patients, and a number of high-throughput methods have now been developed. However, these are limited by a requirement for existing knowledge of the relevant blood group gene polymorphisms, and rare or novel mutations will not be detected. These mutations could be successfully identified by DNA sequencing of the blood group genes, and such an approach has been made feasible by the introduction of Next Generation Sequencing (NGS) technology. NGS enables many genes from multiple samples to be sequenced in parallel, resulting in sequencing information that could be used to obtain accurate blood group phenotype predictions in both blood donors and patients. PMID:24667159

  10. Design and test of a simplified and reliable cryogenic system for high speed superconducting generator applications

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Haran, K.; Laskaris, E. T.; Bray, J. W.

    2011-07-01

    Under the contract with Air Force Research Lab (AFRL), General Electric has successfully tested a high speed, superconducting generator for a Multimegawatt Electric Power System (MEPS). As the first successful full-power test of a superconducting generator for the Air Force, the demonstration tested the generator's load up to 1.3 MW and over 10,000 rpm. A key component of the generator system is a closed loop cryo-refrigeration system to cool the field excitation coil at liquid neon temperature. This paper reports the design and tests of the cryogenic system, including the liquid neon dewar, cryogenic cooling loop for the high temperature superconducting (HTS) field coil and the cryostat. Performance data during both short-term load run and long-term non-load run were presented. Also, some key issues to design a reliable cryogenic system for a superconducting generator were discussed.

  11. 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

    2015-01-01

    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

  12. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments.

    PubMed

    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

  13. Neurochemical and neuroanatomical identification of central pattern generator neuron homologues in Nudipleura molluscs.

    PubMed

    Lillvis, Joshua L; Gunaratne, Charuni A; Katz, Paul S

    2012-01-01

    Certain invertebrate neurons can be identified by their behavioral functions. However, evolutionary divergence can cause some species to not display particular behaviors, thereby making it impossible to use physiological characteristics related to those behaviors for identifying homologous neurons across species. Therefore, to understand the neural basis of species-specific behavior, it is necessary to identify homologues using characteristics that are independent of physiology. In the Nudipleura mollusc Tritonia diomedea, Cerebral Neuron 2 (C2) was first described as being a member of the swim central pattern generator (CPG). Here we demonstrate that neurochemical markers, in conjunction with previously known neuroanatomical characteristics, allow C2 to be uniquely identified without the aid of electrophysiological measures. Specifically, C2 had three characteristics that, taken together, identified the neuron: 1) a white cell on the dorsal surface of the cerebral ganglion, 2) an axon that projected to the contralateral pedal ganglion and through the pedal commissure, and 3) immunoreactivity for the peptides FMRFamide and Small Cardioactive Peptide B. These same anatomical and neurochemical characteristics also uniquely identified the C2 homologue in Pleurobranchaea californica (called A1), which was previously identified by its analogous role in the Pleurobranchaea swim CPG. Furthermore, these characteristics were used to identify C2 homologues in Melibe leonina, Hermissenda crassicornis, and Flabellina iodinea, species that are phylogenetically closer to Tritonia than Pleurobranchaea, but do not display the same swimming behavior as Tritonia or Pleurobranchaea. These identifications will allow future studies comparing and contrasting the physiological properties of C2 across species that can and cannot produce the type of swimming behavior exhibited by Tritonia. PMID:22363716

  14. 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

  15. Setting the Pace: New Insights into Central Pattern Generator Interactions in Box Jellyfish Swimming

    PubMed Central

    Stöckl, Anna Lisa; Petie, Ronald; Nilsson, Dan-Eric

    2011-01-01

    Central Pattern Generators (CPGs) produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora) with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs) considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians. PMID:22073288

  16. Next-generation genetic testing for retinitis pigmentosa

    PubMed Central

    Neveling, Kornelia; Collin, Rob W.J.; Gilissen, Christian; van Huet, Ramon A.C.; Visser, Linda; Kwint, Michael P.; Gijsen, Sabine J.; Zonneveld, Marijke N.; Wieskamp, Nienke; de Ligt, Joep; Siemiatkowska, Anna M.; Hoefsloot, Lies H.; Buckley, Michael F.; Kellner, Ulrich; Branham, Kari E.; den Hollander, Anneke I.; Hoischen, Alexander; Hoyng, Carel; Klevering, B. Jeroen; van den Born, L. Ingeborgh; Veltman, Joris A.; Cremers, Frans P.M.; Scheffer, Hans

    2012-01-01

    Molecular diagnostics for patients with retinitis pigmentosa (RP) has been hampered by extreme genetic and clinical heterogeneity, with 52 causative genes known to date. Here, we developed a comprehensive next-generation sequencing (NGS) approach for the clinical molecular diagnostics of RP. All known inherited retinal disease genes (n = 111) were captured and simultaneously analyzed using NGS in 100 RP patients without a molecular diagnosis. A systematic data analysis pipeline was developed and validated to prioritize and predict the pathogenicity of all genetic variants identified in each patient, which enabled us to reduce the number of potential pathogenic variants from approximately 1,200 to zero to nine per patient. Subsequent segregation analysis and in silico predictions of pathogenicity resulted in a molecular diagnosis in 36 RP patients, comprising 27 recessive, six dominant, and three X-linked cases. Intriguingly, De novo mutations were present in at least three out of 28 isolated cases with causative mutations. This study demonstrates the enormous potential and clinical utility of NGS in molecular diagnosis of genetically heterogeneous diseases such as RP. De novo dominant mutations appear to play a significant role in patients with isolated RP, having major implications for genetic counselling. PMID:22334370

  17. 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 important role in identifying testing requirements which are infeasible. This is especially true for data flow testing and modified condition/decision coverage. Our system uses in an essential way symbolic analysis and theorem proving technology, and we believe this work represents one of the few successful uses of a theorem prover working in a completely automatic fashion to solve a problem of practical interest. We believe this work anticipates an important trend away from purely syntactic-based methods for program analysis to semantic methods based on symbolic processing and inference technology. Other results demonstrating the practical use of automatic inference is being reported in hardware verification, although there are significant differences between the hardware work and ours. However, what is common and important is that general purpose theorem provers are being integrated with more special-purpose decision procedures to solve problems in analysis and verification. We are pursuina commercial opportunities for this work, and will use and extend the work in other projects we are engaged in. Ultimately we would like to rework the system to analyze C, C++, or Java as a key step toward commercialization.

  18. Modelling the time-keeping function of the central pattern generator for locomotion using artificial sequential neural network.

    PubMed

    Prentice, S D; Patla, A E; Stacey, D A

    1995-05-01

    The paper investigates the ability of a sequential neural network to model the time-keeping function (fundamental frequency oscillation) of a central pattern generator for locomotion. The intention is not to strive for biological fidelity, but rather to ensure that the network obeys the organisational and operational principles of central pattern generators developed through empirical research. The timing function serves to produce the underlying locomotor rhythm which can be transformed by nonlinear static shaping functions to construct the necessary locomotor activation patterns. Using two levels of tonic activations in the form of a step increase, a network consisting of nine processing units was successfully trained to output both sine and cosine waveforms, whose frequencies were modified in response to the level of input activation. The network's ability to generalise was demonstrated by appropriately scaling the frequency of oscillation in response to a range of input amplitudes, both within and outside the values on which it was trained. A notable and fortunate result was the model's failure to oscillate in the absence of input activation, which is a necessary property of the CPG model. It was further demonstrated that the oscillation frequency of the output waveforms exhibited both a high temporal stability and a very low sensitivity to input noise. The results indicate that the sequential neural network is a suitable candidate to model the time-keeping functions of the central pattern generator for locomotion. PMID:7475369

  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. UML for Validation: Experimenting Automatic Test Generation for Flight Software Validation

    NASA Astrophysics Data System (ADS)

    Hyounet, P.; Pouly, J.

    2009-05-01

    UML for validation is a CNES study that aims at prototyping and experimenting automatic test generation technologies in the context of a model- based approach applied to on-board software development and tests. Starting from real test cases and test procedures taken from a state-of-the-art onboard software, we first applied a reverse engineering methodology to obtain an augmented software specification model, i.e. ready to support automated test generation. In parallel, we defined and prototyped a test generation tool using innovative model-based technologies based on EMF (Eclipse Modeling Framework). Finally, a representative end-to-end experiment was performed to evaluate the benefit of such technologies .

  1. 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.

  2. Generating custom test plans for CASE{sup *}Dictionary 5.0

    SciTech Connect

    Atkins, K.D. [Boeing Computer Services, Richland, WA (United States)

    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.

  3. Electronic speckle pattern interferometric testing of JWST primary mirror segment assembly

    NASA Astrophysics Data System (ADS)

    Smith, Koby Z.; Chaney, David M.; Saif, Babak N.

