Relevant bibliographies by topics / Sparkr

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Sparkr'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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

Select a source type:

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

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 "Sparkr"

1

Sedlmayr, Martin, Tobias Würfl, Christian Maier, Lothar Häberle, Peter Fasching, Hans-Ulrich Prokosch, and Jan Christoph. "Optimizing R with SparkR on a commodity cluster for biomedical research." Computer Methods and Programs in Biomedicine 137 (December 2016): 321–28. http://dx.doi.org/10.1016/j.cmpb.2016.10.006.

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

Chang, Bao Rong, Yun-Da Lee, and Po-Hao Liao. "Development of Multiple Big Data Analytics Platforms with Rapid Response." Scientific Programming 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/6972461.

Full text
Abstract:
The crucial problem of the integration of multiple platforms is how to adapt for their own computing features so as to execute the assignments most efficiently and gain the best outcome. This paper introduced the new approaches to big data platform, RHhadoop and SparkR, and integrated them to form a high-performance big data analytics with multiple platforms as part of business intelligence (BI) to carry out rapid data retrieval and analytics with R programming. This paper aims to develop the optimization for job scheduling using MSHEFT algorithm and implement the optimized platform selection based on computing features for improving the system throughput significantly. In addition, users would simply give R commands rather than run Java or Scala program to perform the data retrieval and analytics in the proposed platforms. As a result, according to performance index calculated for various methods, although the optimized platform selection can reduce the execution time for the data retrieval and analytics significantly, furthermore scheduling optimization definitely increases the system efficiency a lot.
APA, Harvard, Vancouver, ISO, and other styles
3

Saka, Chika, Tomoki Oshika, and Masayuki Jimichi. "Visualization of tax avoidance and tax rate convergence." Meditari Accountancy Research 27, no. 5 (October 7, 2019): 695–724. http://dx.doi.org/10.1108/medar-02-2018-0298.

Full text
Abstract:
Purpose This study aims to explore the evidence of the probability of firms’ tax avoidance and the downward convergence trend of national statutory tax rates and firms’ effective tax rates. Design/methodology/approach This research employs exploratory data analysis using interactive data manipulation and visualization tools, namely, R with SparkR, dplyr, ggplot2 and googleVis (GeoChart and Motion Chart) packages. This analysis is based on the world-scale accounting data of all listed firms from 148 countries spanning 30 years. Findings The results reveal the following: three types of evidences on probability of firms’ tax avoidance, showing a non-random distribution of firms’ effective tax rates and return on assets, cross-sectional variation of firms’ effective tax rates in each country, and the trend of difference between effective tax rates and statutory tax rates, and the downward convergence trend of statutory tax rates and firms’ effective tax rates. Practical implications The results highlight the prominent issues of world-scale tax avoidance and tax rate competition and facilitate a collaborative discussion between laymen and professionals using objective evidence. Originality/value A novel methodology is adopted through the visualization of world-scale accounting data, which can facilitate a new perspective, revealing unexpected patterns and trends in otherwise hidden information. This study also highlights the importance of global consideration of firms’ tax avoidance and tax rate competition, using objective evidence.
APA, Harvard, Vancouver, ISO, and other styles
4

Laasmaa, Martin, Niina Karro, Rikke Birkedal, and Marko Vendelin. "IOCBIO Sparks detection and analysis software." PeerJ 7 (March 29, 2019): e6652. http://dx.doi.org/10.7717/peerj.6652.

Full text
Abstract:
Analysis of calcium sparks in cardiomyocytes can provide valuable information about functional changes of calcium handling in health and disease. As a part of the calcium sparks analysis, sparks detection and characterization is necessary. Here, we describe a new open-source platform for automatic calcium sparks detection from line scan confocal images. The developed software is tailored for detecting only calcium sparks, allowing us to design a graphical user interface specifically for this task. The software enables detecting sparks automatically as well as adding, removing, or adjusting regions of interest marking each spark. The results of the analysis are stored in an SQL database, allowing simple integration with statistical tools. We have analyzed the performance of the algorithm using a large set of synthetic images with varying spark sizes and noise levels and also compared the analysis results with results obtained by software established in the field. The use of our software is illustrated by an analysis of the effect of isoprenaline (ISO) on spark frequency, amplitude, and spatial and temporal characteristics. For that, cardiomyocytes from C57BL/6 mice were used. We demonstrated an increase in spark frequency, tendency of having larger spark amplitudes, sparks with a longer duration, and occurrence of multiple sparks from the same site in the presence of ISO. We also show that the duration and the width of sparks with the same amplitude were similar in the absence and presence of ISO. The software was released as an open source repository and is available for free use and collaborative development.
APA, Harvard, Vancouver, ISO, and other styles
5

Bao, Rongfeng, Lawrence M. Lifshitz, Richard A. Tuft, Karl Bellvé, Kevin E. Fogarty, and Ronghua ZhuGe. "A Close Association of RyRs with Highly Dense Clusters of Ca2+-activated Cl− Channels Underlies the Activation of STICs by Ca2+ Sparks in Mouse Airway Smooth Muscle." Journal of General Physiology 132, no. 1 (June 30, 2008): 145–60. http://dx.doi.org/10.1085/jgp.200709933.

