• Journal of Korea Water Resources Association
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• v.44 no.6
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• pp.487-495
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• 2011

The sampling and measuring methods of root fiber quantity which greatly governs the stability evaluation of a vegetated levee revetment are proposed by this study and the erosion characteristics related to root fiber quantity are analysed by the experiments. The Phragmites Japonica Steud confirmed the dominant species in a vegetated levee revetment and the Zoysinagrass are selected as the experimental vegetations. The characteristics of erosion depth and erosion rate are analysed according to the root fiber quantity and their corresponding regression equations are suggested. The erosion depth and erosion rate highly decrease with root fiber quantity by experimental results which results in great increasing the erosion resistance of a vegetated levee revetment. The corresponding regression equations for both vegetations of the Phragmites Japonica Steud and the Zoysinagrass are suggested with high determination coefficients. The erosion resistance of the Zoysinagrass is better than that of the Phragmites Japonica Steud.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.538-547
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• 2017

Korea's water management system is typically a multi-ministerial system, so its efficiency is declining. In order to propose current state and improvement plan of the water management in Korea, this study discussed the improvement of central and local water management. The water management problems are lack of water policy coordination system, conflicts between ministries due to function of water quantity, water quality and agricultural water, redundant investment and inefficiency, insufficient recognition of water autonomy, concentrated central management and deepening regional disparities, lack of financial resources, etc. Hence, improvement to solve the problem includes strengthening the coordination of water management functions between ministries, transferring water management functions of central ministries and strengthening local capacity, and desirable role allocation of central and local governments. In addition, improvement at the local include efforts to change awareness of the water detailed and get water autonomy, integrate management of the watershed, strengthen the local community, secure financial resources, etc.

• KCID journal
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• v.16 no.1
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• pp.72-78
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• 2009

• Journal of the Korean Home Economics Association
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• v.3 no.1
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• pp.368-384
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• 1962

• The Journal of Fisheries Business Administration
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• v.37 no.1 s.70
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• pp.73-93
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• 2006

This paper tries to apply the standard method for the estimation of range and degree of fisheries damages caused by warm water drained by generating plants to a real situation. The theoretic foundation of the study has been shown in the article published on the journal of fisheries business administration of last year. The paper tries to examine the degree of external appicability of the theoretic model through empirical study. The results of the study are as follows. The model has been found a successful device for the estimation of fisheries damages caused by warm water drained by generating plants. It also shows a possibility to work in any other fisheries damage cases caused by several kinds of public undertaking on coastal areas. The key of the model is the successful derivation of the quantity amount of the critical variation of environmental factors for example, in this case, water thermal variation. Therefore the countinous and appropriate collection of law data on the environmental factors under a viewpoint of statistics is essential to the usefulness of the model.

• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.291-297
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• 2015

A water jet cleaning robot system for micro drill bits is to refurbish micro drill bits used for the PCB manufacturing process. It can refurbish drill bits with the minimum diameter of ${\phi}0.15{\sim}0.075mm$ of which the total quantity have been discarded before. Micro drill bits with the minimum diameter of ${\phi}0.075mm$ can be cleaned by applying the water jet cleaning robot system out of the manual ultrasonic cleaning in the past for the cleaning equipment as the initial process in refurbishing. This study analyzed problems, while applying the apparatus mechanism for the workability such as the robot traces of Transfer Robot I and II, drill bit loading and unloading, and cleaning tasks in the water jet cleaning robot system in an effort to carry out simulations. In addition, the cleaning work process was optimized as the work process was verified in advance and the production quantity was analyzed through simulations.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.973-984
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• 2007

This study developed and calculated alternative evaluation index (AEI) from the effectiveness analyses of alternatives for rehabilitation of distorted hydrologic cycle. The feasible alternatives for the poor-conditioned region in the Anyangcheon watershed were proposed and quantitatively analyzed using continuous water quantity/quality simulation model, Hydrological Simulation Program-Fortran (HSPF). The effectiveness analyses include 355th flow and 275th flow of flow duration curve and number of increased days to satisfy the target monthly flow for water quantity and BOD average concentration, total daily loads and number of increased days to satisfy the target concentration and total daily loads. The feasible alternatives are restoration of covered stream, prevention of streamflow loss through sewers, redevelopment of existing reservoir, reuse of treated wastewater, use of groundwater collected by subway stations and construction of small wastewater treatment plant. Therefore, alternative priority ranking was derived from AEIs. It will be effective to make an integrated watershed management for sustainable development.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.62-70
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• 2009