    2011-09-01

    The James Webb Space Telescope (JWST) Primary Mirror Segment Assembly (PMSA) was required to meet NASA Technology Readiness Level (TRL) 06 requirements in the summer of 2006. These TRL06 requirements included verifying all mirror technology systems level readiness in simulated end-to-end operating conditions. In order to support the aggressive development and technology readiness schedule for the JWST Primary Mirror Segment Assembly (PMSA), a novel approach was implemented to verify the nanometer surface figure distortion effects on an in-process non-polished beryllium mirror surface. At the time that the TRL06 requirements needed to be met, a polished mirror segment had not yet been produced that could have utilized the baselined interferometric optical test station. The only JWST mirror segment available was a finished machined segment with an acid-etched optical surface. Therefore an Electronic Speckle Pattern Interferometer (ESPI) was used in coordination with additional metrology techniques to perform interferometric level optical testing on a non-optical surface. An accelerated, rigorous certification program was quickly developed for the ESPI to be used with the unfinished optical surface of the primary mirror segment. The ESPI was quickly implemented into the PMSA test program and optical testing was very successful in quantifying the nanometer level surface figure deformation changes in the PMSA due to assembly, thermal cycling, vibration, and acoustic testing. As a result of the successful testing, the PMSA passed all NASA TRL06 readiness requirements.

  4. Generating Sexually Differentiated Vocal Patterns: Laryngeal Nerve and EMG Recordings from Vocalizing Male and Female African

    E-print Network

    Kelley, Darcy B.

    by asynchronous activity of motoneurons, a pattern shared with vocal production in females. We suggest that these distinct neuronal activity patterns in males may be subserved by two populations of motor units in males in assigning sex-specific acoustic features to brain nuclei or motor nerves has been achieved in songbirds

  5. Exhaustive Generation and Visual Browsing for Radiation Patterns of Linear Array Antennas

    Microsoft Academic Search

    Darren Leigh; Tom Lanning; Neal Lesh; Kathy Ryall

    2004-01-01

    Almost any obtainable radiation pattern can be achieved with a phased array antenna if the phases and amplitudes are chosen correctly. However, if these are quantized, it can be a time consuming and difficult process for a human expert to determine the best Quantized excitation coefficients to produce a desired radiation pattern. In this paper, we explore the use of

  6. A Search Based Automated Test-Data Generation Framework for Safety-Critical Systems

    Microsoft Academic Search

    Nigel Tracey; John Clark; John McDermid; Keith Mander

    2002-01-01

    This paper presents the results of a three year research program to develop an auto- mated test-data generation framework to support the testing of safety-critical software systems. The generality of the framework comes from the exploitation of domain inde- pendent search techniques, allowing new test criteria to be addressed by constructing functions that quantify the suitability of test-data against the

  7. Plant species richness belowground: higher richness and new patterns revealed by next-generation sequencing.

    PubMed

    Hiiesalu, Inga; Opik, Maarja; Metsis, Madis; Lilje, Liisa; Davison, John; Vasar, Martti; Moora, Mari; Zobel, Martin; Wilson, Scott D; Pärtel, Meelis

    2012-04-01

    Variation in plant species richness has been described using only aboveground vegetation. The species richness of roots and rhizomes has never been compared with aboveground richness in natural plant communities. We made direct comparisons of grassland plant richness in identical volumes (0.1 × 0.1 × 0.1 m) above and below the soil surface, using conventional species identification to measure aboveground richness and 454 sequencing of the chloroplast trnL(UAA) intron to measure belowground richness. We described above- and belowground richness at multiple spatial scales (from a neighbourhood scale of centimetres to a community scale of hundreds of metres), and related variation in richness to soil fertility. Tests using reference material indicated that 454 sequencing captured patterns of species composition and abundance with acceptable accuracy. At neighbourhood scales, belowground richness was up to two times greater than aboveground richness. The relationship between above- and belowground richness was significantly different from linear: beyond a certain level of belowground richness, aboveground richness did not increase further. Belowground richness also exceeded that of aboveground at the community scale, indicating that some species are temporarily dormant and absent aboveground. Similar to other grassland studies, aboveground richness declined with increasing soil fertility; in contrast, the number of species found only belowground increased significantly with fertility. These results indicate that conventional aboveground studies of plant richness may overlook many coexisting species, and that belowground richness becomes relatively more important in conditions where aboveground richness decreases. Measuring plant belowground richness can considerably alter perceptions of biodiversity and its responses to natural and anthropogenic factors. PMID:22168247

  8. 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.

  9. 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.

  10. Bearing options, including design and testing, for direct drive linear generators in wave energy converters 

    E-print Network

    Caraher, Sarah

    2011-11-22

    The key focus of this research was to investigate the bearing options most suited to operation in a novel direct drive linear generator. This was done through bearing comparisons, modelling and testing. It is fundamental ...

  11. An enhanced algorithm for protocol conformance test sequence generation based on the UIO method

    E-print Network

    Allada, Ravindra

    1993-01-01

    in protocol conformance test generation", Manuscript, Dept. of Computer Science, University of Maryland, College Park, 1990. 41 [9] J. A. Bondy, U. S. R Murty, Graph Theory with Applications, North-Holland, New York, 1984. [10] Cormen, Leiserson, Rivest...

  12. Cube corner retroreflector test and analysis. [of laser far field diffraction pattern

    NASA Technical Reports Server (NTRS)

    Zurasky, J. L.

    1976-01-01

    Cube corner retroreflectors with nominal dihedral angles of 90 deg 0 min 1.5 sec were fabricated, tested, and analyzed to determine the return energy in the annular ring of the far field diffraction pattern required by the Laser Geodynamic Satellite. Performance was assessed for variations in the dihedral angles, optical surfaces, and thermal environment. Despite relatively high independent axial and radial sensitivities, the changes caused by the anticipated thermal environment were found to be negligible; however, there were substantial variations between the analytical predictions and measured performance.-

  13. Validation of the step test method for generating Haigh diagrams for Ti–6Al–4V

    Microsoft Academic Search

    Richard S. Bellows; Sandeep Muju; Theodore Nicholas

    1999-01-01

    Step testing provides a method for generating an endurance stress for a particular stress ratio with a single specimen as well as a method of generating endurance limits for one-of-a-kind specimens, e.g. specimens that may have been subjected to pre-test damage that cannot be accurately reproduced. The objective of this paper was to determine the statistical validity of the step

  14. Pattern-based generation to augment EMF editors with business rules, materialized views, statecharts,

    E-print Network

    Moeller, Ralf

    , statecharts, transaction demarcation, ORM persistence, and GUI generation hints Miguel Garcia Software.a Problem statement demarcation, ORM persistence, and GUI generation hints. The interaction between these capabilities is taken

  15. Fundamental characteristics of test facility for micro hydroelectric power generation system

    Microsoft Academic Search

    T. Sakurai; H. Funato; S. Ogasawara

    2009-01-01

    This paper proposes a test facility for micro hydraulic generation system. Micro hydraulic generation system is very difficult to exam their characteristics including hydraulic turbine because water flow in various conditions is necessary but it is very difficult to realize in laboratory. In this paper water flow is realized using general purpose pump that can add pressure to water flow

  16. A load history generation approach for full-scale accelerated fatigue tests

    Microsoft Academic Search

    J. J. Xiong; R. A. Shenoi

    2008-01-01

    This paper seeks to establish a load history generation approach for full-scale accelerated fatigue tests. Primary focus is placed on the load cycle identification such as to minimize experimental time while having no significant effects on the new generated load history. The load cycles extracted from an original load history are identified into three kinds of cycles namely main, secondary

  17. 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.

  18. Vocal behavior and vocal central pattern generator organization diverge among toadfishes.

    PubMed

    Chagnaud, Boris P; Bass, Andrew H

    2014-01-01

    Among fishes, acoustic communication is best studied in toadfishes, a single order and family that includes species commonly known as toadfish and midshipman. However, there is a lack of comparative anatomical and physiological studies, making it difficult to identify both shared and derived mechanisms of vocalization among toadfishes. Here, vocal nerve labeling and intracellular in vivo recording and staining delineated the hindbrain vocal network of the Gulf toadfish Opsanus beta. Dextran-biotin labeling of the vocal nerve or intracellular neurobiotin fills of motoneurons delineated a midline vocal motor nucleus (VMN). Motoneurons showed bilaterally extensive dendritic arbors both within and lateral to the paired motor nuclei. The motoneuron activity matched that of the spike-like vocal nerve motor volley that determines the natural call duration and frequency. Ipsilateral vocal nerve labeling with biocytin or neurobiotin yielded dense bilateral transneuronal filling of motoneurons and coextensive columns of premotor neurons. These premotor neurons generated pacemaker-like action potentials matched 1:1 with vocal nerve and motoneuron firing. Transneuronal transport further revealed connectivity within and between the pacemaker-motor circuit and a rostral prepacemaker nucleus. Unlike the pacemaker-motor circuit, prepacemaker firing did not match the frequency of vocal nerve activity but instead was predictive of the duration of the vocal nerve volley that codes for call duration. Transneuronally labeled terminal-like boutons also occurred in auditory-recipient hindbrain nuclei, including neurons innervating the inner ear and lateral line organs. Together with studies of midshipman, we propose that separate premotor populations coding vocal frequency and duration with direct premotor coupling to auditory-lateral line nuclei are plesiomorphic characters for toadfishes. Unlike in midshipman, transneuronal labeling in toadfishes reveals an expansive column of pacemaker neurons that is weakly coupled to prepacemaker neurons, a character that likely depends on the extent of gap junction coupling. We propose that these and other anatomical characters contribute to neurophysiological properties that, in turn, sculpt the species-typical patterning of frequency and amplitude-modulated vocalizations. PMID:25115796

  19. Implementing a Generative Urban Design Model: Grammar-based design patterns for urban design

    Microsoft Academic Search

    J. N. Beirao; G. Mendes; J. Duarte; R. M. F. Stouffs

    2010-01-01

    This paper shows the first results of a prototype implementation of a generative urban design tool. This implementation will form part of a design support tool for a GIS based platform defined to formulate, generate and evaluate urban designs. These three goals, formulation, generation and evaluation are integrated by connecting three modules developed individually for each goal. In this paper

  20. 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

  1. 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.