Full text
Abstract:
Ca2+ sparks are highly localized, transient releases of Ca2+ from sarcoplasmic reticulum through ryanodine receptors (RyRs). In smooth muscle, Ca2+ sparks trigger spontaneous transient outward currents (STOCs) by opening nearby clusters of large-conductance Ca2+-activated K+ channels, and also gate Ca2+-activated Cl− (Cl(Ca)) channels to induce spontaneous transient inward currents (STICs). While the molecular mechanisms underlying the activation of STOCs by Ca2+ sparks is well understood, little information is available on how Ca2+ sparks activate STICs. In the present study, we investigated the spatial organization of RyRs and Cl(Ca) channels in spark sites in airway myocytes from mouse. Ca2+ sparks and STICs were simultaneously recorded, respectively, with high-speed, widefield digital microscopy and whole-cell patch-clamp. An image-based approach was applied to measure the Ca2+ current underlying a Ca2+ spark (ICa(spark)), with an appropriate correction for endogenous fixed Ca2+ buffer, which was characterized by flash photolysis of NPEGTA. We found that ICa(spark) rises to a peak in 9 ms and decays with a single exponential with a time constant of 12 ms, suggesting that Ca2+ sparks result from the nonsimultaneous opening and closure of multiple RyRs. The onset of the STIC lags the onset of the ICa(spark) by less than 3 ms, and its rising phase matches the duration of the ICa(spark). We further determined that Cl(Ca) channels on average are exposed to a [Ca2+] of 2.4 μM or greater during Ca2+ sparks. The area of the plasma membrane reaching this level is <600 nm in radius, as revealed by the spatiotemporal profile of [Ca2+] produced by a reaction-diffusion simulation with measured ICa(spark). Finally we estimated that the number of Cl(Ca) channels localized in Ca2+ spark sites could account for all the Cl(Ca) channels in the entire cell. Taken together these results lead us to propose a model in which RyRs and Cl(Ca) channels in Ca2+ spark sites localize near to each other, and, moreover, Cl(Ca) channels concentrate in an area with a radius of ∼600 nm, where their density reaches as high as 300 channels/μm2. This model reveals that Cl(Ca) channels are tightly controlled by Ca2+ sparks via local Ca2+ signaling.
APA, Harvard, Vancouver, ISO, and other styles
6

Kou, Jie, Xinman Zhang, Yuxuan Huang, and Cong Zhang. "SAVSDN: A Scene-Aware Video Spark Detection Network for Aero Engine Intelligent Test." Sensors 21, no. 13 (June 29, 2021): 4453. http://dx.doi.org/10.3390/s21134453.

Full text
Abstract:
Due to carbon deposits, lean flames, or damaged metal parts, sparks can occur in aero engine chambers. At present, the detection of such sparks deeply depends on laborious manual work. Considering that interference has the same features as sparks, almost all existing object detectors cannot replace humans in carrying out high-precision spark detection. In this paper, we propose a scene-aware spark detection network, consisting of an information fusion-based cascading video codec-image object detector structure, which we name SAVSDN. Unlike video object detectors utilizing candidate boxes from adjacent frames to assist in the current prediction, we find that efforts should be made to extract the spatio-temporal features of adjacent frames to reduce over-detection. Visualization experiments show that SAVSDN can learn the difference in spatio-temporal features between sparks and interference. To solve the problem of a lack of aero engine anomalous spark data, we introduce a method to generate simulated spark images based on the Gaussian function. In addition, we publish the first simulated aero engine spark data set, which we name SAES. In our experiments, SAVSDN far outperformed state-of-the-art detection models for spark detection in terms of five metrics.
APA, Harvard, Vancouver, ISO, and other styles
7

Picht, Eckard, Aleksey V. Zima, Lothar A. Blatter, and Donald M. Bers. "SparkMaster: automated calcium spark analysis with ImageJ." American Journal of Physiology-Cell Physiology 293, no. 3 (September 2007): C1073—C1081. http://dx.doi.org/10.1152/ajpcell.00586.2006.

Full text
Abstract:
Ca sparks are elementary Ca-release events from intracellular Ca stores that are observed in virtually all types of muscle. Typically, Ca sparks are measured in the line-scan mode with confocal laser-scanning microscopes, yielding two-dimensional images (distance vs. time). The manual analysis of these images is time consuming and prone to errors as well as investigator bias. Therefore, we developed SparkMaster, an automated analysis program that allows rapid and reliable spark analysis. The underlying analysis algorithm is adapted from the threshold-based standard method of spark analysis developed by Cheng et al. ( Biophys J 76: 606–617, 1999) and is implemented here in the freely available image-processing software ImageJ. SparkMaster offers a graphical user interface through which all analysis parameters and output options are selected. The analysis includes general image parameters (number of detected sparks, spark frequency) and individual spark parameters (amplitude, full width at half-maximum amplitude, full duration at half-maximum amplitude, full width, full duration, time to peak, maximum steepness of spark upstroke, time constant of spark decay). We validated the algorithm using images with synthetic sparks embedded into backgrounds with different signal-to-noise ratios to determine an analysis criteria at which a high sensitivity is combined with a low frequency of false-positive detections. Finally, we applied SparkMaster to analyze experimental data of sparks measured in intact and permeabilized ventricular cardiomyocytes, permeabilized mammalian skeletal muscle, and intact smooth muscle cells. We found that SparkMaster provides a reliable, easy to use, and fast way of analyzing Ca sparks in a wide variety of experimental conditions.
APA, Harvard, Vancouver, ISO, and other styles
8

Herrera, Gerald M., Thomas J. Heppner, and Mark T. Nelson. "Voltage dependence of the coupling of Ca2+ sparks to BKCa channels in urinary bladder smooth muscle." American Journal of Physiology-Cell Physiology 280, no. 3 (March 1, 2001): C481—C490. http://dx.doi.org/10.1152/ajpcell.2001.280.3.c481.