The principal objective of this study was to determine the optimal dilution magnification for Omi-Galsu. The pH of Omi-Galsu generated by varying the temperature of 200cc of water ($4^{\circ}C$ and $80^{\circ}C$) and quantity of Omi-Galsu concentrate (36 g, 45 g, 54 g) was $3.24{\sim}3.33$ and the sugar content of the solution was $6.60{\sim}9.50$, higher than the tea beverages on the market and slightly lower than fruit juice beverages. The Omi-Galsu had a caloric content of $30.65{\sim}38.70\;kcal$, and a protein content of $0.45{\sim}0.65%$. As a result of the sensory evaluations conducted during the summer season, it was determined that the Omi-Galsu produced by mixing 54 g of Omi-Galsu concentrate into 200cc water at $4^{\circ}C$ or $80^{\circ}C$ was the most preferred; however, during the winter months, the "gusto" of the Omi-Galsu produced by mixing 54g concentrate into 200cc water at $4^{\circ}C$ or 45 g of concentrate into 200cc water of $80^{\circ}C$ was preferred most strongly. All in all, the optimal dilution magnification for Omi-Galsu was found to be $4.7{\sim}5.4$.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.513-523
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• 2001

This study was conducted to investigate influences of solifluction and sediment runoff on the stream water qualities during the spring season. The study sites were four points in the northeastern area of the Bukhansan National Park. And, field surveys were carried out in the spring of 1999, 2000 and 2001. The results of this study were summarized as follows; During the investigation period, the amounts of sediment caused by solifluction on stream side slopes in the downstream were 1.3~1.7 times as large as those in the upstream. The pH of sediment caused by solifluction was a potential influence on the pH of stream water. Amounts of dissolved $Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$ in stream water were proportion to the average amounts of $Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$ in the sediment caused by solifluction. In the spring, the average pH of stream water was lower than the first class of the river water quality standard because of increasing chemical concentration as well as the contents of anions($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) in the spring season. Also, the average electrical conductivity of water in downstream was about 2.3-3.3 times higher than that in upstream. The amounts of anions($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) of water in downstream were about 1.2~7.4, 1.1~3.9, 1.1~1.4 times higher than those in upstream, respectively. Therefore, these results showed that the water quality of downstream was worse than that of upstream. As a result of regression analyses, the linear and exponential equation of pH and water quantity was pH = 1.7926 ${\times}$ stream water quantity + 5.9577($R^2=0.46$), and those of electrical conductivity and water quantity was $EC=34.417e^{3.6334{\times}\text{stream water quantity}(m^3/sec)}$ ($R^2=0.44$).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.3
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• pp.266-273
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• 2007

The change patterns of the water quanity, water quality(WQ, exclusively COD in this study) and monthly / annual pollutant loads(PL) estimated using the daily effluent discharges and WQ measurement data are analyzed in the Nakdong river estuarine seadike. The contribution factor defined by the ratio of the water quantity range and WQ range shows that the PL pattern in this estuary is classified as the strongly flow(water quantity)-dominated situation. The estimated PL(EPL)s with respect to the increasing sampling periods, e.g., 2-days, 5-days, 7-days, and so on, show that the mean values of the EPLs remain nearly same, whereas the standard deviations of the EPLs have an obvious increasing trend. The PL values using the monthly-averaged water quantity and WQ measurement data could have approximately 100% estimation error in annual mean and $300\sim400%$ estimation errors in summer season because its confidence level is relatively low. It is recommended that the PL should be estimated using at least $10\sim20$ day interval data sets and also the water quantity(river discharges) and WQ should be measured at the intervals of at least 1 day interval and 5 to 7 days, respectively in summer.