  2. Low-capture-power test generation for scan-based at-speed testing

    Microsoft Academic Search

    Xiaoqing Wen; Yoshiyuki Yamashita; Shohei Morishima; Seiji Kajihara; Laung-Terng Wang; Kewal K. Saluja; Kozo Kinoshita

    2005-01-01

    Scan-based at-speed testing is a key technology to guarantee timing-related test quality in the deep submicron era. However, its applicability is being severely challenged since significant yield loss may occur from circuit malfunction due to excessive IR drop caused by high power dissipation when a test response is captured. This paper addresses this critical problem with a novel low-capture-power X-filling

  3. Brain activation patterns elicited by the 'Faces Symbol Test' -- a pilot fMRI study.

    PubMed

    Grabner, Rh; Popotnig, F; Ropele, S; Neuper, C; Gorani, F; Petrovic, K; Ebner, F; Strasser-Fuchs, S; Fazekas, F; Enzinger, C

    2008-04-01

    The Faces Symbol Test (FST) has recently been proposed as a brief and patient-friendly screening instrument for the assessment of cognitive dysfunction in patients with multiple sclerosis (MS). However, in contrast to well-established MS screening tests such as the Paced Auditory Serial Addition Test, the neural correlates of the FST have not been investigated so far. In the present study, we developed a functional MRI (fMRI) version of the FST to provide first data on brain regions and networks involved in this test. A sample of 19 healthy participants completed a version of the FST adapted for fMRI, requiring matching of faces and symbols in a multiple choice test and two further experimental conditions drawing on cognitive subcomponents (face matching and symbol matching). Imaging data showed a differential involvement of a fronto-parieto-occipital network in the three conditions. The most demanding FST condition elicited brain activation patterns related with sustained attention and executive control. These results suggest that the FST recruits brain networks critical for higher-order cognitive functions often impaired in MS patients. PMID:18208887

  4. Disparity index: a simple statistic to measure and test the homogeneity of substitution patterns between molecular sequences.

    PubMed Central

    Kumar, S; Gadagkar, S R

    2001-01-01

    A common assumption in comparative sequence analysis is that the sequences have evolved with the same pattern of nucleotide substitution (homogeneity of the evolutionary process). Violation of this assumption is known to adversely impact the accuracy of phylogenetic inference and tests of evolutionary hypotheses. Here we propose a disparity index, ID, which measures the observed difference in evolutionary patterns for a pair of sequences. On the basis of this index, we have developed a Monte Carlo procedure to test the homogeneity of the observed patterns. This test does not require a priori knowledge of the pattern of substitutions, extent of rate heterogeneity among sites, or the evolutionary relationship among sequences. Computer simulations show that the ID-test is more powerful than the commonly used chi2-test under a variety of biologically realistic models of sequence evolution. An application of this test in an analysis of 3789 pairs of orthologous human and mouse protein-coding genes reveals that the observed evolutionary patterns in neutral sites are not homogeneous in 41% of the genes, apparently due to shifts in G + C content. Thus, the proposed test can be used as a diagnostic tool to identify genes and lineages that have evolved with substantially different evolutionary processes as reflected in the observed patterns of change. Identification of such genes and lineages is an important early step in comparative genomics and molecular phylogenetic studies to discover evolutionary processes that have shaped organismal genomes. PMID:11454778

  5. 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

  6. Awk Pattern-Procedure Test from Gilly D. et al., UNIX in a Nutshell, O'Reilly, 1986

    E-print Network

    Cerveny, Vlastislav

    Awk Pattern-Procedure Test from Gilly D. et al., UNIX in a Nutshell, O'Reilly, 1986 Print first field of each line: Print all lines that contain pattern: Print first field of lines that contain to a blank line: Print fields 2 and 3 in switched order, but only on lines whose first field matches

  7. A Quantitative Test of Population Genetics Using Spatio-Genetic Patterns in Bacterial Colonies

    E-print Network

    Korolev, Kirill S; Nelson, David R; Foster, Kevin R; 10.1086/661897

    2011-01-01

    It is widely accepted that population genetics theory is the cornerstone of evolutionary analyses. Empirical tests of the theory, however, are challenging because of the complex relationships between space, dispersal, and evolution. Critically, we lack quantitative validation of the spatial models of population genetics. Here we combine analytics, on and off-lattice simulations, and experiments with bacteria to perform quantitative tests of the theory. We study two bacterial species, the gut microbe Escherichia coli and the opportunistic pathogen Pseudomonas aeruginosa, and show that spatio-genetic patterns in colony biofilms of both species are accurately described by an extension of the one-dimensional stepping-stone model. We use one empirical measure, genetic diversity at the colony periphery, to parameterize our models and show that we can then accurately predict another key variable: the degree of short-range cell migration along an edge. Moreover, the model allows us to estimate other key parameters in...

  8. What Is Web 2.0: Design Patterns and Business Models for the Next Generation of Software

    Microsoft Academic Search

    Tim O'Reilly

    2007-01-01

    was the first initiative to try to define Web 2.0 and understand its implications for the next generation of software, looking at both design patterns and business modes. Web 2.0 is the network as platform, spanning all connected devices; Web 2.0 applications are those that make the most of the intrinsic advantages of that platform: delivering software as a continually-updated

  9. 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…

  10. Pattern-mixture-type Estimation and Testing of Neuroblastoma Treatment Regimes

    PubMed Central

    Tang, Xinyu; Wahed, Abdus S.

    2014-01-01

    Sequentially randomized designs are commonly used in biomedical research, particularly in clinical trials, to assess and compare the effects of different treatment regimes. In such designs, eligible patients are first randomized to one of the initial therapies, then patients with some intermediate response (e.g. without progressive diseases) are randomized to one of the maintenance therapies. The goal is to evaluate dynamic treatment regimes consisting of an initial therapy, the intermediate response, and a maintenance therapy. In this article, we demonstrate the use of pattern-mixture model (commonly used for analyzing missing data) for estimating the effects of treatment regimes based on familiar survival analysis techniques such as Nelson-Aalen and parametric models. Moreover, we demonstrate how to use estimates from pattern-mixture models to test for the differences across treatment regimes in a weighted log-rank setting. We investigate the properties of the proposed estimators and test in a Monte Carlo simulation study. Finally we demonstrate the methods using the long-term survival data from the high risk neuroblastoma study. PMID:25750601

  11. Wave Pattern Peculiarities of Different Types of Explosions Conducted at Semipalatinsk Test Site

    NASA Astrophysics Data System (ADS)

    Sokolova, Inna

    2014-05-01

    The historical seismograms of the explosions conducted at the STS in 1949 - 1989 are of great interest for the researchers in the field of monitoring. Large number of air (86), surface (30) and underground nuclear explosions were conducted here in boreholes and tunnels (340). In addition to nuclear explosions, large chemical explosions were conducted at the Test Site. It is known that tectonic earthquakes occur on the Test Site territory and near it. Since 2005 the Institute of Geophysical Researches conducts works on digitizing the historical seismograms of nuclear explosions. Currently, the database contains more than 6000 digitized seismograms of nuclear explosions used for investigative monitoring tasks, major part of them (4000) are events from the STS region. Dynamic parameters of records of air, surface and underground nuclear explosions, as well as large chemical explosions with compact charge laying were investigated for seismic stations located on the territory of Kazakhstan using digitized records of the STS events. In addition, the comparison between salvo wave pattern and single explosions was conducted. The records of permanent and temporary seismic stations (epicentral distances range 100 - 800 km) were used for the investigations. Explosions spectra were analyzed, specific features of each class of events were found. The seismograms analysis shows that the wave pattern depends significantly on the explosion site and on the source type.