Full text
Abstract:
Large-conductance Ca2+-dependent K+(BKCa) channels play a critical role in regulating urinary bladder smooth muscle (UBSM) excitability and contractility. Measurements of BKCa currents and intracellular Ca2+ revealed that BKCa currents are activated by Ca2+ release events (Ca2+ sparks) from ryanodine receptors (RyRs) in the sarcoplasmic reticulum. The goals of this project were to characterize Ca2+ sparks and BKCa currents and to determine the voltage dependence of the coupling of RyRs (Ca2+ sparks) to BKCachannels in UBSM. Ca2+ sparks in UBSM had properties similar to those described in arterial smooth muscle. Most Ca2+ sparks caused BKCa currents at all voltages tested, consistent with the BKCa channels sensing ∼10 μM Ca2+. Membrane potential depolarization from −50 to −20 mV increased Ca2+ spark and BKCacurrent frequency threefold. However, membrane depolarization over this range had a differential effect on spark and current amplitude, with Ca2+ spark amplitude increasing by only 30% and BKCa current amplitude increasing 16-fold. A major component of the amplitude modulation of spark-activated BKCa current was quantitatively explained by the known voltage dependence of the Ca2+ sensitivity of BKCa channels. We, therefore, propose that membrane potential, or any other agent that modulates the Ca2+sensitivity of BKCa channels, profoundly alters the coupling strength of Ca2+ sparks to BKCa channels.
APA, Harvard, Vancouver, ISO, and other styles
9

Stern, Michael D., Eduardo Ríos, and Victor A. Maltsev. "Life and death of a cardiac calcium spark." Journal of General Physiology 142, no. 3 (August 26, 2013): 257–74. http://dx.doi.org/10.1085/jgp.201311034.

Full text
Abstract:
Calcium sparks in cardiac myocytes are brief, localized calcium releases from the sarcoplasmic reticulum (SR) believed to be caused by locally regenerative calcium-induced calcium release (CICR) via couplons, clusters of ryanodine receptors (RyRs). How such regeneration is terminated is uncertain. We performed numerical simulations of an idealized stochastic model of spark production, assuming a RyR gating scheme with only two states (open and closed). Local depletion of calcium in the SR was inevitable during a spark, and this could terminate sparks by interrupting CICR, with or without assumed modulation of RyR gating by SR lumenal calcium. Spark termination by local SR depletion was not robust: under some conditions, sparks could be greatly and variably prolonged, terminating by stochastic attrition–a phenomenon we dub “spark metastability.” Spark fluorescence rise time was not a good surrogate for the duration of calcium release. Using a highly simplified, deterministic model of the dynamics of a couplon, we show that spark metastability depends on the kinetic relationship of RyR gating and junctional SR refilling rates. The conditions for spark metastability resemble those produced by known mutations of RyR2 and CASQ2 that cause life-threatening triggered arrhythmias, and spark metastability may be mitigated by altering the kinetics of the RyR in a manner similar to the effects of drugs known to prevent those arrhythmias. The model was unable to explain the distributions of spark amplitudes and rise times seen in chemically skinned cat atrial myocytes, suggesting that such sparks may be more complex events involving heterogeneity of couplons or local propagation among sub-clusters of RyRs.
APA, Harvard, Vancouver, ISO, and other styles
10

Zhou, J., G. Brum, A. González, B. S. Launikonis, M. D. Stern, and E. Ríos. "Ca2+ Sparks and Embers of Mammalian Muscle. Properties of the Sources." Journal of General Physiology 122, no. 1 (June 30, 2003): 95–114. http://dx.doi.org/10.1085/jgp.200308796.

Full text
Abstract:
Ca2+ sparks of membrane-permeabilized rat muscle cells were analyzed to derive properties of their sources. Most events identified in longitudinal confocal line scans looked like sparks, but 23% (1,000 out of 4,300) were followed by long-lasting embers. Some were preceded by embers, and 48 were “lone embers.” Average spatial width was ∼2 μm in the rat and 1.5 μm in frog events in analogous solutions. Amplitudes were 33% smaller and rise times 50% greater in the rat. Differences were highly significant. The greater spatial width was not a consequence of greater open time of the rat source, and was greatest at the shortest rise times, suggesting a wider Ca2+ source. In the rat, but not the frog, spark width was greater in scans transversal to the fiber axis. These features suggested that rat spark sources were elongated transversally. Ca2+ release was calculated in averages of sparks with long embers. Release current during the averaged ember started at 3 or 7 pA (depending on assumptions), whereas in lone embers it was 0.7 or 1.3 pA, which suggests that embers that trail sparks start with five open channels. Analysis of a spark with leading ember yielded a current ratio ranging from 37 to 160 in spark and ember, as if 37–160 channels opened in the spark. In simulations, 25–60 pA of Ca2+ current exiting a point source was required to reproduce frog sparks. 130 pA, exiting a cylindric source of 3 μm, qualitatively reproduced rat sparks. In conclusion, sparks of rat muscle require a greater current than frog sparks, exiting a source elongated transversally to the fiber axis, constituted by 35–260 channels. Not infrequently, a few of those remain open and produce the trailing ember.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Sparkr"

