• Title/Summary/Keyword: Geographical Discrepancies

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AUTOMATIC ADJUSTMENT OF DISCREPANCIES BETWEEN LIDAR DATA STRIPS - USING THE CONTOUR TREE AND ITERATIVE CLOSEST POINT ALGORITHM

  • Lee, Jae-Bin;Han, Dong-Yeob;Yu, Ki-Yun;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.500-503
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    • 2006
  • To adjust the discrepancy between Light Detection and Ranging (LIDAR) strips, previous researches generally have been conducted using conjugate features, which are called feature-based approaches. However, irrespective of the type of features used, the adjustment process relies upon the existence of suitable conjugate features within the overlapping area and the ability of employed methods to detect and extract the features. These limitations make the process complex and sometimes limit the applicability of developed methodologies because of a lack of suitable features in overlapping areas. To address these drawbacks, this paper presents a methodology using area-based algorithms. This approach is based on the scheme that discrepancies make complex the local height variations of LIDAR data whithin overlapping area. This scheme can be helpful to determine an appropriate transformation for adjustment in the way that minimizes the geographical complexity. During the process, the contour tree (CT) was used to represent the geological characteristics of LIDAR points in overlapping area and the Iterative Closest Points (ICP) algorithm was applied to automatically determine parameters of transformation. After transformation, discrepancies were measured again and the results were evaluated statistically. This research provides a robust methodology without restrictions involved in methods that employ conjugate features. Our method also makes the overall adjustment process generally applicable and automated.

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Geographical Discrepancies in Residential Outcomes and Housing Expenditure of Young Married Couples in Chonsei Housing (전세 거주 청년 부부가구의 지역 간 거주환경과 주거비 차이)

  • Hyunjeong Lee;Sangjun Nam
    • Land and Housing Review
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    • v.14 no.3
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    • pp.17-36
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    • 2023
  • This research aims to investigate the socio-demographic, financial, and housing statuses of young married couples in Chonsei housing and to analyze the determinants of their residential environment quality and housing expenditure in four districts - Seoul and Gyeonggi-Incheon Area(GIA) of the Seoul Metropolitan Area(SMA), and metropolises and non-metropolises of non-SMA. From the 2020 Korean Housing Survey(KHS), this cross-sectional analysis examined a sample of 691 households, and the findings revealed that most were headed by college-educated, salaried male workers aged 31 years old. While childless dual-earner couples were common in Seoul, single-income families of three were prevalent in non-SMA. The financial status of the couples in Seoul was a lot better than in the other three areas, particularly much higher in Chonsei deposit and total asset value. Further, many lived in a three-bedroom apartment unit sized 60m2 and bigger, using a Chonsei loan. Regardless of areas, almost all the households spent a very low portion of their living expenses and income on housing costs. However, dual-earner families positively increased borrowing capacity, which improves the household's financial position that is likely to lead to equity increment in a volatile asset market in the long run. The statistical results indicated that residential environment assessment was influenced by neighborhood quality and housing expenditure was affected by housing size in Seoul, urban amenities in GIA and householder's gender in non-metropolises. Thus, this research proposes that strong measures be considered to mitigate housing inequality embedded in geographical and socio-economic disparities.

Recognition Saves a Space where Invisible, Inaudible, and Unwritable - Another Reason for Geography as Humanities - (인정, 보이지 않고, 들리지 않고, 쓰여지지 않은 공간을 발견하다: 지리학이 인문학인 또 다른 이유)

  • Park, Seung-Kyu
    • Journal of the Korean Geographical Society
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    • v.46 no.6
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    • pp.767-780
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    • 2011
  • The present paper discusses the relationship between human being and space through 'recognition.' Recognition is the natural desire of human being. Every human being wants to be recognized for what they do in everywhere. Human being enhances their own identity and fight for the raison d'etre to be recognized by others. Hegel's recognition is grounded by a process of mutual recognition based on the subject-object view of human beings. On the other hand, the recognition based on inter-subjectivity is founded by the view of human beings emphasizing "we" on the basis of the relationship between you and I. These two meanings of recognition make it possible to newly recognize the relationship between human beings and space. In the paper, I emphasize the role of geography about the invisible space over the geographical recognition regarding the visible space dealing in previously geography. I expect to be recovered the nature of geography by revealing the invisible space. Also, the geographical discovery is presented about two spaces including inaudible space and unwritable space but having story via '$\acute{e}$criture blanche.' In terms of the discovery, I criticize irrationalities and discrepancies of our society and suggest ways of solving problems. The goal of the discussion is to support the overcoming of the immediate geography crisis as well as communicate with the world as humanity.

