• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.11-11
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• 2020

18년 물관리일원화 이후 인프라와 사람 중심으로부터 자연과 인간의 조화를 위한 환경·생태계의 자연성 회복으로의 물관리 패러다임 전환이 빠르게 이루어지고 있으며, 대규모 국책사업이후의 하천 관리에 있어서도 기존의 이수, 치수, 환경이라는 단순한 기능적 구분을 벗어나 보다 근본적이고 장기적인 대국민 서비스로의 전환을 도모하고 있다. 또한, ICBAM 등으로 정의되는 4차산업혁명 기반 기술의 접목이 거의 대부분의 분야에서 이루어지고 있는 것을 실질적으로 체감하는 시기가 도래하였다. 그러나, 하천 및 수자원 관리분야에서의 기술은 근대 엔지니어링의 기초가 되는 수로 건설 등으로부터 시발되어 사실상 가장 앞선 과학적 진보의 토대를 갖추었으나 최근의 기술적 트렌드를 잘 추종하지 못하는 것처럼 비추어 지는 것이 사실이다. 주된 이유로서 기후변화라는 광범위하고 장기적인 입력요소를 가진 하천관리 시스템의 특성상 불확실성의 추정 및 즉각적인 응답이 어려운 부분이 분명히 존재하지만, 실질적으로 여전히 해소되지 않는 부분은 하천의 기초자료 수집에 대한 효율성과 신뢰도가 낮은 것이라고 하겠다. 또한, 유역으로부터 댐-다기능보-하천으로 이어지는 의사결정을 위한 다양한 형태의 자료로부터 적절한 정보를 수집하는 체계(거버넌스의 문제이자 기술적/재정적 한계)가 확립되지 않은 점도 고려해야 할 것이다. 본 연구에서는 인공지능을 활용한 하천의 유량 예측 등을 위해 필요한 수자원 기초데이터의 근원적인 수집 및 관리상의 문제점에 대해서 검토하고자 하였으며, ARIMA, Kalman Filtering, MA 및 복합기법을 통한 자료처리 기법을 적용하여 상황에 맞게 오차 및 불확실성의 저감을 위한 방안을 찾고자 하였다. 또한, 이용자 중심의 하천 관리에 근접한다고 볼 수 있는 스마트워터시티 개념에서의 바람직한 하천관리 기법에 대해서 논의하고, 관련하여 근자에 개발한 하천의 물리적 해석 도구들에 대해서 적용 사례를 검토한다. 마지막으로, 지식기반의 하천관리 의사결정 플랫폼 개발을 위해서 기존의 기계학습을 통한 자동화된 의사결정에 부가하여 전문가와 시스템이 상호작용을 통해서 AI를 학습시켜 결정한 사항을 전문가의 의사결정에 참고하는 MCRDR기법의 적용의 적용 가능성과 도입 방향에 대해서 논의하였다.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.45-50
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• 1997

The change of industrial structure has brought the sharp declination of mine products, and has made many mines closed, which results in environmental pollution by untreated acid mine drainage(AMD). AMD with low pH and high concentration of heavy metals could severely destroy the ecosystem. Many researches have been carried out for the treatment of AMD. In this study, we have treated AMD with oak compost, mushroom compost, sludge cake and cow manure which usually used in AMD treatment systems, and compared the capability of each organic matter. Cow manure and oak compost have been most effective among 4 organic materials. Oak compost removed the heavy metals by ion exchange between Ca-rich particles and soluble heavy metal ions. It also captured the heavy metals using bound functional groups like -OH and -COO-. Sulfate reducing bacteria existing in the cow manure removed effectively heavy metals by producing metal sulfide compound. Therefore, it is effective to use both organic materials in mixture on the treatment of AMD.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.386-399
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• 2023