1

Flamigni, Bianca. "Supporto all'Analisi Statistica basata su R in Ambiente Apache Spark." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

Find full text
Abstract:
Le ultime tendenze nell’analisi di Big Data indicano il sempre più crescente bisogno di poter effettuare analisi interattiva su questi grandi dataset. Tipicamente si utilizza il linguaggio R per fare analisi avanzata sui dati, ma, a causa di limitazioni di livello tecnico, questo non è in grado di gestire Big Data in modo efficiente. Per tale motivo è stato ideato SparkR, un progetto, basato su Spark, per l’esecuzione distribuita di programmi in R scalabili e adatti a diversi tipi di carichi di lavoro. In questo documento, analizzeremo approfonditamente il progetto SparkR e ne osserveremo le prestazioni, a fronte di diverse applicazioni tipiche dell’analisi di Big Data (algoritmi di clustering e query interattive), in modo da poter identificare possibili limiti o colli di bottiglia e, grazie alla conoscenza acquisita, proporremo delle soluzioni in grado di ottenere buoni miglioramenti prestazionali. Tra queste, un componente che, sfruttando lo storico delle applicazioni lanciate, è capace di configurare in automatico alcune proprietà interne a Spark ed ottenere di conseguenza una riduzione nei tempi di esecuzione degli applicativi in R. Forniremo i risultati che dimostrano come grazie alla nostra proposta sia possibile ottenere un miglioramento del 18% rispetto alla configurazione di default di Spark. Infine, proporremo l’implementazione di un supporto efficiente e ben scalabile ad un algoritmo di clustering gerarchico, Bisecting K-means, e dimostreremo, tramite un’attenta valutazione delle prestazioni, come rappresenti un buon compromesso per garantire l’utilizzo di una tecnica così diffusa, come quella del clustering gerarchico, in un ambiente distribuito, nonostante algoritmi di questo genere siano noti per non essere particolarmente compatibili con un modello di programmazione tale.
APA, Harvard, Vancouver, ISO, and other styles
2

Cox-Richard, Lillian. "Spark Gap." VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/698.

Full text
Abstract:
"Spark Gap" is an invisible electrical force made visible in spaces between things. This usually describes the space of air between two conductors; a non-conductive gap in an otherwise complete electric circuit, across which a quick luminous disruptive electrical discharge occurs. This interstitial space is the distance between two ideas, arced with a running leap. The arc can also be the difference between two things, a gap that becomes apparent only when the two are held in close proximity. In my thesis exhibition, "Spark Gap," a sea urchin shaped orb sits atop a tower of ladders. The orb is broken into five sections and reassembled, each fault line occurring along the perfect zigzag line of its cellular structure. On the floor, there is a linen shag rug, marked as if struck by lightning. This exhibition is named for an interstitial charge, arcing across distance or difference. But this charge is also found in intersections and similarities. Imagine the friction created by rubbing together the circles of a Venn diagram: the overlapping section would begin to spark. It is in these gaps and overlaps that I find the impetus for my work.
APA, Harvard, Vancouver, ISO, and other styles
3

Samandari, Farshid. "Sparks of Union." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46483.

Full text
Abstract:
This document delves into the precept of unity in diversity from a musical perspective, in order to replace the timeworn aesthetic norms with ones that may induce a music befitting the fabric of our contemporary global village. It deals with the contemporary musical zeitgeist from this perspective and examines the transformations in musical substance derived from the copious changes in dissemination since the information revolution. It also presents Sparks of Union, a 20-minute composition for ten Western instruments and interactive electronics. This composition aims to focus on different musical languages in search of polarizing and uniting elements, and explores free interactions between the different musical elements. As a result it strives to create new sonorities derived from a fully democratic multicultural interaction.
APA, Harvard, Vancouver, ISO, and other styles
4

Hwang, Suk Hyun. "Optimization of the Photovoltaic Time-series Analysis Process Through Hybrid Distributed Computing." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1587128073434884.

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

Kim, Kwanghoon. "Infrared luminescence from spark-processed silicon and erbium-doped spark-processed silicon." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012860.

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

Mahajan, Rohan. "Adaptive scheduling in Spark." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105977.

