• Title/Summary/Keyword: Space Images

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Ensemble Downscaling of Soil Moisture Data Using BMA and ATPRK

  • Youn, Youjeong;Kim, Kwangjin;Chung, Chu-Yong;Park, No-Wook;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.587-607
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    • 2020
  • Soil moisture is essential information for meteorological and hydrological analyses. To date, many efforts have been made to achieve the two goals for soil moisture data, i.e., the improvement of accuracy and resolution, which is very challenging. We presented an ensemble downscaling method for quality improvement of gridded soil moisture data in terms of the accuracy and the spatial resolution by the integration of BMA (Bayesian model averaging) and ATPRK (area-to-point regression kriging). In the experiments, the BMA ensemble showed a 22% better accuracy than the data sets from ESA CCI (European Space Agency-Climate Change Initiative), ERA5 (ECMWF Reanalysis 5), and GLDAS (Global Land Data Assimilation System) in terms of RMSE (root mean square error). Also, the ATPRK downscaling could enhance the spatial resolution from 0.25° to 0.05° while preserving the improved accuracy and the spatial pattern of the BMA ensemble, without under- or over-estimation. The quality-improved data sets can contribute to a variety of local and regional applications related to soil moisture, such as agriculture, forest, hydrology, and meteorology. Because the ensemble downscaling method can be applied to the other land surface variables such as temperature, humidity, precipitation, and evapotranspiration, it can be a viable option to complement the accuracy and the spatial resolution of satellite images and numerical models.

Comparison between Possibilistic c-Means (PCM) and Artificial Neural Network (ANN) Classification Algorithms in Land use/ Land cover Classification

  • Ganbold, Ganchimeg;Chasia, Stanley
    • International Journal of Knowledge Content Development & Technology
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    • v.7 no.1
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    • pp.57-78
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    • 2017
  • There are several statistical classification algorithms available for land use/land cover classification. However, each has a certain bias or compromise. Some methods like the parallel piped approach in supervised classification, cannot classify continuous regions within a feature. On the other hand, while unsupervised classification method takes maximum advantage of spectral variability in an image, the maximally separable clusters in spectral space may not do much for our perception of important classes in a given study area. In this research, the output of an ANN algorithm was compared with the Possibilistic c-Means an improvement of the fuzzy c-Means on both moderate resolutions Landsat8 and a high resolution Formosat 2 images. The Formosat 2 image comes with an 8m spectral resolution on the multispectral data. This multispectral image data was resampled to 10m in order to maintain a uniform ratio of 1:3 against Landsat 8 image. Six classes were chosen for analysis including: Dense forest, eucalyptus, water, grassland, wheat and riverine sand. Using a standard false color composite (FCC), the six features reflected differently in the infrared region with wheat producing the brightest pixel values. Signature collection per class was therefore easily obtained for all classifications. The output of both ANN and FCM, were analyzed separately for accuracy and an error matrix generated to assess the quality and accuracy of the classification algorithms. When you compare the results of the two methods on a per-class-basis, ANN had a crisper output compared to PCM which yielded clusters with pixels especially on the moderate resolution Landsat 8 imagery.

An Analysis of Incheon's Identity of Place through Movies (영화를 통한 인천의 장소 정체성 분석)

  • Ahn, Chong-Uk
    • Journal of the Korean association of regional geographers
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    • v.11 no.6
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    • pp.501-516
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    • 2005
  • Although Incheon metropolitan city is the third largest city in Korea, it is called 'the gateway to Seoul', 'the second city of port', and 'the satellite city'. The people in Incheon as well as other regions unconsciously recognize this city as 'border' and 'periphery' of Seoul through those expressions. These perceptions also develop a negative sense of place about Incheon. This study starts with analysis about marginal landscape images of Incheon in texts such as movies, stories, and geography textbooks. The represented text as movie has a gap between real space and it. Nevertheless, Its strong point is a making problems clear about recognition of reality. I will inquire the origin of senses of place about Incheon through analysis of represented texts. Moreover, I will present the notion of 'flight' that stands on the basis of Deleuze's Nomadism. Here, 'flight' means that the active subject continuously challenges and reforms the nature of periphery and dependency, the capital, and the economic subordination, and it will have to be new identity and direction of Incheon.

