• Title/Summary/Keyword: Light Curve

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Multi Characters Detection Using Color Segmentation and LoG operator characteristics in Natural Scene (자연영상에서 컬러분할과 LoG연산특성을 이용한 다중 문자 검출에 관한 연구)

  • Shin, Seong;Baek, Young-Hyun;Moon, Sung-Ryong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.2
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    • pp.216-222
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    • 2008
  • This paper proposed the multi characters detection algorithm using Color segmentation and the closing curve feature of LoG Operator in order to complement the demerit of the existing research which is weak in complexity of background, variety of light and disordered line and similarity of left and background color, etc. The proposed multi characters detection algorithm divided into three parts : The feature detection, characters format and characters detection Parts in order to be possible to apply to image of various feature. After preprocess that the new multi characters detection algorithm that proposed in this paper used wavelet, morphology, hough transform which is the synthesis logical model in order to raise detection rate by acquiring the non-perfection characters as well as the perfection characters with processing OR operation after processing each color area by AND operation sequentially. And the proposal algorithm is simulated with natural images which include natural character area regardless of size, resolution and slant and so on of image. And the proposal algorithm in this paper is confirmed to an excellent detection rate by compared with the conventional detection algorithm in same image.

Physical Measurement of Color Changes in Foods (식품(食品)의 색도변화(色度變化) 측정법(測定法))

  • Cho, Sung-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.1
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    • pp.1-8
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    • 1984
  • The tools and techniques for measuring the spectral distribution of light emitted by, transmitted by, or reflected from food surfaces are described for determining the extent to which original natural color is preserved in processing and subsequent storage of foods. Color differences may be evaluated indirectly in terms of some physical characteristic of the sample or extracted fraction thereof that is largely responsible for the color characteristics. For evaluation more directly in terms of what the observer actually seen, color differences are measured by reflectance spectrophotometry and photoelectric colorimetry and expressed as differences in psychophysical indexes such as luminous reflectance and chromaticity. The standard system, against which other systems could be compared, is the one recommended by the International Committee on illumination and which is based on the 'standard observer', which is a simulated standard eye, consisting of three primary color filters Z, with X being essentially amber in color, Y, green and Z, blue. Any spectrophotometric curve of reflectance obtained from the surface of an object can be integrated in terms of X, Y and Z. Psychophysical notation may be converted by standard methods to the colorimetrically more descriptive terms of Munsell hue, value and chroma.

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A Study on the Evaluation according to the Situation of Subway Station Canopy - Focused on the Subway Station in Daegu - (지하철역 캐노피의 설치현황에 따른 디자인 평가에 관한 연구 - 대구광역시 지하철역 캐노피를 대상으로 -)

  • Kim, Min-Hee;Kim, Jong-Ha;Lee, Jeong-Ho
    • Korean Institute of Interior Design Journal
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    • v.18 no.3
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    • pp.74-83
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    • 2009
  • This study is subway station canopy evaluation to improve the landscape of a street furniture design. From a survey of the professional abstracted the design elements of subway station canopy in Daegu. And then, it practiced a canopy design appreciation by the analysis of appreciation items. The results are as follows. First, this research analyzes each quality a classified by the four characteristics at the subway station. In general station case, the slope roof was consistent in used to be unified. If the symbol of the express station wasn't common in cross-section or material. In addition, the design evaluation in the lower canopy were evaluated. Therefore, in case of the city installed in the canopy, the characteristic of city gateway and the symbolic characteristic of a design that is required. Second, subway station canopy existed in widely opened site come out a lower rating about safety. Therefore, considering the safety light device or system need to do. Third, if the horizontal or sloping roof shape come out in a lower rating, the highly evaluated curve shape is considered to apply. Forth, a structure material of the canopy was highly evaluated the aluminum composite panels and structural steel pipes. Therefore, to improve a beauty of the city, to give rhythm to a structure material of the canopy of the aluminum composite panels and structural steel pipes will be desirable to use as the main ingredient.

A Study on Assessment of MTF Performance and Theoretical Analysis of Convex Trial Lenses (볼록 검안렌즈의 MTF 성능 분석 및 이론적 해석에 대한 연구)

  • Bang, Hyun Jin;Lee, Jong Ung;Son, Byung Ho;Ahn, Kyo Hoon;Choi, Eun Jung
    • Korean Journal of Optics and Photonics
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    • v.24 no.5
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    • pp.217-223
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    • 2013
  • White light MTF(Modulation Transter Function)s of biconvex trial lenses from 10 to 20 diopter (D) were represented as a function of angular frequency and visual acuity, and then they were compared with AIM(Aerial Image Modulation) curves. All of the biconvex trial lenses evaluated in on-axis mode had MTF performance that could resolve Landolt's ring up to visual acuity 2.0. However, in a half field angle of five degrees, the trial lens of 10 diopters was able to resolve Landolt's ring up to visual acuity 0.9, and that of 20 diopter only up to visual acuity 0.8. This means that the trial lenses in the case of a half field angle of five degrees do not have sufficient resolution to measure visual acuity by 1.0.