Full text
Abstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 33).
Because most data processing systems are distributed in nature, data must be transferred between machines. Currently, Spark, a prominent such system, predetermines the strategies for shuffling this data, but in certain situations, different shuffle strategies would improve performance. We add functionality to track metrics about the data during the job and appropriately adapt the shuffle strategy. We show improvements in ShuffledRDD performance, joins using Spark's RDD interface, and joins in Spark SQL.
by Rohan Mahajan.
M. Eng.
APA, Harvard, Vancouver, ISO, and other styles
7

Walls, Kate. "Muriel Spark and Catholicism." Thesis, Queen's University Belfast, 2014. https://pure.qub.ac.uk/portal/en/theses/muriel-spark-and-catholicism(2d16b200-588b-4866-a1d6-dea6396b68cb).html.

Full text
Abstract:
My PhD thesis analyses Catholic themes in the novel,s of Scottish born writer Muriel Spark. Spark's career spanned five decades, and much of her work was influenced by her conversion to Catholicism. She is a sophisticated and enigmatic writer whose work defies categorisation. Part of this difficulty stems from her position as "other" within Catholicism· -a result of her conversion and her refusal to adhere to traditional Catholic gender roles. What does become clear upon examining Spark's fiction is that she uses subversive and paradoxical rhetoric to highlight the problems inherent in being unable to fully comprehend God's mystery. Spark appears to be obsessed with several religious concepts that appear constantly in her fiction. In the case of the Catholic convert and the Book of Job, these threads appear repeatedly and build to a climax-once Spark comprehensively addresses them in her fiction, the threads disappears from her work entirely. In exploring these Catholic themes, it becomes clear that, despite Spark's work being abundant with references to religion, there is very little narrative space devoted to the character's internal thoughts regarding God and religious thought. I argue that in Spark's fiction, creativity is a proxy for religious faith. Spark draws parallels to the personal and individual nature of both, but devotes more narrative space to explaining a sense of faith in the creative process. She also appears to grant narrative endorsement to characters who believe in and ate guided by their creativity, even when they clearly traverse the boundaries of acceptable "moral" behaviour.
APA, Harvard, Vancouver, ISO, and other styles
8

Kim, Jaecheol. "The role of radicals supplied directly and indirectly on ignition." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53001.

Full text
Abstract:
The ignition process is a critical consideration for combustion devices. External energy transfer to the combustor is required for ignition in common combustion systems. There are many ways to deposit energy into the flow but a standard method is a spark discharge because it is simple, compact, and reliable. Sparks can be categorized as either inductive or capacitive sparks that use a coil or an electrical resonance circuit with capacitor, respectively, to amplify the voltage. The creation of a successful ignition event depends on the spark energy deposited into the flow, the initial composition, pressure, temperature, turbulence level of flow etc. The deposited energy by the spark into the flow is critical for estimation of initial energy available for ignition of the mixture. Therefore, the electrical characteristics of the sparks were investigated under various flow conditions. Then measurements of deposited energy into the flow were conducted using a very accurate experimental procedure that was developed in this research. The results showed considerable electric energy losses to the electrodes for the relatively long, inductive sparks. However, the short, capacitive spark deposits electric energy into the flow with minimal loss (above 90% deposition efficiency). In addition, the characteristics of inductive spark are affected by flow velocity and by the existence of a flame. However, variations in the flow conditions do not affect the characteristics of the capacitive spark such as voltage-current time trace and energy deposition efficiency. Two ignition systems using above mentioned two spark types were developed. First, the capacitive spark energy was directly deposited into the premixed flow. Most researchers have not concentrated on the early initiation process but on the flame growth. Therefore, the generated kernel formed by the energy deposition was observed and characterized using optical methods, immediately following the spark. In addition, the mixing effect for this ignition kernel with surrounding gas was simulated using a numerical method. Based on the time trace of the OH* chemiluminescence, the reaction starts with the discharge and it is continuous until combustion begins. This means that in the presence of a high density spark in premixed flow, there exists no traditional delay as defined by other researchers for auto ignition. A simple Radical Jet Generator (RJG) was developed that is able to ignite and stabilize a flame in a high-speed flow. The inductive spark initiates the combustion in the RJG chamber. The RJG then injects the partially-burned products carrying large amounts of heat and radicals into a rapidly moving flammable main stream. Then it ignites and stabilizes a flame. The RJG requires low levels of electrical power as long as the flow velocity is relatively low since most of the radicals are produced by the incomplete combustion in its chamber. The importance of radicals was analyzed by RJG experiments and numerical methods. The reaction zone for RJG using a rich mixture was located both inside and outside of the RJG chamber. Therefore, the RJG using a rich mixture performed better in the ignition and stabilization of combustion in the main flow. According to an analysis using the CHEMKIM simulation software combined with the San Diego chemical mechanism, the RJG jet resulting from a rich mixture contains more radicals and intermediates than that produced by a lean mixture for the same sensible enthalpy. In addition, the burned gas contains less radicals and intermediates than the partially burned gas. If the RJG is operating with a high speed main flow, the flow rate through the RJG chamber must be increased to allow the radical jet to penetrate well into the rapid flow due to their higher injection velocity. Unfortunately, this leads to unsteady combustion in the RJG, which results in the pulsation of the radical jet. This reduces the number of radicals injected into the main flow. To investigate this operating condition, special attention was focused on four possible factors: unburned reactant pockets caused by motion of the spark channel, spark frequency, flame propagation speed and ignition delay. It was shown that the unsteadiness is affected by the flame speed and ignition delay because the frequency of pulsation in the chamber is highly dependent on the equivalence ratio. In addition, the interaction between the RJG operation and the combustion dynamics in the main combustor was documented. The acoustic pressure oscillations in the main combustor were suppressed when the RJG jet was turned on because the reaction region is relocated by the operation of the RJG.
APA, Harvard, Vancouver, ISO, and other styles
9

Mattsson, Niklas, and Jonas Brorsson. "Kommer företagen att sparka ut revisorn?" Thesis, Umeå University, Umeå School of Business, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1774.

