• Journal of the Korean Geosynthetics Society
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• v.10 no.1
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• pp.29-36
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• 2011

The remediation efficiency of the contaminant through laboratory experiment of the pilot scale was evaluated for the influence factors in the contaminated soils for the applicability of the prefabricated vertical drain system. It was performed numerical analysis by the method that the finite element and finite differences based on the drawn result about the remediation of contaminated soils. The parametric analysis for the applied parameter value was performed. In the pilot scale remediation experiment, as a result of evaluating with the minimum limit concentration ratio, in the case of dense and loose conditon, the remediation time was much longer. And the remediation efficiency was rapidly progressed as the time was elapsed. It was analyzed that the contaminant concentration is reduced around the extraction well as the contamination remediating rate by numerical analysis result as the time was elapsed.

• Journal of Environmental Impact Assessment
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• v.31 no.4
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• pp.265-270
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• 2022

With the implementation of the fox restoration project, the number of foxes released into nature are increasing; therefore, in the future, foxes will be dispersed to other areas and will appear in human habitats. In this study, the habitat suitability index (HSI) of foxes was developed to predict and prepare for the effects. After extracting major environmental variables through literature research and GIS analysis, 5 suitability indices (SIs) were constructed. The forest physiognomy, slope, aspect, distance from water source, and distance from road are the main variables, and the arithmetic average value by giving twice the weight to the forest physiognomy is the HSI result. As a result of comparing with the data from the Natural Environment Survey, it is found that the fox coordinates have an average HSI value of 0.64, and the probability of appearance is high when it is 0.53 or higher. Using the results of this study, it is expected to be able to predict the distribution of foxes in advance, to use them as basic data for future restoration plans, or to identify the distribution of the species and the reduction plan in future environmental impact assessments.

• Journal of Conservation Science
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• v.36 no.6
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• pp.533-540
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• 2020

Mt. Neoseongsan (NSS) is the only natural Neorok source in Korea. The geological, historical, and cultural values of NSS were recognized in 2013, and NSS has since been designated and maintained as a natural monument (No. 547), which has restricted the research and utilization of NSS Neorok. The limited NSS Neorok supply has hindered the restoration research of traditional pigments. Recently, a large amount of Neorok has been mined from Mt. Gwangeongsan (GJS) and is expected to be the main supply source of Neorok for restoring traditional pigments. Therefore, this study analyzed the characteristics of NSS- and GJS-Neorok-based pigments to evaluate the feasibility of substituting GJS Neorok for NSS Neorok in pigments. The NSS Neorok was mostly comprised of celadonite, whereas the GJS Neorok included minerals containing glassy phases such as celadonite, cristobalite, tridymite, etc. Because both Neorok samples were vitrified under identical conditions, the GJS Neorok grains were larger than the NSS Neorok ones. The GJS Neorok pigment showed that the chromaticity, grain size, oil absorption, and stability varied depending on the mineral types and contents. In particular, GJS-2 and NSS Neorok showed similar mineral compositions, physical properties, and stabilities, suggesting that GJS-2 can be substituted for NSS Neorok, which has been difficult to source and utilize ever since NSS was designated as a natural monument.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.187-187
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• 2012

최근 환경에 대한 관심이 증대하면서 생물다양성, 홍수조절, 온실가스 저감 등 다양한 기능을 수행하는 습지에 대한 보전 및 복원을 위한 많은 노력들이 진행되고 있다. 습지 보전 및 복원을 위한 다양한 방안 중 하나가 댐 및 주변지역을 습지로 조성하여 활용하는 방안이라고 할 수 있으며, 이를 위해서는 댐 및 주변지역의 습지로서의 활용을 위한 특성 파악이 우선적으로 이루어져야 한다. 따라서 본 연구에서는 댐 주변지역에 조성된 습지와 댐 저수지 자체를 모두 포함하여 댐습지라고 정의하고, 댐습지가 지니고 있는 습지의 기능 및 경제적 가치를 추정하고자 하였다. 본 연구의 대상지역은 기준습지와 대상습지로 구분되며, 기준습지는 우포늪과 보령댐, 대상습지는 용담댐이다. 댐습지의 기능평가는 수문지형학적 특성을 고려하는 HGM(Hydrogeomorphic Method)을 이용하였으며, 가치평가는 조건부가치측정법(CVM)을 이용하였다. 기능평가 결과는 우포늪과 보령댐을 각각 기준지역으로 선정하였을 경우로 구분하여 나타낼 수 있다. 자연습지인 우포늪을 기준지역으로 선정하였을 경우에는 댐의 주목적과 관련이 있는 수문학적 기능이 높게 평가되었으나 습지 내에서 진행되는 생지화학적 기능과 다양한 식물 종에 대한 서식처로써의 기능은 다소 미흡한 것으로 평가되었다. 보령댐을 기준지역을 선정하였을 경우에는 일부 기능을 제외하고 대부분의 기능이 유사한 것으로 평가되었다. 조건부가치측정법을 이용한 용담댐의 경제적 가치평가는 댐습지 생태공원조성에 따른 훼손된 습지의 보호, 희귀생물종의 보호, 휴양 및 여가기능 제공을 주요인으로 설정하고 설문조사를 수행하여 가치를 추정하였다. 그 결과 용담댐의 총 가치는 우포늪의 가치와 비교하였을 때 우포늪의 35~41%에 해당하는 것으로 추정되었다. 본 연구에서 수행된 댐습지의 기능 및 가치평가 결과는 댐이 단순히 이 치수 측면으로만 이용되는 것이 아니라 생태학적으로도 활용성이 있다는 사실을 나타내고 있다. 이를 통해서 향후 댐의 친환경적 활용 방안 및 댐습지 관리 방안에 중요한 기초자료로 활용될 수 있을 것으로 판단되며, 댐에 대한 긍정적인 인식 증진에도 많은 도움이 될 것으로 판단된다.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.645-673
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• 2019