ON THE COMPLEX VARIABILITY OF THE SUPERORBITAL MODULATION PERIOD OF LMC X-4

  • HU, CHIN-PING;LIN, CHING-PING;CHOU, YI;YANG, TING-CHANG;SU, YI-HAO;HSIEH, HUNG-EN;CHUANG, PO-SHENG;LIAO, NAI-HUI
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.595-597
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    • 2015
  • LMC X-4 is an eclipsing high-mass X-ray binary exhibiting a superorbital modulation with a period of ~ 30:5 days. We present a detailed study of the variations of the superorbital modulation period with a time baseline of ~ 18 years. The period determined in the light curve collected by the Monitor of All-sky X-ray Image (MAXI) significantly deviates from that observed by the All Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE). Using the data collected by RXTE/ASM, MAXI, and the Burst Alert Telescope (BAT) onboard Swift, we found a significant period derivative, $\dot{P}=(2.08{\pm}0.12){\times}10^{-5}$. Furthermore, the O{C residual shows complex short-term variations indicating that the superorbital modulation of LMC X-4 exhibits complicated unstable behaviors. In addition, we used archive data collected by the Proportional Counter Array (PCA) on RXTE to estimate the orbital and spin parameters. The detected pulse frequencies obtained in small time segments were fitted with a circular orbital Doppler shift model. In addition to orbital parameters and spin frequency for each observation, we found a spin frequency derivative of $\dot{v}=(6.482{\pm}0.011){\times}10^{-13}Hz{\cdot}s^{-1}$. More precise orbital and spin parameters will be evaluated by the pulse arrival time delay technique in the future.

FOLLOW-UP PHOTOMETRY OF TWO NEW ECLIPSING PCEBs FROM THE SLOAN DIGITAL SKY SURVEY

  • WANGNOK, KITTIPONG;SANGUANSAK, NUANWAN;IRAWATI, PUJI;DHILLON, VIK;MARSH, TOM R.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.217-218
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    • 2015
  • In this work, we present the result of our follow-up observations of SDSS J092741.73+332959.1 and SDSS J130733.49+215636.7 using the 2.35 m Thai National Telescope and ULTRASPEC instrument. Both systems are listed among the recently found white dwarf main sequence binaries from the Sloan Digital Sky Survey. SDSS J092741.73+332959.1 is a new PCEB with a period of 2.3 days, the longest orbital period known to date for white dwarf binaries. SDSS J130733.49+215636.7 is confirmed to be an eclipsing system with a period of 0.21 days from the Catalina Survey's light curve, however the parameters for the white dwarf are still uncertain. Our goal is to determine precise parameters for both systems using the Binary Maker 3 software. The observation for SDSS J0927+3329 was done on 9 January 2014 in the SDSS r' filter while the data for SDSS J1307+2156 were taken in the z' filter on 27 April 2014. Our models show that the red dwarf companions in both systems are well constrained inside their Roche Lobes. We find that the binary M2/M1 ratio in SDSS J0927+3329 is close to 0.5, with white dwarf and M-dwarf temperatures of 12000 K and 3300 K, respectively. Our preliminary result for SDSS J1307+2156 show that this system has an extreme mass ratio of 0.3. The white dwarf in this system has a temperature of 7500 K and the companion star has an effective temperature of 3150 K.

Experimental and analytical investigation on seismic behavior of RC framed structure by pushover method

  • Sharma, Akanshu;Reddy, G.R.;Eligehausen, R.;Vaze, K.K.
    • Structural Engineering and Mechanics
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    • v.39 no.1
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    • pp.125-145
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    • 2011
  • Pushover analysis has gained significant popularity as an analytical tool for realistic determination of the inelastic behaviour of RC structures. Though significant work has been done to evaluate the demands realistically, the evaluation of capacity and realistic failure modes has taken a back seat. In order to throw light on the inelastic behaviour and capacity evaluation for the RC framed structures, a 3D Reinforced concrete frame structure was tested under monotonically increasing lateral pushover loads, in a parabolic pattern, till failure. The structure consisted of three storeys and had 2 bays along the two orthogonal directions. The structure was gradually pushed in small increments of load and the corresponding displacements were monitored continuously, leading to a pushover curve for the structure as a result of the test along with other relevant information such as strains on reinforcement bars at critical locations, failure modes etc. The major failure modes were observed as flexural failure of beams and columns, torsional failure of transverse beams and joint shear failure. The analysis of the structure was by considering all these failure modes. In order to have a comparison, the analysis was performed as three different cases. In one case, only the flexural hinges were modelled for critical locations in beams and columns; in second the torsional hinges for transverse beams were included in the analysis and in the third case, joint shear hinges were also included in the analysis. It is shown that modelling and capturing all the failure modes is practically possible and such an analysis can provide the realistic insight into the behaviour of the structure.

