• Title/Summary/Keyword: survey of structure

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A Study on the Species Distribution Modeling using National Ecosystem Survey Data (전국자연환경조사 자료를 이용한 종분포모형 연구)

  • Kim, Jiyeon;Seo, Changwan;Kwon, Hyuksoo;Ryu, Jieun;Kim, Myungjin
    • Journal of Environmental Impact Assessment
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    • v.21 no.4
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    • pp.593-607
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    • 2012
  • The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.

Digital Image Processing of Side Scan Sonar for Underwater Man-made Structure (수중 인공구조물에 대한 사이드스캔소나 탐사자료의 영상처리)

  • Shin, Sung-Ryul;Lim, Min-Hyuk;Kim, Kwang-Eun
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.2
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    • pp.344-354
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    • 2009
  • Side scan sonar using acoustic wave plays a very important role in the underwater, sea floor, and shallow marine geologic survey. In this study, we have acquired side scan sonar data for the underwater man-made structures, artificial reefs and fishing grounds, installed and distributed in the survey area. We applied digital image processing techniques to side scan sonar data in order to improve and enhance an image quality. We carried out digital image processing with various kinds of filtering in spatial domain and frequency domain. We tested filtering parameters such as kernel size, differential operator, and statistical value. We could easily estimate the conditions, distribution and environment of artificial structures through the interpretation of side scan sonar.

The Effect of Group Mean Differences upon Factor Analysis (상관행렬의 구조분석에서 집단평균차이의 효과: 요인분석기법을 중심으로)

  • 김청택;이소영
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2001.04a
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    • pp.109.2-130
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    • 2001
  • The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g., factor analysis), (2) to highlight the importance of the data analytic method considering group differences, and (3) to provide ways of incorporating group differences in data analysis. In study, 1, ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this, z-transform method and group analysis tool in covariance structure models were suggested. In study 2, the group differences effect was illustrated by using real data (IQ test data).

The Effect of Group Mean Differences upon Factor Analysis (상관행렬의 구조분석에서 집단평균차이의 효과: 요인분석기법을 중심으로)

  • 김청택;이소영
    • Survey Research
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    • v.2 no.2
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    • pp.109-130
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    • 2001
  • The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g.. factor analysis). (2) to highlight the importance of the data analytic method considering group differences. and (3) to provide ways of incorporating group differences in data analysis. In study 1. ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this. z-transform method and group analysis tool in covariance structure models were suggested. In study 2. the group differences effect was illustrated by using real data (IQ test data).

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Survey Results of the Organic Farmers' Attitude on Agriculture and Rural Area (친환경농업 특화지역 농업인의 농업.농촌에 대한 의식조사)

  • Heo, Seung-Wook
    • Korean Journal of Organic Agriculture
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    • v.15 no.3
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    • pp.257-275
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    • 2007
  • The objectives of this study were to analysis the farmer's attitude on agriculture and rural area where is developed Environmentally Friendly Agriculture (EFA). To analysis satisfaction level and prospect about EFA, famer's survey were conducted. The sample size of the survey was 176 respectively. Of the famers surveyed, 85.9% thought their income is higher than general farmer in the same area. However, when asked how the future income change, 40.7% responded that will be decreasing step by step. 89.2% of the farmer respondent thought that they want dwelling in rural area and continuing agriculture in the future. However, 29.9% of the farmer respondent thought that rural area is not proper to their children as the future residence. In order to training of new lamer, it is very important to set up stable income structure, improving of welfare facilities, medical facilities and education infra and so on. In addition, it need to develop and spread of environmentally friendly agri-technology, price preservation of environmentally friendly agri-product and supply extension of environmentally friendly agri-material etc.

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Characteristics of Lime-cavities and Survey Design for Bridge Foundation in the Karst Area (석회 공동의 특성과 카르스트 지역 내 교량 기초를 위한 조사 설계)

  • 윤운상;김학수;최원석
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.399-406
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    • 1999
  • Recently, the construction of the several highway bridges in the karst area have encountered severe problems associated with cavities and sinkholes. To solve this problems, it is important to understand the distribution characteristics of cavities in the construction site on limestone area. This paper briefly describes the different types, the distribution control factors and the infill sediment types of lime-cavities in the study area, bridge site in the karst area and propose the effective method of survey design. Cavity system may be divided into two main groups, 1)'slot and cave system'and 2)'sinkhole and cave system'. And the shape, the size and the distribution pattern of cavity are controlled by three main factors - rock type, geological structure and ground water condition. Additionally, infill sediment may be considered as one of the important design factors for foundation design and divided into four types by sediment properties. There are geophysical thechnics and geologic survey and drilling test, etc. by the survey method to interpretate characteristics of cavity system, and this methods are optimally designed at the site investigation stage.