  12. Correlation between Different Patterns of Hypo-Osmotic Swelling and Sperm Functional Tests

    PubMed Central

    Bassiri, Farzaneh; Tavalaee, Marziyeh; Nasr Esfahani, Mohammad Hossein

    2013-01-01

    Background: Sperm membrane integrity is not only important as a barrier between intra- and extra-cellular spaces, but also it can be considered as a sign of DNA integrity. Hypoosmotic swelling test reflects membrane integrity and has been used to evaluate sperm quality. Intracytoplasmic sperm injection (ICSI) in adjunct with hypo-osmotic swelling test (HOST) has been used for treatment of males with asthenozoospermia. Therefore, this study aims to evaluate correlation of different pattern of HOST with sperm parameters, protamine deficiency and apoptosis. Materials and Methods: In this case-control study, sixteen semen samples were randomly collected from infertile normozospermic men. Semen samples were divided into two portions as follows: one portion was assessed for sperm parameters according toWorld Health Organization (WHO)-2010, while the other portion, after applying HOST procedure, was used for assessment of sperm morphology, protamine deficiency and late or early apoptosis. Statistical analysis was carried out using the Statistical Package for the Social Studies (SPSS 11.5). Results: Our results showed that, the lowest odds ratio (OR) of abnormal sperm head morphology and abnormal acrosome was in d-sperm as compared to a-pattern or nonviable spermatozoa (p=0.00, p=0.01). In addition, a significant correlation was observed between d-sperm with sperm concentration and percentage of DNA damage (p=0.03 and p=0.04, respectively). A significant correlation was observed between percentage of sperm motility and DNA fragmentation (r=-0.56; p=0.01). Furthermore, significant correlations were observed between percentages of early apoptotic sperm with protamine deficiency and sperm concentration (p=0.009 and p=0.01, respectively). Conclusion: Significant correlations exist between d-pattern and sperm DNA integrity. Semen samples with low sperm concentration have low percentage of d-sperm which are mature and intact sperms. PMID:24520486

  13. Wind Turbine Generator System Safety and Function Test Report for the Entegrity EW50 Wind Turbine

    SciTech Connect

    Smith, J.; Huskey, A.; Jager, D.; Hur, J.

    2012-11-01

    This report summarizes the results of a safety and function test that NREL conducted on the Entegrity EW50 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

  14. Wind Turbine Generator System Safety and Function Test Report for the Ventera VT10 Wind Turbine

    SciTech Connect

    Smith, J.; Huskey, A.; Jager, D.; Hur, J.

    2012-11-01

    This report summarizes the results of a safety and function test that NREL conducted on the Ventera VT10 wind turbine. This test was conducted in accordance with the International Electrotechnical Commissions' (IEC) standard, Wind Turbine Generator System Part 2: Design requirements for small wind turbines, IEC 61400-2 Ed.2.0, 2006-03.

  15. Description and test results of a variable speed, constant frequency generating system

    NASA Technical Reports Server (NTRS)

    Brady, F. J.

    1985-01-01

    The variable-speed, constant frequency generating system developed for the Mod-0 wind turbine is presented. This report describes the system as it existed at the conclusion of the project. The cycloconverter control circuit is described including the addition of field-oriented control. The laboratory test and actual wind turbine test results are included.

  16. Short Time Rated And Protected High Voltage Ac Testing Of Generator Stators Using Parallel Resonant Circuits

    Microsoft Academic Search

    Wade Enright; Pat Bodger

    Power station generators require short duration HV ac testing of their insulation as part of their acceptance before being put into service. Depending on the value of the capacitance of the insulation, the rating of the test power supply can be large. One method of reducing this supply requirement is to compensate the capacitance with inductance. The paper describes a

  17. Modeling heat generation and flow in the Advanced Neutron Source Corrosion Test Loop specimen

    Microsoft Academic Search

    R. E. Pawel; D. W. Yarbrough

    1988-01-01

    A finite difference computer code HEATING5 was used to model heat generation and flow in a typical experiment envisioned for the Advanced Neutron Source Corrosion Test Loop. The electrical resistivity and thermal conductivity of the test specimen were allowed to vary with local temperature, and the corrosion layer thickness was assigned along the length of the specimen in the manner

  18. Diagnostic Test Generation for silicon diagnosis with an incremental learning framework based on search state compatibility

    Microsoft Academic Search

    Maheshwar Chandrasekar; Michael S. Hsiao

    2009-01-01

    Silicon Diagnosis is the process of locating potential defect sites (candidates) in a defective chip. These candidates are then used as an aid during physical failure analysis. It is desired that the cardinality of the candidate set returned by silicon diagnosis be as small as possible. To this end, effective test patterns that can distinguish many faults in the candidate

  19. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  20. SRG110 Stirling Generator Dynamic Simulator Vibration Test Results and Analysis Correlation

    NASA Technical Reports Server (NTRS)

    Suarez, Vicente J.; Lewandowski, Edward J.; Callahan, John

    2006-01-01

    The U.S. Department of Energy (DOE), Lockheed Martin (LM), and NASA Glenn Research Center (GRC) have been developing the Stirling Radioisotope Generator (SRG110) for use as a power system for space science missions. The launch environment enveloping potential missions results in a random input spectrum that is significantly higher than historical RPS launch levels and is a challenge for designers. Analysis presented in prior work predicted that tailoring the compliance at the generator-spacecraft interface reduced the dynamic response of the system thereby allowing higher launch load input levels and expanding the range of potential generator missions. To confirm analytical predictions, a dynamic simulator representing the generator structure, Stirling convertors and heat sources was designed and built for testing with and without a compliant interface. Finite element analysis was performed to guide the generator simulator and compliant interface design so that test modes and frequencies were representative of the SRG110 generator. This paper presents the dynamic simulator design, the test setup and methodology, test article modes and frequencies and dynamic responses, and post-test analysis results. With the compliant interface, component responses to an input environment exceeding the SRG110 qualification level spectrum were all within design allowables. Post-test analysis included finite element model tuning to match test frequencies and random response analysis using the test input spectrum. Analytical results were in good overall agreement with the test results and confirmed previous predictions that the SRG110 power system may be considered for a broad range of potential missions, including those with demanding launch environments.

  1. NOX4 activity is determined by mRNA levels and reveals a unique pattern of ROS generation

    PubMed Central

    Serrander, Lena; Cartier, Laetitia; Bedard, Karen; Banfi, Botond; Lardy, Bernard; Plastre, Olivier; Sienkiewicz, Andrzej; Fórró, Lászlo; Schlegel, Werner; Krause, Karl-Heinz

    2007-01-01

    NOX4 is an enigmatic member of the NOX (NADPH oxidase) family of ROS (reactive oxygen species)-generating NADPH oxidases. NOX4 has a wide tissue distribution, but the physiological function and activation mechanisms are largely unknown, and its pharmacology is poorly understood. We have generated cell lines expressing NOX4 upon tetracycline induction. Tetracycline induced a rapid increase in NOX4 mRNA (1 h) followed closely (2 h) by a release of ROS. Upon tetracycline withdrawal, NOX4 mRNA levels and ROS release decreased rapidly (<24 h). In membrane preparations, NOX4 activity was selective for NADPH over NADH and did not require the addition of cytosol. The pharmacological profile of NOX4 was distinct from other NOX isoforms: DPI (diphenyleneiodonium chloride) and thioridazine inhibited the enzyme efficiently, whereas apocynin and gliotoxin did not (IC50>100 ?M). The pattern of NOX4-dependent ROS generation was unique: (i) ROS release upon NOX4 induction was spontaneous without need for a stimulus, and (ii) the type of ROS released from NOX4-expressing cells was H2O2, whereas superoxide (O2?) was almost undetectable. Probes that allow detection of intracellular O2? generation yielded differential results: DHE (dihydroethidium) fluorescence and ACP (1-acetoxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine) ESR measurements did not detect any NOX4 signal, whereas a robust signal was observed with NBT. Thus NOX4 probably generates O2? within an intracellular compartment that is accessible to NBT (Nitro Blue Tetrazolium), but not to DHE or ACP. In conclusion, NOX4 has a distinct pharmacology and pattern of ROS generation. The close correlation between NOX4 mRNA and ROS generation might hint towards a function as an inducible NOX isoform. PMID:17501721

  2. An abnormal pattern of multiple platelet function abnormalities and increased thromboxane generation in patients with primary thrombocytosis and thrombotic complications.

    PubMed

    Zahavi, J; Zahavi, M; Firsteter, E; Frish, B; Turleanu, R; Rachmani, R

    1991-11-01

    Platelet aggregation (PA) induced by ADP, collagen and epinephrine, plasma levels of beta-thromboglobulin (beta TG) and thromboxane B2 (TXB2) and serum TXB2 generation were studied in 11 patients with primary thrombocytosis (7 with essential thrombocythaemia and 4 with polycythaemia vera) and compared with 16 healthy subjects. 5 patients suffered from peripheral vascular ischaemia and another 3 had venous thrombosis, but none had bleeding complications. The patients showed an abnormal pattern of platelet function and of thromboxane generation distinct from the healthy subjects in three aspects. a) Shape change was 5-26 times greater, the lag-time of collagen PA was 2.3-2.9 times longer and the extent of epinephrine PA was nil or very low. ADP- or collagen-induced PA was also reduced (p less than 0.02). b) Plasma TXB2 generation (corrected to a normal platelet concentration) stimulated by the three PA inducers was within the range of the healthy subjects in spite of the reduced extent of PA. c) Plasma beta TG level and serum TXB2 generation (both corrected to a normal platelet concentration) were 2.9-7.1 times higher (p less than 0.001) indicating enhanced in vivo platelet activation and possibly increased thrombin generation. These abnormalities were not detected in another 4 patients with secondary thrombocytosis. The abnormal pattern of platelet function and thromboxane generation can be a useful laboratory method in the evaluation of patients with primary thrombocytosis. It might also explain the thrombotic complications which occurred in 8 of the patients in a manner such that increased or normal TXB2 generation overcomes the reduced extent of PA. In this respect, the pronounced serum TXB2 synthesis might be a marker of intravascular thrombosis. PMID:1836999

  3. Pattern recognition approaches for the detection and characterization of discontinuities by eddy current testing

    SciTech Connect

    Shyamsunder, M.T.; Rajagopalan, C.; Raj, B.; Dewangan, S.K.; Rao, B.P.C.; Ray, K.K.

    2000-01-01

    Eddy current signals (ECS) generated under varied experimental conditions from different types of discontinuities like partial/through thickness holes and notches of various dimensions, fatigue cracks, stress corrosion cracks, etc. in AISI type 316 stainless steel sheets/plates have been analyzed using pattern recognition (PR) approaches to understand their quality of performance for detection and characterization of several aspects of the discontinuities. The PR analyses have been carried out using linear discriminant (LD), minimum distance (MD), empirical Bayesian (EB) and K-nearest neighbor (KNN) statistical classifiers, and multilayered perceptron (MLP) and Kohonen's artificial neural network (KANN). The MLP approach has been extended to eddy current images also to achieve deblurring. The practical feasibility and application potential of ANNs is demonstrated through a case study on nuclear fuel cladding tubes where both the online and the offline approaches have been implemented.

  4. Digital test signal generation: An accurate SNR calibration approach for the DSN

    NASA Technical Reports Server (NTRS)

    Gutierrez-Luaces, B. O.

    1991-01-01

    A new method of generating analog test signals with accurate signal to noise ratios (SNRs) is described. High accuracy will be obtained by simultaneous generation of digital noise and signal spectra at a given baseband or bandpass limited bandwidth. The digital synthesis will provide a test signal embedded in noise with the statistical properties of a stationary random process. Accuracy will only be dependent on test integration time with a limit imposed by the system quantization noise (expected to be 0.02 dB). Setability will be approximately 0.1 dB. The first digital SNR generator to provide baseband test signals is being built and will be available in early 1991.

  5. Evaluation of novel second-generation RSV and influenza rapid tests at the point of care.

    PubMed

    Tuttle, Ryan; Weick, Anja; Schwarz, Wiebke Sabrina; Chen, Xi; Obermeier, Patrick; Seeber, Lea; Tief, Franziska; Muehlhans, Susann; Karsch, Katharina; Peiser, Christian; Duwe, Susanne; Schweiger, Brunhilde; Rath, Barbara

    2015-03-01

    Acute respiratory infections represent common pediatric emergencies. Infection control warrants immediate and accurate diagnoses. In the past, first-generation respiratory syncytial virus (RSV) rapid tests (strip tests) have shown suboptimal sensitivities. In 2013, the Food and Drug Administration licensed a second-generation RSV rapid test providing user-independent readouts (SOFIA™-RSV) using automated fluorescence assay technology known to yield superior results with influenza rapid testing. We are reporting the first point-of-care evaluation of the SOFIA™-RSV rapid test. In the Charité Influenza-Like Disease Cohort, 686 nasopharyngeal samples were tested in parallel with SOFIA™-RSV and SOFIA™-Influenza A+B. Compared to real-time PCR, SOFIA™-RSV sensitivities/specificities were 78.6%/93.9%, respectively (SOFIA™-Influenza A: 80.6%/99.3%). Performance was greatest in patients below 2years of age with a test sensitivity of 81.8%. RSV sensitivities were highest (85%) in the first 2days of illness and with nasopharyngeal compared to nasal swabs (P=0.055, McNemar's test). Second-generation RSV and influenza rapid testing provides highly accurate results facilitating timely patient cohortation and management. PMID:25583129

  6. Testing of solid-oxide fuel cells for micro to macro power generation

    SciTech Connect

    Graffm R; Hayes, J; Jankowski, A; Morse, J

    1999-05-01

    Thin film, solid-oxide fuel cells (TFSOFCs) are developed using photolithographic patterning and physical vapor deposition. In this study, both electrode layers of nickel (Ni) and silver (Ag) as well as the solid- oxide electrolyte layer of yttria-stabilized zirconia (YSZ) are synthesized on the micrometer scale for thickness. The anode layer enables combination of the reactive gases, is conductive to pass the electric current, and provides mechanical support to the electrolyte and cathode layers. The morphology desired for both the anode and cathode layers facilitates generation of maximum current density from the fuel cell. For these purposes, the parameters of the deposition process and post- deposition patterning are optimized for continuous porosity across both electrode layers. The electrodes are characterized using scanning electron microscopy and the power output generated through current-voltage measurement. We find that a TFSOFC based on Ni-YSZ-Ag can be operate d with dilute fuel mixtures at temperatures below 300 C.

  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. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  9. Predicting Slag Generation in Sub-Scale Test Motors Using a Neural Network

    NASA Technical Reports Server (NTRS)

    Wiesenberg, Brent

    1999-01-01

    Generation of slag (aluminum oxide) is an important issue for the Reusable Solid Rocket Motor (RSRM). Thiokol performed testing to quantify the relationship between raw material variations and slag generation in solid propellants by testing sub-scale motors cast with propellant containing various combinations of aluminum fuel and ammonium perchlorate (AP) oxidizer particle sizes. The test data were analyzed using statistical methods and an artificial neural network. This paper primarily addresses the neural network results with some comparisons to the statistical results. The neural network showed that the particle sizes of both the aluminum and unground AP have a measurable effect on slag generation. The neural network analysis showed that aluminum particle size is the dominant driver in slag generation, about 40% more influential than AP. The network predictions of the amount of slag produced during firing of sub-scale motors were 16% better than the predictions of a statistically derived empirical equation. Another neural network successfully characterized the slag generated during full-scale motor tests. The success is attributable to the ability of neural networks to characterize multiple complex factors including interactions that affect slag generation.

  10. FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

    2003-06-01

    In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to commercialization for the gas generator technology developed in this program.

  11. COFI-tree Mining: A New Approach to Pattern Growth with Reduced Candidacy Generation

    E-print Network

    Zaiane, Osmar R.

    , clever pruning reduces the search space drastically. Finally, a sim- ple and non-recursive mining process that counts on the fre- quent pattern discovery is the market basket analysis. In most cases when the support of a clever pruning technique based on an interesting property drawn from our top-down approach, and some

  12. The negative cascade of incongruent generative study-test processing in memory and metacomprehension.

    PubMed

    Thomas, Ayanna Kim; McDaniel, Mark A

    2007-06-01

    Previous research suggests that when participants engage in generative study activities, the processing of text is enhanced and improvements in memory and metacomprehension result. However, few studies have investigated the influence of processes required by the testing situation or the interaction between encoding and retrieval processes on metacomprehension accuracy. The present experiments examine whether the congruency of processes generated during study and required at retrieval affect memory, metacomprehension, and control processes. Study orientation and test type were congruent (i.e., letter-reinsertion: detailed test), incongruent (i.e., letter-reinsertion: conceptual test), or neutral (i.e., read: conceptual test). After generative study, but before testing, participants made metacomprehension predictions for previously studied texts. Controlled strategy selection was measured in Experiment 2. When processes at study and test were congruent, cued recall performance and metacomprehension predictions were more accurate than when study and test were incongruent. For incongruent conditions, metacomprehension predictions were no better than chance; thus, controlled strategy selection was based on inaccurate metacomprehension, thereby further penalizing memory performance relative to congruent conditions. These findings extend a transfer-appropriate processing framework to metacomprehension. PMID:17848025

  13. Simple Process-Based Simulators for Generating Spatial Patterns of Habitat Loss and Fragmentation: A Review and Introduction to the G-RaFFe Model

    PubMed Central

    Pe'er, Guy; Zurita, Gustavo A.; Schober, Lucia; Bellocq, Maria I.; Strer, Maximilian; Müller, Michael; Pütz, Sandro

    2013-01-01

    Landscape simulators are widely applied in landscape ecology for generating landscape patterns. These models can be divided into two categories: pattern-based models that generate spatial patterns irrespective of the processes that shape them, and process-based models that attempt to generate patterns based on the processes that shape them. The latter often tend toward complexity in an attempt to obtain high predictive precision, but are rarely used for generic or theoretical purposes. Here we show that a simple process-based simulator can generate a variety of spatial patterns including realistic ones, typifying landscapes fragmented by anthropogenic activities. The model “G-RaFFe” generates roads and fields to reproduce the processes in which forests are converted into arable lands. For a selected level of habitat cover, three factors dominate its outcomes: the number of roads (accessibility), maximum field size (accounting for land ownership patterns), and maximum field disconnection (which enables field to be detached from roads). We compared the performance of G-RaFFe to three other models: Simmap (neutral model), Qrule (fractal-based) and Dinamica EGO (with 4 model versions differing in complexity). A PCA-based analysis indicated G-RaFFe and Dinamica version 4 (most complex) to perform best in matching realistic spatial patterns, but an alternative analysis which considers model variability identified G-RaFFe and Qrule as performing best. We also found model performance to be affected by habitat cover and the actual land-uses, the latter reflecting on land ownership patterns. We suggest that simple process-based generators such as G-RaFFe can be used to generate spatial patterns as templates for theoretical analyses, as well as for gaining better understanding of the relation between spatial processes and patterns. We suggest caution in applying neutral or fractal-based approaches, since spatial patterns that typify anthropogenic landscapes are often non-fractal in nature. PMID:23724108

  14. Simple process-based simulators for generating spatial patterns of habitat loss and fragmentation: a review and introduction to the G-RaFFe model.

