Integrating spatial data analysis functionalities in a GIS environment: Spatial Analysis using ArcGIS Engine and R (SAAR)          下载免费PDF全文

Hyeongmo Koo  Yongwan Chun  Daniel A. Griffith 《Transactions in GIS》2018,22(3):721-736

Spatial data analysis (SDA) tools to efficiently handle and explore spatial data have become readily available. Although these SDA tools have their own strengths and purposes, they suffer from limited support in terms of a development environment offering easy customization and high extensibility, a strength of open source software. This article presents a standalone software package for SDA in a geographic information system (GIS) environment, called Spatial Analysis using ArcGIS Engine and R (SAAR), which provides an integrated GIS and SDA environment. A set of SDA tools in SAAR utilizes functions in R using R.NET, while other tools were developed in .NET independent of R. SAAR provides an efficient working environment for both general and advanced GIS users. For general GIS users with limited programming skills, SAAR furnishes advanced SDA tools in a popular ArcGIS environment with graphical user interfaces. For advanced GIS users, SAAR offers an extensible GIS platform to help them customize and implement SDA functions with relatively little development effort. This article demonstrates some functionalities of SAAR using census data for Texas counties.  相似文献   

Fully nonlinear wave-body interactions with surface-piercing bodies   总被引：1，自引：0，他引：1  

W.C. Koo  M.H. Kim   《Ocean Engineering》2007,34(7):1000-1012

Fully nonlinear wave-body interactions for stationary surface-piercing single and double bodies are studied by a potential-theory-based fully nonlinear 2D numerical wave tank (NWT). The NWT was developed in time domain by using boundary element method (BEM) with constant panels. MEL free surface treatment and Runge–Kutta fourth-order time integration with smoothing scheme was used for free-surface time simulation. The acceleration-potential scheme is employed to obtain accurate time derivative of velocity potential. Using the steady part of nonlinear force time histories, mean and a series of higher-harmonic force components are calculated and compared with the experimental and numerical results of other researchers. The slow-decaying second-harmonic vertical forces are investigated with particle velocities and corresponding body pressure. Typical patterns of two-body interactions, shielding effect, and the pumping/sloshing modes of water column in various gap distances are investigated. The pumping mode in low frequencies is demonstrated by the comparison of velocity magnitudes.  相似文献   

Geology, Mineralogy and Geochemistry of Carbonate Replacement-Type Lead-Zinc-Silver Deposits in Janggun Mine, Republic of Korea     

Lee Hyun Koo Lee Chan Hee Yoo Bong Cheal Lee Jong Chang Department of Geology  Chungnam National University  Taejon  Korea 《中国地质大学学报(英文版)》2000,11(2)

INTRODUCTIONThe Janggun mine,Republic of Korea,is located in thesoutheast of the Seoul,about latitude36°5 1′N and longitude12 9°0 4′E. In this mine area is situated the Bonghwa m ineral-ized zone of the Taebaegsan mining district,Korea.The geo-logic setting of the region was described as the Samgeum riQuadrangle(Kim et al.,196 2 ) .The general and local geolo-gy near the mine area have been studied by L ee (196 7) ,Hwang and Reedman(1975 ) .This mine consists of four min-eral de…  相似文献   

韩国东海Ulleung盆地天然气水合物沉积层的地震属性分析     

Snons Cheong  Wonsik Kim  Namhyung Koo  孙萍 《海洋地质前沿》2009,25(2):22-23

地震属性可以由多种地震子波的特征来定义。并且根据不同的标准分类。选择叠前地震数据特征可提供丰富的诸如偏移和方向的资料,此次研究中,我们将限制叠后地震数据以提取地震属性,叠后地震数据可以通过子波特征和瞬时特征来分类。  相似文献   

Pre-stack sea bottom detection and swell correction within an expected hyperbolic range for noisy high-resolution 8-channel airgun seismic data     

Lee  Ho-Young  Koo  Nam-Hyung  Kim  Byoung-Yeop  Kim  Young-Jun  Son  Woohyun  Joo  Yonghwan 《Marine Geophysical Researches》2021,42(1):1-22

Marine Geophysical Research - The Hugin Fracture, discovered in 2011, is an approximately 3.5 km long seafloor fracture in the North Sea. This fracture was unexpected and, due to the...  相似文献   

Keck spectroscopy and imaging of faint galaxies identified as microjansky radio sources     

Nathan D.Roche  James D.Lowenthal  David C.Koo 《Monthly notices of the Royal Astronomical Society》2002,330(2):307-328

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The DEEP2 Galaxy Redshift Survey: the relationship between galaxy properties and environment at z∼ 1     

Michael C. Cooper  Jeffrey A. Newman †  Darren J. Croton  Benjamin J. Weiner  Christopher N. A. Willmer  Brian F. Gerke  Darren S. Madgwick †  S. M. Faber  Marc Davis  Alison L. Coil †  Douglas P. Finkbeiner  Puragra Guhathakurta  David C. Koo 《Monthly notices of the Royal Astronomical Society》2006,370(1):198-212

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A numerical model for estimating groundwater flux from subsurface temperature profiles     

Ashok K. Keshari  Min-Ho Koo 《水文研究》2007,21(25):3440-3448

A simple numerical model is presented for estimating vertical groundwater flux from transient subsurface temperature profiles obtained from field measurements. The model developed utilizes the MacCormack scheme, which is based on the Finite Difference Method (FDM), for solving the governing partial differential equation of convection–diffusion heat transport with appropriate initial and boundary conditions within the subsurface. In order to validate the model, numerical solutions obtained for the study area located in the Nagoka plain, Japan are compared with the published measured data and results obtained by others. Results obtained show good agreement and fit the observed data with a correlation coefficient, R², of 0·88. The estimated groundwater flux is 1·85 × 10⁻⁷ m s⁻¹. Sensitivity analyses were also carried out to investigate the effect of variations in groundwater fluxes, thermal properties and the annual thermal variability due to climatic changes on the transient subsurface temperature profiles and to have a better understanding of the subsurface thermal dynamics. A substantial effect of annual climatic variability is observed on the temporal distributions of temperature depth profiles, and a better estimate of thermal parameters is required to estimate vertical groundwater flux. The largest change in subsurface temperature depth profiles due to groundwater flux over a year is within ± 4 °C. The influence of groundwater flux on subsurface temperature distributions in space and time may be more pronounced in areas where the top of the saturated layer fluctuates considerably. Variation in thermal diffusivity results in temperature change up to ± 1·5% and may cause change in groundwater flux estimate by ± 18%. The model presented has merits over analytical solutions (type curve matching techniques) in terms of suitability and applicability to real field problems, and can be a good asset to hydrological models as quantifying groundwater recharge or deducing it from other quantities, such as rainfall, evapotranspiration and runoff, is often complicated. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Oxygen penetration through invertebrate burrow walls in Korean tidal flat     

Bon Joo Koo  Chul-Hwan Koh 《Ocean Science Journal》2013,48(4):329-338

Macrofaunal burrows increase the surface area of the sediment-water interface, which has a great impact on the metabolism of aerobic microbes and the oscillation of reduced metabolites within the sediment. Given the importance of macrofauna in surficial sediments, the aim of this study is to examine the effects of burrow architectures on dissolved oxygen diffusion rates in comparison with unburrowed sediment, and thereby to evaluate the theoretical assumption used for modeling solute distribution in the burrow system using field samples. Employing microsensors, horizontal oxygen profiles were measured on a micrometer scale around burrows of seven invertebrates in tidal flats of the west coast of Korea. Oxygen diffusion distance through the burrow walls of seven invertebrates showed spatio-temporal variation with a range of 0.6 to 2.9 mm. Two groups of burrows were identified based on their oxygen diffusive properties relative to unburrowed sediments: 1) oxygen penetration similar to that of ambient sediments and 2) clearly enhanced oxygen penetration. Differences in the diffusive properties of the burrow wall were related to the burrow depth and diameter, existence of mucus lining on the wall, sediment grain size, and tidal phases. Also inhabitant activity was an important factor affecting oxygen penetration, which is discussed in the paper. These results further demonstrate that simplified assumptions (i.e. burrow structures are viewed as direct biogeochemical extensions of the sediment-water interface) may not be exact representation of the nature.  相似文献   

Does the restoration of an inner-city stream in Seoul affect local thermal environment?     

Y.-H. Kim  S.-B. Ryoo  J.-J. Baik  I.-S. Park  H.-J. Koo  J.-C. Nam 《Theoretical and Applied Climatology》2008,92(3-4):239-248

Summary Changes in local thermal environment associated with the restoration of an inner-city stream in Seoul, Korea, are investigated using observational data. The stream, called the Cheonggye stream, which had been hidden and covered with cement/asphalt for 46 years, runs 5.8 km eastward through a central region of Seoul. Intensive observations were made in the stream area for a number of summertime periods before, during, and after the stream restoration to detect the effects of the stream on local environment and to quantify them. It is estimated that after the stream restoration the near-surface temperature averaged over the stream area dropped by 0.4 °C, with the largest local temperature drop being 0.9 °C. However, it cannot be stated that this 0.4 °C temperature drop is due entirely to the stream effect only, because synoptic-scale and local-scale weather conditions during the two periods were inevitably not identical. The stream effect on air temperature is also evident in the temperature distribution along a street traversing the stream. In the daytime after the stream restoration, the sensible heat flux was greatly reduced and the ratio of sensible heat flux to net radiative flux dramatically decreased. These first-time results of the restored-stream effects on urban thermal environment could contribute to the scientific basis of urban planning which aims to make a large city comfortable to live in and nature- and environment-friendly. Authors’ addresses: Yeon-Hee Kim, Il-Soo Park, Hae-Jung Koo, and Jae-Cheol Nam, Meteorological Research Institute, Korea Meteorological Administration, Seoul 156-720, Korea; Sang-Boom Ryoo, Suwon Meteorological Office, Korea Meteorological Administration, Suwon 441-856, Korea; Jong-Jin Baik, School of Earth and Environmental Sciences, Seoul National University, Seoul 151-742, Korea  相似文献