• Journal of The Korean Astronomical Society
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• v.53 no.5
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• pp.103-115
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• 2020

We analyze the spatially resolved kinematics of gas and stars for a sample of ten hidden type 1 AGNs in order to investigate the nature of their central sources and the scaling relation with host galaxy stellar velocity dispersion. We select our sample from a large number of hidden type 1 AGNs, which are identified based on the presence of a broad (full width at half maximum ≳1000 km s^-1) component in the Hα line profile and which are frequently mis-classified as type 2 AGNs because AGN continuum and broad emission lines are weak or obscured in the optical spectral range. We used the Blue Channel Spectrograph at the 6.5-m Multiple Mirror Telescope to obtain long-slit data with a spatial scale of 0.3 arcsec pixel^-1. We detected broad Hβ lines for only two targets; however, the presence of strong broad Hα lines indicates that the AGNs we selected are all low-luminosity type 1 AGNs. We measured the velocity, velocity dispersion, and flux of stellar continuum and gas emission lines (i.e., Hβ and [O III]) as a function of distance from the center. The spatially resolved gas kinematics traced by Hβ or [O III] are generally similar to the stellar kinematics except for the inner center, where signatures of gas outflows are detected. We compare the luminosity-weighted effective stellar velocity dispersions with the black hole masses and find that our hidden type 1 AGNs, which have relatively low back hole masses, follow the same scaling relation as reverberation-mapped type 1 AGN and more massive inactive galaxies.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.3 s.110
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• pp.18-30
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• 2005

Since the 1990s, with the beginning of local autonomy, most Korean cities have tried to establish and reinforce their own identity. The Law on the Planning and the Use of National Land, which took effect in January 2003, requires major and minor cities to manage and develop a city image and a marketing strategy to reflect their current condition. However, many cities continue to experience confusion in implementing urban landscape planning because no efficient and systematic method has been provided for the analysis of a city's image. The absence of systematic analysis methods makes it difficult not only to assess the current condition of a city accurately but also to choose an appropriate policy for the given city. Consequently, many cities suffer excessive trials and errors in implementing the correct policies for their city. The purpose of this study was to analyze the image: of Kongju, which has many historical properties. For this purpose, adjective questionnaires and multi-dimensional scaling (MDS) were made use of in order to assess the city image. The results of this study can be summarized as follows: 1. There are five properties that serve as landmarts lie symbolize Kongju: Muryeong royal tomb, Castle Kong, Mt. Gyeoiryong, Forest Museum, and Kongju National Museum. 2. Based on the citizen survey regarding the city type, Kongju is seen as a historical and an educational city. 3. Based on the image positioning (image spatial plot), Kongju is described as an old and familiar city. There we, however, no landmarks which are in accord with the image of Kongju. It is difficult to establish and reinforce the image of a city with a single element like a landmark However, with steady follow-up research, this study may serve as a systematic and logical model to improve the urban landscape and image.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.805-814
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• 2010

The Crank-Nicolson isotropic-dispersion finite difference time domain(CN ID-FDTD) scheme is proposed based on isotropic-dispersion finite difference(ID-FD) $equation^{[1],[2]}$. The dispersion relation of CN ID-FDTD is derived for lossy media by solving the eigenvalue problem of iteration matrix in spatial spectral domain, in addition, the weighting factors and scaling factors of the CN ID-FDTD scheme are presented for low dispersion error. The CN ID-FDTD scheme makes the dispersion error drastically reduced and shows accurate numerical results compared to the conventional Crank-Nicolson FDTD method.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.115-123
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• 2005

