• Journal of Korea Water Resources Association
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• v.46 no.9
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• pp.921-932
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• 2013

Runoff data availability is a substantial factor for precise flood control such as flood frequency or flood forecasting. However, runoff depths and/or peak discharges for small watersheds are rarely measured which are necessary components for hydrological analysis. To compensate for this discrepancy, a lumped concept such as a Storage Function Method (SFM) was applied for the partitioned Choongju Dam Watershed in Korea. This area was divided into 22 small watersheds for measuring the capability of spatial extension of runoff data. The chosen total number of flood events for searching parameters of SFM was 21 from 1991 to 2009. The parameters for 22 small watersheds consist of physical property based (storage coefficient: k, storage exponent: p, lag time: $T_l$) and flood event based parameters (primary runoff ratio: $f_1$, saturated rainfall: $R_{sa}$). Saturated rainfall and base flow from event based parameters were explored with respect to inflow at Choongju Dam while other parameters for each small watershed were fixed. When inflow of Choongju Dam was optimized, Youngchoon and Panwoon stations obtained average of Nash-Sutcliffe Efficiency (NSE) were 0.67 and 0.52, respectively, which are in the satisfaction condition (NSE > 0.5) for model evaluation. This result is showing the possibility of spatial data extension using a lumped concept model.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.1-13
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• 2016

This study attempts to establish a precise forecast model for the container inventory demand of shipping companies through forecasts based on equipment type/size, ports, and weekly system dynamics. The forecast subjects were Shanghai and Yantian Ports. Only dry containers (20, 40) and high cubes (40) were used as the subject container inventory in this study due to their large demand and valid data computation. The simulation period was from 2011 to 2017 and weekly data were used, applying the actual data frequency among shipping companies. The results of the model accuracy test obtained through an application of Mean Absolute Percentage Error (MAPE) verified that the forecast model for dry 40' demand, dry 40' high cube demand, dry 20' supply, dry 40' supply, and dry 40' high cube supply in Shanghai Port provided an accurate prediction, with $0%{\leq}MAPE{\leq}10%$. The forecast model for supply and demand in Shanghai Port was otherwise verified to have relatively high prediction power, with $10%{\leq}MAPE{\leq}20%$. The forecast model for dry 40' high cube demand and dry 20' supply in Yantian Port was accurate, with $0%{\leq}MAPE{\leq}10%$. The forecast model for supply and demand in Yantian Port was generally verified to have relatively high prediction power, with $10%{\leq}MAPE{\leq}20%$. The forecast model in this study also had relatively high accuracy when compared with the actueal data managed in shipping companies.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.302-311
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• 2020

There are limitations to cope with flood damage by structural strategies alone because both frequency and intensity of floods are increasing due to climate change. Therefore, it is one of the necessary factors in the nonstructural countermeasures to collect and analyze historical flood damage records for the future flood damage assessments. In order to estimate flood damage costs in Gyeongsangbuk-do where severe flood damage occurs frequently due to geographical and climatic effects, this paper has performed the regression analysis on flood damage records over the past 20 years (1999-2018) by rainfall characteristics, which is one of the major causes of flood damage. This paper has then examined the relationship between the terrain features and rainfall characteristics in the regional regression functions, and also estimated the flood damage risk for 100-year rainfall by using the regional regression functions presented for the 22 administrative districts in Gyeongsangbuk-do excluding Ulleung-gun. The flood damage assessment shows that the relatively high damage risk is estimated for county areas adjacent to the eastern coast in Gyeongsangbuk-do. The regional damage estimate functions in this paper are expected to be used as one of the nonstructural countermeasures to estimate flood damage risk for the design or forecasting rainfall data.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.655-666
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• 2013

Lately, intensity and frequency of natural disasters such as flood are increasing because of abnormal climate. Casualties and property damages due to large-scale floods such as Typhoon Rusa in 2002 and Typhoon Maemi in 2003 rapidly increased, and these show the limits of the existing disaster prevention measures and flood forecasting systems regarding irregular climate changes. In order to efficiently respond to extraordinary flood, it is important to provide effective countermeasures through an inundation model that can accurately simulate flood inundation patterns. However, the existing flood inundation analysis model has problems such as excessive take of analysis time and accuracy of the analyzed results. Therefore, this study conducted a flood inundation analysis by using the Gerris flow solver that uses quadtree grid, targeting the Baeksan Levee in the Nakdong River Basin that collapsed because of a concentrated torrential rainfall in August, 2002. Through comparisons with the FLUMEN model that uses unstructured grid among the existing flood inundation models and the actual flooded areas, it determined the applicability and efficiency of the quadtree grid-based flood inundation model of the Gerris flow solver.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.143-152
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• 2005