Full text
Abstract:

Sverige har sedan 1983 haft lagstadgad revisionsplikt för alla aktiebolag. Med anledning av regeringens mål att reducera de administrativa kostnaderna för de svenska företagen tillsattes en utredning om hur revisionsplikten ska avskaffas för de svenska aktiebolagen. Enligt regeringens förslag som presenterades i mars 2008 föreslås en avskaffad revisionsplikt för 96 % av de svenska aktiebolagen.

Avskaffad revisionsplikt innebär en förändring som berör hela näringslivet. Konsekvenserna av avskaffandet är framförallt av intresse för revisionsbranschen och samhället.

Efterfrågan av revision förklaras huvudsakligen genom agentteorin om att det sker en separation mellan ägande och företagsledning. Tidigare studier visar även att faktorer som exempelvis krav från kreditgivare, val av revisionsbyrå och förbättrad kvalité på redovisningen påverkar valet av revision.

Vi har utifrån ett deduktivt angreppssätt genomfört en enkätstudie bland företag i Umeå med 1-49 anställda. Tack vare ekonomiskt stöd från en revisionsbyrå postades enkäten ut till 300 företag fördelade på tre olika urvalskategorier (1-3, 4-9 och 10-49 anställda) och vi erhöll svar från 118 st företag. Syftet med studien vara att få en uppfattning om företagens val av revisions utifrån antagandet om att revisionsplikten är avskaffad samt att förklara de faktorer som har betydelse för företagens val av revision.

Resultaten av studien visar att 54,2 % av företagen i Umeå kommer att fortsätta med revision förutsatt att plikten är avskaffad. Fördelat på de tre olika urvalskategorierna ökar benägenheten att välja revision med storleken. Av företag med 1-3 anställda kommer 45,2 % välja revision, av företag med 4-9 anställda kommer 62,9 % välja revision och av företag med 10-49 kommer 87,8 % att välja revision.

De faktorer som förklarar Umeå-företagens val är företagets storlek, skuldsättningsgrad och upplevd förbättrad internkontroll som alla visat positiva signifikanta samband med valet av revision. Även uppfattad kvalité på redovisning och ökad tillförlitlighet gentemot intressenterna är faktorer som är viktiga i valet av revision.

Vi anser att generaliserbarheten från studien är god eftersom vi erhållit en representativ fördelning av svar från alla kategorier samt att vi viktat svaren efter hur hela populationen ser ut. Detta för att få ett rättvisande resultat på i vilken utsträckning företagen kommer fortsätta med revision.

Resultaten skall dock sättas i perspektivet av att de bygger på att hypotetiskt val och inte företagens faktiska val. Detta innebär vissa implikationer och det är rimligt att anta att det faktiska utfallet kan förändras eftersom vissa faktorer aktualiseras först när plikten är avskaffad, exempelvis krav från kreditgivare för att erhålla lån.

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

Eketorp, Erik, and Jonas Finnman. "Hemautomation - Sparar man så kostar det!" Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199259.

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

Books on the topic "Sparkr"

1

Halloran, Richard. Sparky: Warrior, peacemaker, poet, patriot : a portrait of Senator Spark M. Matsunaga. Honolulu: Watermark Pub., 2002.

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

Jeff, Gottesfeld, ed. Sparks. New York: Little, Brown, 2004.

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

Thompson, Vicki Lewis. Sparks. Toronto: Harlequin Books, 2001.

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

Anderson, Sparky. Sparky! New York: Prentice Hall Press, 1990.

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

Sparks. Beijing, China: Chinese Literature Press, 1988.

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

Sparks. Toronto: Harlequin Books, 1988.

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

Sparks. New York: Wendy Lamb Books, 2002.

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

Bickle, Laura. Sparks. New York: Pocket Books, 2010.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

ill, Appelhans Chris, ed. Sparky! New York: Schwartz & Wade Books, 2014.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Anderson, Sparky. Sparky! New York: Prentice Hall Press, 1990.

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

Book chapters on the topic "Sparkr"

1

Chellappan, Subhashini, and Dharanitharan Ganesan. "Working with SparkR." In Practical Apache Spark, 237–60. Berkeley, CA: Apress, 2018. http://dx.doi.org/10.1007/978-1-4842-3652-9_9.

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

Kaur, Navneet, and Niranjan Lal. "Clustering of Social Networking Data Using SparkR in Big Data." In Communications in Computer and Information Science, 217–26. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1813-9_22.

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

Seymour, Jessica. "When Spares Are Spared." In Cultural Politics in Harry Potter, 122–32. New York : Routledge 2020.: Routledge, 2019. http://dx.doi.org/10.4324/9780429322792-12.

