Relevant bibliographies by topics / Firing unit

Academic literature on the topic 'Firing unit'

Author: Grafiati
Published: 9 March 2023
Last updated: 10 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Firing unit.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Firing unit"

1

Contessa, Paola, Alexander Adam, and Carlo J. De Luca. "Motor unit control and force fluctuation during fatigue." Journal of Applied Physiology 107, no. 1 (July 2009): 235–43. http://dx.doi.org/10.1152/japplphysiol.00035.2009.

Full text
Abstract:
During isometric contractions, the fluctuation of the force output of muscles increases as the muscle fatigues, and the contraction is sustained to exhaustion. We analyzed motor unit firing data from the vastus lateralis muscle to investigate which motor unit control parameters were associated with the increased force fluctuation. Subjects performed a sequence of isometric constant-force contractions sustained at 20% maximal force, each spaced by a 6-s rest period. The contractions were performed until the mean value of the force output could not be maintained at the desired level. Intramuscular EMG signals were detected with a quadrifilar fine-wire sensor. The EMG signals were decomposed to identify all of the firings of several motor units by using an artificial intelligence-based set of algorithms. We were able to follow the behavior of the same motor units as the endurance time progressed. The force output of the muscle was filtered to remove contributions from the tracking task. The coefficient of variation of the force was found to increase with endurance time ( P < 0.001, R2 = 0.51). We calculated the coefficient of variation of the firing rates, the synchronization of pairs of motor unit firings, the cross-correlation value of the firing rates of pairs of motor units, the cross-correlation of the firing rates of motor units and the force, and the number of motor units recruited during the contractions. Of these parameters, only the cross-correlation of the firing rates ( P < 0.01, R2 = 0.10) and the number of recruited motor units ( P = 0.042, R2 = 0.22) increased significantly with endurance time for grouped subjects. A significant increase ( P < 0.001, R2 = 0.16) in the cross-correlation of the firing rates and force was also observed. It is suggested that the increase in the cross-correlation of the firing rates is likely due to a decrease in the sensitivity of the proprioceptive feedback from the spindles.
APA, Harvard, Vancouver, ISO, and other styles
2

Contessa, Paola, Carlo J. De Luca, and Joshua C. Kline. "The compensatory interaction between motor unit firing behavior and muscle force during fatigue." Journal of Neurophysiology 116, no. 4 (October 1, 2016): 1579–85. http://dx.doi.org/10.1152/jn.00347.2016.

Full text
Abstract:
Throughout the literature, different observations of motor unit firing behavior during muscle fatigue have been reported and explained with varieties of conjectures. The disagreement amongst previous studies has resulted, in part, from the limited number of available motor units and from the misleading practice of grouping motor unit data across different subjects, contractions, and force levels. To establish a more clear understanding of motor unit control during fatigue, we investigated the firing behavior of motor units from the vastus lateralis muscle of individual subjects during a fatigue protocol of repeated voluntary constant force isometric contractions. Surface electromyographic decomposition technology provided the firings of 1,890 motor unit firing trains. These data revealed that to sustain the contraction force as the muscle fatigued, the following occurred: 1) motor unit firing rates increased; 2) new motor units were recruited; and 3) motor unit recruitment thresholds decreased. Although the degree of these adaptations was subject specific, the behavior was consistent in all subjects. When we compared our empirical observations with those obtained from simulation, we found that the fatigue-induced changes in motor unit firing behavior can be explained by increasing excitation to the motoneuron pool that compensates for the fatigue-induced decrease in muscle force twitch reported in empirical studies. Yet, the fundamental motor unit control scheme remains invariant throughout the development of fatigue. These findings indicate that the central nervous system regulates motor unit firing behavior by adjusting the operating point of the excitation to the motoneuron pool to sustain the contraction force as the muscle fatigues.
APA, Harvard, Vancouver, ISO, and other styles
3

Sauvage, Chloe, Mario Manto, Alexander Adam, Rick Roark, Patrice Jissendi, and Carlo J. De Luca. "Ordered Motor-Unit Firing Behavior in Acute Cerebellar Stroke." Journal of Neurophysiology 96, no. 5 (November 2006): 2769–74. http://dx.doi.org/10.1152/jn.00268.2006.

Full text
Abstract:
It is known that at any given force level, the lower-threshold motor units generally fire at greater rates than the higher-threshold units during isometric tasks of extremity muscles. In addition to this hierarchical arrangement, firing rates of motor units fluctuate in unison with nearly no time delay; an observation that has led to the concept of common drive, a basic motoneuronal rule. Although it is established that the cerebellum plays a critical function in motor control, its role in the genesis, triggering, selection, and monitoring of motor-unit firing pattern discharges during isometric tasks is unknown. We applied an electromyographic (EMG) decomposition technique, known as precision decomposition, to accurately identify motor-unit firing times from the EMG signal recorded from the first dorsal interosseous muscle to unravel the features of motor-unit firings in three patients presenting a unilateral cerebellar stroke and exhibiting an acute cerebellar syndrome. We observed ataxic isometric force during visually guided abduction of the index finger on the affected side. However, the hierarchical response of individual motor units was spared. Furthermore, acute cerebellar ataxia was not associated with a loss of the common drive.
APA, Harvard, Vancouver, ISO, and other styles
4

Eggermont, Jos J., and Jennifer E. Mossop. "Azimuth Coding in Primary Auditory Cortex of the Cat. I. Spike Synchrony Versus Spike Count Representations." Journal of Neurophysiology 80, no. 4 (October 1, 1998): 2133–50. http://dx.doi.org/10.1152/jn.1998.80.4.2133.

