• 한국물환경학회지
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• 제25권3호
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• pp.425-431
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• 2009

It is very important to know the probability distribution of water-quality constituents for water-quality control and management of rivers and reservoirs effectively. The probability distribution of BOD in Anseong Stream was analyzed in this paper using Kolmogorov-Smirnov test which is widely used goodness-of-fit method. It was known that the distribution of BOD in Anseong Stream is closer to Log-normal, Gamma and Weibull distributions than Normal distribution. Normal distribution can be partially applied depending on significance level, but Log-normal, Gamma and Weibull distributions can be used in any significance level. Also the estimated Log-normal distribution of BOD at Jinwi3 station was to be compared with the measured in 2001, 2002 and 2003 years. It was revealed that the estimated probability distribution of BOD at Jinwi3 follows a theoretical distribution very well. The applicable probability distribution of BOD can be used to explain more rigorously and scientifically the achievement or violation of target concentration in TMDL(Total Maximum Daily Load).

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.669-676
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• 2018

Transmission system has been well studied since long time and power system techniques of distribution system are more or less derived from transmission system. However, unlike transmission systems, many practical issues are encountered in the distribution system. Considerable amount of error is observed in voltage obtained from the Feeder Remote Terminal Units (FRTUs) measured by the pole mounted PTs along the distribution feeder. Load uncertainty is also an issue in distribution system. Further, penetration of Distributed Generators (DGs) creates voltage variations in the system. Hybrid radial/ loop distribution system also make it complicated to handle distribution system. How these constraints to be handled under Distribution Automation (DAS) environment in order to obtain error free voltage is described in this paper and therefore, a new approach of voltage error correction technique has been proposed. The proposed technique utilizes reliable data from substation and the FRTUs installed in DAS. The proposed technique adopts an iterative process for voltage error correction. It has been tested and proved accurate not only for conventional radial systems but also for loop distribution systems.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.289-292
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• 2004

In order to identify the origin and nature of the spilled oil in the potential source, we analyzed the pattern of alkyi PAM(Polynuclear Aromatic Hydrocarbons) in fuel standard and environmental samples. Alkyl PAM patterns are used for fuel-type identification in weathered environmental samples. Detection of alkyl PAH was achieved by operation CC/MS in the SIM mode. We chose ions of naphthalene(m/z 128), C1-naphthalene(m/z 142), C2-naphthalene(m/z 156), C3-naphthalene(m/z 170), C4-naphthalene(m/z 184) for the comparison of this pattern according to the type of fuel. We analyzed tile pattern of alkyl PAH in neat gasoline, kerosene, diesel, and JP-8, and in groundwater samples which were collected in monitoring wells. The distribution map of alkyl-naphthalene shows different patterns among four different fuel types (gasoline, kerosene, diesel, and JP-8). Particularly, tile distribution map of kerosene and JP-8 is found to be of value in identifying fuel type in that the difference is clear. Therefore distribution patterns of alkyl-PAH compounds provide another useful tool for fuel-type identification of petroleum fuels.

• 한국대기환경학회지
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• 제11권2호
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• pp.137-144
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• 1995

The I.A.P.(Index of Atmospheric Purity) by the distribution of Bryophtes on the bark of various latifoliate tree trunks was investigated at four sites(Daeheung, Songkwang, Jeungsim, and Heunggook Temple) from April, 1991 to April, 1993. The IAP was in inverse proportion to the degree of air pollution. The I.A.P at four sites were estimated 78.2 at Daeheung temple, 61.0 at Songkwang temple, 28.3 at Jeungsim temple, and 10.3 at Heunggook temple, respectively. The distribution degree of Bryophytes in Heunggook temple progressed during the last ten years. It represents the bettrment of air quality. Bioassay by means of lichens seems to have great potential for better and less expensive ways of measuring pollution levels instead of the high cost of buying and maintaining air pollution monitoring equipment.

• 산경연구논집
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• 제11권11호
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• pp.39-53
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• 2020

Purpose: With a rapid advance of communication technology, distributional systems of sport contents continue to show improvements. In particular, a traditional framework in creating sport cartoon has been influenced by the environment of the communication industry. Despite the development of distributional systems, the current sport cartoon industry still lacks in advancement. To this day, various research about sport contents have been conducted; yet, not many studies of the interaction between sport cartoons and communication technology have been done. In this respect, this study is to review the distributional environment of the sport cartoon industry and provide distributional strategies for developing sport cartoon industry. Research design, data, and methodology: In addition to in-depth interviews with five practitioners in sport cartoon industry, the study employed case study methodology. Interview data were analyzed by qualitative content analysis. Results: With new environments allowing anyone allowing to create and share webtoons, various genres including sports webtoons appear, and this became amotive to the growth of sports webtoons. Today, sports comics acted as a sports advertisement platform which not only created additional profit but also became an opportunity as a marketing method. On the contrary, the formal attributes of webtoons cause hardship in consistently creating sports webtoons. Hence, it is needed that supporting policies need to be established to nurture sport webtoon expertise. For example, Korea Creative Content Agency allows future webtoon authors to have an opportunity to be educated and equipped in producing creative sport webtoon contents. Moreover, revenue systems should be developed for motivating webtoon authors to involve in sport contents in their works. Conclusions: In order to promote the sports cartoon industry based on the findings, it is first necessary to create sports comics that reflect the formal characteristics of webtoons and the changing consumer environment. Second, it is important to acknowledge the industrial value of sports comics and it is necessary to promote policies regarding sports webtoon production and distribution from a national level. Third, by diversifying profits through OSMU and sports advertisements, it is possible to enhance the work environment and the treatment of authors. Implications and future directions were discussed.