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An Extended TIP Technique for Android Platform (Android Platform에서의 확장된 TIP 기술)

  • Kim, Young-Ja;Lee, Yon-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.57-63
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    • 2012
  • TIP technology enables navigation of the internal contents of images by extracting geometry information from two-dimensional drawing or a picture and generating three-dimensional effects from extracted information. The technology can be applied to a variety of practical fields including game, entertainment, education, public relations and so on. This paper proposes extended application of TIP technology and realization method for smart devices using OpenGL ES Library for Android platform. Considering problems associated with a foreground object extraction, the proposed method uses vanishing points chosen by the user to facilitate more realistic scene configuration. Then, method acquires three-dimensional background model using OpenGL ES Library, develops three-dimensional virtual space and enables image navigation via camera viewpoint conversion. The experimental image is made on Android 2.1 and OpenGL ES 1.0 using the image taken on devices built on the Android platform. Thus, the proposed technology can be implemented to various smart devices built on the Android platform at lower cost and in less time.

Relationship between Image Compression and Gamut Variation Using JPEG and JPEG2000 (JPEG 및 JPEG2000을 이용한 영상 압축과 색역 변화의 관계)

  • Ko, Kyung-Woo;Park, Tae-Yong;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.1-8
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    • 2009
  • Image compression schemes, such as JPEG and JPEG2000, degrade the Quality of a reconstructed image due to their lossy characteristics. Accordingly, this paper investigates the relationship between the compression ratio and the gamut variation for a reconstructed image using JPEG and JPEG2000. To analyze the relationship between compression ratio and gamut variation, i.e. the hue and chroma shift in the uniform color space, eighteen color samples from the Macbeth ColorChecker are initially used. Based on the color shift phenomenon for the color samples, twelve natural color images, classified into two groups depending on four color attributes, are also used to investigate the relationship between the level of compression and the variation in the gamut area. As a results, through the experiments, least square method is applied to obtain the fitting curves as an equation minimizing the error between the real data and its corresponding approximated values.

LOW FREQUENCY OBSERVATIONS OF A RADIO LOUD DWARF GALAXY

  • Park, Songyoun;Sengupta, Chandreyee;Sohn, Bong Won;Paudel, Sanjaya
    • Journal of The Korean Astronomical Society
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    • v.50 no.5
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    • pp.151-155
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    • 2017
  • We investigate the radio properties of the dwarf galaxy SDSS J133245.62+263449.3 which shows optical signatures of black hole activity. Dwarf galaxies are known to host intermediate mass black holes (IMBHs) with masses $M_{BH}{\sim}10^{4-6}M_{\odot}$, some of them being radio loud. Recently, Reines et al. (2013) found dwarf galaxy candidates which show signatures of being black hole hosts based on optical spectral lines. SDSS J133245.62+263449.3 is one of them; it shows a flux density of ~ 20 mJy at 1.4 GHz, which corresponds to $L_{1.4GHz}{\sim}10^{23}W\;Hz^{-1}$. This is much brighter than other black hole host dwarf galaxies. However, star formation activity can contribute to radio continuum emission as well. To understand the nature of the radio emission from SDSS J133245.62+263449.3, we imaged this radio loud dwarf galaxy at low frequencies (325 MHz and 610 MHz) using the Giant Metrewave Radio Telescope (GMRT). We present here the high resolution images from our GMRT observations. While we detect no obvious extended emission from radio jets from the central AGN, we do find the emission to be moderately extended and unlikely to be dominated by disk star formation. VLBI observations using the Korean VLBI Network (KVN) are now being planned to understand the emission morphology and radiation mechanism.