Full text
Abstract:
Eggermont, Jos J. and Jennifer E. Mossop. Azimuth coding in primary auditory cortex of the cat. I. Spike synchrony versus spike count representations. J. Neurophysiol. 80: 2133–2150, 1998. The neural representation of sound azimuth in auditory cortex most often is considered to be average firing rate, and azimuth tuning curves based thereupon appear to be rather broad. Coincident firings of simultaneously recorded neurons could provide an improved representation of sound azimuth compared with that contained in the firing rate in either of the units. In the present study, a comparison was made between local field potentials and several measures based on unit firing rate and coincident firing with respect to their azimuth-tuning curve bandwidth. Noise bursts, covering a 60-dB intensity range, were presented from nine speakers arranged in a semicircular array with a radius of 55 cm in the animal's frontal half field. At threshold intensities, all local field potential (LFP) recordings showed preferences for contralateral azimuths. Multiunit recordings showed in 74% a threshold for contralateral azimuths, in 16% for frontal azimuths, and in only 5% showed an ipsilateral threshold. The remaining 5% were not spatially tuned. Representations for directionally sensitive units based on coincident firings provided significantly sharper tuning (50–60° bandwidth at 25 dB above the lowest threshold) than those based on firing rate (bandwidths of 80–90°). The ability to predict sound azimuth from the directional information contained in the neural population activity was simulated by combining the responses of the 102 single units. Peak firing rates and coincident firings with LFPs at the preferred azimuth for each unit were used to construct a population vector. At stimulus levels of ≥40 dB SPL, the prediction function was sigmoidal with the predicted frontal azimuth coinciding with the frontal speaker position. Sound azimuths >45° from the midline all resulted in predicted values of −90 or 90°, respectively. No differences were observed in the performance of the prediction based on firing rate or coincident firings for these intensities. This suggests that although coincident firings produce narrower azimuth tuning curves, the information contained in the overall neural population does not increase compared with that contained in a firing rate representation. The relatively poor performance of the population vector further suggests that primary auditory cortex does not code sound azimuth by a globally distributed measure of peak firing rate or coincident firing.
APA, Harvard, Vancouver, ISO, and other styles
5

Deburchgraeve, W., K. Van Damme, T. Adriaensen, A. Spaepen, S. Van Huffel, and J. Taelman. "Detection Algorithm for Single Motor Unit Firing in Surface EMG of the Trapezius Muscle." Methods of Information in Medicine 49, no. 05 (2010): 492–95. http://dx.doi.org/10.3414/me09-02-0042.

Full text
Abstract:
Summary Background: Work-related musculoskeletal disorders (MSD) of the neck and the shoulders are a growing problem in society. An interesting pattern of spontaneous muscle activity, the firing of a single motor unit, in the trapezius muscle is observed during a laboratory study in a rest state or a state with a mental load. Objective: In this study, we report on the finding of the single motor unit firing and we present a detection algorithm to localize these single motor unit firings. Methods: A spike train detection algorithm, using a nonlinear energy operator and correlation, is presented to detect burst of highly correlated, high energetic spike-like segments. Results: This single motor unit was visible in 65% of the test subjects on one or both trapezius muscles although there was no change in posture of the test subjects. All the segments in the data that were determined as single motor unit firings were detected by the algorithm. Discussion: The physiological meaning of this firing pattern is a very low and subconscious contraction of the muscle. A long-term contraction could lead to the exhaustion of the muscle fibers, thus resulting in musculoskeletal disorders. The detection algorithm is able to localize this phenomenon in a sEMG measurement. The ability of detecting these firings is helpful in the research of its origin. Conclusion: The detection algorithm can be used to gain insight in the physiological origin of this phenomenon. In addition, the algorithm can also be used in a biofeedback system to warn the user for this undesired contraction to prevent MSD.
APA, Harvard, Vancouver, ISO, and other styles
6

Adam, Alexander, Carlo J. De Luca, and Zeynep Erim. "Hand Dominance and Motor Unit Firing Behavior." Journal of Neurophysiology 80, no. 3 (September 1, 1998): 1373–82. http://dx.doi.org/10.1152/jn.1998.80.3.1373.

Full text
Abstract:
Adam, Alexander, Carlo J. De Luca, and Zeynep Erim. Hand dominance and motor unit firing behavior. J. Neurophysiol. 80: 1373–1382, 1998. Daily preferential use was shown to alter physiological and mechanical properties of skeletal muscle. This study was aimed at revealing differences in the control strategy of muscle pairs in humans who show a clear preference for one hand. We compared the motor unit (MU) recruitment and firing behavior in the first dorsal interosseous (FDI) muscle of both hands in eight male volunteers whose hand preference was evaluated with the use of a standard questionnaire. Myoelectric signals were recorded while subjects isometrically abducted the index finger at 30% of the maximal voluntary contraction (MVC) force. A myoelectric signal decomposition technique was used to accurately identify MU firing times from the myoelectric signal. In MUs of the dominant hand, mean values for recruitment threshold, initial firing rate, average firing rate at target force, and discharge variability were lower when compared with the nondominant hand. Analysis of the cross-correlation between mean firing rate and muscle force revealed cross-correlation peaks of longer latency in the dominant hand than in the nondominant side. This lag of the force output with respect to fluctuations in the firing behavior of MUs is indicative of a greater mechanical delay in the dominant FDI muscle. MVC force was not significantly different across muscle pairs, but the variability of force at the submaximal target level was higher in the nondominant side. The presence of lower average firing rates, lower recruitment thresholds, and greater firing rate/force delay in the dominant hand is consistent with the notion of an increased percentage of slow twitch fibers in the preferentially used muscle, allowing twitch fusion and force buildup to occur at lower firing rates. It is suggested that a lifetime of preferred use may cause adaptations in the fiber composition of the dominant muscle such that the mechanical effectiveness of its MUs increased.
APA, Harvard, Vancouver, ISO, and other styles
7

Bennett, David J., Yunru Li, Philip J. Harvey, and Monica Gorassini. "Evidence for Plateau Potentials in Tail Motoneurons of Awake Chronic Spinal Rats With Spasticity." Journal of Neurophysiology 86, no. 4 (October 1, 2001): 1972–82. http://dx.doi.org/10.1152/jn.2001.86.4.1972.