• Geomechanics and Engineering
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• 제18권2호
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• pp.205-213
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• 2019

A calculation model of reservoir pressure field distribution around multiple production wells in a heavy oil reservoir is established, which can overcome the unreasonable uniform-pressure value calculated by the traditional mathematical model in the multiwell mining areas. A calculating program is developed based on the deduced equations by using Visual Basic computer language. Based on the proposed mathematical model, the effects of drainage rate and formation permeability on the distribution of reservoir pressure are studied. Results show that the reservoir pressure drops most at the wellbore. The farther the distance away from the borehole, the sparser the isobaric lines distribute. Increasing drainage rate results in decreasing reservoir pressure and bottom-hole pressure, especially the latter. The permeability has a significant effect on bottom hole pressure. The study provides a reference basis for studying the dynamic pressure field distribution before thermal recovery technology in heavy oilfield and optimizing construction parameters.

• 한국산림과학회지
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• 제100권2호
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• pp.256-265
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• 2011

본 연구에서는 Intergovernmental Panel on Climate Change(IPCC) 기후변화 시나리오 A2와 B1에 따른 산림분포 취약성을 평가하였다. 산림분포 취약성은 한국형 산림 생태계 분포 모델 Thermal Analogy Groups(TAG) 의 산림분포예측 방법과 Hydrology Thermal Analogy Groups(HyTAG)에서 정의한 식생유형을 이용하여 기후 변화에 따른 잠재 식물상(Plant Functional Type: PFT)의 분포 변화를 기후변화 민감성과 적응성으로 나누어 평가되었다. 그 결과, 산림분포가 취약한 지역의 면적은 A2 시나리오에서 전체 국토 면적의 30.78%, B1에서는 2.81%로 나타났다. 행정구역별 취약성 평가 결과는 부산이 A2 시나리오에서 가장 취약하고 대구가 B1 시나리오에서 가장 큰 취약성을 나타냈다. 미래 발전 방향에 따라서 상이하게 구축된 시나리오 별 산림 분포 취약성 결과는 앞으로 산림 분야 적응대책 수립에 중요한 자료로 이용될 것이다.

• 한국물환경학회지
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• 제39권4호
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• pp.329-342
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• 2023

Turbid water and suspended sediment (SS) load are having negative consequences such as water quality degradation and ecological damage, thus necessitating the establishment of management guidelines to reduce their impact. The present work investigates the spatio-temporal distribution of fish species and the effects of turbid water from 2011-2016 in the upper reaches of Soyang-Dam. The family Cyprinidae is the largest population in the study area, among which Zacco platypus and Zacco koreanus are the dominant species. The diversity of species is relatively abundant in the upper watershed, while the seasonal effect on the population distribution remains unclear. Using two main common components of the empirical orthogonal function (EOF) analysis, the distribution characteristics of 27 species at five survey sites are revealed. Zacco koreanus is found to be predominant at the upstream A-Naerincheon, while Zacco platypus and Rhinogobius brunneus are found to be predominant at the upstream B-Bukcheon. Disturbance of an aquatic ecosystem has a relatively greater impact in the downstream, as-compared to the upper area-the high proportion of forest area is decreased whereas that of agricultural and urbanized areas is increased. The patterns of representative species are changed according to the mid- to long-term effects of turbid water and SS. Accordingly, the significant correlation between the SS load and fish distribution EOF analysis indicates that it should be considered as a potential alternative that can overcome the limitations of impact assessment on turbid water to the Fish Assessment Index (FAI). A comprehensive study examining the long-term effects of SS load to the fish ecosystems with a systematic statistical analysis of sufficiently accumulated data at the national level is needed as future research.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권4호
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• pp.21-26
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• 2003

황과 Powers(2003)는 입도분포와 공극크기분포에 로그분포함수를 적용하여, 입도분포로부터 토양수분특성을 직접 추정하는 간단한 모형을 개발하였다. 본 연구의 목적은 황과 Powers(2003)가 개발한 모형의 추정능력이 토성에 의해 영향을 받는가를 밝히는 것이다. 연구결과, 모형은 토성에 의해 영향을 받았고, 특히 토양내 세립질 분율이 커질수록 모형의 추정능력은 감소하였다. 또한 입도와 공극크기사이의 관계를 비선형으로 가정한 비선형모형이 선형모형보다 토성에 관계없이 그 추정능력이 크게 나타났다.

• 한국환경복원기술학회지
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• 제11권3호
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• pp.87-93
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• 2008

In order to manage national environment effectively, one has to understand its ecological traits. The difference of temperature determines ecological traits of each respective region. In other words, temperature differentials on surface make a great impact on botanical structure. Currently, isothermal data-produced by meteorological stations based upon time series analysis-are widely used to plan and manage national environment. Nonetheless, the isothermal data do not reflect real surface temperature of regions. Because of numerous mountainous terrains in the Korean peninsula where temperature varies widely according to altitude, the range of temperature distribution-that reflects altitudinal change-has to be paid special attention. This study aims at expressing in space isothermal distribution that is necessary to plan and manage national environment effectively. In addition, not just South Korea, but also North Korea was included for isothermal distribution. As a result, this study corrected established isothermal lines up to date and demonstrated that altitude, latitude, and distance from coastal lines greatly influence temperature distribution of the Korean peninsula.