• Title/Summary/Keyword: Large data

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Large Solvent and Noise Peak Suppression by Combined SVD-Harr Wavelet Transform

  • Kim, Dae-Sung;Kim, Dai-Gyoung;Lee, Yong-Woo;Won, Ho-Shik
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.971-974
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    • 2003
  • By utilizing singular value decomposition (SVD) and shift averaged Harr wavelet transform (WT) with a set of Daubechies wavelet coefficients (1/2, -1/2), a method that can simultaneously eliminate an unwanted large solvent peak and noise peaks from NMR data has been developed. Noise elimination was accomplished by shift-averaging the time domain NMR data after a large solvent peak was suppressed by SVD. The algorithms took advantage of the WT, giving excellent results for the noise elimination in the Gaussian type NMR spectral lines of NMR data pretreated with SVD, providing superb results in the adjustment of phase and magnitude of the spectrum. SVD and shift averaged Haar wavelet methods were quantitatively evaluated in terms of threshold values and signal to noise (S/N) ratio values.

WALLABY - the ASKAP HI All-Sky Survey

  • Oh, Se-Heon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.235-235
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    • 2012
  • The "Widefield ASKAP L-band Legacy All-sky Blind surveY" (WALLABY) is an extragalactic HI survey which aims to examine HI properties and large-scale distribution of ~500,000 galaxies out to z ~ 0.27, covering a wide range of science goals associated with galaxy formation and evolution (P.I.: B. Koribalski & L. Staveley-Smith). The combination of ASKAP's exquisite column density sensitivity and a large primary beam will make it possible to systematically investigate the rarely explored low column-density HI in the universe. Ultimately, the largest and most homogeneous data set from WALLABY will drastically improve and broaden our knowledge on galaxy formation and evolution. ASKAP will be on-line in 2013, so to ensure timely and efficient reduction and analysis of the large WALLABY data set, we have been developing and testing reliable source finding tools and data analysis pipelines. In this talk I present recent progress of WALLABY, especially on the kinematic parameterisation pipeline for the spatially resolved galaxies detected by WALLABY.

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Model-Ship Correlation Study on the Powering Performance for a Large Container Carrier

  • Hwangbo, S.M.;Go, S.C.
    • Journal of Ship and Ocean Technology
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    • v.5 no.4
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    • pp.44-50
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    • 2001
  • Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

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Physical Experiments for Large Deformation Problems

  • Yoo, Wan-Suk;Lee, Jeong-Han;Sohn, Jeong-Hyun;Park, Su-Jin
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.705-710
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    • 2003
  • Many papers have studied computer simulations of elastic bodies undergoing large deflections and large deformations. But there have not been many attempts to check the validity of the numerical formulations because the simulation results could not be matched without correct input data such as material properties and damping effects. In this paper, these values are obtained from real experiment with a high-speed camera and a data acquisition system. The simulation results with the absolute nodal coordinate formulation (ANCF) are compared with the results of real experiments. Two examples, a thin cantilever beam and a thin plate, are studied to verify whether the simulation results are well matched to experimental results.

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Faraday Rotation Measurein the Large-Scale Structure II

  • Akahori, Takuya;Ryu, Dong-Su
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.83.1-83.1
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    • 2010
  • In the last meeting of KAS, we reported the first statistical study of Faraday rotation measure (RM) in the large-scale structure of the universe using the data of cosmological structure formation simulations. With a turbulence dynamo model for the intergalactic magnetic field (IGMF), we predicted that the root mean square of RM through filaments is \sim 1 rad/m^2. Future radio observatories such as the Square Kilometer Array (SKA) could detect this signal level. However, it is known that the typical foreground galactic RM is a few tens and less than ten rad/m^2 in the low and high galactic latitudes, respectively. So the RM in the large-scale structure could be detected only after the foreground galactic RM is removed. In this talk, we show how we remove the foreground galactic RM and what we obtain from the masked data, by using some noise models and masking techniques. Our results can be used to simulate future RM observations by SKA, and eventually to constrain the origin and evolution of the IGMF in the large-scale structure.