The purpose of this study was to predict the failure or success of the Snatch-lifting trial as a consequence of the stand-up phase simulated in Kane's equation of motion that was effective for the dynamic analysis of multi-segment. This experiment was a case study in which one male athlete (age: 23yrs, height: 154.4cm, weight: 64.5kg) from K University was selected The system of a simulation included a multi-segment system that had one degree of freedom and one generalized coordinate for the shank segment angle. The reference frame was fixed by the Nonlinear Trans formation (NLT) method in order to set up a fixed Cartesian coordinate system in space. A weightlifter lifted a 90kg-barbell that was 75% of subject's maximum lifting capability (120kg). For this study, six cameras (Qualisys Proreflex MCU240s) and two force-plates (Kistler 9286AAs) were used for collecting data. The motion tracks of 11 land markers were attached on the major joints of the body and barbell. The sampling rates of cameras and force-plates were set up 100Hz and 1000Hz, respectively. Data were processed via the Qualisys Track manager (QTM) software. Landmark positions and force-plate amplitudes were simultaneously integrated by Qualisys system The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 9Hz calculated with Andrew & Yu's formula. The input data of the model were derived from experimental data processed in Matlab6.5 and the solution of a model made in Kane's method was solved in Matematica5.0. The conclusions were as follows; 1. The torque motor of the shank with 246Nm from this experiment could lift a maximum barbell weight (158.98kg) which was about 246 times as much as subject's body weight (64.5kg). 2. The torque motor with 166.5 Nm, simulated by angular displacement of the shank matched to the experimental result, could lift a maximum barbell weight (90kg) which was about 1.4 times as much as subject's body weight (64.5kg). 3. Comparing subject's maximum barbell weight (120kg) with a modeling maximum barbell weight (155.51kg) and with an experimental maximum barbell weight (90kg), the differences between these were about +35.7kg and -30kg. These results strongly suggest that if the maximum barbell weight is decided, coaches will be able to provide further knowledge and information to weightlifters for the performance improvement and then prevent injuries from training of weightlifters. It hopes to apply Kane's method to other sports skill as well as weightlifting to simulate its motion in the future study.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.1
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• pp.9-21
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• 2020

The proper operation and safety management of water and wastewater treatment systems are essential for providing stable water service to the public. However, various natural disasters including floods, large storms, volcano eruptions and earthquakes threaten public water services by causing serious damage to water and wastewater treatment plants and pipeline systems. Korea is known as a country that is relatively safe from earthquakes, but the recent increase in the frequency of earthquakes has increased the need for a proper earthquake management system. Interest in research and the establishment of legal regulations has increased, especially since the large earthquake in Gyeongju in 2016. Currently, earthquakes in Korea are managed by legal regulations and guidelines integrated with other disasters such as floods and large storms. The legal system has long been controlled and relatively well managed, but technical research has made limited progress since it was considered in the past that Korea is safe from earthquake damage. Various technologies, including seismic design and earthquake forecasting, are required to minimize possible damages from earthquakes, so proper research is essential. This paper reviews the current state of technology development and legal management systems to prevent damages and restore water and wastewater treatment systems after earthquakes in Korea and other countries. High technologies such as unmanned aerial vehicles, wireless networks and real-time monitoring systems are already being applied to water and wastewater treatment processes, and to further establish the optimal system for earthquake response in water and wastewater treatment facilities, continuous research in connection with the Fourth Industrial Revolution, including information and communications technologies, is essential.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.538-543
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• 2013

During summer in Korea, the excessively high temperature causes growth retardation and quality reduction in cut roses grown in greenhouse. Mist treatments were conducted to reduce the temperature and avoid quality reduction of cut roses. The temperature change in the greenhouse, growth and quality of cut roses, and injuries caused by insects or fungi were investigated during mist treatment. Daily maximum temperature reduced as the number of mist treatment increased, resulting in $6^{\circ}C$ reduction by mist treatment for 10 seconds at 5 min interval. This temperature reduction occurred only when maximum temperature was over $40^{\circ}C$ in greenhouse, and not when it was less than $40^{\circ}C$ or rainy and/or cloudy day. Plant height and fresh weight of the cut roses were increased at the range of 10-20% by mist treatment. As frequency of mist treatment increased, however, malformed flowers increased and vase life of cut rose was largely shortened. The injuries by insects like as beet armyworm larvae and scale insect increased as well. In conclusion, it is recommended that mist treatment must be used when the daily maximum temperature in a green house is over $40^{\circ}C$ and forecasting for disease or insects should be conducted as well.

• Fire Science and Engineering
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• v.19 no.4 s.60
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• pp.75-79
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• 2005

This study has developed Forest Fire Occurrence Danger Index (FFODI) using fuel and topographical characteristics for the practical purposes of forecasting forest fire occurrence danger rating. This was made on the basis of the 126 forest fire site according to field survey. The result of fire frequency analysis showed 87 sites on conifer $(69\%)$, 21 on mixed $(16.7\%)$ and 18 $(14.3\%)$ on non-conifer. The scale for Fuel Model Index(FMI) ranges from 1 to 10 and Topography Model Index(TMI) from 1 to 5. FMI is 10 on the conifer, 3 on the mixed and 2 on the non-conifer. In case of topographical analysis, it was estimated that 90 site $(71.4\%)$ of ignition point was bottom foot hill and 22 site $(17.5\%)$ was on the southwest. TMI in southwest direction is 5.0, 4.5 in the northwest and the northeast, 4.0 in the southeast and the south, 2.5 in the north and the west and 1.5 in the east. TMI in the bottom foot hill is 5 in the bottom foot hill, 1.5 in the upper foot hill, 1.0 in the bottom middle slope and 0.5 in the upper middle slope and bottom ridge.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.839-850
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• 2018

The flood damage in urban areas due to torrential rain is increasing with urbanization. For this reason, accurate and rapid flooding forecasting and expected inundation maps are needed. Predicting the extent of flooding for certain rainfalls is a very important issue in preparing flood in advance. Recently, government agencies are trying to provide expected inundation maps to the public. However, there is a lack of quantifying the extent of inundation caused by a particular rainfall scenario and the real-time prediction method for flood extent within a short time. Therefore the real-time prediction of flood extent is needed based on rainfall-runoff-inundation analysis. One/two dimensional model are continued to analyize drainage network, manhole overflow and inundation propagation by rainfall condition. By applying the various rainfall scenarios considering rainfall duration/distribution and return periods, the inundation volume and depth can be estimated and stored on a database. The Rainfall-Duration-Flooding Quantity (RDF) relationship curve based on the hydraulic analysis results and the Self-Organizing Map (SOM) that conducts unsupervised learning are applied to predict flooded area with particular rainfall condition. The validity of the proposed methodology was examined by comparing the results of the expected flood map with the 2-dimensional hydraulic model. Based on the result of the study, it is judged that this methodology will be useful to provide an unknown flood map according to medium-sized rainfall or frequency scenario. Furthermore, it will be used as a fundamental data for flood forecast by establishing the RDF curve which the relationship of rainfall-outflow-flood is considered and the database of expected inundation maps.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.545-550
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• 2019

The frequency of natural disasters and the scale of damage are increasing due to the abnormal weather phenomenon occurring all over the world. As a result, as the hydrological aspect of the urban watershed changes, the increase in impervious area leads to serious domestic flood damage due to increased rainfall. In order to minimize the damage of life and property, domestic flooding prediction system is needed. In this study, we developed a flood nomogram capable of predicting flooding only by rainfall intensity and duration. This study suggests a method to set the internal water immersion alarm criterion by analyzing the characteristics of the flooding damage in the flooded area in the metropolitan area where flooding is highly possible and the risk of flooding is high. In addition, based on the manhole and the pipe, the water level was set as follows under the four conditions. 1) When manhole overflows, 2) when manhole is full, 3) when 70% of the pipe is reached, and 4) when 60% of the pipe is reached. Therefore, it can be used as a criterion and a predictive measure to cope with the pre-preparation before the flooding starts, through the rainfall that causes the flooding and the flooding damage.