• Journal of Korea Water Resources Association
• /
• v.48 no.10
• /
• pp.807-816
• /
• 2015

In general, the water stage-discharge relationship curve is established based on the assumptions of linearity and homoscedasticity. However, the relationship between the water stage and discharge is affected from geomorphological factors, which violates the basic assumptions of the water stage-discharge relationship curve. In order to reduce the error due to the violations, the curve is divided into several sections based on the manager's judgement considering change of cross-sectional shape. In this research, the objective-splitting criteria of the curve is proposed based on the measured data without the subjective decision. First, it is assumed that the coefficient of variation follows the normal distribution. Then, if the newly calculated coefficient of variation is outside of the 95% confidential interval, the curve is divided. Namely, the groups is divided by the characteristics of the coefficient of variation and the reasonable criteria is provided for establishing a multi-segmented rating curve. To validate the proposed method, it was applied to the data generated by three artificial power functions. In addition, to confirm the applicability of the proposed method, it is applied to the water stage and discharge data of the Muju water stage gauging station and Sangegyo water stage gauging station. As a result, it is found that the automatically divided rating curve improves the accuracy and extrapolation accuracy of the rating curve. Finally, through the residual analysis using Shapiro-Wilk normality test, it is confirmed that the residual of water stage-discharge relationship curve tends to follow the normal distribution.

• Journal of Korea Water Resources Association
• /
• v.46 no.2
• /
• pp.205-218
• /
• 2013

The likelihood of rip current at Haeundae beach according to wave parameters, such as wave height, period, direction, and tidal elevation, was estimated by using numerical simulations with a Boussinesq model, FUNWAVE. To examine the estimation, the rip current occurred on 12th June, 2011 at Haeundae beach was simulated based on observations. For the estimation, the following procedure was carried out. First, extensive numerical simulations of nearshore circulations are performed under various random sea conditions according to the wave parameters. Second, from the numerical results, cross shore components of two-wave-period averaged velocities over the nearshore area were computed, and their seawardly maximum was defined as rip current velocity of the area. Third, using time series of the rip current velocity, we computed the ratio of the simulation time and the time period in which the rip current velocity exceed a threshold velocity for rip-current accidents, and thus the ratio was quantified as the likelihood of rip current at Haeundae beach for the input wave parameters. From the resultant estimations, it was found that the rip current likelihood increases as wave height and period increase, and tidal elevation decreases.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.04a
• /
• pp.53-53
• /
• 2018

전라북도 동부권 지역은 중산악지형으로 표고 100~500m 산지가 69%, 500~1,000m가 26%로 이루어져 있어, 산채를 재배하기에 유리한 지리적 조건을 갖고 있다. 따라서 소비자의 수요가 높은 산채류의 재배 및 이용에 대한 농업인들의 기술개발이 요구되고 있다. 이에 전라북도 준고랭지역에서 재배하기 적합한 산채작목을 선발하고자 본 시험을 실시하였다. 시험은 표고 500m 전라북도 남원시 운봉읍 허브시험장에서 노지재배, 남원시 주천면 표고 530~540m, 진안군 주천면 표고 340~350m에 위치한 농가포장에서 임간재배를 실시하였다. 대상작물은 개미취(Aster tataricus), 갯기름나물(Peucedanum japonicum), 곤달비(Ligularia stenocephala), 눈개승마(Aruncus dioicus var. kamtschaticus), 단풍취(Ainsliaea acerifolia), 산마늘(Allium microdictyon), 섬쑥부쟁이(Aster glehnii), 어수리(Heracleum moellendorffii), 우산나물(Syneilesis palmata) 등 9종을 2016년 종묘를 정식하였다. 정식 2년차에 해당지역의 5월~9월 평균기온 및 조도 등 생육환경을 조사하고, 시험작물의 출현율, 생육특성, 수량 등을 조사하였다. 조사기간 동안의 평균기온은 노지가 $20.8^{\circ}C$, 남원임간은 $20.3^{\circ}C$, 진안임간은 $20.5^{\circ}C$이었으며, 평균조도는 노지가 37,362Lux, 남원임간은 7,816Lux, 진안임간은 25,316Lux이었다. 노지에서 출현율은 개미취, 갯기름나물, 눈개승마, 산마늘, 섬쑥부쟁이, 우산나물이, 임간에서는 개미취, 곤달미, 눈개승마, 단풍취, 산마늘, 어수리, 우산나물이 높았다. 생육특성은 노지에서 개미취, 갯기름나물, 눈개승마, 섬쑥부쟁이, 임간에서는 단풍취, 산마늘, 우산나물의 생육이 좋았다. 수량은 노지에서 개미취, 갯기름나물, 곤달비, 산마늘, 섬쑥부쟁이, 어수리가 높았으며, 남원임간에서는 곤달비, 단풍취, 우산나물, 어수리가, 진안임간에서는 개미취, 갯기름나물, 산마늘, 우산나물의 수량이 많았다. 이와 더불어 준고랭지에 적합한 산채류률 선발하기 위해서는 차후 재배 지역 및 방법의 차이에 따른 산채작물의 연차별 수량성과 경제성에 관한 연구가 이루어져야 할 것으로 여겨진다.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.16 no.3
• /
• pp.73-82
• /
• 2017