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Matching of Physical Experiments and Multibody Dynamic Simulation for Large Deformation Problems

  • Yoo, Wan-Suk;Lee, Jeong-Han;Sohn, Jeong-Hyun;Park, Su-Jin;Oleg Dmitrochenko;Dmitri Pogorelov
    • Journal of Mechanical Science and Technology
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    • v.18 no.5
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    • pp.742-752
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    • 2004
  • Many papers have studied computer simulations of elastic bodies undergoing large deflections and large deformations. But there have not been many attempts to check the validity of the numerical formulations because the simulation results could not be matched without correct input data such as material properties and damping effects. In this paper, these values are obtained from real experiment with a high-speed camera and a data acquisition system. The simulation results with the absolute nodal coordinate formulation (ANCF) are compared with the results of real experiments. Two examples, a thin cantilevers beam and a thin plate, are studied to verify whether the simulation results are well matched to experimental results.

Variation of fisheries conditions of mackerel (Scomber japonicus) fishing ground for large purse seine fisheries (대형선망어업에 있어서 고등어 (Scomber japonicus) 어장의 어황변동)

  • Lee, Haet-Nim;Kim, Hyung-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.2
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    • pp.108-117
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    • 2011
  • In order to offer data about fisheries resources management and prediction of catch on large purse seine fisheries, the fluctuation of the fisheries condition and distributions of fishing ground for mackerel were analysed with monthly catch data for 1990.2009. The overall catch has decreased to about 70% since 1997, with approximately 70% of the mackerel (Scomber japonicus) catch and monthly fluctuations showing a similar pattern. Monthly distribution of fishing ground is like distribution of mackerel in large purse seine fishery. The main fishing grounds are near Jeju Island and the Yellow sea with the main fishing season existing between October to December. The catches fluctuations and distribution of fishing ground were related to the effect of regime shifts. Therefore, in order to prediction of catch on large purse seine fisheries should be studied these relationships.

An Algorithm for Updating Discovered Association Rules in Data Mining (데이타 마이닝에서 기존의 연관 규칙을 갱신하는 앨고리듬 개발)

  • 이동명;지영근;황종원;강맹규
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.265-276
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    • 1997
  • There have been many studies on efficient discovery of association rules in large databases. However, it is nontrivial to maintain such discovered rules in large databases because a database may allow frequent or occasional updates and such updates may not only invalidate some existing strong association rules but also turn some weak rules into strong ones. The major idea of updating algorithm is to resuse the information of the old large itemsets and to integrate the support information of the new large itemsets in order to substantially reduce the pool of candidate sets to be re-exmained. In this paper, an updating algorithm is proposed for efficient maintenance of discovered assocation rules when new transaction data are added to a transaction database. And superiority of the proposed updating algorithm will be shown by comparing with FUP algorithm that was already proposed.

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Analysis of X-ray luminosities of isolated elliptical galaxies in SDSS

  • Choi, Yun-Young;Kim, Eun-Bin;Kim, Sung-Soo S.;Park, Chang-Bom
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.58.2-58.2
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    • 2011
  • Park, Gott, & Choi (2008) found that when a galaxy is located within the virial radius from its closest neighbor and the neighbor is an elliptical, the probability of the galaxy to be an elliptical is very sensitive to the large-scale background density over a few Mpc scales. They suggested that the large-scale dependence can be arise if the temperature of a diffuse hot gas held by elliptical galaxies are higher in higher density environment. In this study, to understand the large-scale environment affects the X-ray properties of individual galaxies, we investigated the dependence of the X-ray luminosities of the elliptical galaxies on the large-scale environment using X-ray and optical data which we selected from the ROSAT All-Sky Survey and the Sloan Digital Sky Survey Data Release 7. To exclude galaxies embedded in an intra-group/cluster medium which could enhance their observed X-ray luminosity, we used isolated elliptical galaxies.

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Comparison Architecture for Large Number of Genomic Sequences

  • Choi, Hae-won;Ryoo, Myung-Chun;Park, Joon-Ho
    • Journal of Information Technology and Architecture
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    • v.9 no.1
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    • pp.11-19
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    • 2012
  • Generally, a suffix tree is an efficient data structure since it reveals the detailed internal structures of given sequences within linear time. However, it is difficult to implement a suffix tree for a large number of sequences because of memory size constraints. Therefore, in order to compare multi-mega base genomic sequence sets using suffix trees, there is a need to re-construct the suffix tree algorithms. We introduce a new method for constructing a suffix tree on secondary storage of a large number of sequences. Our algorithm divides three files, in a designated sequence, into parts, storing references to the locations of edges in hash tables. To execute experiments, we used 1,300,000 sequences around 300Mbyte in EST to generate a suffix tree on disk.