The Impacts on Flow by Hydrological Model with NEXRAD Data: A Case Study on a small Watershed in Texas, USA (레이더 강수량 데이터가 수문모델링에서 수량에 미치는 영향 -미국 텍사스의 한 유역을 사례로-)

  • Lee, Tae-Soo
    • Journal of the Korean Geographical Society
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    • v.46 no.2
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    • pp.168-180
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    • 2011
  • The accuracy of rainfall data for a hydrological modeling study is important. NEXRAD (Next Generation Radar) rainfall data estimated by WRS-88D (Weather Surveillance Radar - 1988 Doppler) radar system has advantages of its finer spatial and temporal resolution. In this study, NEXRAD rainfall data was tested and compared with conventional weather station data using the previously calibrated SWAT (Soil and Water Assessment Tool) model to identify local storms and to analyze the impacts on hydrology. The previous study used NEXRAD data from the year of 2000 and the NEXRAD data was substituted with weather station data in the model simulation in this study. In a selected watershed and a selected year (2006), rainfall data between two datasets showed discrepancies mainly due to the distance between weather station and study area. The largest difference between two datasets was 94.5 mm (NEXRAD was larger) and 71.6 mm (weather station was larger) respectively. The differences indicate that either recorded rainfalls were occurred mostly out of the study area or local storms only in the study area. The flow output from the study area was also compared with observed data, and modeled flow agreed much better when the simulation used NEXRAD data.

A GIS-Based Public Health-Geographical Analysis of Oral Health Programs for Primary School Students (학교구강보건사업의 보건지리학적 분석을 위한 지리정보체계의 활용)

  • Yang, Jin-Young
    • Journal of dental hygiene science
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    • v.13 no.2
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    • pp.174-181
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    • 2013
  • The objective of this research is to compare and analyze regional accessibility of Korean primary school students to oral health services from the perspective of public health geography by using geographic information system in which the choropleth map has been regarded as the most popular method. Statistical proximity on the basis of calculus of 205 regions-based school oral health data is optimized to set five class intervals for five maps. These choropleth maps of oral heal programs such as oral health education, tooth-brushing method education, preventive dental care and curative dental care, demonstrate that there exist wide regional discrepancies throughout the country in terms of primary school students' accessibility to oral health services within the programs. The paper not just contributes to overcoming the existing paradigm by actively considering an interdisciplinary research among public health dentistry, dental hygiene and geography of public health, but provides clear evidence for national oral health policy in South Korea.

A Study on the Static Behaviors of Steel Deck Plates of Skew Bridges (사교(斜橋)의 강상판(鋼床板)의 정적거동(靜的擧動)에 대한 연구(研究))

  • Yang, Chang Hyun;Oh, Gi Taek
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.4
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    • pp.815-826
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    • 1994
  • Skew bridges are found frequently in new bridge construction due to geographical conditions when new constructing bridges are put across the existing highways, railroads or rivers. This study is to investigate the static behaviors of the steel deck plates of skew bridges which are increasingly used in bridges due to outstanding quality of structural steels, development of welding techniques, in order to reduce dead loads and period of constructions. The static behaviours of steel deck plates are analyzed using general purpose FE code SAP90 by modeling the skewed deck plates with rigorous finite elements, as the skew angles vary. The results of finite element analysis for the behaviors of steel deck plates and concrete slabs in acute, obtuse corners and center of decks are compared and discussed as the skew angles vary from $90^{\circ}$ to $30^{\circ}$. Two types of decks are treated, as isotropic plates and orthotropic plates, respectively. From the results of finite element analysis, it is found that more moments, reactions, and deflections occur at the obtuse corners than at the center of skewed decks regardless of isotropy or orthotropy. Especially, in case of the skewed deck plates with skew angles less than 45 degrees, significantly large discrepancies for the values of those internal forces are shown between the skewed and right deck plates. This study estimates the characteristics of deck behaviors according to skew angles, and proposes limitations of skew angles and the ciritical regions of decks.

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A Reconsideration of the List of National Endemic Plants (appendix 4-1) Under the Creation and Furtherance of Arboretums Act Proposed by Korea Forest Service (산림청 수목원 조성 및 진흥에 관한 법률의 특산식물 목록의 재고)

  • Park, Soo Kyung;Gil, Hee-Young;Kim, Hui;Chang, Chin-Sung
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.38-58
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    • 2013
  • The existence of endemism in many parts of the world is an important factor for conservationists. Conservation can only be carried out under national legislation, and national endemics, which have very limited ranges, fully depend on the effort and success of conservation. A total of 523 vascular plant taxa were listed in the latest national checklist by Ministry of Environment in 2005, while the 'Creation and Furtherance of Arboretums Act' including a national endemic list (appendix 4-1) was established by Korea Forest Service and was legislated as a law in late 2011. This legislation by Korea Forest Service on endemism of Korean vascular plants have required much attention because of discrepancies of nomenclature, taxonomic bias and inflation. Examining data for both lists proposed by Ministry of Environment and Korea Forest Service, of the total of 360 legislated taxa, around 286 taxa are shared with the list of Ministry of Environment, of which about 80% have been found as common taxa. Around 67(18.7%) are typographic errors, and 14 taxa (3.9%) are recorded as illegitimate and invalidly published names. Through this analysis 12 taxa (3.4%) were found in China as well as in Korea and these are thought to be non Korean endemic taxa. Taken together, the legislated list displayed 1/4 (24.9%) errors out of the total list. Only 59 taxa (16.5%) are identified as national endemic species. The remainder are either unresolved candidates (73 taxa, 20.4%) or synonyms (196 taxa, 54.7%) status. It must be noted, that the concept of endemism very much depends on the knowledge of the species concept, taxonomic bias and geographical range of a species. Also, the most major nomenclatural problem tend to be more stable if the information on database about Korea Plant Name, which is managed by Korea National Arboretum are well updated year to year. These exaggerated numbers underscore the urgency for regional conservation planning and implementing effective strategies to preserve these real endemic taxa into the future.