Microplastics and nanoplastics (NMPs) are considered one of hazardous contaminants in marine ecosystems due to their toxic effects, such as reproduction disorder and oxidative stress, on marine organisms. Although water temperature is rising due to global climate change, little information on the toxicological interaction between NMPs and temperature is available. Therefore, in this study, we confirmed the toxicity of NMPs (polystyrene [PS] beads; 0.05- and 6-㎛) on brackish water fleas (Diaphanosoma celebensis) depending on increased temperature (30℃ and 35℃) at individual and molecular levels. In the chronic toxicity test, the group exposed to high temperatures showed an earlier first reproduction time compared to the normal temperatures group, but it was delayed by co-exposure to NMPs at 35℃. Notably, the total reproduction decreased significantly only after 0.05-㎛ PS beads exposure at 30℃. Interaction analysis showed that first reproduction time, modulation of the antioxidant-related gene (GSTS1), heat shock gene (Hsp70), and ecdysteroid pathway-related genes (EcR_A, EcR_B, and CYP314A1) were closely related to temperature and PS beads size. These results indicate that microplastics have size-dependent toxicity, and their toxicity can be enhanced at high temperatures. In addition, higher temperatures and PS beads exposure may have negative effects on reproduction. This study suggests that various factors such as water temperature should be considered when evaluating the toxicity of microplastics in marine ecosystems, and provides an understanding of the complex toxic interaction between water temperature and microplastics for marine zooplankton.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.214-227
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• 2018

An object oriented crop model was developed to perform crop growth simulation taking into account complex interaction between biotic and abiotic factors in an agricultural ecosystem. A set of classes including Atmosphere class, Plant class, Soil class, and Grower class were designed to represent weather, crop, soil, and crop management, respectively. Objects, which are instance of class, were linked to construct an integrated system for crop growth simulation. In a case study, yield of corn and soybean, which was obtained at an experiment farm in Rural Development Administration from 1984 to 1986, were compared with yield simulated using the integrated system. The integrated system had relatively low error rate of corn yield, e.g., <4%, under sole and intercropping conditions. In contrast, the system had a relatively large underestimation error for above ground biomass except for grain compared with those observed for corn and soybean. For example, estimates of biomass of corn leaf and stem was 31% lower than those of observed values. Although the integrated system consisted of simple models, the system was capable of simulating crop yield under an intercropping condition. This result suggested that an existing process-based model would be used to have more realistic simulation of crop growth once it is reengineered to be compatible to the integration system, which merits further studies for crop model improvement and implementation in object oriented paradigm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.3
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• pp.80-86
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• 2000

Eddy covariance method is widely used in measuring vertical fluxes of mass and energy between the atmosphere and the biosphere. In this method, scalar concentration is measured with either open-path or closed-path sensors. For the latter, fluctuations of scalar concentration are attenuated as the sample travels through a long tube, resulting in flux loss. To quantify this tube attenuation, water vapor concentrations measured with both closed-path and open-path sensors were analyzed. Our statistical analysis showed that the power spectral density obtained from the closed-path sensor was different from that from the open-path sensor in the frequency range of > 0.5 Hz. The loss of water vapor flux due to tube attenuation was < 5% during midday. At nighttime, however, the flux loss increased significantly because of the low wind speeds and the weak turbulence sources. Theoretical calculation for the tube attenuation showed a small bias in high frequency range probably because of the interaction of sticky water vapor with a tube wall.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.246-260
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• 2014

A 90-m horizontal-resolution numerical model was configured to study the micrometeorological features of local winds in the valley of Gwangneung KoFlux (Korea Flux network) Sites (GDK: Gwangneung Deciduous forest site in Korea, GCK: Gwangneung Coniferous forest site in Korea) during summer days. The U. S. Geological Survey (USGS) Shuttle Radar Topography Mission (SRTM) data were employed for high-resolution model terrain height. Model performance was evaluated by comparing observed and simulated near-surface temperature and winds. Detailed qualitative analysis of the model-simulated wind field was carried out for two selected cases which are a clear day (Case I) and a cloudy day (Case II). Observed winds exhibited that GDK and GCK, as well as Case I and Case II, had differences in timing, duration and strength of daytime and nighttime wind direction and speeds. The model simulation results strongly supported the existence of the drainage flow in the valley of the KoFlux tower sites. Overall, the simulated model fields realistically presented the diurnal cycle of local winds in and around the valley, including the morning drainage-upslope transition and the evening reversal of upslope wind. Also, they indicated the complexity of local winds interactions by presenting that daytime westerly winds in the valley were not always pure mountain winds and were often coupled with larger-scale wind systems, such as synoptic-scale winds or mesoscale sea breezes blowing from the west coast of the peninsula.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.2
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• pp.31-46
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• 2019