Quantitative understanding of spatial characteristics of the study site is a prerequisite to investigate water and carbon cycles in agricultural and forest ecosystems, particularly with complex, heterogeneous landscapes. The spatial characteristics of variables related with topography, vegetation and soil in Gwangneung forest watershed are quantified in this study. To characterize topography, information on elevation, slope and aspect extracted from DEM is analyzed. For vegetation and soil, a land-cover map classified from LANDSAT TM images is used. Four satellite images are selected to represent different seasons (30 June 1999, 4 September 2000, 23 September 2001 and 14 February 2002). As a flux index for CO₂ and water vapor, normalized difference vegetation index (NDVI) is calculated from satellite images for three different grid sizes: MODIS grid (7km x 7km), intensive observation grid (3km x 3km), and unit grid (1km x 1km). Then, these data are analyzed to quantify the spatial scale of heterogeneity based on semivariogram analysis. As expected, the scale of heterogeneity decreases as the grid size decreases and are sensitive to seasonal changes in vegetation. For the two unit grids where the two 40 m flux towers are located, the spatial scale of heterogeneity ranges from 200 to 1,000m, which correspond well to the climatology of the computed tower flux footprint.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.374-381
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• 2008

Spatial and temporal changes of fish communities were studied at four study sites in the Cheonggye Stream from October 2005 to August 2006 after the rehabilitation process. During the survey period, 19 species in 6 families were sampled. Species Rhynchocypris oxycephalus and Zacco platypus were identified as dominant species. Korean endemic species such as Acheilognathus yamatsutae and Zacco koreanus were observed in the sites. Overall, species richness and abundance increased as time passes after the rehabilitation, reflecting colonization process of the fish community. Meanwhile species richness and abundance were higher at the downstream than at the upstream. Community indices such as dominant index, richness index and diversity index showed also similar spatial and temporal pattern. Nonmetric multidimensional scaling (NMDS), multivariate ordination technique, was used to analyze spatial and temporal variation of the fish communities, and the results showed spatial variation of fish communities with high species richness at downstream as well as the temporal variation of fish communities with high values of species richness and diversity index at later part of the study period, presenting colonization process of the fish community after the rehabilitation project.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.195-209
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• 1996

The purpose of this study is to suggest objective basic data for the national park development through the quantitative analysis of the visual quality included in the physical environment of the Dukyu National Park. For this, spatial images structure of physical elements have been analyzed by factor analysis algorithm and degree of visual quality have been measured mainly by questionnaires. Result of this thesis can be summarized as follows. Factors covering the spatial image of the Dukyu National Park landscape have been found to be the overall synthetic evaluation spatial, appeal, natural quality and physical factors such as the overall the synthetic evaluation, spatial and appear yield high factor scores. Thus, these factors can be considered to represent the site spatial image of Dukyu Korean-National Park. By using the control method for the number of factors, Total variance explained by the factors has been obtained as 45.46% and 45.45%. Principal variables of main factors explained above may be the scaling containing the functional criteria of quantitative approach for landscape management of national park development. According to difference of special image from each place, for these variables that decided the visual quality can be differed, and even the same place due to landscape control point change the visual quality can be affected affirmately or negatively, according to recognized by the landscape control point.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.32.3-33
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• 2015

There exist scaling relations that link the mass of supermassive black holes with both the velocity dispersion and the mass of the central stellar cusp of their host galaxies. This implies that these two components grow in tandem. Feedback from actively accreting supermassive black holes (AGN), in the form of multi-phase gas outflows, has been argued to be the agent of this co-evolution. Here we employ the powerful GMOS integral field spectroscopy unit on the 8.2m Gemini-North telescope to investigate ionized gas outflows of luminous Type 2 AGN in the local Universe (z<0.1). Our sample of 6 galaxies is drawn from the Sloan Digital Sky Survey (SDSS) and was selected based on their [OIII] dust-corrected luminosity (>1042 erg/s) and signatures of outflows in the [OIII] line profile of their spatially integrated SDSS spectra. These are arguably the best candidates to explore AGN feedback in action since they are < 1% of a large local type 2 AGN SDSS sample selected based on their [OIII] kinematics. We combine a careful spectral decomposition of the [OIII] and $H{\alpha}$ line profiles with spatial information on ~0.5kpc scales to understand the outflow kinematics and energetics in these objects. We find clear evidence for strong outflows in [OIII] and occasionally $H{\alpha}$ that are clearly driven by the ionizing radiation of the AGN. We kinematically and spatially decompose outflowing and rotating ionized gas components. We find [OIII] to be a better tracer of AGN outflows, while $H{\alpha}$ appears to be strongly affected by both stellar rotation and outflows induced by ongoing star formation. The observed kinematics and spatial distribution of the ionized gas imply a large opening angle for the outflow. Finally, we find the projected outflow velocity to decrease as a function of distance, while its dispersion shows a more complex structure with a potentially initially increasing trend (out to 0.5-1kpc distances).

