• The Bulletin of The Korean Astronomical Society
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• v.30 no.1
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• pp.66.1-66.1
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• 2005

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.63.1-63.1
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• 2013

To improve the forecast capability of geomagnetic storms, we consider the real time solar and near Earth conditions together, since the characteristics of CMEs can be modified during their transit from the Sun to the Earth, and the geomagnetic storms may be directly affected by not only solar events but also near Earth interplanetary conditions. Using 55 CME-Dst pairs associated with M- and X-class solar flares, which have clearly identifiable source regions during 1997 to 2003, we confirm that the peak values of negative magnetic field Bz and duskward electric field Ey prior to Dst minimum are strongly related with Dst index. We suggest the solar wind criteria (Bz<-5 nT or Ey>3 mV/m for t>2 hr) for moderate storm less than -50 nT by modifying the criteria for intense storms less than -100 nT proposed by Gonzalez and Tsurutani (GT, 1987). As the results, 90% (28/31) of the storms are correctly forecasted by our criteria. For 15 exceptional events that are incorrectly forecasted by only CME parameters, 12 cases (80%) can be properly forecasted by solar wind criteria. When we applying CME and solar wind conditions together, all geomagnetic storms (Dst<-50 nT) are correctly forecasted. Our results show that, the storm forecast capability of the 2~3 days advanced warning based on CME parameters can be improved by combining with the urgent warning based on the near Earth solar wind condition.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.150.2-150.2
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• 2011

Volume Phase Holographic (VPH) gratings are getting more popular as dispersion elements in spectrographs. High efficiency, compact configuration, and easy handling are driving many visual spectrographs to use VPH gratings for their main dispersers or for their cross-dispersers in higher resolution spectrographs. More recently, VPH gratings are being adopted in near-infrared by some spectrographs and by a number of next generation instrument projects. IGRINS (Immersion Grating Infrared Spectrograph) uses a VPH grating as a cross-disperser in each H or K band arm. J or H band performance of VPH gratings has been proven by other instruments. But K-band VPH gratings are new to the field. In this presentation, we are going to present test results we have got so far for verification of H-band VPH gratings and development of K-band VPH gratings.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.43-49
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• 2006

The KASINICS (KASI Near Infrared Camera System) is a ground-based Near-Infrared (NIR) imaging instrument developed by the Korea Astronomy and Space Science Institute (KASI). In this paper, we report the test results of the KASINICS camera optics system which is comprised of a 1-1 Offner relay. We measure that the surface RMS fluctuations of the Offner mirrors are at the level of $10^{-1}-10^{-2}$ of the target wavelengths, showing that the mirrors are sufficiently smooth for NIR observations. The alignment of the Offner optics system has been checked too. Our ray-tracing simulations find that the image quality should not degrade more than the pixel size of the KASINICS ($40{\mu}m$), if a de-centering or a tilt of the Offner mirrors are within 5mm, or $2.5^{\circ}$. Our measurement shows that the de-centering or the tilt of the Offner mirrors are less than 1 mm or $0.5^{\circ}$, assuring that the KASINICS image quality are not affected by the alignment errors. We have also measured that the optics resolution is $20{\mu}m$ and it does not degrade more than 10% over the detector surface area of 14.3 mm ${/times}$ 14.3mm. Overall, we conclude that the KASINICS optics system satisfies the design requirements for NIR imaging observations.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.76-76
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• 2011

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) project is a next-generation astronomical mission optimized for mid- and far-infrared observation with a cryogenically cooled 3m-class telescope. Due to its high angular resolution and unprecedented sensitivity, SPICA will enable us to resolve many key issues from the star-formation history of the universe to the planetary formation. As an international collaboration, KASI proposed the near-infrared instrument which is composed of two parts; (1) science observation with the capability of imaging and spectroscopy covering $0.7{\mu}m$ to $5{\mu}m$ (FPC-S) (2) fine guiding to stabilize and improve the attitude (FPC-G). Here, we present the current status of SPICA/FPC.

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.34-34
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.93-93
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• 2000

No Abstract, See Full Text

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.87.1-87.1
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• 2007

• Bulletin of the Korean Space Science Society
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• 2009.04a
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• pp.30.4-31
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• 2009

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.1
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• pp.208-223
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• 2015

To solve the problem of face recognition with complex changes and further improve the efficiency, a new near-infrared face recognition algorithm which fuses E-GV-LBP and FKNN algorithm is proposed. Firstly, it transforms near infrared face image by Gabor wavelet. Then, it extracts LBP coding feature that contains space, scale and direction information. Finally, this paper introduces an improved FKNN algorithm which is based on spatial domain. The proposed approach has brought face recognition more quickly and accurately. The experiment results show that the new algorithm has improved the recognition accuracy and computing time under the near-infrared light and other complex changes. In addition, this method can be used for face recognition under visible light as well.