As the importance of venture firms has increased as a new growth engine, the South Korea government makes various efforts to establish healthy ecosystems for ventures and start-ups. Especially in order to foster the competitiveness of venture firms, various support policies such as financial and R&D expenses are being expanded and promoted. In this study, the author analyzed the impact of government funding on venture firms' internal competencies and management performance by using the resource-based theory. Moreover, this study tested the moderation effect of firm's growth stages. Unlike previous studies, this study focused on qualitative rather than quantitative aspects of internal competencies and the financial and non-financial performance are used to measure the management performance of the ventures to examine the effects of government funding for venture firms in more details. For the purpose of verifying the hypothesis of this research, "The Research On The Precision Status Of Venture Firms" in 2017 from the Ministry of Small and Medium Business was utilized, which has been compiled since 1999. According to the results of this study, the government funding experience did not significantly affect the company's internal competencies and financial performance, but had a significant impact on the non-financial performance, which in turn seemed to have a significant effect on the financial performance. In addition, it was found that the technology, price, design, and quality competencies affected non-financial performance, while the organizational management and marketing competencies did not. However, the price, design, organizational management, and marketing competencies affected financial performance, while the technology competency was not. Finally, there were no differences in the effectiveness of government funding, depending on the growth stages.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.800-804
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• 2007

전 세계에서 홍수로 인한 인명손실과 재산적 피해의 기록을 살펴보면 최근 몇 년 동안 꾸준히 증가하고 있다. 이로 인해서 홍수를 방어하기 위한 노력은 증가하게 되었다. 이로 인해 홍수터에서 인구집중과 개발로 인해 홍수방어를 위해서 막대한 투자가 필요하다. 이와 동시에 지속가능하고 효과적인 수자원 관리는 전체적인 접근방법이 요구되며, 사회와 경제발전과 생태계 보호 및 토지이용과 수자원 이용의 적절한 관리와 연결된 개념이 필요하다. 유역은 육지와 수계 사이의 많은 상호작용이 있는 동적인 시스템이다. 이러한 관점에서 유역을 간단한 고정된 지역적인 문제라고 생각하는 것보다 전체로서의 유역 기능을 개선하는데 노력이 필요하고 시도되어야 할 것이다. 통합홍수관리(IFM : Integrated Flood Management)는 홍수의 긍정적인 측면과 부정적인 측면을 고려한 새로운 접근방법이며, 홍수가 자원적 가치를 지닌 것이라고 생각하는 개념이다. 통합홍수관리의 특징은 홍수조절 대책의 적절한 혼합, 대책의 목적 및 형태(구조적 및 비구조적 대책), 단기간 및 장기간 대책 등의 대책들을 통합하는 것이다. 여기에는 전유역의 수문순환 관리, 통합 토지이용 및 수자원 관리, 최적 혼합대책의 적용 및 통합재해관리 적용 등이 있다. 홍수는 자연적인 수문학적 체계의 중요한 요소이며, 주요 수자원이기도 하다. 그리고 빈번한 홍수로 인해 제방을 넘어 홍수터를 점령한다. 이 결과로 상습 홍수범람지역은 점점 더 인구가 밀집되고 있고 홍수에 더 취약하게 된다. 그러므로 금호강유역에 발생한 홍수의 개요, 원인 및 결과에 대해서 살펴보고, 홍수관리대책과 실효성에 대해서 조사 분석하였다. 그리고 홍수가 발생한 후 홍수관리대책과 관리기술의 변화를 통합홍수관리의 개념에서 분석하였다.Jones matrix, which allows a new interpretation in the conversion efficiency of the thin-film optical waveguides.있다는 장점이 있었다. 따라서 소아에서 복막투석도관 수술 시 복강경적 방법을 이용하는 것이 효율적인 복막 투석을 위해 유용하다고 생각된다.상부 방광천자에 비해 민감도 59.5%(25/42), 특이도 86.6%(13/15)였고 위양성률 13.3%(2/15), 위음성률 40.5%(17/42) 로 정확도가 낮았다. 결론 : 소변을 가리지 못하는 영유아에서 요로 감염을 진단하기 위해서는 도뇨관 채뇨에 비해 초음파 감시하 치골상부 방광천자가 정확하고 안전한 채뇨법으로 권장되어야 한다고 생각한다.應裝置) 및 운용(運用)에 별다른 어려움이 없고, 내열성(耐熱性)이 강(强)하므로 쉬운 조건하(條件下)에서 경제적(經濟的)으로 공업적(工業的) 이용(利用)에 유리(有利)하다고 판단(判斷)되어진다.reatinine은 함량이 적었다. 관능검사결과(官能檢査結果) 자가소화(自家消化)시킨 크릴간장은 효소(酵素)처리한 것이나 재래식 콩간장에 비하여 품질 면에서 손색이 없고 저장성(貯藏性)이 좋은 크릴간장을 제조(製造)할 수 있다는 결론을 얻었다.이 있음을 확인할 수 있었다.에 착안하여 침전시 슬러지층과 상등액의 온도차를 측정하여 대사열량의 발생량을 측정하고 슬러지의 활성을 측정할 수 있는 방법을 개발하였다.enin과 Rhaponticin의 작용(作用)에 의(依)한 것이며, 이는 한의학(韓醫學) 방제(方劑) 원리(原理)인 군신좌사(君臣佐使) 이론(理論)에서 군약(君藥)이 주증(主症)에 주(主)로 작용(作用)하는 약물(藥物)이라는 것을 밝혀주는 것이라고 사료(思料)된다.일전 $

