• Title/Summary/Keyword: Wada

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Secular Evolution of Nuclear Bulges through Sustained Star Formation

  • Kim, Sung-Soo S.;Saitoh, Takayuki;Jeon, Myoung-Won;Merritt, David;Figer, Donal F.;Wada, Keiich
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.72.1-72.1
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    • 2010
  • Gas materials in the inner Galactic disk continuously migrate toward the Galactic center (GC) due to interactions with the bar potential, magnetic fields, stars, and other gaseous materials. In case of the Milky Way, those in forms of molecules appear to accumulate around 200 pc from the center (the central molecular zone, CMZ) to form stars there and further inside. The bar potential in the GC is thought to be responsible for such acculmulation of molecules and subsequent star formation, which is believed to have been continous throughout the lifetime of the Galaxy. We present 3-D hydrodynamic simulations of the CMZ that consider self-gravity, radiative cooling, and supernova feedback, and discuss the efficiency and role of the star formation in that region. We find that the gas accumulated in the CMZ by a bar potential of the inner bulge effectively turns into stars, supporting the idea that the stellar cusp inside the central 200 pc is a result of the sustained star formation in the CMZ. The obtained star formation rate in the CMZ, 0.03-0.1 Msun, is consistent with the recent estimate based on the mid-infrared observations by Yusef-Zadeh et al. We discuss the secular evolution of nuclear bulges in general, based on our results.

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Smoothness of the Zodiacal Light and Emission from the AKARI North Ecliptic Pole Monito rObservations

  • Pyo, Jeong-Hyun;Matsumoto, Toshio;Tange, Tsutomu;Jeong, Woong-Seob;Matsuhara, Hideo;Matsuura, Shuji;Wada, Takehiko;Seo, Hyun-Jong;Hong, Seung-Soo
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.52.1-52.1
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    • 2010
  • The Japanese infrared (IR) space mission AKARI monitored the brightness in the fields very close to the north ecliptic pole (NEP) with nine wavebands in Infrared Camera (IRC), which cover the wavelength range from 2 to $24{\mu}m$. We reduced the NEP monitor observations and examined the smoothness of the sky background brightness. Our analysis shows that the background brightness is smooth over a frame of about $10'\times10'$ within about 0.1% deviation in mid-IR. Because the zodiacal light (ZL) and emission (ZE) dominate the diffuse sky brightness in the near- and mid-IR wavelengths, the background brightness varies with season through a year. We tried sinusoidal fittings to the observed NEP background brightness. The fitting analysis shows that the sine function is successful in describing the seasonal variation of the ZL and ZE within 2% deviations from the observed brightness, especially for the 15, 18, and $24{\mu}m$ bands, within 0.3%. These results will provide limits and caveats for the studies of the cosmic infrared background radiation.

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Clinical Analysis of Funnel Chest - Reports of 15 cases - (누두흉의 임상적 고찰;15례 보고)

  • Gang, Jeong-Ho;Ji, Haeng-Ok
    • Journal of Chest Surgery
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    • v.25 no.8
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    • pp.837-843
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    • 1992
  • The most common deformity of the sternum is the depression deformity, variously calid pectus Excavatum, funnel chest, schwusterbrust, trichterburst, thorax en entonnoir. During the period 1983 to 1991 a total of 15 cases of funnel chest were treated surgically at Department of Thoracic Surgery, Hanyang University Hospital. The age at the time of operation ranged from 4 to 26 years 73.3 percent of the patients were under 12 years of age They all had symptoms of feeling Inferiority about chest deformity. The concavity on the funnel chest varied in its Extent, and the severity, which was measured by water volume filled into it, varied from 45ml to 100ml. We have Experienced 15 cases of pectus Exc-avatum with several operative method, i.e., Ravitch operation in 2 cases, Taguchi operation in 3 cases[using by Both IMA], Adkins operation in 5 cases, Modified wada operation [sternal costal cartilage Elevation Technique] in 5 cases. After surgery, follow up vertebral Index showed 44%, preoperatively and 29% postoperatively, average decrement of 15%. We Reported 15 cases of funnel chest and the surgical results of thease cases were satisfactory Except one case of Ravitch operation.

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Estimation of Surface Color with Use of Subjective Feeling: On the Influence of Contrast by Complementary Color

  • Sakamoto, Kazuyoshi;Wada, Mitsuyoshi;Min, Byung-Chan
    • Science of Emotion and Sensibility
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    • v.5 no.2
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    • pp.73-78
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    • 2002
  • The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. subject gazed the monochrome or the unique color, which was tailed target rotor. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling for the target color presented, the estimation of the unique color was cai\ulcornerlied out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law, The color difference saturated In the increase of area of background with the ratio more than 2:1.

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Estimation of surface color with use of subjective feeling: On the influence of contrast by complementary color

  • Sakamoto, Kazuyoshi;Wada, Mitsuyoshi;Min, Byung-Chan
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2002.05a
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    • pp.261-265
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    • 2002
  • The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. Subject gazed the monochrome or the unique color, which was called target color. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling fer the target color presented, the estimation of the unique color was carried out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law. The color difference saturated in the increase of area of background with the ratio more than 2:1.