As of December 2016, the number of registered automobiles in Korea exceeds 21million. As a result, greenhouse gas emission by transportation sector are increasing every year. It was concluded that the development of the driving strategy considering the driving behavior and the road conditions, which are known to affect the fuel efficiency and the greenhouse gas emissions, could be the most effective fuel economy improvement. Therefore, this study aims to develop a fuel efficient driving strategy in a complex linear section with uphill and curved sections. The road topography was designed according to 'Rules about the Road Structure & Facilities Standards'. Various scenarios were selected. After generating the speed profile, it was applied to the Comprehensive Modal Emission Model and fuel consumption was calculated. The scenarios with the lowest fuel consumption were selected. After that, the fuel consumption of the manual driver's driving record and the selected optimal driving strategy were compared and analyzed for verification. As a result of the analysis, the developed optimal driving strategy reduces fuel consumption by 21.2% on average compared to driving by manual drivers.

• Journal of Korea Water Resources Association
• /
• v.46 no.11
• /
• pp.1115-1128
• /
• 2013

The purpose of this study is to evaluate the suspended solids and eutrophication processes relationships in Chungju lake using CE-QUAL-W2, two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model. For water quality modeling, the lake segmentation was configured as 7 branches system according to their shape and tributary distribution. The model was calibrated (2010) and validated (2008) using 2 years of field data of water temperature, suspended solids (SS), total nitrogen (TN), total phosphorus (TP) and algae (Chl-a). The water temperature began to increase in depth from April and the stratification occurred at about 10 m early July heavy rain. The high SS concentration of the interflow density currents entering from the watershed was well simulated especially for July 2008 heavy rainfall event. The simulated concentration range of TN and TP was acceptable, but the errors might occur form the poor reflection for sedimentation velocity of nitrogen component and adsorption-sediment of phosphorus in model. The concentration of Chl-a was simulated well with the algal growth patterns in summer of 2010 and 2008, but the error of under estimation may come from the use of width-averaged velocity and concentration, not considering the actual to one side inclination by wind effect.

• Journal of Korea Water Resources Association
• /
• v.49 no.12
• /
• pp.981-993
• /
• 2016

This study explains the GIS database of flood inundation area developed for Samsung-1 Drainage Sector, Seoul, Korea. The XP-SWMM dual drainage model was developed for the study area, and the time series observed at the watershed outlet was used to obtain the watershed time of concentration and to calibrate the XP-SWMM model. The rainfall scenario was developed by dividing the 40 minute watershed time of concentration into two 20-minute time steps and then applying the gradually increasing 5 mm/hr interval rainfall intensity to each of the time step up to 200 mm/hr, which is the probable maximum precipitation of the study area. The developed rainfall scenarios was used as the input of the XP-SWMM model to obtain the database of the flood inundation area. The analysis on the developed GIS database revealed that: (1) For the same increment of the rainfall, the increase of the flooded area can be different, and this was caused by topographic characteristics and spatial formation of pipe network of the study area; (2) For the same flooded area, the spatial extent can be significantly different depending on the temporal distribution of rainfall; and (3) For the same amount of the design rainfall, the flood inundation area and the extent can be significantly different depending on the temporal distribution of rainfall.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.6
• /
• pp.57-65
• /
• 2014