Full text
Abstract:
Motor units of segmental tail muscles were recorded in awake rats following acute (1–2 days) and chronic (>30 days) sacral spinal cord transection to determine whether plateau potentials contributed to sustained motor-unit discharges after injury. This study was motivated by a companion in vitro study that indicated that after chronic spinal cord injury, the tail motoneurons of the sacrocaudal spinal cord exhibit persistent inward currents ( I PIC) that cause intrinsically sustained depolarizations ( plateau potentials) and firing ( self-sustained firing). Importantly, in this companion study, the plateaus were fully activated at recruitment and subsequently helped sustain the firing without causing abrupt nonlinearities in firing. That is, after recruitment and plateau activation, the firing rate was modulated relatively linearly with injected current and therefore provided a good approximation of the input to the motoneuron despite the plateau. Thus in the present study, pairs of motor units were recorded simultaneously from the same muscle, and the firing rate ( F) of the lowest-threshold unit (control unit) was used as an estimate of the synaptic input to both units. We then examined whether firing of the higher-threshold unit (test unit) was intrinsically maintained by a plateau, by determining whether more synaptic input was required to recruit the test unit than to maintain its firing. The difference in the estimated synaptic input at recruitment and de-recruitment of the test unit (i.e., change in control unit rate, Δ F) was taken as an estimate of the plateau current ( I PIC) that intrinsically sustained the firing. Slowly graded manual skin stimulation was used to recruit and then de-recruit the units. The test unit was recruited when the control unit rate was on average 17.8 and 18.9 Hz in acute and chronic spinal rats, respectively. In chronic spinal rats, the test unit was de-recruited when the control unit rate (re: estimated synaptic input) was significantly reduced, compared with at recruitment (Δ F = −5.5 Hz), and thus a plateau participated in maintaining the firing. In the lowest-threshold motor units, even a brief stimulation triggered very long-lasting firing (seconds to hours; self-sustained firing). Higher-threshold units required continuous stimulation (or a spontaneous spasm) to cause firing, but again more synaptic input was needed to recruit the unit than to maintain its firing (i.e., plateau present). In contrast, in acute spinal rats, the stimulation did not usually trigger sustained motor-unit firing that could be attributed to plateaus because Δ F was not significantly different from zero. These results indicate that plateaus play an important role in sustaining motor-unit firing in awake chronic spinal rats and thus contribute to the hyperreflexia and hypertonus associated with chronic injury.
APA, Harvard, Vancouver, ISO, and other styles
8

Masakado, Yoshihisa. "Motor Unit Firing Behavior in Man." Keio Journal of Medicine 43, no. 3 (1994): 137–42. http://dx.doi.org/10.2302/kjm.43.137.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Mettler, Joni A., and Lisa Griffin. "Motor Unit Firing Patterns during Fatigue." Medicine & Science in Sports & Exercise 39, Supplement (May 2007): S330. http://dx.doi.org/10.1249/01.mss.0000274284.63883.9d.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Kline, Joshua C., and Carlo J. De Luca. "Synchronization of motor unit firings: an epiphenomenon of firing rate characteristics not common inputs." Journal of Neurophysiology 115, no. 1 (January 1, 2016): 178–92. http://dx.doi.org/10.1152/jn.00452.2015.

Full text
Abstract:
Synchronous motor unit firing instances have been attributed to anatomical inputs shared by motoneurons. Yet, there is a lack of empirical evidence confirming the notion that common inputs elicit synchronization under voluntary conditions. We tested this notion by measuring synchronization between motor unit action potential trains (MUAPTs) as their firing rates progressed within a contraction from a relatively low force level to a higher one. On average, the degree of synchronization decreased as the force increased. The common input notion provides no empirically supported explanation for the observed synchronization behavior. Therefore, we investigated a more probable explanation for synchronization. Our data set of 17,546 paired MUAPTs revealed that the degree of synchronization varies as a function of two characteristics of the motor unit firing rate: the similarity and the slope as a function of force. Both are measures of the excitation of the motoneurons. As the force generated by the muscle increases, the firing rate slope decreases, and the synchronization correspondingly decreases. Different muscles have motor units with different firing rate characteristics and display different amounts of synchronization. Although this association is not proof of causality, it consistently explains our observations and strongly suggests further investigation. So viewed, synchronization is likely an epiphenomenon, subject to countless unknown neural interactions. As such, synchronous firing instances may not be the product of a specific design and may not serve a specific physiological purpose. Our explanation for synchronization has the advantage of being supported by empirical evidence, whereas the common input does not.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Firing unit"

1

Griffin, Lisa. "Role of afferent input on motor unit firing rate modulation during submaximal fatigue tasks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0002/NQ42524.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sykes, Robert Philip. "Definition study, design and development of a firing unit to initiate two pyrotechnic chains." Thesis, Cape Technikon, 1988. http://hdl.handle.net/20.500.11838/1086.

Full text
Abstract:
Thesis (Masters Diploma (Electrical Engineering)--Cape Technikon, Cape Town, 1988
The subject of this thesis is the development of ahighly ruggedised, reliable electronic circuit. The circuit is to be used for the initiation of fuze heads and to charge a capacitor for later use in apyrotechnic chain. This circuit and its associated packaging will be called the firing unit. The thesis can be broadly divided into the following facets. I. The definition study, which defines what is needed and proposed means of achieving the customer requirements. 11. The design of the electronic circuitry in the system. Ii!. The design of the packaging containing the electronics. Iv. Adaptation of environmental testing, to verify system design. V. Implementation of environmental testing. Vi. Reliability analysis. Vii. Failure analysis and the determination of the effect of the supposed failure. Actions vto vii were used as inputs to improve 11 and ill, so achieving optimum performance and safety. The whole system was designed with the overriding objective of reliability and safety of personnel and equipment.
APA, Harvard, Vancouver, ISO, and other styles
3

Dale, Jill Harmony. "An investigation of an electrotherapy based on the natural motor unit firing pattern of human skeletal muscle." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304669.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Contessa, Paola. "A muscle-force model with physiological bases." Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3426891.

