• Journal of Korean Society on Water Environment
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• v.25 no.3
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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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• v.13 no.2
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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.

• The Journal of Industrial Distribution & Business
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• v.11 no.11
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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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• v.18 no.2
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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.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.256-265
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• 2011

This study was aiming at assessing the vulnerability of forest distribution by the A2 and B1 climate change scenarios of Intergovernmental Panel on Climate Change (IPCC). The vulnerability of forest distribution was assessed using its sensitivity and adaptation to climate change with the help of the simulations of Korean-specific forest distribution model, so-called the Thermal Analogy Group (TAG), and the Plant Functional Type (PFT) defined in the HyTAG (Hydrological and Thermal Analogy Groups) model. As a result, the vulnerable area occupied 30.78% and 2.81% of Korea in A2 and B1 scenario, respectively. When it comes to the administrative districts, Pusan in A2 and Daegu in B1 appeared the most vulnerable area. This study would be employed into preparation of adaptative measures for forest in future in terms of using climate change scenarios reflecting different future development conditions.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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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.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.2
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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.

• Journal of Soil and Groundwater Environment
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• v.8 no.4
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• pp.21-26
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• 2003

Hwang and Powers (2003) developed a simple model for estimating water retention characteristic (WRC) directly from particle-size distribution (PSD) data, by applying a lognormal distribution law to both PSD and pore-size distribution. The objective of this work was to determine if the performance of the model developed by Hwang and Powers (2003) would be affected by soil texture. The results of this research proved that the performance of the model was indeed affected by soil texture. In particular, its performance diminished with increases in the fine particle fractions. Also, the nonlinear model, which assumes a nonlinear relation between particle-size and pore-size, performed better than the linear model, regardless of soil texture classes.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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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.