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.3 s.309
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• pp.43-53
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• 2006

As wireless network technology has advanced, demands for multimedia contents through mobile environment have tendered to upward. Since network situation is changing every moment and types of user terminals are diverse, it is difficult for a content provider to consider network situation and type of user terminal to provide multimedia contents. As one solution, transcoding techniques have been proposed, but those have much complexity. In this paper, in order to reduce computational complexity, we propose a fast mode decision using input modes, motion vectors, and residual energies which are obtained from input bitstream for 2:1 down-scaling spatial transcoding application. The proposed method reduces processing time in mode decision by restricting possible mode types based on input information. Experimental results show that the proposed method achieves about 2.66 times improvement in encoding time compared to the normal encoding process while the PSNR is degraded by about 0.04dB, and bit-rate is increased by 1.6%.

• Spatial Information Research
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• v.9 no.2
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• pp.341-352
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• 2001

This study was carried out to developed that appraisement model of Potential Productivity Index(PPI). PPI model was used Farmland Productivity Index(FPI) and Labor Productivity Index(LPI) by GIS, and PPI model applied to farm land consolidation region which has been completed recently. FPI was determined by overlapping Poly Grid of the soil properties at the analyzed project region. LPI was estimated by addition productive wages ratio of total direct productive cost. Addition productive wages determined by GIS Network analysis GIS Network analysis of working distance between farm house to paddy and each paddy. PPI variation of each the analyzed paddy of Masu and Weoncheon region was 0.967~0.780 respectively, and could be showed relative largely PPI value. PPI will provide basic element for large scaling and gathering of farm land and a substitute lot of farm land consolidation, and will be maximize productivity of paddy.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.2
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• pp.149-166
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• 2006

The purpose of this study is to produce time-distance cartograms based on the various Korean transportation networks, and to analyze the spatial structure of time-distance accessibilities. For the purpose this study attempts to develop continuous area cartogram by utilizing Wolf's algorithm for creating contiguous cartogram in ArcGIS 9. The absolute physical space was transformed to the functional space indexed by time-distances along various transportation networks in Korea. We examined the differences in the time-distance accessibilities among transportation networks. This study makes a comparison between the spatial structure of time-distance accessibility of KTX network with them of existing railroad network, as well as with them of road network. In order to clarify the spatial structures of time-distance accessibilities, we restructured them on the time-distance circular diagrams and performing Multi-Dimensional Scaling analysis. Overall structure of time-distance accessibilities shows similar patterns: The time distances are shrinked a lot along the Seoul-Busan axis, while coastal parts, in particular the eastern part of the county, are shrinked relatively little via all transportation networks. The Road network affects significantly on the accessibilities of cities in Gangwon-do and Gyeonggi-do, while railway network affects on the accessibilities of cities in Jeolla-do and Gyeongsang-do in general. When we compared the time-distance accessibilities based on the 5 largest cities, Seoul appears as the most accessible city from/to all other cities in Korea. We can also find significant changes in the time-distance accessibility between KTX network and existing railroad network. Cities along the KTX network, in particular cities which has KTX stops, improved significantly in time-distance accessibilities.