Full text
Abstract:
Muscle force is regulated by varying two main motor unit properties: the recruitment and the firing rates of motor units. Discrepancies still exist on the mechanisms involved in motor unit control and muscle force generation. This study investigated the behavior of motor unit firing rate during sustained fatiguing contractions and the motor unit parameters that are most likely to influence force fluctuation increase. We also studied the firing rate of motor units during linearly increasing force contractions up to maximum, or near maximum voluntary contraction force, at different rates of force increase, and developed an equation that models the firing rate behavior as a function of increasing excitation to the motor unit pool. Results were used to create a model of muscle force production that is based on verifiable physiological concepts and data. The model also includes the concept of common drive, i.e. of an oscillatory common input received by all motor units in the motor unit pool, the time-dependent changes of motor unit twitches, and a feedback loop to simulate force generation in a target-force tracking mode. Simulations showed that the model is able to mimic the force and firing rate patterns which have been experimentally observed during repeated contractions sustained to exhaustion: the excitation to the motoneuron pool must be adjusted in response to an increased or decreased force generation capacity of the muscle fibers, and the firing rates of all motor units respond consequently with a decreased or increased firing rate. The simulation of prolonged contractions showed that the increase in force variability may be attributed to the gradual recruitment of higherrecruitment threshold larger-amplitude force twitch motor units. The level of cross-correlation between firing rates appeared to influence force variability, whereas the variability in the firing rates had no clear effect on force variability.
Il controllo della forza muscolare si basa principalmente su due fenomeni: il reclutamento di unità motorie e la regolazione della loro frequenza di scarica. Molti aspetti riguardanti i meccanismi coinvolti nel controllo delle unità motorie e nella generazione di forza muscolare restano ancora da investigare. Parte del lavoro di questa tesi ha riguardato lo studio del comportamento della frequenza di scarica delle unità motorie e dei parametri alla base dell’incremento delle fluttuazioni dell’output di forza durante l’esecuzione di contrazioni muscolari sostenute fino all’affaticamento. Inoltre, è stato analizzato il comportamento della frequenza di scarica delle unità motorie durante lo svolgimento di contrazioni muscolari a livelli di forza crescente fino alla massima forza di contrazione volontaria (a diverse velocità di incremento della forza); ed è stata messa a punto una equazione in grado di modellare il comportamento della frequenza di scarica in funzione dell’eccitazione ricevuta dal pool di unità motorie. I risultati di questa prima analisi sono serviti per creare un modello di produzione della forza muscolare basato su dati fisiologici verificabili. Il modello include il concetto di “common drive”, ovvero di un input oscillatorio comune ricevuto da tutte le unità motorie del pool; la dipendenza temporale dei “twitch” di forza delle unità motorie; ed un “feedback loop” per simulare la generazione di forza in contrazioni in “target-force tracking mode”. Si è dimostrato come il modello sviluppato sia in grado di simulare il pattern di forza e il comportamento delle unità motorie sperimentalmente osservati durante l’esecuzione di contrazioni prolungate e sostenute fino all’affaticamento. In particolare, si è potuto osservare come l’eccitazione ricevuta dal pool di unità motorie si modifichi in seguito ad un aumento o ad una diminuzione della capacità di produrre forza delle fibre muscolari e come la variazione dell’eccitazione comporti di conseguenza una diminuzione o un aumento della frequenza di scarica delle unità motorie e del numero di unità motorie attive. La simulazione di contrazioni muscolari prolungate ha anche evidenziato come la crescente variabilità della forza muscolare sia da attribuire al reclutamento di unità motorie caratterizzate da “twitch” di ampiezza maggiore e da un maggiore grado di cross-correlazione tra la frequenza di scarica delle unità motorie attive, mentre la variabilità della frequenza di scarica non sembra influire sull’output di forza.
APA, Harvard, Vancouver, ISO, and other styles
5

Rasheed, Sarbast. "A Multiclassifier Approach to Motor Unit Potential Classification for EMG Signal Decomposition." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/934.

Full text
Abstract:
EMG signal decomposition is the process of resolving a composite EMG signal into its constituent motor unit potential trains (classes) and it can be configured as a classification problem. An EMG signal detected by the tip of an inserted needle electrode is the superposition of the individual electrical contributions of the different motor units that are active, during a muscle contraction, and background interference.
This thesis addresses the process of EMG signal decomposition by developing an interactive classification system, which uses multiple classifier fusion techniques in order to achieve improved classification performance. The developed system combines heterogeneous sets of base classifier ensembles of different kinds and employs either a one level classifier fusion scheme or a hybrid classifier fusion approach.
The hybrid classifier fusion approach is applied as a two-stage combination process that uses a new aggregator module which consists of two combiners: the first at the abstract level of classifier fusion and the other at the measurement level of classifier fusion such that it uses both combiners in a complementary manner. Both combiners may be either data independent or the first combiner data independent and the second data dependent. For the purpose of experimentation, we used as first combiner the majority voting scheme, while we used as the second combiner one of the fixed combination rules behaving as a data independent combiner or the fuzzy integral with the lambda-fuzzy measure as an implicit data dependent combiner.
Once the set of motor unit potential trains are generated by the classifier fusion system, the firing pattern consistency statistics for each train are calculated to detect classification errors in an adaptive fashion. This firing pattern analysis allows the algorithm to modify the threshold of assertion required for assignment of a motor unit potential classification individually for each train based on an expectation of erroneous assignments.
The classifier ensembles consist of a set of different versions of the Certainty classifier, a set of classifiers based on the nearest neighbour decision rule: the fuzzy k-NN and the adaptive fuzzy k-NN classifiers, and a set of classifiers that use a correlation measure as an estimation of the degree of similarity between a pattern and a class template: the matched template filter classifiers and its adaptive counterpart. The base classifiers, besides being of different kinds, utilize different types of features and their performances were investigated using both real and simulated EMG signals of different complexities. The feature sets extracted include time-domain data, first- and second-order discrete derivative data, and wavelet-domain data.
Following the so-called overproduce and choose strategy to classifier ensemble combination, the developed system allows the construction of a large set of candidate base classifiers and then chooses, from the base classifiers pool, subsets of specified number of classifiers to form candidate classifier ensembles. The system then selects the classifier ensemble having the maximum degree of agreement by exploiting a diversity measure for designing classifier teams. The kappa statistic is used as the diversity measure to estimate the level of agreement between the base classifier outputs, i. e. , to measure the degree of decision similarity between the base classifiers. This mechanism of choosing the team's classifiers based on assessing the classifier agreement throughout all the trains and the unassigned category is applied during the one level classifier fusion scheme and the first combiner in the hybrid classifier fusion approach. For the second combiner in the hybrid classifier fusion approach, we choose team classifiers also based on kappa statistics but by assessing the classifiers agreement only across the unassigned category and choose those base classifiers having the minimum agreement.
Performance of the developed classifier fusion system, in both of its variants, i. e. , the one level scheme and the hybrid approach was evaluated using synthetic simulated signals of known properties and real signals and then compared it with the performance of the constituent base classifiers. Across the EMG signal data sets used, the hybrid approach had better average classification performance overall, specially in terms of reducing the number of classification errors.
APA, Harvard, Vancouver, ISO, and other styles
6

NIANG, DJIBRIL. "Performance evaluation of LIDAR demonstrator." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2023. https://hdl.handle.net/10281/404777.