The hypothetical nature of stated preferences can lead to a hypothetical bias that might work as a normative pressure, influencing survey responses. This paper aims to test the impact of social desirability bias by comparing economic estimates based on both subjective and objective valuation questions. The case study is about an urban riverine restoration project in Deajeon, South Korea. As valuation methods both contingent valuation and choice experiments were comparatively applied. Based on a nationally representative sample of 1,000 respondents, the test results offered contrasting conclusions between two test approaches. Accroding to the estimation results based on the conventional valuation, the marginal willingness to pay estimates are 10,500 KRW from CV; and 18,600 KRW for improving water quality, 2,200 KRW for the inside view, 8,900 KRW for the outside view, and 5,800 KRW for biodiversity from CE. A segmentation-based approach is a conventionally used method, which showed a limited impact of social desirability on willingness to pay estimates. The alternative parameterization-based approach measures a model-wide impact of social desirability, proving a significant bias. Although the study positioned a cheap-talk statement before the valuation section of the survey questionnaires, which might have pre-screened the bias, the overall implications of the results suggest a caution in reducing and observing hypothetical bias. There might remain a significant and substantial hypothetical bias even after cheap-talk, particularly in situations with strong social desirability, so that the potential role of objective valuation questions is guaranteed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.155-165
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• 2014

In this study, using a complex of physical, chemical, and biological evaluation factors, the ecological vulnerability to climate change were evaluated at each river in the Nakdong river basin. First, runoff, sediment rate, and low flow discharge changes according to AIB climate change scenario using the SWAT model were simulated. Also, for the assessment of chemical and biological factors, 48 points that water quality monitoring sites and ecological health measurement points are matched with each other was selected. The water quality data of BOD and T-P and the biological data of IBI and KSI in each point were reflected in the assessment. Also, the future rise in water temperature of the rivers in Nakdong river basin was predicted, and the impact of water temperature rise on the fish habitat was evaluated. The top 10 most vulnerable points was presented through a summary of each evaluation factor. This study has a contribution to river restoration or management plan according to the characteristics of each river.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.99-106
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• 2016

In this paper, we will discuss about correction method of missing data on noisy observation matrix and uncertainty analysis for the potential noise. In situations without missing data in an observation matrix, this solution is known to be accurately induced by SVD (Singular Value Decomposition). However, usually the several entries of observation matrix have not been observed and other entries have been perturbed by the influence of noise. In this case, it is difficult to find the solution as well as cause the 3D reconstruction error. Therefore, in order to minimize the 3D reconstruction error, above all things, it is necessary to correct reliably the missing data under noise distribution and to give a quantitative evaluation for the corrected results. This paper focuses on a method for correcting missing data using geometrical properties between 2D projected object and 3D reconstructed shape and for estimating a noise level of the observation matrix using ranks of SVD in order to quantitatively evaluate the performance of the correction algorithm.

• Journal of KIISE
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• v.44 no.3
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• pp.275-286
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• 2017

In this study, we propose a novel technique of software clustering to recover the software module-view by using the dependency and author entropy of modules. The proposed method first performs clustering of modules based on structural and logical dependencies, then it migrates selected modules from the clustered result by utilizing the author entropy of each module. In order to evaluate the proposed method, we calculated the MoJoFM values of the recovery result by applying the method to open-source projects among which ground-truth decompositions are well-known. Compared to the MoJoFM values of previously studied techniques, we demonstrated the effectiveness of the proposed method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.63-71
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• 2004

This research is to reconstruction of railway alignment using GPS data, an investigation is made on the method of optimum simplification for reduction of unnecessary linear data, improve the accuracy by using four simplification algorithms among the methods. By applying two measured of displacement between observed data and it's simplification methods have been evaluated. The results showed that the complexities of lines is not practical to investigate simplification algorithms, the Douglas-Peucker method produced a little displacement between observed data and it's simplification. Its by using the Douglas-Peucker method to observed linear GPS data in railway track, design elements of horizontal alignment have been calculated. Then we could know that obtain the good results fur reconstruction of alignment elements through the methods and algorithns of this study.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.389-390
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• 2018

본 논문에서는 3차원 복원을 위한 특징점 추출 및 매칭에 대한 보다 정확한 방법을 제안한다. 이 방법은 컴퓨터 비전의 기본이 되는 분야로 복원뿐 만 아니라 SLAM과 같은 지도 작성 및 자율 운행에도 필요한 방법이다. 본 연구는 3차원 물체 복원을 위해서 사용하는 방법 중 하나인 Column space fitting(CSF)을 이용하여 turntable-image data에 적용하여 성능을 평가하여 정확성을 검증을 한다. 오늘날 3D scanner를 이용하여 물체를 3차원 모델을 획득하고 3D프린터를 이용하여 다양한 분야에 적용한다. 그러나 고가의 장비이기 때문에 접근성이 떨어진다. 본 연구는 영상들만을 가지고 기하학적 계산을 통해 3차원 모델을 획득한다. 본 연구결과는 기존의 방법인 KLT 알고리즘과 비교하여 RMSE의 값을 약 5배를 줄이는 성능 향상을 보인다.