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.4
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• pp.13-25
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• 2014

This study advances research on new venture by taking the organizational ecology perspective to explore the relationship between social legitimacy and new venture performance. We examine how entrepreneurs' organizing activity and social norm shape the social legitimacy. This paper also categorizes the social norms into three parts: social norm that is 1) supporting success achieved through one's own effort 2) encouraging start-up, and 3) promoting risk-taking. Using a dataset of PSED(Panel Study of Entrepreneurial Dynamics) from 2005 to 2011, we found that entrepreneurs' organizing activity has a positive effect on new venture performance. In addition, this study presents the moderating effects of 'liability of newness' that decreases the effect of organizing activity on new venture performance. Interestingly, with respect to the social norm, 'liability of newness' only moderates the relationship between start-up encouraging social norm and new venture performance.

• Korean Journal of Environment and Ecology
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• v.17 no.2
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• pp.144-152
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• 2003

The purpose of this study was to investigate the effects of lime fertilization and light intensity on beech regeneration strategy in a mature beech forest(ca. 150 years old) gaps, which was located in the soiling areas Germany, where the soil is an acid brown earth. For the experiment canopy gaps of 30m diameter were cut, and one canopy gap remained as untreated while the other was limed(3t dolomite h $a^{-1}$). Soil chemistry, soil water potential, light intensity(PAR), ground vegetation, beech seedlings and mycorrhiza were investigated along transect from the stands into gaps to the north. The results of this study are followings: 1) In the limed gap, soil chemistry was greatly improved and a vigorous herb layer developed as compared to the unlimed gap. 2) Development and growth of the beech seedlings in the unlimed gap were generally deficient. Specially, developments of lateral roots were very lack. 3) Through the lime fertilization, the minerals contents of beech leaves such as calcium(Ca) and magnesium(Mg) were increased, while manganese(Mn) was decreased. There was antagonism between potassium(K) and calcium(Ca) or magnesium(Mg). 4) The relative mycorrhiza frequency(RM) in beech seedlings of the southern edge was very higher than that of the middle part, and through the lime fertilization extension of the species Laccaria amethystina appeared clearly. The results of this study showed that lime fertilize in forest, where the soil is acid, will be necessary..