Full text
Abstract:
In questa tesi, sono state realizzate tre diverse board: un DC-DC per il supply, un control unit per programmare i segnali d'ingresso del driver, un firing unit che contiene il chip principale(driver e GaN). Abbiamo usato il nitruro di galio perché è meglio adatto del silicio ad alte frequenze. L'obbiettivo principale è di raggiungere 50A di picco di corrente con soli 5ns di pulse. Sono stati usati Altium design per il disegno delle board e Ansys per l'evaluazione delle induttanze parassite. Questo ultimo crea diversi problemi e può limitare il raggiungimento del picco di corrente. Quindi bisogna fare il layout tenendo molta attenzione ai parassiti
In our three years of work, we have achieved the realization of a Firing unit board with the GaN and driver in a system in package. Three different boards were realized: A first board with only the resistor, the second one with the resistor and a shunt resistor and a third board with the laser diode and a shunt resistor. A DC-DC was realized for the supply while a control unit was realized for the control of the input signals of the driver.Unfortunately, no measurements of the firing unit have been done yet as we are still waiting for the chip to be completed. The DC-DC and the control unit board have been measured and tested. LIDAR application is the most attractive and efficient solution for this market. The challenges of LIDAR application consist in the development of the electronics generating a current pulse of 50A that lasts for less than 5ns. The technical area of this activity is fully autonomous self-driving car, and in particular what helps an autonomous vehicle to understand the world around it.
APA, Harvard, Vancouver, ISO, and other styles
7

Dean, Valarie Nichole. "Time Constant Analysis of Initial 'Jump' in Firing Rate of Human Motor Units During Isometic Contraction." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/146201.

Full text
Abstract:
Ongoing research studying the underlying mechanism and prevalence of Persistent Inward Currents (PICs) has posed a challenge to the conventional view that the firing rate of a motor unit is proportional to the amount of synaptic input it receives. Near the time of human motor unit recruitment during isometric muscle contraction, a sudden steep rise in firing rate is observed, which is suggested to result from rapid triggering of PICs, an intrinsic property of motor neurons. In evaluating the time constants associated with these steep rises in firing rate across different contractile speeds, it has been found that the time course of the steep rise is dependent on the time course of muscle contraction. This evidence suggests that the mechanism underlying this steep rise in firing rate is not PIC-associated, but rather depends on an alternate, unknown mechanism.
APA, Harvard, Vancouver, ISO, and other styles
8

Sampò, Luca. "Le Corbusier, 1957-1965 : traguardi di una ricerca teorica, artistica ed architettonica : il complesso di firminy." Paris, EPHE, 2007. http://www.theses.fr/2007EPHE4163.

Full text
Abstract:
Gli ultimi anni dell'opera di Le Corbusier si presentano come i più controversi, offrendo un panorama che spazia dalla realizzazione alla disillusione, dall'incomprensione al riconoscimento internazionale. La tesi affronta quest'articolata produzione sotto molteplici punti di vista, cercando di operare una duplice lettura: una sincronica trasversalmente ai vari campi della sua attività, l'altra diacronica rispetto ai singoli temi. Il periodo 1957-1965 è studiato prendendo in considerazione l'opera artistica, gli scritti, la teoria urbanistica, i progetti non realizzati e l'architettura. In particolare, oggetto di grande attenzione è il "metodo operativo" di Le Corbusier: dall' idea all'architettura. Entrano in gioco, in questa fase, documenti inediti ed interviste ad allievi ed ex-collaboratori, tra i quali: Roger Aujame, Fernand Gardien, José Oubrerie, Claude Parent, Robert Rebutato, André Wogenscky, Dominique Claudius-Petit, fils d'Eugène Claudius-Petit. Particolare attenzione è data alle architetture di Firminy, inquadrate come un possibile frammento della sua urbanistica. La Maison de la Culture, lo stade, l'Unité d'Habitation e l'église de Saint-Pierre sono lette analiticamente: dall'idea originaria all'iter di elaborazione in atelier, dal cantiere alla realizzazione; ed oltre, affrotando la problematica vita di questi edifici dopo il completamento, i diversi interventi di restauro condotti ed in corso, ed i progetti futuri. In particolare, il completamento, i diversi interventi di restauro condotti ed in corso, ed i progetti futuri. In particolare, il completamento dell'église de Saint-Pierre è stato seguito in tempo reale, tra il 2003 e il 2006, a contatto con i progettisti, il cantiere e le imprese
Les derniers ans de l'oeuvre de Le Corbusier sont parmi les plus controversé de sa vie, y sont mélangés indissolublement: accomplissement et désillusion, incompréhension et célébrité. La thèse étudie cette production si articulée à partir de deux modalités d'analyse: une synchronique, transversalement aux différents domaines de son activité, l'autre diachronique par rapport à chaque thème de recherche. La période 1957-1965 est étudiée sous multiples points de vue: l'oeuvre plastique, les livres, les théories d'urbanisme, les projets réalisés et non. Dans cette complexité, l'étude de la "méthode de travail" de Le Corbusier s'est avérée être un passage décisif pour comprendre l'évolution qui conduit de l'idée à l'architecture. Nombreux entretiens avec anciens élèves et collaborateurs de Le Corbusier ont été conduits, notamment avec: Roger Aujame, Fernand Gardien, José Oubrerie, Claude Parent, Robert Rebutato, André Wogenscky, Dominique Claudius-Petit, fils d'Eugène Claudius-Petit. L'ensemble d'architectures de Le Corbusier à Firminy occupe un rôle de premier plan dans l'étude, soit sur le plan d'urbanisme, soit du point de vue architecturale. La Maison de la Culture, le Stade, l'Unité d'Habitation et l'église de Saint-Pierre sont étudiés analytiquement: de l'idée originaire à l'iter d'élaboration en atelier, du chantier à l'oeuvre réalisée; et, ensuite, la vie du bâtiment, les interventions de restauration et les projets en cours d'étude en 2005-2006. Enfin, une attention particulière a été donnée au projet de l'église de Saint-Pierre, dont l'achèvement a été suivi en "temps réel", entre 2003 et 2006, en liaison étroite avec les architectes, le chantier et les entreprises
The last years of Le Corbusier's work are the most debated and controversial of his life, they offer a wide panorama that roved freely from accomplishment to disillusion, from incomprehension to international acknowledgement. The thesis faces this articulated production from multiple points of view trying to make a double reading of his production: one synchronic that embrace crosswise the different domains of his activity, the second diachronic of every single theme research. The period 1957-1965 has been studied considering Le Corbusier's artistic activity, writings, town-planning vision, realized and non-realized architectural projects, focusing particularly on his "operating method": from idea to architecture. Many interesting interviews were conducted during the research, with personalities like: Roger Aujame, Fernand Gardien, José Oubrerie, Claude Parent, Robert Rebutato, André Wogenscky, Dominique Claudius-Petit, fils d'Eugène Claudius-Petit. The thesis focuses particularly on the architectural complex of Firminy which is, after Chandigarh, the most important fragment of Le Corbusier's town-planning teories. The Maison de la Culture, le Stade, the Unité d'Habitation and the Saint-Pierre church are deeply and widely analyzed: from the primary idea throughout all the evolution of the project in atelier, from construction process to achievement; and more after, including restoration projects and future plans for the site. A great attention was pointed to the achievement of the Firminy's Saint Pierre church, which has been followed in "real time", from 2003 to 2006, in connection with architects and the building contractors
APA, Harvard, Vancouver, ISO, and other styles
9

Wu, Chrong-Min, and 吳崇民. "Quantification of Motor Unit Firing Patterns." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/46893074048891162051.