Recently, Construction business is changing from on the ground to underground space because of deficit of developing space, creation of green space and of incremental of land compensation expenses. Meanwhile, 3D Topographic, Marine and Cadastral maps need to have Spatial Interrelation. Also, understanding of the information is also needed. Spatial information object registration system is impossible to contact and understanding intelligence mutually because the former one is managed as automatic ID system. Therefore, 3D Object information ID System of underground space is managed based on Object Identifier. Construction of Spatial information integration ID System is required and it will offer Division Code (Ground, Index, Underground) and depth information. We are defined and classified Under Spatial Information in this paper. Moreover, we developed the integration ID System based on UFID for cadastral information Construction. We supposed underground spatial information DB Construction and a developed the way of exploiting 3D cadastral information system through the study. The research result will be the base data of Standard ID system, DB Construction and system Development of National spatial data which is considered together with spatial interrelation.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.6
• /
• pp.17-29
• /
• 2014

A remedial investigation was conducted at five military training ranges in northern Gyeonggi province to collect information necessary for the design of on-site treatment facilities for the abatement of explosive compounds release to the environment. These information includes (i) identification of dominant explosive compounds in each range, (ii) discharge/migration routes, and (iii) contaminant distribution in particle size fraction and settling velocity of the soils. The results of investigation showed that TNT and RDX are the major contaminants but the extent of contamination varied depending on the types of military training practices and topography of the site. RDX was also detected in the subsurface soil and in the nearby stream within the training ranges, suggesting release of contaminants to streams. The median concentrations of explosives in the surface soil were less than 20 mg/kg despite several 'hot spots' in which explosives concentrations often exceeds several hundred mg/kg. The average clay contents in the soil of target area was less than 5 % compared to 12 % in the control, indicating loss of smaller particles by surface runoff during rainfall due to lack of vegetative land cover. Analysis of explosive compounds and particle size distribution showed that the amount of explosive compounds in soil particles smaller than 0.075 mm was less than 10 % of the total. Settling column tests also revealed that the quantity of explosive compounds in the liquid phase of the effluent was greater than that in the solid phase. Therefore, pre-treatment of particulate matter in surface runoff of shooting range with a simple settling basin and subsequent effluent treatment with planted constructed wetlands as polishing stage for explosives in the aqueous phase would provide the shooting ranges with a self-standing, sustainable, green solution.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.21 no.1
• /
• pp.80-85
• /
• 2011

This paper presents the design of the power-assisted controller for the in-wheel type smart wheelchair by using torque estimation that is predicted by relationship between input voltage and output wheel angular velocity. Nowadays, interest of the moving assistant aids is increased according to the increase in population of the elderly and the handicapped person. However some of the moving assistant aids have problems. For example, manual wheelchair has difficulty moving at the slope, because users lack the muscular strength of their arm. In electric wheelchair case, users should be weak by being decreased muscles of upper body. To overcome these problems, power-assisted electric wheelchair are proposed. Most of the power-assisted electric wheelchair have the special rims that can measure the user's power. In here, the rims have to be designed to install the sensors to measure user's power. In this paper, we don't design the rim to measure the man power. To predict the man power, we propose a control algorithm of the in-wheeled electric wheelchair by using torque estimation from the wheel. First, we measure the wheel velocity and voltage at the in-wheel electric wheelchair. And then we extract driving will forces by using proposed mathematical model. Also they are applied at the controller as the control input, we verify to be able to control in-wheel type smart wheelchair by using simulation.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.5
• /
• pp.624-630
• /
• 2012

The peer review learning is a method which improves learning outcome of students through feedback between students and the observation and analysis of other students. One of the important problems in a peer review system is to find proper evaluators to each learner considering characteristics of students for improving learning outcomes. Some of peer review systems randomly assign peer review evaluators to learners, or chose evaluators based on limited strategies. However, these systems have a problem that they do not consider various characteristics of learners and evaluators who participate in peer reviews. In this paper, we propose a novel prediction approach of learning outcomes to apply peer review systems considering various characteristics of learners and evaluators. The proposed approach extracts representative attributes from the profiles of students and predicts learning outcomes using various regression models. In order to verify how much outliers affect on the prediction of learning outcomes, we also apply several outlier removal methods to the regression models and compare the predictive performance of learning outcomes. The experiment result says that the SVR model which does not removes outliers shows an error rate of 0.47% on average and has the best predictive performance.