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

Romanova, Alex. "Building Knowledge Graph in Spark Without SPARQL." In Communications in Computer and Information Science, 96–102. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59028-4_9.

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

Lewis, Ted G. "Sparks." In Book of Extremes, 35–50. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06926-5_3.

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

Graux, Damien, Louis Jachiet, Pierre Genevès, and Nabil Layaïda. "SPARQLGX: Efficient Distributed Evaluation of SPARQL with Apache Spark." In Lecture Notes in Computer Science, 80–87. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-46547-0_9.

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

Wiktorski, Tomasz. "Spark." In Advanced Information and Knowledge Processing, 85–97. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-04603-3_9.

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

Page, Norman. "A Writer’s Life." In Muriel Spark, 1–9. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-20716-9_1.

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

Page, Norman. "Angels Dining at the Ritz: The Early Novels." In Muriel Spark, 10–53. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-20716-9_2.

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

Page, Norman. "Interlude." In Muriel Spark, 54–63. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-20716-9_3.

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

Conference papers on the topic "Sparkr"

1

Venkataraman, Shivaram, Zongheng Yang, Davies Liu, Eric Liang, Hossein Falaki, Xiangrui Meng, Reynold Xin, et al. "SparkR." In SIGMOD/PODS'16: International Conference on Management of Data. New York, NY, USA: ACM, 2016. http://dx.doi.org/10.1145/2882903.2903740.

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

Monish, Prema, Santoshi Kumari, and C. Narendra Babu. "Automated Topic Modeling and Sentiment Analysis of Tweets on SparkR." In 2018 9th International Conference on Computing, Communication and Networking Technologies (ICCCNT). IEEE, 2018. http://dx.doi.org/10.1109/icccnt.2018.8493973.

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

Jung, Young Gyo, Kyung Tae Kim, Byungjun Lee, and Hee Yong Youn. "Enhanced Naive Bayes Classifier for real-time sentiment analysis with SparkR." In 2016 International Conference on Information and Communication Technology Convergence (ICTC). IEEE, 2016. http://dx.doi.org/10.1109/ictc.2016.7763455.

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

Elsayed, Ahmed, Mohamed Shaheen, and Osama Badawy. "Caching Techniques for Flight Delays Prediction in Big Data Using SparkR." In 2018 28th International Conference on Computer Theory and Applications (ICCTA). IEEE, 2018. http://dx.doi.org/10.1109/iccta45985.2018.9499131.

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

Eun, Sung-Soo, Min-Hyun Cho, Ki-Hong Kim, and Hyun-Seung Lee. "Development of Optimum Welding Heat Input Device Based on Welding Frequency and Spark Detection." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90403.

Full text
Abstract:
According to the previous researches, the welding frequency increases as the load impedance decreases when the narrow gap shorts out during ERW welding process. The proper welding frequency is theoretically calculated and also measured for OCTG pipe manufacturing. Also, to assure the quality of ERW tube, the spark detection device developed. According to signals from the spark detection device, there are two types of sparks found as a single-shot spark and sustainable spark. The formation of single-shot spark is too short to recognize the existence of spark with operator’s naked eyes during ERW process. Thus, the paint spraying system was used to mark the sparking location for screening at the inspection unit. Therefore, spark detecting devices (bad signal detection) are used to increase the productivity of products and improve its quality. In addition, the database server system developed according to the accumulated data can provide the cost savings and the creation of new demands.
APA, Harvard, Vancouver, ISO, and other styles
6

Garg, Nishank, and Dharanipragada Janakiram. "Sparker: Optimizing Spark for Heterogeneous Clusters." In 2018 IEEE International Conference on Cloud Computing Technology and Science (CloudCom). IEEE, 2018. http://dx.doi.org/10.1109/cloudcom2018.2018.00017.

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

Gould, D., D. P. Gardiner, M. LaViolette, and W. D. Allan. "Further Development of a Smoke Sensor for Diesel Engines." In ASME 2005 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/icef2005-1302.

Full text
Abstract:
This paper describes experimental research aimed at developing an on-board smoke sensor for diesel engines. The sensor element was similar to a conventional spark plug. Electrical heating of the insulator was used to prevent carbon fouling from the diesel soot. The sensing element created sparks within the exhaust pipe and changes in smoke levels were detected through analysis of the voltage levels of the sparks. The system was tested in a heavy duty diesel engine equipped with Exhaust Gas Recirculation (EGR)) and compared with reference measurements of the Filter Smoke Number (FSN). The experiments showed good sensitivity to step changes in smoke levels (accomplished by varying EGR levels) at smoke levels below 0.5 FSN. However, the sensor suffered from temperature induced signal drift and was unstable under some circumstances. The use of a spark plug with a smaller electrode tip diameter improved the signal stability. It is proposed that measurement and control of the electrode temperature will be necessary to control the signal drift.
APA, Harvard, Vancouver, ISO, and other styles
8

Murray, John, Edmund Muehlner, and Guibog Choi. "A Comparison of Radial Wellbay and Traditional Truss Spar Designs." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49272.