Full text
Abstract:
碩士
國立成功大學
醫學工程研究所
86
AbstractAnalysis of single motor unit (MU) discharge patterns provides an understanding of the neurophysiologic basis for quantifying the motor control ability. The aim of this research is to apply the surface motor unit action potentials (MUAPs) measured with noninvasive multielectrode for studying the firing characteristics of stroke, neuropathy, myopathy, and healthy volunteers.To investigate the firing rate variation, the measures of singular value decomposition (SVD), joint interval histogram (JIH), and autoregessive model (AR), derived from interpulse interval (IPI) train, were adopted in this research. This study first verifies the JIH parameters, including slope and area obtained from the AR model of simulated IPI sequences. Our simulation results indicate that the JIH slope reflects the stability of firing sequence and the JIH area indicates the whole firing variation. However, the measurement of SVD slope is too sensitive to the data distribution which is discarded in later clinical studies. Furthermore, this study extends the JIH representation to the second-order AR model. For second-order AR model, the firing characteristics can be observed from the location of poles, in terms of radius and phasic angle in z- plane. The phasic angle of the dominated pole, i.e. with larger radius, can be used to quantify the firing stability. An IPI sequence with larger radian of phasic angle indicates better controllability and vice versus.For each of the recruited subjects, sessions of the electromyographic (EMG) signal from the first dorsal interosseus (1st DI) during voluntary and isometric contraction were recorded. A multistage approach, including spatial filtering for peak localization and spatial decomposition for overlapping MUAPs, was utilized for the MU activity analysis of stroke patients. From limited numbers of clinical cases, the changes of firing characteristics of stroke patient, a upper motor neuron disease, significantly differ from the normal mainly in JIH slope indicating lower firing stability. However, the subjects with neuropathy and myopathy have higher firing variation in comparison with that of normal subjects. Our results indicate that the extracted parameters of the JIH ellipse as well as AR model can provide quantitative assessment for motor control ability in stroke patients.
APA, Harvard, Vancouver, ISO, and other styles
10

Shah, Kena Pankajkumar. "Motor unit firing patterns during sustained ischemic submaximal contractions." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2418.

Full text
Abstract:
The aim of this study was to determine motor unit firing patterns during ischemic versus non-ischemic sustained submaximal isometric contractions of the tibialis anterior muscle. 10 healthy adults attended two experimental sessions approximately 48 hours apart. Both sessions were identical except that the fatigue task in one was performed with a pressure cuff placed above the knee and inflated to 180 mm Hg. Three 5s maximum voluntary contractions (MVCs) were performed prior to and after the fatigue task. Each participant held a target force of 20% MVC until endurance time (peak-to-peak tremor amplitude exceeded 5% MVC). Single motor unit firing rates (11 non ischemic, 9 ischemic) were recorded with intramuscular fine wire electrodes. Mean interspike intervals over 5s time bins were calculated at every 5% endurance time. The endurance time for the ischemic (3.7 ± 0.58 min) fatigue task was significantly (p<0.001) shorter than the non-ischemic (9.5 ± 0.57 min) task. There was no significant difference in mean motor unit firing rates between the two conditions (p=0.883). Within both tests, there was a significant decline in firing rate (ischemic initial: 12.95 ± 0.71 Hz, minimum: 11.41 ± 0.81 Hz, p=0.023; non-ischemic initial: 13.13 ± 0.87 Hz, minimum: 11.15 ± 0.48 Hz, p=0.012). The time to minimum firing rate was significantly (p<0.001) less in the ischemic (1.29 ± 0.2 min) compared to non-ischemic (3.14 ± 0.23 min) condition. Muscle ischemia significantly reduced endurance time and the time to minimum firing rate. However, there were no differences in average motor unit firing rates between the two conditions across the relative phases of endurance time.
text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Firing unit"

1

Channel firing: The tragedy of Exercise Tiger. London, England: Viking, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Lewis, Nigel. Channel firing: The tragedy of Exercise Tiger. London: Viking, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Channel firing: The tragedy of Exercise Tiger. London: Penguin, 1990.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Iyer, Meenakshi Balkrishna. Firing behavior of human motor units during quasi-sinusoidal isometric muscle contractions. [New York]: Columbia University, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Mānnā, Diwān. Indo-French glances, Chandigarh-Firminy: Exhibition being held at the Unité d'habitation, Firminy, France, the Art Gallery of the Alliance Franç̆aise le Corbusier de Chandigarh, India and in the Alliance Française network in India. Chandigarh: Alliance Francaise Le Corbusier de Chandigarh-India, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Le Corbusier: L'Unité d'habitation de Marseille et les autres unités d'habitation à Rezé-les-Nantes, Berlin, Briey en Forêt et Firminy = the Unité d'Habitation in Marseilles and the four other unité blocks in Rezé-les-Nantes, Berlin, Briey en Forêt and Firminy. Paris: Fondation Le Corbusier, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Linden, Darl W. Vander. Effect of muscle length on motor unit firing behavior in human tibialis anterior muscle. 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Pitt, Matthew. Motor unit anatomy and physiology. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198754596.003.0006.

Full text
Abstract:
This chapter focuses on the signals recorded with needle electromyography (EMG) and the measurement of their specific parameters. These parameters include duration, amplitude, number of phases, and stability. The concept of the electrophysiologic biopsy and the explanation of unusual findings seen on EMG are introduced. In relation to the interference pattern, discussions of the firing rate, recruitment order, and interference pattern are given. Moving from the theoretical explanation of the findings, the problems of the accurate quantitative analysis of the motor unit potential are discussed and measures to improve quantification, particularly in children, are highlighted. The importance of filter settings, the storage of signals, and the different ways of collecting and analysing the potentials are all covered. This section finishes with discussion of the normative range for motor unit duration, and concludes with the automatic analysis of the interference pattern, including turns/amplitude analysis, number of short segments measurement, and envelope analysis.
APA, Harvard, Vancouver, ISO, and other styles
9

Shaibani, Aziz. Electromyogram (EMG) Findings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190661304.003.0028.