HST/WFPC2 Imaging of the Dwarf Satellites And XI and And XIII : HB Morphology and RR Lyraes

  • Yang, Soung-Chul;Sarajedini, Ata
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.68.1-68.1
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    • 2012
  • We present a comprehensive study of the stellar populations in two faint M31 dwarf satellites, And XI and And XIII. Using deep archival images from the Wide Field Planetary Camera 2 (WFPC2) onboard the Hubble Space Telepscope (HST), we characterize the horizontal branch (HB) morphologies and the RR Lyrae (RRL) populations of these two faint dwarf satellites. Our new template light curve fitting routine (RRFIT) detected RRL populations from both galaxies. The mean periods of $RR_{ab}$ (RR0) stars in And XI and And XIII are < $P_{ab}$ > = $0.621{\pm}0.040$, and < $P_{ab}$ > = $0.648{\pm}0.038$ respectively. Even though the RRL populations show a lack of $RR_{ab}$ stars with high amplitudes (Amp(V) > 1.0 mag) and relatively short periods ($P_{ab}$ ~ 0.5 days), their period - V band amplitude (P-Amp(V)) relations track the lower part of the general P-Amp(V) trend in the M31 outer halo RRL populations. The metallicities of $RR_{ab}$ stars were calculated via the [Fe/H]-log $P_{ab}$-Amp(V) relationship of Alcock et al. The metallicities thus obtained ($[Fe/H]_{And}$ $_{XI}=-1.75%$; $[Fe/H]_{And}$ $_{XIII}=-1.74$) are consistent with the values calculated from the RGB slope indicating that our measurements are not significantly affected by the evolutionary effects of RRL stars. We discuss the origins of And XI and And XIII based on a comparative analysis of the luminosity-metallicity (L-M) relation of Local Group dwarf galaxies.

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Development of Controlling and Analyzing Software for Portable Atomic Emission Spectrometry (휴대용 원자 방출 분광계를 위한 제어 및 분석용 소프트웨어 개발)

  • Lee, Sang Chun;Lee, Chang-Soo;Jung, Min-Soo;Ryu, Dong-Hang
    • Analytical Science and Technology
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    • v.11 no.1
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    • pp.1-7
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    • 1998
  • This study focuses on developing a controlling and analyzing software for the portable atomic emission spectrometer equipped with an electrothermal vaporizer(ETV) that can perform the in-situ trace analysis of heavy metal ions dissolved in water. The software works well for a notebook PC and it is exclusively developed for the real time analysis with a line filter and a photomultiplier light detector. The program is designed to operate under Windows 95 environment and either Korean or English can be used as a main language. The Delphi 2.0 language software is mainly used for programing. The program is designed to make a calibration curve and the system users can get the analytical data in a short time. And a final report can be generated without having difficulties. This software can be easily modified for other analytical atomic spectrometers.

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Effect of Corrosion Atmosphere and Strain Rate on the Stress Corrosion Cracking of High Strength 7xxx Aluminum Alloy (고강도 7xxx 알루미늄 합금의 응력부식균열에 미치는 부식환경과 응력속도의 영향)

  • Yun, Yeo-Wan;Kim, Sang-Ha
    • Journal of the Korean institute of surface engineering
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    • v.41 no.3
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    • pp.121-128
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    • 2008
  • High strength 7xxx aluminum alloys have been applied to automotive bump back beam of the some limited model for light weight vehicle. The aluminum bump back beam is manufactured through extrusion, bending and welding. The residual stress given on these processes combines with the corrosive atmosphere on the road spreaded with corrosive chemicals to melt snow to occur the stress corrosion cracking. The composition of commercial 7xxx aluminum has Zn/Mg ratio about 3 and Cu over 2 wt% for better strength and stress corrosion cracking resistivity. But this composition isn't adequate for appling to the automotive bump back beam with high resistance to extrusion and bad weldability. In this study the composition of 7xxx aluminum alloy was modified to high Zn/Mg ratio and low Cu content for better extrusion and weldability. To estimate the resistivity against stress corrosion cracking of this aluminum alloy by slow strain rate test, the corrosion atmosphere and strain rate separate the stress corrosion cracking from conventional corrosion must be investigated. Using 0.6 Mol NaCl solution on slow strain rate test the stress corrosion cracking induced fracture was not observed. By adding 0.3% $H_2O_2$ and 0.6M $Na_2SO_4$ to 1M NaCl solution, the corrosion potential and current density of polarization curve moved to active potential and larger current density, and on the slow strain rate test the fracture energy in solution was lower than that in pre-exposure. These mean the stress corrosion cracking induced fracture can be estimated in this 1M NaCl + 0.3% $H_2O_2$ + 0.6M $Na_2SO_4$ solution. When the strain rate was below $2{\times}10^{-6}$, the stress corrosion cracking induced fracture start to be observed.