Full text
Abstract:
The Spar continues to be a popular drilling and production platform design for ultra-deep water. In recent years, developers have introduced a number of design variations such as the Arctic Spar, closed centerwell Spar, and long Spar. As the industry moves production into ultra-deep water, the escalation in drilling costs, particularly for deeper more complicated wells, prompts the need to look for new deepwater floater designs, including Spars. This paper introduces some new features to the Truss Spar, including a radial wellbay layout and an adjustable buoyancy centerwell device. This new Radial Wellbay Spar design is investigated and compared to the traditional Truss Spar for the same topside and riser weights and subjected to the same environments. The base case assumes a drilling and production platform with the performance comparison made in terms of hull weights and dimensions and hull motions for post-Katrina Gulf of Mexico conditions. In general, the Radial Wellbay Spar offers a smaller hull with fewer mooring lines for the same payload while maintaining the Spar’s low motion performance.
APA, Harvard, Vancouver, ISO, and other styles
9

Madhu, P., V. K. Jain, T. Sundararajan, and K. P. Rajurkar. "Analysis of EDM Process: A Finite Element Approach." In ASME 1991 International Computers in Engineering Conference and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/cie1991-0106.

Full text
Abstract:
Abstract A model has been proposed for predicting the material removal rate and depth of damaged layer during Electro Discharge Machining (EDM). The transient heat conduction equation for the workpiece which accounts for the heat absorption due to melting, has been solved by the finite element method (FEM). Gaussian heat distribution of power within a spark has been considered and unlike in earlier theoretical works, the periodical updating of the shape of the workpiece surface has been performed. Computations have been performed for a single spark in the form of a pulse and a multi-sparks situation with a continuous power input and zero off time. The estimated results match fairly well with the experimental results.
APA, Harvard, Vancouver, ISO, and other styles
10

Bharadwaj, Ujjwal R., Vadim V. Silberschmidt, John B. Wintle, and Julian B. Speck. "A Risk Based Methodology for Spare Parts Inventory Optimisation." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68845.

Full text
Abstract:
Spare parts inventories assist maintenance staff to keep equipment in operating condition. Thus the inventory level of spares has a direct bearing on machine availability, a factor that is increasingly important in capital-intensive industries. This paper presents a risk based approach for spare parts inventory optimization. At the outset, the paper highlights the unique features of maintenance inventories, such as spare parts inventories, compared to other inventories such as work-in-progress or finished product inventories. After a brief mention of the principles on which many of the current inventory management models are based and their limitations, the paper presents a risk-based methodology to spares inventory management. ‘Risk’ in the current context is the risk in monetary terms that arises when a component (spare) is not available on demand. It is the expected value of loss, i.e., the product of the likelihood of unavailability of the spare from the inventory and an estimate of the consequence(s) of that unavailability. Given a budgetary constraint and the risk profile of a number of spares, the model gives an optimal inventory of spares. By basing the inventory on the risk profile of spares, the model includes factors that are not normally considered in various other models. The ultimate aim of the methodology is to have an optimal level of spares inventory such that machine availability, to the extent it is dependent on the level of spares inventory, is maximized subject to constraints. The methodology is expected to benefit both, operational and financial managers.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Sparkr"

1

Foltz, M. F., and L. R. Simpson. LLNL small-scale static spark machine: static spark sensitivity test. Office of Scientific and Technical Information (OSTI), August 1999. http://dx.doi.org/10.2172/14485.

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

Hill, Curtis W., Lynn A. Boatner, Dennis Tucker, James A. Kolopus, and Zhongyang Cheng. Spark Plasma Sintering of Ultracapacitors. Office of Scientific and Technical Information (OSTI), January 2016. http://dx.doi.org/10.2172/1236598.

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

Warne, Larry Kevin, Roy Eberhardt Jorgenson, and Jane Marie Lehr. Resistance of a water spark. Office of Scientific and Technical Information (OSTI), November 2005. http://dx.doi.org/10.2172/876385.

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

Morley, David. Introduction to SPARK. Version 0.3. Fort Belvoir, VA: Defense Technical Information Center, July 2004. http://dx.doi.org/10.21236/ada459669.

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

Sugar, Thomas. SPARKy-Spring Ankle with Regenerative Kinematics. Fort Belvoir, VA: Defense Technical Information Center, September 2011. http://dx.doi.org/10.21236/ada618766.

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

Sayre, Amanda M., and Jarrod R. Olson. Development of a SPARK Training Dataset. Office of Scientific and Technical Information (OSTI), March 2015. http://dx.doi.org/10.2172/1228354.

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

Santavicca, D. A. Spark Ignited Turbulent Flame Kernel Growth. Office of Scientific and Technical Information (OSTI), June 1995. http://dx.doi.org/10.2172/6605.

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

Weissenburger, D. W. SPARK Version 1. 1 user manual. Office of Scientific and Technical Information (OSTI), January 1988. http://dx.doi.org/10.2172/5387213.

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

Ramirez, Ignacio, and Guillermo Sapiro. Universal Sparse Modeling. Fort Belvoir, VA: Defense Technical Information Center, March 2010. http://dx.doi.org/10.21236/ada520463.

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

Kurita, C. H. OCH Spacer Design. Office of Scientific and Technical Information (OSTI), February 1987. http://dx.doi.org/10.2172/1030743.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Sparkr' 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