• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.77-82
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• 2015

Slamming means that the hull hits the waves and receives impact pressure. This slamming effect may cause harm to people and when you put the hull at risk. so it is very harmful for cargo safety. Therefor slamming impact pressure should be fully considered in ship designing. In this study the model of wedged type structure are produced aimed to simulate a free fall that the experiments were carried out on different weight and free fall height. The flow field has been obtained by 2-frame grey level cross correlation PIV(Particle Image Velocimetry) method and experiment was divided into water entry and water exit. The impact pressure of free fall structure by a pressure acquisition system apply to dewetron system. The angles between a model and the water surface are adapted $15^{\circ}$ respectively. The weight change of models was given as 1.5, 1.8 and 2.0kg. To study slamming phenomenon for free fall height the experiments were carried out by the free fall height of 100, 200 and 300mm. The experimental value of the impact pressure according to the changes in weight was increase impact pressure in proportion to the increase in weight and higher free falling height has also influenced the increase in impact pressures.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.27-33
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• 2019

The future water management needs decentralization of facilities, diversity of technology and integration of management to overcome the waste of financial resources and increase in scale of facilities that occurred from centralized water management. In addition, citizen's environmental awareness and participation is important because all infrastructure installed in the watershed where citizens live should have the function of water management. Therefore, the research was performed by investigating the citizen's recognition about urban environment와 LID application to analyze citizen's perceptions and analyze the feasibility and possibility of LID application. The LID awareness of citizens was about 59%, but only about 46% of citizens agreed on the extension of application. However, after contacting LID photographs and information, 90% of respondents agreed on the application of LID, and 94% of respondents were able to distinguish between grey infrastructure and LID infrastructure. Citizens appeared to have a tendency to recognize green spaces as multi-functional LID infrastructure or green infrastructure. If citizens recognize multi-functional LIDs only as landscapjng area, it will be very difficult to extend the LID on the city areas. Therefore, for the extended application of the LID facilities, it is necessary to use public relations strategy to utilize the results and visual data on the actual effect verification. In addition, as every social infrastructure is formed in watershed where citizens live, it is necessary to plan and manage the infrastructure through governance with citizen participation.

• Journal of Conservation Science
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• v.16 s.16
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• pp.39-51
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• 2004

The standing Buddha named Taehwa 4 yew in the Jincheon were sculptured with rock cliff of the dark grey shale. Front of the Buddha statue shows $N40^{\circ}W$ strike with nearly vertical dip toward the back side. Rock blocks of the Buddha statue well developed with bedding and laminations whereas rock surface distributed into the various irregular discontinuities. Sculptured lines of the Buddha were uncertain because of degradation and exfoliations on the rock surface. The surface near the Buddha statue is highly contaminated with lichen and mosses, and accelerate physical and biological weathering owing to the roots of weed and bush along the fracture systems. For the conservational treatment, we treated with primary wet cleaning by air gun and secondary cleaning treatment using distilled water. Separated rock surface and fractured parts fasten and/or fill up the boundaries of the rock blocks using epoxy resin for conservation of rock properties. Some brittle surface was treatment with water repellent consolidant of ethyl silicates, and heterogeneous surface carried out color matching by acrylic pigments. Upper part of the Buddha statue dig out small ditch for rain water drainage, and near surface of the Buddha statue treat removal works for lichen, weeds and bush. The duration capacity of the Buddha constituting rocks are degraded by various weathering factors, therefore we suggest that this Buddha statue have need to do long term monitoring and synthetic conservation researches.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.387-388
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• 2010

An open water rudder test was carried out to figure out the flow characteristics around a twin rudder at $Re=1.5\times10^4$. In the analysis, the unique characteristics of a twin rudder, which effects rudder farces, were explained. The analysis is included varying angles of attack fram 10 to 30 degree. In this paper, the measured results has been compared with each other to predict the performance characteristics of a twin rudder's 2-dimensional section by 2-frame grey level cross correlation PIV method. The side force of the rudder could be mainly improved at 0.75L.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.162-172
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• 1978