Full text
Abstract:
While this chapter, and even this book, are not intended to be a textbook in electrodiagnosis, we have chosen video samples of typical abnormal discharges that often are faced by neuromuscular specialists, such as myopathic units, myotonic discharges, myokymia, fibrillation, and neurogenic firing. Other electromyogram (EMG) clips are embedded in other chapters. Firing frequency of the motor unit potentials can be calculated and it is increased in denervation. Observation for 40–60 seconds may be needed to detect infrequent fasciculations after needle placement. Mixed short and long duration is a features of chronic myopathy and can be confused with chronic denervation.
APA, Harvard, Vancouver, ISO, and other styles
10

Lewis, Nigel. Channel Firing. Harbour Books, 1998.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Firing unit"

1

Perczel, György, Loránd Erőss, Dániel Fabó, László Gerencsér, and Zsuzsanna Vágó. "Modeling Neuronal Firing in Epilepsy: Fitting Hawkes Processes to Single-Unit Activity." In Progress in Industrial Mathematics at ECMI 2018, 257–65. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-27550-1_32.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Piotrkiewicz, M., R. Person, and L. Kudina. "The Effect of Repetitive Stimulation on Firing Motoneurons. Computer Simulation Based on a Motor Unit Study." In Stance and Motion, 239–49. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4899-0821-6_22.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Thomas, Christine K., Jane E. Butler, and Inge Zijdewind. "Patterns of Pathological Firing in Human Motor Units." In Advances in Experimental Medicine and Biology, 237–44. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0713-0_29.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Grimby, Lennart, Jan Hannerz, Jörgen Borg, and Björn Hedman. "Firing Properties of Single Human Motor Units on Maintained Maximal Voluntary Effort." In Novartis Foundation Symposia, 157–77. Chichester, UK: John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470715420.ch10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Rodríguez, Francisco B., and Vicente López. "Periodic and synchronic firing in an ensemble of identical stochastic units: Structural stability." In Lecture Notes in Computer Science, 367–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/bfb0098193.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Khurram, Obaid U., Gregory E. P. Pearcey, Matthieu K. Chardon, Edward H. Kim, Marta García, and C. J. Heckman. "The Cellular Basis for the Generation of Firing Patterns in Human Motor Units." In Advances in Neurobiology, 233–58. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-07167-6_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Wood, Leslie, Ronald H. Baxendale, William R. Ferrell, Jay R. Rosenberg, and David Halliday. "Effects of Mechanical Stimulation of Knee Joint Mechanoreceptors on Firing of Quadriceps Motor Units." In Mechanoreceptors, 389–90. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4899-0812-4_74.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Holobar, Aleš. "Decomposition of Compound Muscle Action Potentials by Convolution Kernel Compensation Method: Improved Segmentation of Motor Unit Firings." In 8th European Medical and Biological Engineering Conference, 324–32. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-64610-3_38.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

"firing unit." In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 526. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_61094.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

"power main(s) firing unit." In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 1033. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_163286.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Firing unit"

1

Parsaei, H., F. J. Nezhad, D. W. Stashuk, and A. Hamilton-Wright. "Validation of motor unit potential trains using motor unit firing pattern information." In 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2009. http://dx.doi.org/10.1109/iembs.2009.5332849.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kasi, Patrick K., Lisa S. Krivickas, Melvin Meister, Effie Chew, Maurizio Schmid, Gary Kamen, Edward A. Clancy, and Paolo Bonato. "Motor unit firing characteristics in patients with amyotrophic lateral sclerosis." In 2009 IEEE 35th Annual Northeast Bioengineering Conference. IEEE, 2009. http://dx.doi.org/10.1109/nebc.2009.4967680.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Heisel, M., and D. Levins. "Design and development of a pyrotechnic arming and firing unit." In 1985 IEEE Power Electronics Specialists Conference (ESA SP-230). IEEE, 1985. http://dx.doi.org/10.1109/pesc-esasp.1985.7069809.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Ma, Shihan, Chen Chen, Bo Lv, Xinjun Sheng, and Xiangyang Zhu. "Estimation of Motor Unit Global Firing Rate by Maximum Power Amplitude." In 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC). IEEE, 2019. http://dx.doi.org/10.1109/embc.2019.8857676.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

DeVries, Derek, F. Duce, John Weinlein, and William Brigham. "Simulated EBW detonation output characteristics of new universal destruct firing unit." In 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1998. http://dx.doi.org/10.2514/6.1998-3629.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Vittal, K. P., Ajay Pai P., Ajay Shenoy B., and C. H. Srinivas Rao. "Computer Controlled Intrusion-Detector and Automatic Firing-Unit for Border Security." In 2010 Second International Conference on Computer and Network Technology. IEEE, 2010. http://dx.doi.org/10.1109/iccnt.2010.32.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Ro̸nnedal, Per, and Hans Bo̸je Nielsen. "Firing Order Selection in Relation to Vibration Aspects." In ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0603.

Full text
Abstract:
Selecting the optimum firing order for a combustion engine is an important decision to make when developing an engine. Typically, the optimum choice is made on the basis of a weighted balance between a number of interrelated engine vibration characteristics, such as: balancing, free forces and free moments, guide force distribution, inner bending moments, bearing load, and torsional and axial vibration behaviour. Also gas dynamic properties making each cylinder do the same amount of work is considered. In addition to the traditional firing sequence selection, implying the same firing interval between cylinder units, also so-called irregular firing orders, characterized by different intervals between the individual firings, are considered. Various methods and strategies can be applied, considering that different engine applications exhibit completely different vibratory behaviour, e.g. marine propulsion plants compared with stationary installations. This paper will give examples relating to various applications for both two-stroke and four-stroke engines. Four-stroke: Realizing that the engine is often an integrated part of a complex system, it is demonstrated in this paper that analysing the whole system in terms of linear vibrations, the optimum firing order is different from the firing order determined with traditional methods. The system analysed here is a genset for marine or stationary application consisting of a 9-cylinder diesel engine, alternator and base frame. All three parts are bolted together as one unit, resiliently mounted on a ship or a land-based foundation. Two-stroke: The traditional 7-cylinder marine propulsion engine firing sequence is modified in order to be able to run safely directly at a two-node torsional resonance without installing a T/V damper. The 12-cylinder stationary engine has been modified so as to reduce installation costs and improve the coupled torsional-axial vibratory behaviour. The 10-cylinder marine engine firing sequence has been modified in order to achieve more favourable structural vibration characteristics.
APA, Harvard, Vancouver, ISO, and other styles
8

Paskach, Thomas J., and John P. Reardon. "Gasification: Eliminating Risks Associated With Co-Firing Biomass." In ASME 2010 Power Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/power2010-27360.