    PubMed

    Pe'er, Guy; Zurita, Gustavo A; Schober, Lucia; Bellocq, Maria I; Strer, Maximilian; Müller, Michael; Pütz, Sandro

    2013-01-01

    Landscape simulators are widely applied in landscape ecology for generating landscape patterns. These models can be divided into two categories: pattern-based models that generate spatial patterns irrespective of the processes that shape them, and process-based models that attempt to generate patterns based on the processes that shape them. The latter often tend toward complexity in an attempt to obtain high predictive precision, but are rarely used for generic or theoretical purposes. Here we show that a simple process-based simulator can generate a variety of spatial patterns including realistic ones, typifying landscapes fragmented by anthropogenic activities. The model "G-RaFFe" generates roads and fields to reproduce the processes in which forests are converted into arable lands. For a selected level of habitat cover, three factors dominate its outcomes: the number of roads (accessibility), maximum field size (accounting for land ownership patterns), and maximum field disconnection (which enables field to be detached from roads). We compared the performance of G-RaFFe to three other models: Simmap (neutral model), Qrule (fractal-based) and Dinamica EGO (with 4 model versions differing in complexity). A PCA-based analysis indicated G-RaFFe and Dinamica version 4 (most complex) to perform best in matching realistic spatial patterns, but an alternative analysis which considers model variability identified G-RaFFe and Qrule as performing best. We also found model performance to be affected by habitat cover and the actual land-uses, the latter reflecting on land ownership patterns. We suggest that simple process-based generators such as G-RaFFe can be used to generate spatial patterns as templates for theoretical analyses, as well as for gaining better understanding of the relation between spatial processes and patterns. We suggest caution in applying neutral or fractal-based approaches, since spatial patterns that typify anthropogenic landscapes are often non-fractal in nature. PMID:23724108

  15. Comparison of the Commercial Color LCD and the Medical Monochrome LCD Using Randomized Object Test Patterns

    PubMed Central

    Wu, Jay; Wu, Tung H.; Han, Rou P.; Chang, Shu J.; Shih, Cheng T.; Sun, Jing Y.; Hsu, Shih M.

    2012-01-01

    Workstations and electronic display devices in a picture archiving and communication system (PACS) provide a convenient and efficient platform for medical diagnosis. The performance of display devices has to be verified to ensure that image quality is not degraded. In this study, we designed a set of randomized object test patterns (ROTPs) consisting of randomly located spheres with various image characteristics to evaluate the performance of a 2.5 mega-pixel (MP) commercial color LCD and a 3 MP diagnostic monochrome LCD in several aspects, including the contrast, resolution, point spread effect, and noise. The ROTPs were then merged into 120 abdominal CT images. Five radiologists were invited to review the CT images, and receiver operating characteristic (ROC) analysis was carried out using a five-point rating scale. In the high background patterns of ROTPs, the sensitivity performance was comparable between both monitors in terms of contrast and resolution, whereas, in the low background patterns, the performance of the commercial color LCD was significantly poorer than that of the diagnostic monochrome LCD in all aspects. The average area under the ROC curve (AUC) for reviewing abdominal CT images was 0.717±0.0200 and 0.740±0.0195 for the color monitor and the diagnostic monitor, respectively. The observation time (OT) was 145±27.6 min and 127±19.3 min, respectively. No significant differences appeared in AUC (p?=?0.265) and OT (p?=?0.07). The overall results indicate that ROTPs can be implemented as a quality control tool to evaluate the intrinsic characteristics of display devices. Although there is still a gap in technology between different types of LCDs, commercial color LCDs could replace diagnostic monochrome LCDs as a platform for reviewing abdominal CT images after monitor calibration. PMID:22701534

  16. Preclinical evidence supporting the clinical development of central pattern generator-modulating therapies for chronic spinal cord-injured patients

    PubMed Central

    2014-01-01

    Ambulation or walking is one of the main gaits of locomotion. In terrestrial animals, it may be defined as a series of rhythmic and bilaterally coordinated movement of the limbs which creates a forward movement of the body. This applies regardless of the number of limbs—from arthropods with six or more limbs to bipedal primates. These fundamental similarities among species may explain why comparable neural systems and cellular properties have been found, thus far, to control in similar ways locomotor rhythm generation in most animal models. The aim of this article is to provide a comprehensive review of the known structural and functional features associated with central nervous system (CNS) networks that are involved in the control of ambulation and other stereotyped motor patterns—specifically Central Pattern Generators (CPGs) that produce basic rhythmic patterned outputs for locomotion, micturition, ejaculation, and defecation. Although there is compelling evidence of their existence in humans, CPGs have been most studied in reduced models including in vitro isolated preparations, genetically-engineered mice and spinal cord-transected animals. Compared with other structures of the CNS, the spinal cord is generally considered as being well-preserved phylogenetically. As such, most animal models of spinal cord-injured (SCI) should be considered as valuable tools for the development of novel pharmacological strategies aimed at modulating spinal activity and restoring corresponding functions in chronic SCI patients. PMID:24910602

  17. The touchscreen operant platform for testing working memory and pattern separation in rats and mice

    PubMed Central

    Oomen, Charlotte A.; Hvoslef-Eide, Martha; Heath, Christopher J.; Mar, Adam C.; Horner, Alexa E.; Bussey, Timothy J.; Saksida, Lisa M.

    2014-01-01

    The automated touchscreen operant chamber for rats and mice allows for the assessment of multiple cognitive domains within the same testing environment. This protocol presents the Location Discrimination task (LD) and the Trial-Unique delayed Nonmatching-to-Location task (TUNL), which both assess memory for location. On these tasks, animals are trained to a pre-defined criterion during ~20-40 daily sessions. In LD-sessions, touching the same location on the screen is rewarded on consecutive trials, followed by a reversal of location-reward contingencies. TUNL, a working memory task, requires animals to “non-match” to a sample location after a delay. In both LD and TUNL spatial similarity can be varied, allowing assessment of “pattern separation” ability, a function thought to be performed by the dentate gyrus. These tasks are therefore particularly useful in animal models of hippocampal, and specifically dentate gyrus function, but additionally permit discernment of changes in pattern separation from those in working memory. PMID:24051961

  18. Sarcoidosis: correlation of pulmonary parenchymal pattern at CT with results of pulmonary function tests

    SciTech Connect

    Bergin, C.J.; Bell, D.Y.; Coblentz, C.L.; Chiles, C.; Gamsu, G.; MacIntyre, N.R.; Coleman, R.E.; Putman, C.E.

    1989-06-01

    The appearances of the lungs on radiographs and computed tomographic (CT) scans were correlated with degree of uptake on gallium scans and results of pulmonary function tests (PFTs) in 27 patients with sarcoidosis. CT scans were evaluated both qualitatively and quantitatively. Patients were divided into five categories on the basis of the pattern of abnormality at CT: 1 = normal (n = 4); 2 = segmental air-space disease (n = 4); 3 = spherical (alveolar) masslike opacities (n = 4); 4 = multiple, discrete, small nodules (n = 6); and 5 = distortion of parenchymal structures (fibrotic end-stage sarcoidosis) (n = 9). The percentage of the volume judged to be abnormal (CT grade) was correlated with PFT results for each CT and radiographic category. CT grades were also correlated with gallium scanning results and percentage of lymphocytes recovered from bronchoalveolar lavage (BAL). Patients in CT categories 1 and 2 had normal lung function, those in category 3 had mild functional impairment, and those in categories 4 and 5 showed moderate to severe dysfunction. The overall CT grade correlated well with PFT results expressed as a percentage of the predicted value. In five patients, CT scans showed extensive parenchymal disease not seen on radiographs. CT grades did not correlate with the results of gallium scanning or BAL lymphocytes. The authors conclude that patterns of parenchymal sarcoidosis seen at CT correlate with the PFT results and can be used to indicate respiratory impairment.

  19. Reliable and efficient PUF-based key generation using pattern matching

    E-print Network

    Paral, Zdenek (Sid)

    We describe a novel and efficient method to reliably provision and re-generate a finite and exact sequence of bits, for use with cryptographic applications, e.g., as a key, by employing one or more challengeable Physical ...

  20. Regional hydrocarbon generation, migration, and accumulation pattern of Cretaceous strata, Powder River Basin

    Microsoft Academic Search

    Fred F. Meissner

    1985-01-01

    A cell of abnormally high fluid pressure in the deep part of the Powder River basin is centered in an area where oil-generation-prone source rocks in the Skull Creek (oldest), Mowry, and Niobrara (youngest) formations are presently at their maximum hydrocarbon-volume generation rate. The overpressures are believed to be caused by the high conversion rate of solid kerogen in the

  1. Evidence of a central pattern generator regulating spermathecal muscle activity in Locusta migratoria and its coordination with oviposition.