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Probing Cosmic Near Infrared Background using AKARI Data

  • Seo, Hyun Jong;Matsumoto, Toshio;Jeong, Woong-Seob;Lee, Hyung Mok;Matsuura, Shuji;Matsuhara, Hideo;Oyabu, Shinki;Pyo, Jeonghyun;Wada, Takehiko
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.34.1-34.1
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    • 2013
  • The first generation stars in the universe are not observed as discrete objects by using current observational facilities, but their contributions are redshifted to the near infrared wavelength bands at present universe. Therefore, investigation of background radiation at near infrared is important for the study of the first stars. In this study, we present new observations of spatial fluctuations in sky brightness toward the north ecliptic pole using data from AKARI. Among pointed observation program of AKARI, we used two pointing surveys named Monitor field and NEP wide field at three wavelength bands 2.4, 3.2, and 4.1 ${\mu}m$. To obtain spatial fluctuations from observed images, first of all, we exclude pixels affected by resolved foreground objects and then obtain diffuse map which consists of diffused radiation only. Because the diffuse map contains not only cosmological components but also various foreground components, in order to detect cosmological components, we estimate the contributions of foreground components separately. The results of this study show that there remains excess spatial fluctuation that cannot be explained by known foreground sources. This work is based on observations with AKARI, a JAXA project with the participation of ESA.

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Probing Cosmic Near Infrared Background using AKARI Data

  • Seo, Hyun Jong;Matsumoto, Toshio;Jeong, Woong-Seob;Lee, Hyung Mok;Matsuura, Shuji;Matsuhara, Hideo;Oyabu, Shinki;Pyo, Jeonghyun;Wada, Takehiko
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.35.1-35.1
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    • 2013
  • The first generation stars in the universe are not observed as discrete objects by using current observational facilities, but their contributions are redshifted to the near infrared wavelength bands at present universe. Therefore, investigation of background radiation at near infrared is important for the study of the first stars. In this study, we present new observations of spatial fluctuations in sky brightness toward the north ecliptic pole using data from AKARI. Among pointed observation program of AKARI, we used two pointing surveys named Monitor field and NEP wide field at three wavelength bands 2.4, 3.2, and 4.1 ${\mu}$. To obtain spatial fluctuations from observed images, first of all, we exclude pixels affected by resolved foreground objects and then obtain diffuse map which consists of diffused radiation only. Because the diffuse map contains not only cosmological components but also various foreground components, in order to detect cosmological components, we estimate the contributions of foreground components separately. The results of this study show that there remains excess spatial fluctuation that cannot be explained by known foreground sources. This work is based on observations with AKARI, a JAXA project with the participation of ESA.

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The Mid-infrared View of Red Sequence Galaxies in Abell 2218 with AKARI

  • Ko, Jong-Wan;Im, Myung-Shin;Lee, Hyung-Mok;Lee, Myung-Gyoon;Hopwood, Ros H.;Serjeant, Stephen;Smail, Ian;Hwang, Ho-Seong;Hwang, Na-Rae;Shim, Hyun-Jin;Kim, Seong-Jin;Lee, Jong-Chul;Seo, Hyun-Jong;Goto, Tomotsugu;Hanami, Hitoshi;Matsuhara, Hideo;Takagi, Toshinobu;Wada, Takehiko;Lim, Sung-Soon
    • The Bulletin of The Korean Astronomical Society
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    • v.34 no.1
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    • pp.193-193
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    • 2009
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Identification Using Orthonormal Functions

  • Bae, Chul-Min;Wada, Kiyoshi;Imai, Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.285-288
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    • 1998
  • A least-squares identification method is studied that estimates a finite number of coefficients in the series expansion of a transfer function, where the expansion is in terms of recently introduced generalized basis functions, We will expand and generalize the orthogonal functions as basis functions for dynamical system representations. To this end, use is made of balanced realizations as inner transfer functions. The orthogonal functions can be considered as generalizations of, for example, the pulse functions, Laguerre functions, and Kautz functions, and give rise to an alternative series expansion of rational transfer functions. We show that the Laplace transform of the expansion for some sets$\Psi_{\kappa}(Z)$ is equivalent to a series expansion . Techniques based on this result are presented for obtaining the coefficients $c_{n}$ as those of a series. One of their important properties is that, if chosen properly, they can substantially increase the speed of convergence of the series expansion. This leads to accurate approximate models with only a few coefficients to be estimated. The set of Kautz functions is discussed in detail and, using the power-series equivalence, the truncation error is obtained.

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Park Tae-hwan v. The Korean Olympic Committee: The Breakdown of Sports Jurisprudence in Korea

  • Phillips, Joe;Lim, Suk-Jun
    • Journal of Arbitration Studies
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    • v.26 no.3
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    • pp.93-119
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    • 2016
  • Park Tae-hwan, the Korean Olympic gold medal swimmer, was suspended for eighteen months by the International Swimming Federation (FINA) in September 2014. Park completed his suspension in March 2016, but the Korea Olympic Committee (KOC), relying on its Article 5.6, then prohibited him from joining the national team for an additional three years for the same doping violation. The KOC's penalty exceeded that provided by the World Anti-Doping Code, which governs the Olympics and most international sports federations, and contravened well-established precedent from the Court of Arbitration for Sport (CAS). The KOC, along with the Korea Swimming Federation, maintained the suspension until decisions by the Seoul Eastern District Court and CAS forced them to retract the penalty. We describe the sports regulations and arbitration decisions governing the Park case, how each side used the law to support their positions, the flaws in the KOC's legal analysis, and the case's resolutions by the Korean court and CAS. Finally, because this legal conflict has damaged the KOC's reputation, created uncertainty over the committee's doping penalties, and undercut the authority of the World Anti-Doping Code and the CAS in Korea, we recommend institutional changes in Korea's sports jurisprudence.