Analysis of Gender Identity of On-line Game Character - focused on - (온라인 게임 캐릭터에 나타난 젠더 정체성 분석 - <리그 오브 레전드>를 중심으로)

  • Han, Hye-Won;Kim, Seo-Yeon;Koo, Hye-In
    • Journal of Korea Game Society
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    • v.14 no.5
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    • pp.147-160
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    • 2014
  • The purpose of this study is to analyze figurations of genders in on-line game character in order to find out the ways of building gender identity of on-line game characters. This study selects characters in on-line game to analyze figurations of genders in game systems, images, discourses of game characters by using gender identity theory and examine the reproducing process of players. As the result, the gender identity of on-line game characters which was pre-given by game developers follows the same conventions and stereotypes in real world and also the players follow it in the same manner. On-line game has the potential of text involvement and modification of the game players, and it has immanent possibilities of becoming alternative space of endless improvement and evolvement.

DISCOVERY OF WHITE DWARFS IN THE GLOBULAR CLUSTERS M13 AND M22 USING HST ACS PHOTOMETRIC DATA

  • CHO, DONG-HWAN;YOON, TAE SEOG;LEE, SANG-GAK;Sung, HYUN-IL
    • Journal of The Korean Astronomical Society
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    • v.48 no.6
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    • pp.333-341
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    • 2015
  • A search for hot and bright white dwarfs (WDs) in the Milky Way globular clusters M13 (NGC 6205) and M22 (NGC 6656) is carried out using the deep and homogeneous V I photometric catalog of Anderson et al. and and Sarajedini et al., based on data taken with the ACS/WFC aboard the Hubble Space Telescope (HST). V versus V − I color-magnitude diagrams (CMDs) of M13 and M22 are constructed and numerous spurious detections are rejected according to their photometric quality parameters qfit(V ) and qfit(I). In the case of M13, further radial restriction is applied to reject central stars with higher photometric errors due to central crowding. From each resultant V versus V −I CMD, sixteen and thirteen WD candidates are identified in M13 and M22, respectively. They are identified as stellar objects in the accompanying ACS/WFC images and are found to be randomly distributed across the central regions of M13 and M22. Their positions in the CMDs are in the bright part of the DA WD cooling sequences indicating that they are true WDs. In order to confirm their nature, follow-up spectroscopic observations are needed.

Biped robot gait pattern generation using frequency feature of human's gait torque analysis (인간의 보행 회전력의 주파수 특징 분석을 이용한 이족로봇의 적응적 보행 패턴 생성)

  • Ha, Seung-Suk;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.1
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    • pp.100-108
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    • 2008
  • This paper proposes a method of adaptively generating a gait pattern of biped robot. The gait synthesis is based on human's gait pattern analysis. The proposed method can easily be applied to generate the natural and stable gait pattern of any biped robot. To analyze the human's gait pattern, sequential images of the human's gait on the sagittal plane are acquired from which the gait control values are extracted. The gait pattern of biped robot on the sagittal plane is adaptively generated by a genetic algorithm using the human's gait control values. However, galt trajectories of the biped robot on the sagittal Plane are not enough to construct the complete gait pattern because the bided robot moves on 3-dimension space. Therefore, the gait pattern on the frontal plane, generated from Zero Moment Point (ZMP), is added to the gait one acquired on the sagittal plane. Consequently, the natural and stable walking pattern for the biped robot is obtained.

Uniform Color Image Transformation based on Color Cluster Model (칼라 클러스터 모델에 근거한 균일 칼라 영상 변환)

  • Lee, Jeong-Hwan;Park, Se-Hyeon;Kim, Jung-Su
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.6
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    • pp.1646-1657
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    • 1996
  • This paper presents a color transformation method based on a uniform color image model. Firstly, color variation factors are grouped into identical (multiplicative) factor and independent(additive) one for the color model, and they are modelled by the Gaussian function. The shape of a color cluster in (R, G, B) feature space is an ellipsoid whose elongated major axis correspond to the direction of mean vector. Secondly, the transformation of a color cluster using the model is studied. A transformation method for three dimensional coordinated is described. The proposed method is applied to artificial and natural color images. By the result of experiments, the elongated major axis of each cluster making up the transformed color image aggress with the direction of its mean vector.

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