    PubMed

    da Silva, Rosa; Lange, Angela B

    2011-03-01

    Electrophysiological recordings were conducted to determine the control of spermathecal contractions during oviposition of interrupted egg-laying locusts, Locusta migratoria. Following transection of the central nervous system below the metathoracic ganglion, rhythmic patterned bursting was detected by extracellular recordings of the nerve N2B2 that innervates the muscles of the spermatheca. Subsequent transections at more posterior regions of the ventral nerve cord revealed more robust rhythmic bursting in N2B2. This rhythmic bursting pattern was found to be coordinated with bursting in the ventral opener nerve (N2B1) that innervates the ventral opener muscle. This muscle controls the ventral ovipositor valves. Electromyographic recordings from the spermathecal muscle and ventral opener muscle confirmed a rhythmic bursting pattern resulting in an increase in muscle activity. Taken together, the results indicate that there is probably a central pattern generator (CPG), which is regulated by descending inhibition, that controls the spermathecal muscle activity. This CPG appears to be located within the VIIth and VIIIth abdominal ganglia, and was found to integrate with the CPG that regulates oviposition digging in locusts. These results provide further insight into the intricate coordination and control of reproductive tissues underlying reproductive behaviours in locusts. PMID:21307061

  2. Applying Model Checking to Generate Model-Based Integration Tests from Choreography Models

    NASA Astrophysics Data System (ADS)

    Wieczorek, Sebastian; Kozyura, Vitaly; Roth, Andreas; Leuschel, Michael; Bendisposto, Jens; Plagge, Daniel; Schieferdecker, Ina

    Choreography models describe the communication protocols between services. Testing of service choreographies is an important task for the quality assurance of service-based systems as used e.g. in the context of service-oriented architectures (SOA). The formal modeling of service choreographies enables a model-based integration testing (MBIT) approach. We present MBIT methods for our service choreography modeling approach called Message Choreography Models (MCM). For the model-based testing of service choreographies, MCMs are translated into Event-B models and used as input for our test generator which uses the model checker ProB.

  3. Performance demonstration tests for eddy current inspection of steam generator tubing

    SciTech Connect

    Kurtz, R.J.; Heasler, P.G.; Anderson, C.M.

    1996-05-01

    This report describes the methodology and results for development of performance demonstration tests for eddy current (ET) inspection of steam generator tubes. Statistical test design principles were used to develop the performance demonstration tests. Thresholds on ET system inspection performance were selected to ensure that field inspection systems would have a high probability of detecting and and correctly sizing tube degradation. The technical basis for the ET system performance thresholds is presented in detail. Statistical test design calculations for probability of detection and flaw sizing tests are described. A recommended performance demonstration test based on the design calculations is presented. A computer program for grading the probability of detection portion of the performance demonstration test is given.

  4. The Interrogator as Critic: The Turing Test and the Evaluation of Generative Music Systems

    Microsoft Academic Search

    Christopher Ariza

    2009-01-01

    Procedural or algorithmic approaches to generating music have been explored in the medium of software for over fifty years. Occasionally, researchers have attempted to evaluate the success of these generative music systems by measuring the perceived quality or style conformity of isolated musical outputs. These tests are often conducted in the form of comparisons between computer-aided output and non-computer-aided output.

  5. Studies of the steam generator degraded tubes behavior on BRUTUS test loop

    SciTech Connect

    Chedeau, C.; Rassineux, B. [EDF/DER/MTC, Moret Sur Loing (France); Flesch, B. [EDF/EPN/DMAINT, Paris (France)] [and others

    1997-04-01

    Studies for the evaluation of steam generator tube bundle cracks in PWR power plants are described. Global tests of crack leak rates and numerical calculations of crack opening area are discussed in some detail. A brief overview of thermohydraulic studies and the development of a mechanical probabilistic design code is also given. The COMPROMIS computer code was used in the studies to quantify the influence of in-service inspections and maintenance work on the risk of a steam generator tube rupture.

  6. The negative cascade of incongruent generative study-test processing in memory and metacomprehension

    Microsoft Academic Search

    Ayanna Kim Thomas; Mark A. McDaniel

    2007-01-01

    Previous research suggests that when participants engage in generative study activities, the processing of text is enhanced\\u000a and improvements in memory and metacomprehension result. However, few studies have investigated the influence of processes\\u000a required by the testing situation or the interaction between encoding and retrieval processes on metacomprehension accuracy.\\u000a The present experiments examine whether the congruency of processes generated during

  7. First-generation black-hole-forming supernovae and the metal abundance pattern of a very iron-poor star.

    PubMed

    Umeda, Hideyuki; Nomoto, Ken'ichi

    2003-04-24

    It has been proposed theoretically that the first generation of stars in the Universe (population III) would be as massive as 100 solar masses (100 M(O)), because of inefficient cooling of the precursor gas clouds. Recently, the most iron-deficient (but still carbon-rich) low-mass star--HE0107-5240--was discovered. If this is a population III star that gained its metals (elements heavier than helium) after its formation, it would challenge the theoretical picture of the formation of the first stars. Here we report that the patterns of elemental abundance in HE0107-5240 (and other extremely metal-poor stars) are in good accord with the nucleosynthesis that occurs in stars with masses of 20-130 M(O) when they become supernovae if, during the explosions, the ejecta undergo substantial mixing and fallback to form massive black holes. Such supernovae have been observed. The abundance patterns are not, however, consistent with enrichment by supernovae from stars in the range 130-300 M(O). We accordingly infer that the first-generation supernovae came mostly from explosions of approximately 20-130 M(O) stars; some of these produced iron-poor but carbon- and oxygen-rich ejecta. Low-mass second-generation stars, like HE0107-5240, could form because the carbon and oxygen provided pathways for the gas to cool. PMID:12712199

  8. First-generation black-hole-forming supernovae and the metal abundance pattern of a very iron-poor star

    NASA Astrophysics Data System (ADS)

    Umeda, Hideyuki; Nomoto, Ken'ichi

    2003-04-01

    It has been proposed theoretically that the first generation of stars in the Universe (population III) would be as massive as 100 solar masses (100M?), because of inefficient cooling of the precursor gas clouds. Recently, the most iron-deficient (but still carbon-rich) low-mass star-HE0107-5240-was discovered. If this is a population III star that gained its metals (elements heavier than helium) after its formation, it would challenge the theoretical picture of the formation of the first stars. Here we report that the patterns of elemental abundance in HE0107-5240 (and other extremely metal-poor stars) are in good accord with the nucleosynthesis that occurs in stars with masses of 20-130M? when they become supernovae if, during the explosions, the ejecta undergo substantial mixing and fallback to form massive black holes. Such supernovae have been observed. The abundance patterns are not, however, consistent with enrichment by supernovae from stars in the range 130-300M?. We accordingly infer that the first-generation supernovae came mostly from explosions of ~20-130M? stars; some of these produced iron-poor but carbon- and oxygen-rich ejecta. Low-mass second-generation stars, like HE0107-5240, could form because the carbon and oxygen provided pathways for the gas to cool.

  9. Lung respiratory rhythm and pattern generation in the bullfrog: role of neurokinin-1 and µ-opioid receptors

    PubMed Central

    Davies, B. L.; Brundage, C. M.; Harris, M. B.

    2010-01-01

    Location of the lung respiratory rhythm generator (RRG) in the bullfrog brainstem was investigated by examining neurokinin-1 and µ-opioid receptor (NK1R, µOR) colocalization by immunohistochemistry and characterizing the role of these receptors in lung rhythm and episodic pattern generation. NK1R and µOR occurred in brainstems from all developmental stages. In juvenile bullfrogs a distinct area of colocalization was coincident with high-intensity fluorescent labeling of µOR; high-intensity labeling of µOR was not distinctly and consistently localized in tadpole brainstems. NK1R labeling intensity did not change with development. Similarity in colocalization is consistent with similarity in responses to substance P (SP, NK1R agonist) and DAMGO (µOR agonist) when bath applied to bullfrog brainstems of different developmental stages. In early stage tadpoles and juvenile bullfrogs, SP increased and DAMGO decreased lung burst frequency. In juvenile bullfrogs, SP increased lung burst frequency, episode frequency, but decreased number of lung bursts per episode and lung burst duration. In contrast, DAMGO decreased lung burst frequency and burst cycle frequency, episode frequency, and number of lung bursts per episode but increased all other lung burst parameters. Based on these results, we hypothesize that NK1R and µOR colocalization together with a metamorphosis-related increase in µOR intensity marks the location of the lung RRG but not necessarily the lung episodic pattern generator. PMID:19184042

  10. BIOMECHANICAL ANALYSIS OF THE STRESSES GENERATED BY DIFFERENT DISOCCLUSION PATTERNS IN AN IMPLANT-SUPPORTED MANDIBULAR COMPLETE DENTURE

    PubMed Central

    Greco, Gustavo Diniz; Jansen, Wellington Corrêa; Landre, Janis; Seraidarian, Paulo Isaías

    2009-01-01

    Objectives: This study evaluated by three-dimensional finite element analysis the tensions generated by different disocclusion patterns (canine guide and bilateral balanced occlusion) in an implant-supported mandibular complete denture. Material and Methods: A three-dimensional model of implant-supported mandibular complete denture was fabricated according to the Brånemark protocol. A 5-element 3.75 x 13-mm screw-shape dental implant system was modeled for this study. The implants were located in the intermental foramen region with 3-mm-high prosthetic components joined by a nickel-chromium framework with 12-mm bilateral cantilever covered by acrylic resin and 12 acrylic denture teeth. SolidWorks® software was used before and after processing the simulations. The mechanical properties of the components were inserted in the model and a 15 N load was established in fixed points, in each one of the simulations. Data were collected in the entire nickel-chromium framework. The results were displayed three-dimensionally as color graphic scales. Results: The canine guide generated greater tensions in the region of the first implant, while the bilateral balanced occlusion generated great tensions in the entire metallic framework. The maximum tension found in the simulation of the bilateral balanced occlusion was 3.22 fold higher than the one found in the simulation of the disocclusion in canine guide. Conclusion: The pattern of disocclusion in canine guide is the ideal for implant-supported mandibular complete denture. PMID:19936535

  11. Copolymer-assisted generation of three-dimensional patterns by replicating two-dimensional substrate motifs

    NASA Astrophysics Data System (ADS)

    Genzer, Jan

    2001-02-01

    We use a three-dimensional self-consistent field model to study copolymer adsorption from polymer melts onto chemically heterogeneous substrates. We show that in situations where the copolymer sequence distribution is commensurate with the spatial distribution of the substrate chemical impurities, the two-dimensional substrate pattern gets transcribed into three dimensions and propagates into the polymer mixture. This transference scheme can assist in designing nanostructures that find use in various areas of science and technology.

  12. Generating Arbitrary Chemical Patterns for Multi-Point Dosing of Single Cells

    PubMed Central

    Hoppe, Todd J.; Moorjani, Samira G.; Shear, Jason B.

    2013-01-01

    Living cells reside within anisotropic microenvironments that orchestrate a broad range of polarized responses through physical and chemical cues. To unravel how localized chemical signals influence complex behaviors, tools must be developed for establishing patterns of chemical gradients that vary over subcellular dimensions. Here, we present a strategy for addressing this critical need in which an arbitrary number of chemically distinct, subcellular dosing streams are created in real time within a microfluidic environment. In this approach, cells are cultured on a thin polymer membrane that serves as a barrier between the cell-culture environment and a reagent chamber containing multiple reagent species flowing in parallel under low Reynolds number conditions. Focal ablation of the membrane creates pores that allow solution to flow from desired regions within this reagent pattern into the cell-culture chamber, resulting in narrow, chemically distinct dosing streams. Unlike previous dosing strategies, this system provides the capacity to tailor arbitrary patterns of reagents on-the-fly to suit the geometry and orientation of specific cells. PMID:23427919

  13. Simple model for polar cap convection patterns and generation of theta auroras

    SciTech Connect

    Lyons, L.R.

    1985-02-01

    The simple addition of a 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. This model is found to account for observed polar-cap convection patterns as a function of the interplanetary magnetic field components B/sub y/ and B/sub z/. In particular, the model offers an explanation for sunward and antisunward convection over the polar caps for B/sub z/>0. Observed field-aligned current patterns within the polar cap and observed auroral arcs across the polar cap are also explained by the model. In addition, the model gives several predictions concerning the polar cap that should be testable. Effects of solar wind pressure and magnetospheric currents on magnetospheric electric and magnetic fields are neglected. That observed polar cap features are reproduced suggests that the neglected effects do not modify the large-scale topology of magnetospheric electric and magnetic fields along open polar cap field lines. Of course, the neglected effects significantly modify the magnetic geometry, so that the results of this paper are not quantitatively realistic and many details may be incorrect. Nevertheless, the model provides a simple explanation for many qualitative features of polar cap convection.

  14. Unwanted sounds generated with test tone presentation can spoil extended high-frequency audiometry.

    PubMed

    Kurakata, Kenji; Mizunami, Tazu; Matsushita, Kazuma; Shiraishi, Kimio

    2010-10-01

    Unwanted sounds from a commercially available audiometer were evaluated in terms of their effects on extended high-frequency (EHF) audiometry. Although the manufacturer reported that the audiometer conformed to relevant International Electrotechnical Commission (IEC) standards, the audiograms obtained using the audiometer were erroneous because the subjects had responded falsely to noise generated with the test tone presentation before detecting the test tone. Analyses of acoustic and electric output signals revealed that the audiometer generated most of the unwanted sounds, not the earphones that were used. Based on the measurement results, clinical implications of the measurement results are discussed for conducting more reliable EHF audiometry. PMID:20968319

  15. Using Patterns of Summed Scores in Paper-and-Pencil Tests and Computer-Adaptive Tests to Detect Misfitting Item Score Patterns

    ERIC Educational Resources Information Center

    Meijer, Rob R.

    2004-01-01

    Two new methods have been proposed to determine unexpected sum scores on sub-tests (testlets) both for paper-and-pencil tests and computer adaptive tests. A method based on a conservative bound using the hypergeometric distribution, denoted p, was compared with a method where the probability for each score combination was calculated using a…

  16. Origin of the patchy emission pattern at the ZERT CO2 Release Test

    SciTech Connect

    Lewicki, J.L.; Pan, L.; Dobeck, L.; Spangler, L.; Oldenburg, C.M.

    2009-10-15

    A numerical experiment was carried out to test whether the patchy CO{sub 2} emission patterns observed at the ZERT release facility are caused by the presence of packers that divide the horizontal injection well into six CO2-injection zones. A three-dimensional model of the horizontal well and cobble-soil system was developed and simulations using TOUGH2/EOS7CA were carried out. Simulation results show patchy emissions for the seven-packer (six-injection-zone) configuration of the field test. Numerical experiments were then conducted for the cases of 24 packers (23 injection zones) and an effectively infinite number of packers. The time to surface breakthrough and the number of patches increased as the number of packers increased suggesting that packers and associated along pipe flow are the origin of the patchy emissions. In addition, it was observed that early breakthrough occurs at locations where the horizontal well pipe is shallow and installed mostly in soil rather than the deeper cobble. In the cases where the pipe is installed at shallow depths and directly in the soil, higher pipe gas saturations occur than where the pipe is installed slightly deeper in the cobble. It is believed this is an effect mostly relevant to the model rather than the field system and arises through the influence of capillarity, permeability, and pipe elevation of the soil compared to the cobble adjacent to the pipe.

  17. MIPoD: A Hypothesis-Testing Framework for Microevolutionary Inference from Patterns of Divergence

    PubMed Central

    Hohenlohe, Paul A.; Arnold, Stevan J.

    2008-01-01

    Despite the many triumphs of comparative biology during the past few decades, the field has remained strangely divorced from evolutionary genetics. In particular, comparative methods have failed to incorporate multivariate process models of microevolution that include genetic constraint in the form of the G matrix. Here we explore the insights that might be gained by such an analysis. A neutral model of evolution by genetic drift that depends on effective population size and the G matrix predicts a probability distribution for divergence of population trait means on a phylogeny. Use of a maximum likelihood (ML) framework then allows us to compare independent direct estimates of G with the ML estimates based on the observed pattern of trait divergence among taxa. We assess the departure from neutrality, and thus the role of different types of selection and other forces, in a stepwise hypothesis-testing procedure based on parameters for the size, shape, and orientation of G. We illustrate our approach with a test case of data on vertebral number evolution in garter snakes. PMID:18194086

  18. Wind load and life-cycle testing of second generation heliostats

    SciTech Connect

    Rorke, W.S. Jr.

    1983-11-01

    As technical manager of the Second Generation Heliostat development contracts for the Department of Energy, Sandia National Laboratories has evaluated four heliostat designs. The evaluation of the heliostats included the life-cycling and simulated wind load testing of prototype heliostats and foundations. All of the heliostats had minor problems during this testing; as a result, specific design improvements were identified for each drive mechanism and for two of the four foundations.

  19. Altered breathing patterns during lumbopelvic motor control tests in chronic low back pain: a case–control study

    Microsoft Academic Search

    Nathalie Roussel; Jo Nijs; Steven Truijen; Liesbet Vervecken; Sarah Mottram; Gaëtane Stassijns

    2009-01-01

    The objective of the study was to evaluate the breathing pattern in patients with chronic non-specific low back pain (LBP)\\u000a and in healthy subjects, both at rest and during motor control tests. Ten healthy subjects and ten patients with chronic LBP\\u000a participated at this case–control study. The breathing pattern was evaluated at rest (standing and supine position during\\u000a both relaxed

  20. OConGraX - Automatically Generating Data-Flow Test Cases for Fault-Tolerant Systems

    NASA Astrophysics Data System (ADS)

    Nunes, Paulo R. F.; Hanazumi, Simone; de Melo, Ana C. V.

    The more complex to develop and manage systems the more software design faults increase, making fault-tolerant systems highly required. To ensure their quality, the normal and exceptional behaviors must be tested and/or verified. Software testing is still a difficult and costly software development task and a reasonable amount of effort has been employed to develop techniques for testing programs’ normal behaviors. For the exceptional behavior, however, there is a lack of techniques and tools to effectively test it. To help in testing and analyzing fault-tolerant systems, we present in this paper a tool that provides an automatic generation of data-flow test cases for objects and exception-handling mechanisms of Java programs and data/control-flow graphs for program analysis.