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Galaxy overdensity around sub-mm sources from SPT-SZ survey

  • KIM, Yeonsik;Shim, Hyujin
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.61.2-61.2
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    • 2020
  • We study the overdensity of near-infrared sources around 508 sub-mm sources classified as dusty galaxies in the SPT-SZ survey catalog observed in 95 GHz (3.15 mm), 150 GHz (2 mm) and 250 GHz (1.2 mm) bands. We used the VISTA hemisphere survey data release 6 (VHS DR6) catalog covering the J, H, Ks bands. The mean number of galaxies within a radius of 60 arcsec (corresponding to about 500 kpc at z=2) from 500 randomly selected positions is 14.4, while the galaxy number distribution is approximated as a Gaussian with a standard deviation of 7.9. From the 2500 deg2 of SPT-SZ survey + VHS DR6 data, there were 27 sub-mm sources that have galaxy overdensity higher than 4σ. We present color-magnitude diagram around 27 selected sub-mm sources with enhanced galaxy surface densities, in order to investigate the presence of structure around sub-mm sources.

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Meromorphic functions, divisors, and proective curves: an introductory survey

  • Yang, Ko-Choon
    • Journal of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.569-608
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    • 1994
  • The subject matter of this survey has to do with holomorphic maps from a compact Riemann surface to projective space, which are also called algebrac curves; the theory we survey lies at the crossroads of function theory, projective geometry, and commutative algebra (although we should mention that the present survey de-emphasizes the algebraic aspect). Algebraic curves have been vigorously and continuously investigated since the time of Riemann. The reasons for the preoccupation with algebraic curves amongst mathematicians perhaps have to do with-other than the usual usual reason, namely, the herd mentality prompting us to follow the leads of a few great pioneering methematicians in the field-the fact that algebraic curves possess a certain simple unity together with a rich and complex structure. From a differential-topological standpoint algebraic curves are quite simple as they are neatly parameterized by a single discrete invariant, the genus. Even the possible complex structures of a fixed genus curve afford a fairly complete description. Yet there are a multitude of diverse perspectives (algebraic, function theoretic, and geometric) often coalescing to yield a spectacular result.

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A Characteristic on Community Structure of Benthic Macroinvertebrates of the Shinbulsan Wetland (신불산 고산습지의 저서성 대형무척추동물 군집구조의 특성)

  • Lee, Dong-Han;Hwang, Jong-Woo;Sung, Sung-Hoon;Yoon, Chun-Sik;Cheong, Seon-Woo
    • Journal of Environmental Science International
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    • v.18 no.5
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    • pp.561-567
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    • 2009
  • The distribution of benthic macroinvertebrates of Shinbulsan wetland was investigated. This study was focused on the degree of recovery of habitat by comparing the community structure of benthic macro invertebrates of zone D to that of zone A, intact habitat. The zone D was destructed due to the construction of a golf club and the survey was performed in zone A and zone D of Shinbulsan wetland. The seasonal survey was performed in April, July and September from 2006 to 2007. From the sampling, 2 phyla, 3 classes, 9 orders, 31 families, 69 species and 1155 individuals of benthic macroinvertebrates were collected. From zone A, 2 phyla, 3 classes, 9 orders, 23 families, 54 species and 678 individuals were identified. From zone D, 2 phyla, 3 classes, 9 orders, 23 families, 43 species and 477 individuals were identified. Species diversity and species richness were higher in zone A than in zone D. The recovery of zone D was inefficient as humidity of soil was not enough to live macroinvertebrates. Also, an endangered species of macroinvertebrates, Nannophya pygmaea was found during this investigation.

A Basic Research for Algorithms of Form Quantity Survey of Green Frame (그린프레임의 거푸집 물량산출 알고리즘 기초연구)

  • Kim, Taekoo;Lim, Chaeyeon;Kim, Sunkuk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.193-194
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    • 2014
  • Green Frame is a building frame system composed of precast concrete columns and beams. For the construction to run smoothly, the quantity of frames should be estimated in the planning phase and a plan on production of members should be established in connection with the overall work plan. The algorithm for calculation of the amount of forms used in Green Frame automatically estimates the quantity of forms using the design structure prepared in the design phase. The number and area of forms are calculated using the member size drawn from the structure design. Based on the quantity calculated, the type and area per form size are estimated to be used in preparing BOQ (Bill of Quantity). Thus, the time required for architectural planning and design can be shortened when the algorithm for calculation of the amount of forms is applied. This study is on the basic research of calculating the quantity of forms using the structure design and of the algorithm for calculation of the amount of forms used for production of composite PC members.

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