Full text
Abstract:
Under certain greenhouse gas (GHG) regulation scenarios, older coal-fired units may be faced with the prospect of shutdown before reaching the end of their useful life. Repurposing this existing asset for 100% biomass fuel is a more efficient use of capital than compared to building a new stand-alone unit. Biomass co-firing is an alternative for an owner to consider to address GHG regulation impacts on older coal-fired power boilers and the growing demands of pending legislation. “Direct” co-firing is a baseline approach where finely divided biomass is injected directly into the boiler furnace. Direct co-firing experience is typically less than 5% heat rate, and technical upper limits have been described in EPRI literature (1) as approximately 10% of boiler heat. Direct co-firing also does not enhance the opportunity to co-fire biomass with natural gas. Direct biomass co-firing may require extensive renovations and emissions/particulate control devices. “Indirect” co-firing is an alternative process that mitigates process risk by first converting the biomass into a fuel gas and then cleaning this gas to remove alkali and chloride contaminants prior to combustion in the power boiler furnace. Indirect co-firing may be a superior approach from an operations perspective because it protects against forced outages and repair costs expected with direct co-firing (2). Gas cleaning to remove alkali metals from the fuel gas prior to combustion reduces process risk by reducing fouling and slagging potential. Removing chloride from the fuel gas dramatically reduces the corrosion potential. Beyond reducing process risk, separating biomass ash before combustion retains the value in separate co-product ash streams, as it prevents intermingling with the coal ash. This paper describes technical and economic considerations for indirect co-firing, contrasted with direct co-firing approaches. The renewable energy ratio of a co-fired unit could be significantly increased by employing biomass gasification of the solid fuel with gas cleanup, in contrast to process risks, added emissions control costs, and technical limitations of direct co-firing of the solid biofuel.
APA, Harvard, Vancouver, ISO, and other styles
9

Ohno, Sadahiro, Hiroyuki Yamazaki, Naoki Hagi, and Hidehiko Nishimura. "Advanced Gas Turbine Technology for Sendai Thermal Power Station, Unit No. 4." In ASME 2011 Power Conference collocated with JSME ICOPE 2011. ASMEDC, 2011. http://dx.doi.org/10.1115/power2011-55384.

Full text
Abstract:
Worldwide environmental concerns are placing center focus on effective utilization of energy and carbon dioxide emission reductions. The power generation industry has engaged in the replacement of existing aged thermal power plants with state-of-the-art natural gas fired power plants capable of achieving considerable reductions in energy consumption and emissions of green house gases. The replacement of three exiting 175MW heavy oil and coal-firing power plants with a highly effective 446MW gas-firing combined cycle power plant owned and operated by Tohoku Electric Power Company is one example of this effort. The construction of the new Sendai thermal power station, Unit No.4 started in November, 2007 achieving commercial operation in July, 2010. Mitsubishi Heavy Industries most recent 50Hz F class gas turbine upgrade, the M701F4 was adopted for this project. This engine is based on the successful M701F3 gas turbine with a 6% air flow increase and a slight bump of the turbine inlet temperature in order to achieve better thermal efficiency and more power output. The application of these advanced technologies resulted in a plant thermal efficiency of approximately 58% LHV of the new unit from the original 43% of the previous coal-firing units. The application of these advanced technologies and the use of natural gas resulted in a 2/3 carbon-dioxide emissions reduction.
APA, Harvard, Vancouver, ISO, and other styles
10

Raatikka, Luther M. "Woody Biomass Co-Firing in Pulverized Coal Fired Boilers." In ASME 2011 Power Conference collocated with JSME ICOPE 2011. ASMEDC, 2011. http://dx.doi.org/10.1115/power2011-55300.

Full text
Abstract:
With legislation requiring utilities to produce a significant fraction of their electrical energy with renewable fuel supplies, it is anticipated that cofiring biomass in large utility boilers will become increasingly popular. Boilers that are designed to burn pulverized coal (PC) can typically burn woody biomass at up to 5% of the rated heat input. An 800 MW PC-fired unit could, therefore, produce up to 40 MW of renewable energy with biomass co-firing. The generating plant may experience a net capacity de-rating whenever biomass is co-fired. This potential reduction in net plant output may be attributed to reduced boiler efficiency and additional auxiliary power requirements. Biomass fuel handling related auxiliary power requirements are dependent upon the form in which biomass is delivered to the plant. Preparation of woody biomass for co-firing in large PC-fired boilers is typically performed onsite with hammer mills or by off-site processing. For an 800 MW unit, onsite fuel size reduction will usually result in an incremental increase in auxiliary power of 3–4 MW, whereas the use of pre-processed biomass such as wood pellets will require a minimal increase in parasitic load. However, delivered fuel costs for raw wood requiring onsite processing are at least 60% lower than that of densified biomass on a heat input basis. This paper includes an economic comparison of co-firing woody biomass that is processed onsite by direct injection vs. co-firing densified woody biomass by co-milling in a large PC-fired boiler. This comparison will consider delivered fuel costs, capital costs, CO2 emissions and impacts upon boiler efficiency and net heat rate.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Firing unit"

1

Wu, Hsin-Fu, and Alexandra M. Newman. Incorporating the SSGN Firing Unit in the TOMAHAWK Missile Phase 1 Predesignation Heuristic. Fort Belvoir, VA: Defense Technical Information Center, October 2002. http://dx.doi.org/10.21236/ada407619.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kassner, M. C., T. C. Kennedy, T. Puttapitukporn, and R. S. Rosen. Mechanical Analysis of an SM 2 Blk IV restrained firing within a concentric canister launcher test unit. Office of Scientific and Technical Information (OSTI), March 1999. http://dx.doi.org/10.2172/14146.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Newman, Alexandra M., Richard E. Rosenthal, Javier Salmeron, Gerald G. Brown, Wilson Price, Anton Rowe, Charles F. Fennemore, and Robert L. Taft. Optimizing Assignment of Tomahawk Cruise Missile Missions to Firing Units. Fort Belvoir, VA: Defense Technical Information Center, January 2009. http://dx.doi.org/10.21236/ada549418.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Firing unit' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography