• Title/Summary/Keyword: Areal measurement

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Research on Areal Interpolation Methods and Error Measurement Techniques for Reorganizing Incompatible Regional Data Units : The Population Weighted Interpolation (지역 자료의 공간 단위 재구성 기법 및 에러 검증 : 인구가중치 내삽법)

  • Shin, Jung-Yeop
    • Journal of the Korean association of regional geographers
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    • v.10 no.2
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    • pp.389-406
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    • 2004
  • with the increasing popularity of regional studies, the importance of regional data has been recognized dramatically in recent years. However, due to potential problems from the intrinsic characteristics of aggregate regional data for the research, and incompatible regional units between source and target regional data units, the method for reorganizing the regional data units for a given research analysis should be required. In this regard, the purpose of this research is to review the significant interpolation methods for reorganizing the data units and, based on it, to propose the population weighted interpolation method. For the first purpose, areal weighted interpolation method, pycnophylactic method, dasymetric method, area-to-point method were reviewed. The proposed population-weighted interpolation method was applied to the case study of population census regional data in Erie County, NY, compared with areal weighted interpolation method, pycnophylactic method in terms of several statistical characteristics.

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Volumetric Bone Mineral Density Measurement: for Surgery Specific Bone Volumes (체적골밀도 측정법 동향: 수술부위 골밀도 분석)

  • Lee, Yeon Soo
    • Journal of the Korean Society of Radiology
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    • v.16 no.1
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    • pp.53-59
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    • 2022
  • DEXA, as the standard areal bone mineral density (aBMD) measurement method, often shows an insuficient correlation between aBMDs of the measured bones and referring bones and is inaccurate due to the mass effect. In contrast, quantitative computer tomography (QCT), as a volumetric BMD (vBMD) measurement method, is being advanced so that it uses less radiation before, owing to improved CT device and computer imaging technology. Because dual-energy CTs can modulate the image signals showing tumor or specific chemicals as well as the ability to measure vBMD, they are expanding their application. For pre-checking vBMD of surgeon-specific bone volume at implantation candidate sites, a finite element creation-based local vBMD measurement technique was developed. The local vBMD measurement function for surgeon-specific shape volumes will be added to clinical imaging systems.

Meta-data Configuration and Wellness Feature Analysis Technique for Wellness Content Recommendation (웰니스 콘텐츠 추천을 위한 메타데이터 구성 및 웰니스 특성 분석 기법)

  • Hong, Min-Sung;Lee, O-Joun;Lee, Won-Jin;Lee, Jae-Dong
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.83-93
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    • 2014
  • Research into recommendation systems for wellness content has focused on representative research on the convergence of wellness and information technology, as interest in wellness has recently increased. But existing research is not suitable because it uses only one or two of the five wellness areas: physical, emotional, social, intellectual, and spiritual. And It cause decline of reliability and satisfaction for recommendation. Thus, a wellness areal feature analysis and integration management technique is needed. In this paper, suggest meta-data configuration and feature analysis technique of content. Also Cosine similarity of wellness areal features of the content was analyzed by applying a wellness areal score calculated in this way and by suggested wellness areal detailed properties and a measurement system to verify the efficiency of this research. This allows the wellness features of contents analyzed, and even will be able to personalized recommendations service for wellness.

Electrostatic 2-axis MEMS Stage with a Large Area Platform for Probe-based Storage Devices (대면적 플랫폼을 갖는 Probe-based Storage Device(PSD)용 정전형 2축 MEMS 스테이지)

  • Chung, Il-Jin;Jeon, Jong-Up
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.9 s.186
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    • pp.179-189
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    • 2006
  • Recently the electrostatic 2-axis MEMS stages have been fabricated f3r the purpose of an application to PSD (Probe-based Storage Device). However, all of the components (platform, comb electrodes, springs, anchors, etc.) in those stages are placed in-plane so that they have low areal efficiencies such as a few percentage, which is undesirable as data storage devices. In this paper, we present a novel structure of an electrostatic 2-axis MEMS stage that is characterized by having a large areal efficiency of about 25%. For obtaining large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. The structure and operational principle of the MEMS stage are described, followed by a design and analysis, the fabrication and measurement results. Experimental results show that the driving ranges of the fabricated stage along the x and y axis were 27$\mu$m, 38$\mu$m at the supplied voltages of 65V, 70V, respectively and the natural frequencies along x and y axis were 180Hz, 310Hz, respectively. The total size of the stage is about 5.9$\times$6.8mm$^2$ and the platform size is about 2.7$\times$3.6mm$^2$.

A Study on Vector-based Converting Method for Hydrological Application of Rainfall Radar Image (레이더 영상의 수문학적 활용을 위한 벡터 변환방법 연구)

  • Jee, Gye-Hwan;Oh, Kyoung-Doo;An, Won-Sik
    • Journal of Korea Water Resources Association
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    • v.45 no.7
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    • pp.729-741
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    • 2012
  • Among the methods of precipitation data acquisition, a rain gauge station has a distinctive advantage of direct measurement of rainfall itself, but multiple stations should be installed in order to obtain areal precipitation data required for hydrological analysis. On the other hand, a rainfall radar may provide areal distribution of rainfall in real time though it is an indirect measurement of radar echoes on rain drops. Rainfall radars have been shown useful especially for forecasting short-term localized torrential storms that may cause catastrophic flash floods. CAPPI (Constant Altitude Plan Position Indicator), which is one of the several types of radar rainfall image data, has been provided on the Internet in real time by Korea Meteorological Administration (KMA). It is one of the most widely available rainfall data in Korea with fairly high level of confidence as it is produced with bias adjustment and quality control procedures by KMA. The objective of this study is to develop an improved way to extract quantitative rainfall data applicable to even very small watersheds from CAPPI using CIVCOM, which is a new image processing method based on a vector-based scheme proposed in this study rather than raster-based schemes proposed by other researchers. This study shows usefulness of CIVCOM through comparison of rainfall data produced by image processing methods including traditional raster-based schemes and a newly proposed vector-based one.

Development of Radar Polygon Method : Areal Rainfall Estimation Technique Based on the Probability of Similar Rainfall Occurrence (Radar Polygon 기법의 개발 : 유사강우발생 확률에 근거한 면적강우량 산정기법)

  • Cho, Woonki;Lee, Dongryul;Lee, Jaehyeon;Kim, Dongkyun
    • Journal of Korea Water Resources Association
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    • v.48 no.11
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    • pp.937-944
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    • 2015
  • This study proposed a novel technique, namely the Radar Polygon Method (RPM), for areal rainfall estimation based on radar precipitation data. The RPM algorithm has the following steps: 1. Determine a map of the similar rainfall occurrence of which each grid cell contains the binary information on whether the grid cell rainfall is similar to that of the observation gage; 2. Determine the similar rainfall probability map for each gage of which each grid cell contains the probability of having the rainfall similar to that of the observation gage; 3. Determine the governing territory of each gage by comparing the probability maps of the gages. RPM method was applied to the Anseong stream basin. Radar Polygons and Thiessen Polygons of the study area were similar to each other with the difference between the two being greater for the rain gage highly influenced by the orography. However, the weight factor between the two were similar with each other. The significance of this study is to pioneer a new application field of radar rainfall data that has been limited due to short observation period and low accuracy.

Regional Distribution Characteristics of Total Gaseous Mercury in Air-Measurements from Urban and Mountainous Sites in Korea (대기 중 수은의 지역적 분포특성에 대한 비교연구-한반도의 도심과 산악지역을 중심으로)

  • 김민영;김기현
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.1
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    • pp.39-50
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    • 2001
  • The spatial distribution characteristics of airborbe mercury(Hg) were investigated used its concentration data from six measurement sites selected to represent:(1) three terminal sites with heavy traffic loads in urban area, (2) one urban residential site and (3) two mountainous sites in Korea. The measurement data obtained during September 1997 through May 1998 indicated that the mean concentration of Hg from different study sites were comparably high with the mean values spanning from 5-9ng./㎥. The concentration from all those sites were systmatically high compared to those of most background sites around world or to other Korean sites investigaed previously. When results of correlation analysis between Hg and relevant parameters were compared among different study sites. temperature was most frequently found out to be in strong correlation with Hg concentrations. Results of factor analysis also indicated that Hg concentrations could be affected simultaneously by th factors affecting such parameters as ozone, temperature, ozone, carbon monoxide, and PM. The findings of enhanced Hg levels from Ji-Ri Mountain relative to terminal site suggest that is distributions may be rather homogeneous not enough to clearly distinguish areal differences and the associated source signatures between urban and rural area. The existence of systmatically high concentrations from all investigated sites also indicate that the impact of its source processes should be quite ubiquitous, while highly variable in relatively long term scale.

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Characterization of Volatile Organic Compounds concentrations in the ambient air of the Kumi industrial complex (구미산업단지 대기중 휘발성유기화합물(VOCs)의 농도특성)

  • Choe, U Geon;Bae, Sang Ho;Park, Deok Sin;Jeong, Yeon Gu;Kim, Tae O
    • Journal of Environmental Science International
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    • v.13 no.3
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    • pp.205-214
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    • 2004
  • This study focuses on the measurement of airborne Volatile Organic Compounds (VOCs) in the Kumi electronic industrial complex during the time periods of August and September, 2002 and January and February, 2003. This study was based on the US-EPA method TO-14 while the VOCs were analyzed with GC/MSD. The toluene level revealed high concentration at all measurement sites. The areal rank of average concentrations of VOCs is as follows: industry1 > industry2 > urban > middle > residential. Concentrations of VOCs in Kumi electronic industrial ones were generally higher than at Yeochon and Ulsan industrial complexes. Dichloromethane and trichloroethylene, which are used as a cleaner in the process of electronic industries, were observed 4 to 8 times higher than those of other areas. Among the aromatic compounds, toluene showed the highest level, while the concentrations of dichloromethane and trichloroethylene were higher than those of other halogen compounds. In Kumi, toluene, trichloroethylene, and dichloromethane were confirmed as the major compounds of VOCs by this research.

Comparison of Compressibility between the Oedometer Tests with the Field Measurements in Namak Clay (계측결과를 이용한 남악점토의 압축특성 비교)

  • Kim, Dongbeum;Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.5
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    • pp.15-20
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    • 2008
  • Compressibility of the marine clay was mainly studied velocity of consolidation and numerical analysis by this time but studies of reevaluated from the field measurement data was a little. For last three years, areal fills and extensive field instrumentations including settlement and pore water pressure were performed in the site of the Youngsan River estuary site, South Korea. From the settlement data, field consolidation curves for sub-layers were reconstructed. Effective surcharge loads during the staged loadings were calculated using the fill heights and the excess pore water pressures in the ground. In the numerical analysis (PLAXIS), prefabricated vertical drains were also simulated. Laboratory, field, and numerical analysis showed good agreements in compressibility. Due to different conditions and limitations of the clay was the same range of the oedometer tests.

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