• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.50.4-51
• /
• 2015

Current and planned deep multicolor wide-area cosmological surveys will map in detail the spatial distribution of galaxies and quasars over unprecedented volumes, and provide a number of objects with photometric redshifts more than an order of magnitude bigger than that of spectroscopic redshifts. Photometric information is statistically more significant for studying cosmological evolution, dark energy, and the expansion history of the universe at a fraction of the cost of a full spectroscopic survey, but intrinsically carries a bias due to noise in the distance estimates. We provide convolution- and deconvolution-based algorithms capable of removing this bias -- thus able to exploit the full cosmological information -- in order to reconstruct intrinsic distributions and correlations between distance-dependent quantities. We then show some direct applications of our techniques to the VIMOS Public Extragalactic Redshift Survey (VIPERS) and the Sloan Digital Sky Survey (SDSS) datasets. Our methods impact a broader range of studies, when at least one distance-dependent quantity is involved; hence, they will be useful for upcoming large-volume surveys, some of which will only have photometric information.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.685-688
• /
• 2004

본 연구에서는 저수지군 연계운영을 위한 표본 추계학적 선형 계획(SSLP, Sampling Stochastic Linear Programming) 모형을 제안한다. 일반적 추계학적 모형은 과거 자료로부터 확률변수의 확률분포를 추정하고 이를 몇 개 구간으로 나누어 이산 확률 값을 산정하여 기댓값이 최대가 되는 운영방안을 도출하지만 저수지 유입량 예측시 고려되어야할 지속성 효과(Persistemcy Effect)와 유역간 또는 시점별 공분산 효과(The joint spatial and temporal correlations)를 반영하는데 많은 한계가 있다. 이를 극복하기 위하여 과거자료 자체를 유입량 시나리오로 적용하여 시${\cdot}$공간적 상관관계를 유지하는 표본 추계학적(Sampling Stochastic)기법을 바탕으로 Simple Recourse Model로 구성한 추계학적 선형 계획 모형을 제시한다. 이 모형은 미국 기상청(NWS)에서 발생 가능한 유입량의 시나리오를 예측하는 방법인 앙상블 유량 예측(ESP, Ensemble Streamflow Prediction)을 통한 시나리오를 적용함으로써 좀더 신뢰성 있는 저수지군 연계운영 계획을 도출 할 수 있을 것으로 기대된다.

• Proceedings of the KIEE Conference
• /
• 2006.07d
• /
• pp.2113-2115
• /
• 2006

This paper proposes a spatio-temporal correlation algorithm that takes advantage of the spatial and temporal correlations in video streams for error concealment. The spatio-temporal correlation algorithm sets the neighborhood area of the damaged part as a reference window, then finds the area that best matches the reference window in the previous frame. The best-matched area in the previous frame replaces the damaged part in the current frame. The results of ten variations of the proposed algorithm are compared with conventional error concealment methods. These methods include the ones applicable to P-frames as well as I-frames. The comparison results show that the proposed algorithm is very efficient for l-frame error concealment with a large motion between frames.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.673-676
• /
• 1998

Future land remote sensing satellite systems will kikely be constrained in terms of communication band-width. To alleviate this limitation, the data must be compressed. Image data obtained from satellite exhibit a high degree of spatial and spectral correlations that must be properly exploited. In this paper we propose multispectral image data compression using wavelet transform and selective predicted vector quantization. Th eproposed method is based on accuratly predicting other band from reference band and reducing bit rate through threshold map. we can achieve better compression effeciency than conventional methods.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.10
• /
• pp.17-26
• /
• 2004

This paper proposes JBSTBC (Joint Beamforming Space-Time Block Coding) scheme for MIMO (Multi-Input Multi-Output) communication systems. To enhance the order of spatial diversity in presence of deteriorative fading correlations as well as inter-substream interferences, the proposed JBSTBC method employs joint eigen-beamforming technique together with the BOLD (block-ordered layered detector) for MIMO-STBC. In order to confirm superiority of the proposed JBSTBC method, the computer simulations are conducted in highly correlated fading situations with providing detailed mathematical derivations for clarifying functionality of the proposed scheme.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.81.4-82
• /
• 2017

We investigate velocity oscillations in the active region plage by using the high-spatial, high-spectral and high-temporal resolution spectral data acquired by the Interface Region Imaging Spectrograph (IRIS). From the Mn I $2801.907{\AA}$ (lower chromosphere), C II (lower transition region) and Si IV (middle transition region) lines, we measure the line of sight Doppler velocity at different atmospheric layers, and present results of wavelet analysis of the plage region with a range of periods from 2 to 8 minutes. In addition, we present correlations of the oscillations from the lower chromosphere to the middle transition region. Finally, we will discuss the regional dependence of the oscillation properties on physical properties such as temperature and magnetic field inclination.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.1851-1854
• /
• 2003

This paper suggests an algorithm which can retrieval images using correlations between the region classification of spatial image and the wavelet transform even though the images are rotated in a ${\pm}$90 degree arc. Owing to this proposed method, it was confirmed from experiments that the search about the whole image is not processed and only a few amount of informations are saved by using the mathematical statistics from the block map and transformed band which is resulted from region classification, and by performing the image search based on these, the improvement of search speed and the efficient search can be done.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.6 no.4
• /
• pp.252-256
• /
• 2006

A low-power ECC check bit generator is presented with competent DRAM implementation with minimal speed loss, area overhead and power consumption. The ECC used in the proposed scheme is a variant form of the minimum weight column code. The spatial and temporal correlations of input data are analyzed and the input paths of the check bit generator are ordered for the on-line adaptable power savings up to 24.4% in the benchmarked cases. The chip size overhead is estimated to be under 0.3% for a 80nm 1Gb DRAM implementation.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.4
• /
• pp.219-225
• /
• 2016

Visual object tracking is one of the key tasks in computer vision. Robust trackers should address challenging issues such as fast motion, deformation, occlusion and so on. In this paper, we therefore propose a visual object tracking method that exploits inter-frame correlations of convolutional feature maps in Convolutional Neural Net (ConvNet). The proposed method predicts the location of a target by considering inter-frame spatial correlation between target location proposals in the present frame and its location in the previous frame. The experimental results show that the proposed algorithm outperforms the state-of-the-art work especially in hard-to-track sequences.

• Progress in Superconductivity and Cryogenics
• /
• v.15 no.2
• /
• pp.16-19
• /
• 2013

The magneto-resistivity and electric field-current density (E-J) curves were investigated up to a magnetic field 9 T in the optimally doped $BaFe_{1.8}Co_{0.2}As_2$ single crystal with a superconducting temperature ($T_c$) of 24.6 K. The E-J Scaling behaviors below and above vortex glass transition temperature ($T_g$) were found, confirming the existence of the vortex glass phase transition. The critical exponents for the diverging spatial and time correlations at $T_g$, were obtained as v = $1.1{\pm}0.1$ and z = $4.5{\pm}0.3$, respectively. The obtained critical exponents are in good agreement with the predicted values of v ~ 1 - 2 and z > 4 within the 3D vortex glass theory.