We have studied to develop a process for the preparation of protein isolates free of isothiocyanate and oxazolidine-thione when defatted meal was extrracted with a cold alkaline solution at pH11.0. The rapeseed protein isolates were separated at $0^{\circ}C$ using 1% sodium algiante of 500 cps as a precipitation aid, also. The proteins had original colors, namely, a grey curd at pH 6.7, a light cream at pH 5.6 and a yellow cream at pH 5.0, The purity and the color was improved by washing with water and freez-drying with acetone, not at room temperature. A countercurrent procedure was a prerequisite for a continuous large scale production of protein isolates.

• Journal of Mushroom
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• v.16 no.3
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• pp.170-174
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• 2018

This study aims to investigate the antifungal and protective effects of water- and 70% methyl alcohol-extracts from spent mushroom substrate (WESMS and MeOHSMS) of Lentinula edodes, on Botrytis cinerea- the causative agent for gray mold disease in ginseng. MeOHSMS inhibited mycelial growth and spore germination of Botrytis cinerea, by 75% and 95%, respectively. MeOHSMS could suppress gray mold disease of ginseng seedlings by 80% and effectively reduce the disease severity by 60%. Compared to the treatment of ginseng leaves with WESMS and DL-${\beta}$-aminobutyric acid (BABA), the MeOHSMS treatment increased the phenolic compounds in the leaves by 36% and 18%, respectively. These results suggest that the SMS extracts suppress gray mold disease in ginseng via dual functions: antifungal activity and increase in a plant defense factor-phenolic compounds.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.325-330
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• 2010

An open water rudder test was carried out to figure out the flow characteristics around a twin rudder at $Re=1.5{\times}10^4$. In the analysis, the unique characteristics of a twin rudder, which affects rudder forces, were explained. The analysis includes varying angles of attack from 10 to 30 degrees. In this paper, the measured results have been compared with each other to predict the performance characteristics of a twin rudder's 2-dimensional section by 2-frame grey level cross correlation PIV method. The length L=0.75C between upper and lower rudders could be defined as the critical length.

• Geomechanics and Engineering
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• v.31 no.4
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• pp.339-352
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• 2022

Studying slope stability is an important branch of civil engineering. In this way, engineers have employed machine learning models, due to their high efficiency in complex calculations. This paper examines the robustness of various novel optimization schemes, namely equilibrium optimizer (EO), Harris hawks optimization (HHO), water cycle algorithm (WCA), biogeography-based optimization (BBO), dragonfly algorithm (DA), grey wolf optimization (GWO), and teaching learning-based optimization (TLBO) for enhancing the performance of adaptive neuro-fuzzy inference system (ANFIS) in slope stability prediction. The hybrid models estimate the factor of safety (F_S) of a cohesive soil-footing system. The role of these algorithms lies in finding the optimal parameters of the membership function in the fuzzy system. By examining the convergence proceeding of the proposed hybrids, the best population sizes are selected, and the corresponding results are compared to the typical ANFIS. Accuracy assessments via root mean square error, mean absolute error, mean absolute percentage error, and Pearson correlation coefficient showed that all models can reliably understand and reproduce the F_S behavior. Moreover, applying the WCA, EO, GWO, and TLBO resulted in reducing both learning and prediction error of the ANFIS. Also, an efficiency comparison demonstrated the WCA-ANFIS as the most accurate hybrid, while the GWO-ANFIS was the fastest promising model. Overall, the findings of this research professed the suitability of improved intelligent models for practical slope stability evaluations.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.8-9
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• 2011

On 4 September 2010 an earthquake of magnitude 7.1 on the Richter scale occurred on the Canterbury Plains in the South Island of New Zealand. The Canterbury Plains are an area of extensive groundwater and spring fed surface water systems. Since the September earthquake there have been several thousand aftershocks (Fig. 1), the largest being a 6.3 magnitude quake which occurred close to the centre of Christchurch on 22February 2011. This second quake caused extensive damage to the city of Christchurch including the deaths of 189 people. Both of these quakes had marked hydrological impacts. Water is a vital natural resource for Canterburywith groundwater being extracted for potable supply and both ground and surface water being used extensively for agricultural and horticultural irrigation.The groundwater is of very high quality so that the city of Christchurch (population approx. 400,000) supplies untreated artesian water to the majority of households and businesses. Both earthquakes caused immediate hydrological effects, the most dramatic of which was the liquefaction of sediments and the release of shallow groundwater containing a fine grey silt-sand material. The liquefaction that occurred fitted within the empirical relationship between distance from epicentre and magnitude of quake described by Montgomery et al. (2003). . It appears that liquefaction resulted in development of discontinuities in confining layers. In some cases these appear to have been maintained by artesian pressure and continuing flow, and the springs are continuing to flow even now. In spring-fed streams there was an increase in flow that lasted for several days and in some cases flows remained high for several months afterwards although this could be linked to a very wet winter prior to the September earthquake. Analysis of the slope of baseflow recession for a spring-fed stream before and after the September earthquake shows no change, indicating no substantial change in the aquifer structure that feeds this stream.A complicating factor for consideration of river flows was that in some places the liquefaction of shallow sediments led to lateral spreading of river banks. The lateral spread lessened the channel cross section so water levels rose although the flow might not have risen accordingly. Groundwater level peaks moved both up and down, depending on the location of wells. Groundwater level changes for the two earthquakes were strongly related to the proximity to the epicentre. The February 2011 earthquake resulted in significantly larger groundwater level changes in eastern Christchurch than occurred in September 2010. In a well of similar distance from both epicentres the two events resulted in a similar sized increase in water level but the slightly slower rate of increase and the markedly slower recession recorded in the February event suggests that the well may have been partially blocked by sediment flowing into the well at depth. The effects of the February earthquake were more localised and in the area to the west of Christchurch it was the earlier earthquake that had greater impact. Many of the recorded responses have been compromised, or complicated, by damage or clogging and further inspections will need to be carried out to allow a more definitive interpretation. Nevertheless, it is reasonable to provisionally conclude that there is no clear evidence of significant change in aquifer pressures or properties. The different response of groundwater to earthquakes across the Canterbury Plains is the subject of a new research project about to start that uses the information to improve groundwater characterisation for the region. Montgomery D.R., Greenberg H.M., Smith D.T. (2003) Stream flow response to the Nisqually earthquake. Earth & Planetary Science Letters 209 19-28.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.131-144
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• 1980

The Linear Regression Model to extend the monthly runoff data in the short-recorded river was proposed by the author in 1979. Here in this study generalization precedure is made to apply that model to any given river basin and to any given station. Lengthier monthly runoff data generated by this generalized model would be useful for water resources assessment and waterworks planning. The results are as follows. 1. This Linear Regression Model which is a transformed water-balance equation attempts to represent the physical properties of the parameters and the time and space varient system in catchment response lumpedly, qualitatively and deductively through the regression coefficients as component grey box, whereas deterministic model deals the foregoings distributedly, quantitatively and inductively through all the integrated processes in the catchment response. This Linear Regression Model would be termed "Statistically deterministic model". 2. Linear regression equations are obtained at four hydrostation in Geum-river basin. Significance test of equations is carried out according to the statistical criterion and shows "Highly" It is recognized th at the regression coefficients of each parameter vary regularly with catchment area increase. Those are: The larger the catchment area, the bigger the loss of precipitation due to interception and detention storage in crease. The larger the catchment area, the bigger the release of baseflow due to catchment slope decrease and storage capacity increase. The larger the catchment area, the bigger the loss of evapotranspiration due to more naked coverage and soil properties. These facts coincide well with hydrological commonsenses. 3. Generalized diagram of regression coefficients is made to follow those commonsenses. By this diagram, Linear Regression Model would be set up for a given river basin and for a given station (Fig.10).